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Tabebuia rosea (rosy trumpet) is an economically important Neotropical tree in Mexico that is highly valued for the quality of its wood, which is used for furniture, crafts, and packing, and for its use as an ornamental and shade tree in parks and gardens. During surveys conducted in the lower Balsas River Basin region in the states of Guerrero and Michoacán, symptoms of floral malformation were detected in T. rosea trees. The main objectives of this study were to describe this new disease, to determine its causal agent, and to identify it using DNA sequence data. A second set of objectives was to analyze the phylogenetic relationship of the causal agent to Fusarium associated with Swietenia macrophylla trees with malformation surveyed in the same region, and to compare mycotoxin production and the mating type idiomorphs of fusaria recovered from T. rosea and S. macrophylla. Tabebuia rosea showed malformed inflorescences with multiple, tightly curled shoots, and shortened internodes. A total of 31 Fusarium isolates recovered from symptomatic T. rosea (N = 20) and S. macrophylla (N = 11) trees were identified by molecular analysis as F. pseudocircinatum. Pathogenicity tests showed that isolates of F. pseudocircinatum recovered from T. rosea, induced malformation in inoculated T. rosea seedlings. Eighteen F. pseudocircinatum isolates were tested for their ability to produce mycotoxins and other secondary metabolites. Moniliformin, fusaric acid, bikaverin, beauvericin, aurofusarin and 8-O-methylbostrycoidin were produced by at least 1 strain of the 18 isolates tested. A multiplex PCR assay for mating type idiomorph revealed that 22 F. pseudocircinatum isolates were MAT1-1 and 9 were MAT1-2. Here we report a new disease of T. rosea in Mexico caused by F. pseudocircinatum.
Amelia C. Montoya-Martínez; Kerry O’Donnell; Mark Busman; Martha M. Vaughan; Susan P. McCormick; Ricardo Santillán-Mendoza; Daniela Pineda-Vaca; Sylvia P. Fernández-Pavía; Randy C Ploetz; Julieta Benítez-Malvido; Juan Carlos Montero-Castro; Gerardo Rodriguez-Alvarado. Malformation Disease in Tabebuia rosea (Rosy Trumpet) Caused by Fusarium pseudocircinatum in Mexico. Plant Disease 2021, 1 .
AMA StyleAmelia C. Montoya-Martínez, Kerry O’Donnell, Mark Busman, Martha M. Vaughan, Susan P. McCormick, Ricardo Santillán-Mendoza, Daniela Pineda-Vaca, Sylvia P. Fernández-Pavía, Randy C Ploetz, Julieta Benítez-Malvido, Juan Carlos Montero-Castro, Gerardo Rodriguez-Alvarado. Malformation Disease in Tabebuia rosea (Rosy Trumpet) Caused by Fusarium pseudocircinatum in Mexico. Plant Disease. 2021; ():1.
Chicago/Turabian StyleAmelia C. Montoya-Martínez; Kerry O’Donnell; Mark Busman; Martha M. Vaughan; Susan P. McCormick; Ricardo Santillán-Mendoza; Daniela Pineda-Vaca; Sylvia P. Fernández-Pavía; Randy C Ploetz; Julieta Benítez-Malvido; Juan Carlos Montero-Castro; Gerardo Rodriguez-Alvarado. 2021. "Malformation Disease in Tabebuia rosea (Rosy Trumpet) Caused by Fusarium pseudocircinatum in Mexico." Plant Disease , no. : 1.
Fusarium graminearum is the causal agent of Fusarium head blight (FHB), which reduces crop yield and contaminates grains with poisonous trichothecene mycotoxins, including deoxynivalenol (DON). DON functions as an important virulence factor that promotes FHB spread in wheat; therefore, reducing DON production will decrease yield losses to FHB and enhance food safety. Recent progress using topical application of double-stranded (dsRNA) to reduce F. graminearum infection has provided encouraging results. In this study, we designed and synthesized dsRNA targeting the transcription factor TRI6 (TRI6-dsRNA), which is a key regulator of DON biosynthesis. The expression of F. graminearum TRI6 was significantly reduced in detached wheat heads treated with TRI6-dsRNA solution compared to water-treated controls. Furthermore, TRI6-dsRNA treatments reduced disease and DON accumulation in inoculated detached wheat heads. Therefore, topical applications of TRI6-dsRNA on wheat heads of intact plants were assessed for their ability to reduce FHB and DON under growth chamber and greenhouse conditions. When wheat heads were treated with TRI6-dsRNA solution in growth chamber condition, TRI6-dsRNA treatments failed to prevent FHB spread. However, when wheat heads were treated with TRI6-dsRNA solution under the greenhouse condition, FHB and DON were significantly reduced, and infection was restricted to the inoculated floret. In addition, addition of TRI6-dsRNA to toxin-induction liquid media had no effect on F. graminearum DON production. Our study demonstrates that the efficacy of dsRNA applications is strongly dependent on application methods and environmental conditions.
Guixia Hao; Susan McCormick; Martha Vaughan. Effects of double-stranded RNAs targeting Fusarium graminearum TRI6 on Fusarium head blight and mycotoxins. Phytopathology® 2021, 1 .
AMA StyleGuixia Hao, Susan McCormick, Martha Vaughan. Effects of double-stranded RNAs targeting Fusarium graminearum TRI6 on Fusarium head blight and mycotoxins. Phytopathology®. 2021; ():1.
Chicago/Turabian StyleGuixia Hao; Susan McCormick; Martha Vaughan. 2021. "Effects of double-stranded RNAs targeting Fusarium graminearum TRI6 on Fusarium head blight and mycotoxins." Phytopathology® , no. : 1.
Fusarium graminearum is the primary cause of Fusarium head blight (FHB), one of the most economically important diseases of wheat worldwide. FHB reduces yield and contaminates grain with the trichothecene mycotoxin deoxynivalenol (DON), which poses a risk to plant, human and animal health. The first committed step in trichothecene biosynthesis is formation of trichodiene (TD). The volatile nature of TD suggests that it could be a useful intra or interspecies signalling molecule, but little is known about the potential signalling role of TD during F. graminearum‐wheat interactions. Previous work using a transgenic Trichoderma harzianum strain engineered to emit TD (Th + TRI5) indicated that TD can function as a signal that can modulate pathogen virulence and host plant resistance. Herein, we demonstrate that Th + TRI5 has enhanced biocontrol activity against F. graminearum and reduced DON contamination by 66% and 70% in a moderately resistant and a susceptible cultivar, respectively. While Th + TRI5 volatiles significantly influenced the expression of the pathogenesis‐related 1 (PR1) gene, the effect was dependent on cultivar. Th + TRI5 volatiles strongly reduced DON production in F. graminearum plate cultures and downregulated the expression of TRI genes. Finally, we confirm that TD fumigation reduced DON accumulation in a detached wheat head assay.
Laurie Taylor; Santiago Gutierrez; Susan P. McCormick; Matthew G. Bakker; Robert H. Proctor; Jennifer Teresi; Ben Kurtzman; Guixia Hao; Martha M. Vaughan. Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat. Microbial Biotechnology 2021, 1 .
AMA StyleLaurie Taylor, Santiago Gutierrez, Susan P. McCormick, Matthew G. Bakker, Robert H. Proctor, Jennifer Teresi, Ben Kurtzman, Guixia Hao, Martha M. Vaughan. Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat. Microbial Biotechnology. 2021; ():1.
Chicago/Turabian StyleLaurie Taylor; Santiago Gutierrez; Susan P. McCormick; Matthew G. Bakker; Robert H. Proctor; Jennifer Teresi; Ben Kurtzman; Guixia Hao; Martha M. Vaughan. 2021. "Use of the volatile trichodiene to reduce Fusarium head blight and trichothecene contamination in wheat." Microbial Biotechnology , no. : 1.
Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. Previously (Geiser et al. 2013; Phytopathology 103:400-408. 2013), the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani Species Complex (FSSC). Subsequently, this concept was challenged by one research group (Lombard et al. 2015 Studies in Mycology 80: 189-245) who proposed dividing Fusarium into seven genera, including the FSSC as the genus Neocosmospora, with subsequent justification based on claims that the Geiser et al. (2013) concept of Fusarium is polyphyletic (Sandoval-Denis et al. 2018; Persoonia 41:109-129). Here we test this claim, and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species recently described as Neocosmospora were recombined in Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural and practical taxonomic option available.
David M Geiser; Abdullah Al-Hatmi; Takayuki Aoki; Tsutomu Arie; Virgilio Balmas; Irene Barnes; Gary C Bergstrom; M.K. K. Bhattacharyya; Cheryl L. Blomquist; Robert Bowden; Balázs Brankovics; Daren W. Brown; Lester William Burgess; Kathryn Bushley; Mark Busman; José F. Cano-Lira; Joseph D. Carrillo; Hao-Xun Chang; Chi-Yu Chen; Wanquan Chen; Martin I. Chilvers; Sofia Noemi Chulze; Jeffrey J. Coleman; Christina A. Cuomo; Z. Wilhelm De Beer; G. Sybren De Hoog; Johanna Del Castillo-Múnera; Emerson Del Ponte; Javier Diéguez-Uribeondo; Antonio Di Pietro; Vérnonique Edel-Hermann; Wade H Elmer; Lynn Epstein; Akif Eskalen; Maria Carmela Esposto; Kathryne L. Everts; Sylvia P. Fernández-Pavía; Gilvan Ferreira Da Silva; Nora A Foroud; Gerda Fourie; Rasmus J.N. Frandsen; Stanley Freeman; Michael Freitag; Omer Frenkel; Kevin K Fuller; Tatiana Gagkaeva; Donald Max Gardiner; Anthony E. Glenn; Scott Gold; Tom Gordon; Nancy F. Gregory; Marieka Gryzenhout; Josep Guarro; Beth Gugino; Santiago Gutiérrez; Kim Hammond-Kosack; Linda J. Harris; Mónika Homa; Cheng-Fang Hong; László Hornok; Jenn-Wen Huang; Macit Ilkit; Adriaana Jacobs; Karin Jacobs; Cong Jiang; Maria Del Mar Jimenez-Gasco; Seogchan Kang; Matthew T Kasson; Kemal Kazan; John Carlyle Kennell; Hyeseon Kim; Harold Corby Kistler; Gretchen A. Kuldau; Tomasz Kulik; Oliver Kurzai; Imane Laraba; Matthew H. Laurence; Theresa Yun Lee; Yin-Won Lee; Yong-Hwan Lee; John F. Leslie; Edward C.Y. Liew; Lily W. Lofton; Antonio Logrieco; Manuel Sánchez López-Berges; Alicia Graciela Luque; Erik Lysøe; Li-Jun Ma; Robert E Marra; Frank N. Martin; Sara Ruth May; Susan McCormick; Chyanna T McGee; Jacques F. Meis; Quirico Migheli; Nik Mohd Izham Mohamed Nor; Michel Monod; Antonio Moretti; Diane Mostert; Giuseppina. Mulé; Françoise Munaut; Gary P Munkvold; Paul Nicholson; Marcio Nucci; Kerry O'Donnell; Matias Pasquali; Ludwig H. Pfenning; Anna Prigitano; Robert Proctor; Stéphane Ranque; Stephen Rehner; Martijn Rep; Gerardo Rodríguez-Alvarado; Lindy J Rose; Mitchell George Roth; Carmen Ruiz-Roldán; Amgad A Saleh; Baharuddin Salleh; Hyunkyu Sang; Mercedes Scandiani; Jonathan Scauflaire; David Schmale; Dylan Pg Short; Adnan Šišić; Jason Smith; Christopher W. Smyth; Hokyoung Son; Ellie Spahr; Jason E Stajich; Emma Steenkamp; Christian Steinberg; Rajagopal Subramaniam; Haruhisa Suga; Brett Anthony Summerell; Antonella Susca; Cassandra Lynn Swett; Christopher Toomajian; Terry Jarianna Torres-Cruz; Anna Maria Tortorano; Martin Urban; Lisa J. Vaillancourt; Gary E Vallad; Theo Van Der Lee; Dan Vanderpool; Anne D. Van Diepeningen; Martha Vaughan; Eduard Venter; Marcele Vermeulen; Paul E. Verweij; Altus Viljoen; Cees Waalwijk; Emma C. Wallace; Grit Walther; Jie Wang; Todd Ward; Brian Wickes; Nathan P. Wiederhold; Michael J. Wingfield; Ana K.M. Wood; Jin-Rong Xu; X. B. Yang; Tapani Yli-Matilla; Sung-Hwan Yun; Latiffah Zakaria; Hao Zhang; Ning Zhang; Sean Zhang; Xue Zhang. Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex. Phytopathology® 2020, 1 .
AMA StyleDavid M Geiser, Abdullah Al-Hatmi, Takayuki Aoki, Tsutomu Arie, Virgilio Balmas, Irene Barnes, Gary C Bergstrom, M.K. K. Bhattacharyya, Cheryl L. Blomquist, Robert Bowden, Balázs Brankovics, Daren W. Brown, Lester William Burgess, Kathryn Bushley, Mark Busman, José F. Cano-Lira, Joseph D. Carrillo, Hao-Xun Chang, Chi-Yu Chen, Wanquan Chen, Martin I. Chilvers, Sofia Noemi Chulze, Jeffrey J. Coleman, Christina A. Cuomo, Z. Wilhelm De Beer, G. Sybren De Hoog, Johanna Del Castillo-Múnera, Emerson Del Ponte, Javier Diéguez-Uribeondo, Antonio Di Pietro, Vérnonique Edel-Hermann, Wade H Elmer, Lynn Epstein, Akif Eskalen, Maria Carmela Esposto, Kathryne L. Everts, Sylvia P. Fernández-Pavía, Gilvan Ferreira Da Silva, Nora A Foroud, Gerda Fourie, Rasmus J.N. Frandsen, Stanley Freeman, Michael Freitag, Omer Frenkel, Kevin K Fuller, Tatiana Gagkaeva, Donald Max Gardiner, Anthony E. Glenn, Scott Gold, Tom Gordon, Nancy F. Gregory, Marieka Gryzenhout, Josep Guarro, Beth Gugino, Santiago Gutiérrez, Kim Hammond-Kosack, Linda J. Harris, Mónika Homa, Cheng-Fang Hong, László Hornok, Jenn-Wen Huang, Macit Ilkit, Adriaana Jacobs, Karin Jacobs, Cong Jiang, Maria Del Mar Jimenez-Gasco, Seogchan Kang, Matthew T Kasson, Kemal Kazan, John Carlyle Kennell, Hyeseon Kim, Harold Corby Kistler, Gretchen A. Kuldau, Tomasz Kulik, Oliver Kurzai, Imane Laraba, Matthew H. Laurence, Theresa Yun Lee, Yin-Won Lee, Yong-Hwan Lee, John F. Leslie, Edward C.Y. Liew, Lily W. Lofton, Antonio Logrieco, Manuel Sánchez López-Berges, Alicia Graciela Luque, Erik Lysøe, Li-Jun Ma, Robert E Marra, Frank N. Martin, Sara Ruth May, Susan McCormick, Chyanna T McGee, Jacques F. Meis, Quirico Migheli, Nik Mohd Izham Mohamed Nor, Michel Monod, Antonio Moretti, Diane Mostert, Giuseppina. Mulé, Françoise Munaut, Gary P Munkvold, Paul Nicholson, Marcio Nucci, Kerry O'Donnell, Matias Pasquali, Ludwig H. Pfenning, Anna Prigitano, Robert Proctor, Stéphane Ranque, Stephen Rehner, Martijn Rep, Gerardo Rodríguez-Alvarado, Lindy J Rose, Mitchell George Roth, Carmen Ruiz-Roldán, Amgad A Saleh, Baharuddin Salleh, Hyunkyu Sang, Mercedes Scandiani, Jonathan Scauflaire, David Schmale, Dylan Pg Short, Adnan Šišić, Jason Smith, Christopher W. Smyth, Hokyoung Son, Ellie Spahr, Jason E Stajich, Emma Steenkamp, Christian Steinberg, Rajagopal Subramaniam, Haruhisa Suga, Brett Anthony Summerell, Antonella Susca, Cassandra Lynn Swett, Christopher Toomajian, Terry Jarianna Torres-Cruz, Anna Maria Tortorano, Martin Urban, Lisa J. Vaillancourt, Gary E Vallad, Theo Van Der Lee, Dan Vanderpool, Anne D. Van Diepeningen, Martha Vaughan, Eduard Venter, Marcele Vermeulen, Paul E. Verweij, Altus Viljoen, Cees Waalwijk, Emma C. Wallace, Grit Walther, Jie Wang, Todd Ward, Brian Wickes, Nathan P. Wiederhold, Michael J. Wingfield, Ana K.M. Wood, Jin-Rong Xu, X. B. Yang, Tapani Yli-Matilla, Sung-Hwan Yun, Latiffah Zakaria, Hao Zhang, Ning Zhang, Sean Zhang, Xue Zhang. Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex. Phytopathology®. 2020; ():1.
Chicago/Turabian StyleDavid M Geiser; Abdullah Al-Hatmi; Takayuki Aoki; Tsutomu Arie; Virgilio Balmas; Irene Barnes; Gary C Bergstrom; M.K. K. Bhattacharyya; Cheryl L. Blomquist; Robert Bowden; Balázs Brankovics; Daren W. Brown; Lester William Burgess; Kathryn Bushley; Mark Busman; José F. Cano-Lira; Joseph D. Carrillo; Hao-Xun Chang; Chi-Yu Chen; Wanquan Chen; Martin I. Chilvers; Sofia Noemi Chulze; Jeffrey J. Coleman; Christina A. Cuomo; Z. Wilhelm De Beer; G. Sybren De Hoog; Johanna Del Castillo-Múnera; Emerson Del Ponte; Javier Diéguez-Uribeondo; Antonio Di Pietro; Vérnonique Edel-Hermann; Wade H Elmer; Lynn Epstein; Akif Eskalen; Maria Carmela Esposto; Kathryne L. Everts; Sylvia P. Fernández-Pavía; Gilvan Ferreira Da Silva; Nora A Foroud; Gerda Fourie; Rasmus J.N. Frandsen; Stanley Freeman; Michael Freitag; Omer Frenkel; Kevin K Fuller; Tatiana Gagkaeva; Donald Max Gardiner; Anthony E. Glenn; Scott Gold; Tom Gordon; Nancy F. Gregory; Marieka Gryzenhout; Josep Guarro; Beth Gugino; Santiago Gutiérrez; Kim Hammond-Kosack; Linda J. Harris; Mónika Homa; Cheng-Fang Hong; László Hornok; Jenn-Wen Huang; Macit Ilkit; Adriaana Jacobs; Karin Jacobs; Cong Jiang; Maria Del Mar Jimenez-Gasco; Seogchan Kang; Matthew T Kasson; Kemal Kazan; John Carlyle Kennell; Hyeseon Kim; Harold Corby Kistler; Gretchen A. Kuldau; Tomasz Kulik; Oliver Kurzai; Imane Laraba; Matthew H. Laurence; Theresa Yun Lee; Yin-Won Lee; Yong-Hwan Lee; John F. Leslie; Edward C.Y. Liew; Lily W. Lofton; Antonio Logrieco; Manuel Sánchez López-Berges; Alicia Graciela Luque; Erik Lysøe; Li-Jun Ma; Robert E Marra; Frank N. Martin; Sara Ruth May; Susan McCormick; Chyanna T McGee; Jacques F. Meis; Quirico Migheli; Nik Mohd Izham Mohamed Nor; Michel Monod; Antonio Moretti; Diane Mostert; Giuseppina. Mulé; Françoise Munaut; Gary P Munkvold; Paul Nicholson; Marcio Nucci; Kerry O'Donnell; Matias Pasquali; Ludwig H. Pfenning; Anna Prigitano; Robert Proctor; Stéphane Ranque; Stephen Rehner; Martijn Rep; Gerardo Rodríguez-Alvarado; Lindy J Rose; Mitchell George Roth; Carmen Ruiz-Roldán; Amgad A Saleh; Baharuddin Salleh; Hyunkyu Sang; Mercedes Scandiani; Jonathan Scauflaire; David Schmale; Dylan Pg Short; Adnan Šišić; Jason Smith; Christopher W. Smyth; Hokyoung Son; Ellie Spahr; Jason E Stajich; Emma Steenkamp; Christian Steinberg; Rajagopal Subramaniam; Haruhisa Suga; Brett Anthony Summerell; Antonella Susca; Cassandra Lynn Swett; Christopher Toomajian; Terry Jarianna Torres-Cruz; Anna Maria Tortorano; Martin Urban; Lisa J. Vaillancourt; Gary E Vallad; Theo Van Der Lee; Dan Vanderpool; Anne D. Van Diepeningen; Martha Vaughan; Eduard Venter; Marcele Vermeulen; Paul E. Verweij; Altus Viljoen; Cees Waalwijk; Emma C. Wallace; Grit Walther; Jie Wang; Todd Ward; Brian Wickes; Nathan P. Wiederhold; Michael J. Wingfield; Ana K.M. Wood; Jin-Rong Xu; X. B. Yang; Tapani Yli-Matilla; Sung-Hwan Yun; Latiffah Zakaria; Hao Zhang; Ning Zhang; Sean Zhang; Xue Zhang. 2020. "Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex." Phytopathology® , no. : 1.
Fusarium graminearum is a causal agent of Fusarium head blight (FHB), a disease that reduces yield and quality of cereal crops and contaminates grain with mycotoxins that pose health risks to humans and livestock. Interpopulation antagonistic interactions between isolates that produce different trichothecene mycotoxins can reduce FHB in wheat, but it is not known if interactions between isolates with a shared population identity that produce the same trichothecenes have a similar effect. Using isolates from the predominant F. graminearum populations in North America (NA1 and NA2), we examined intrapopulation interactions by comparing growth, disease progression, and toxin production of individual isolates with multi-isolate mixes. In vitro, mycelial growth was significantly greater when most NA1 and NA2 isolates were cultured individually versus when cultured as a mixture of isolates from the same population. In susceptible wheat Norm, FHB generally progressed faster in heads inoculated with an individual isolate versus a multi-isolate mixture, but the antagonistic effect of intrapopulation interactions was more pronounced for NA1 than NA2 isolates. By contrast, in moderately resistant wheat Alsen, mixtures of isolates from either population caused obvious reductions in FHB development. Mycotoxin contamination was not consistently affected by intrapopulation interactions and varied depending on the interacting isolates from either population. Our results indicate that antagonistic intrapopulation interactions can influence FHB in controlled environmental conditions. Understanding if the regional composition of pathogen populations similarly influences FHB in the field could improve disease forecasting and management practices.
Martha M. Vaughan; Todd J. Ward; Susan P. McCormick; Nathane Orwig; William Hay; Robert Proctor; Debra Palmquist. Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum. Phytopathology® 2020, 110, 916 -926.
AMA StyleMartha M. Vaughan, Todd J. Ward, Susan P. McCormick, Nathane Orwig, William Hay, Robert Proctor, Debra Palmquist. Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum. Phytopathology®. 2020; 110 (4):916-926.
Chicago/Turabian StyleMartha M. Vaughan; Todd J. Ward; Susan P. McCormick; Nathane Orwig; William Hay; Robert Proctor; Debra Palmquist. 2020. "Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum." Phytopathology® 110, no. 4: 916-926.
Specialized metabolites constitute key layers of immunity underlying crop resistance; however, challenges in resolving complex pathways limit our understanding of their functions and applications. In maize (Zea mays) the inducible accumulation of acidic terpenoids is increasingly considered as a defense regulating disease resistance. To understand maize antibiotic biosynthesis, we integrated association mapping, pan-genome multi-omic correlations, enzyme structure-function studies, and targeted mutagenesis. We now define ten genes in three zealexin (Zx) gene clusters comprised of four sesquiterpene synthases and six cytochrome P450s that collectively drive the production of diverse antibiotic cocktails. Quadruple mutants blocked in the production of β-macrocarpene exhibit a broad-spectrum loss of disease resistance. Genetic redundancies ensuring pathway resiliency to single null mutations are combined with enzyme substrate-promiscuity creating a biosynthetic hourglass pathway utilizing diverse substrates and in vivo combinatorial chemistry to yield complex antibiotic blends. The elucidated genetic basis of biochemical phenotypes underlying disease resistance demonstrates a predominant maize defense pathway and informs innovative strategies for transferring chemical immunity between crops.
Yezhang Ding; Philipp R. Weckwerth; Elly Poretsky; Katherine M. Murphy; James Sims; Evan Saldivar; Shawn A. Christensen; Si Nian Char; Bing Yang; Anh-Dao Tong; Zhouxin Shen; Karl A. Kremling; Edward S. Buckler; Thomas John Y Kono; David R. Nelson; Jörg Bohlmann; Matthew G. Bakker; Martha M. Vaughan; Ahmed S. Khalil; Mariam Betsiashvili; Steven P. Briggs; Philipp Zerbe; Eric A. Schmelz; Alisa Huffaker. Genetic elucidation of complex biochemical traits mediating maize innate immunity. 2020, 1 .
AMA StyleYezhang Ding, Philipp R. Weckwerth, Elly Poretsky, Katherine M. Murphy, James Sims, Evan Saldivar, Shawn A. Christensen, Si Nian Char, Bing Yang, Anh-Dao Tong, Zhouxin Shen, Karl A. Kremling, Edward S. Buckler, Thomas John Y Kono, David R. Nelson, Jörg Bohlmann, Matthew G. Bakker, Martha M. Vaughan, Ahmed S. Khalil, Mariam Betsiashvili, Steven P. Briggs, Philipp Zerbe, Eric A. Schmelz, Alisa Huffaker. Genetic elucidation of complex biochemical traits mediating maize innate immunity. . 2020; ():1.
Chicago/Turabian StyleYezhang Ding; Philipp R. Weckwerth; Elly Poretsky; Katherine M. Murphy; James Sims; Evan Saldivar; Shawn A. Christensen; Si Nian Char; Bing Yang; Anh-Dao Tong; Zhouxin Shen; Karl A. Kremling; Edward S. Buckler; Thomas John Y Kono; David R. Nelson; Jörg Bohlmann; Matthew G. Bakker; Martha M. Vaughan; Ahmed S. Khalil; Mariam Betsiashvili; Steven P. Briggs; Philipp Zerbe; Eric A. Schmelz; Alisa Huffaker. 2020. "Genetic elucidation of complex biochemical traits mediating maize innate immunity." , no. : 1.
Martha Vaughan. Stetrophomonas Bacteria Readily Colonizes Fusarium graminearum Perithecia and Reduced Perithecia Formation. ASPB PLANT BIOLOGY 2020 2020, 1 .
AMA StyleMartha Vaughan. Stetrophomonas Bacteria Readily Colonizes Fusarium graminearum Perithecia and Reduced Perithecia Formation. ASPB PLANT BIOLOGY 2020. 2020; ():1.
Chicago/Turabian StyleMartha Vaughan. 2020. "Stetrophomonas Bacteria Readily Colonizes Fusarium graminearum Perithecia and Reduced Perithecia Formation." ASPB PLANT BIOLOGY 2020 , no. : 1.
Species of the fungus Fusarium cause Fusarium head blight (FHB) of cereal crops and contaminate grain with sesquiterpenoid mycotoxins, including culmorin (CUL) and trichothecenes. While the phytotoxicity of trichothecenes, such as deoxynivalenol (DON), and their role in virulence are well characterized, less is known about the phytotoxicity of CUL and its role in the development of FHB. Herein, we evaluated the phytotoxic effects of purified CUL and CUL-trichothecene mixtures using Chlamydomonas reinhardtii growth and Triticum aestivum (wheat) root elongation assays. By itself, CUL did not affect growth in either system. However, mixtures of CUL with DON, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, or NX-3, but not with nivalenol, inhibited growth in a synergistic manner. Synergistic phytotoxic effects of CUL and DON were also observed on multiple plant varieties and species. The severity of wheat FHB caused by 15 isolates of Fusarium graminearum was negatively correlated with the CUL/DON ratio, but positively correlated with the sum of both CUL and DON. Additionally, during the first week of infection, CUL biosynthetic genes were more highly expressed than the TRI5 trichothecene biosynthetic gene. Furthermore, genomic analysis of Fusarium species revealed that CUL and trichothecene biosynthetic genes consistently co-occur among species closely related to F. graminearum.
Rebecca Wipfler; Susan P. McCormick; Robert H. Proctor; Jennifer M. Teresi; Guixia Hao; Todd J. Ward; Nancy J. Alexander; Martha M. Vaughan; Hao; Ward. Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins. Toxins 2019, 11, 555 .
AMA StyleRebecca Wipfler, Susan P. McCormick, Robert H. Proctor, Jennifer M. Teresi, Guixia Hao, Todd J. Ward, Nancy J. Alexander, Martha M. Vaughan, Hao, Ward. Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins. Toxins. 2019; 11 (10):555.
Chicago/Turabian StyleRebecca Wipfler; Susan P. McCormick; Robert H. Proctor; Jennifer M. Teresi; Guixia Hao; Todd J. Ward; Nancy J. Alexander; Martha M. Vaughan; Hao; Ward. 2019. "Synergistic Phytotoxic Effects of Culmorin and Trichothecene Mycotoxins." Toxins 11, no. 10: 555.
Fusarium head blight (FHB) of wheat and barley caused by the fungus Fusarium graminearum reduces crop yield and contaminates grain with mycotoxins. In this study, we investigated two exo-1,5-α-L-arabinanases (Arb93A and Arb93B) secreted by F. graminearum and their effect on wheat head blight development. Arabinan is an important component of plant cell walls but it was not known whether these arabinanases play a role in FHB. Both ARB93A and ARB93B were induced during the early stages of infection. arb93A mutants did not exhibit a detectable change in ability to cause FHB, whereas arb93B mutants caused lower levels of FHB symptoms and deoxynivalenol contamination compared with the wild type. Furthermore, virulence and deoxynivalenol contamination were restored to wild-type levels in ARB93B complemented mutants. Fusion proteins of green fluorescent protein (GFP) with the predicted chloroplast peptide or the mature protein of Arb93B were not observed in the chloroplast. Reactive oxygen species (ROS) production was reduced in the infiltrated zones of Nicotiana benthamiana leaves expressing ARB93B-GFP. Coexpression of ARB93B-GFP and Bax in N. benthamiana leaves significantly suppressed Bax-programmed cell death. Our results indicate that Arb93B enhances plant disease susceptibility by suppressing ROS-associated plant defense responses.
Guixia Hao; Susan McCormick; Martha M. Vaughan; Todd A. Naumann; Hye-Seon Kim; Robert Proctor; Amy Kelly; Todd J. Ward. Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity. Molecular Plant-Microbe Interactions® 2019, 32, 888 -898.
AMA StyleGuixia Hao, Susan McCormick, Martha M. Vaughan, Todd A. Naumann, Hye-Seon Kim, Robert Proctor, Amy Kelly, Todd J. Ward. Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity. Molecular Plant-Microbe Interactions®. 2019; 32 (7):888-898.
Chicago/Turabian StyleGuixia Hao; Susan McCormick; Martha M. Vaughan; Todd A. Naumann; Hye-Seon Kim; Robert Proctor; Amy Kelly; Todd J. Ward. 2019. "Fusarium graminearum arabinanase (Arb93B) Enhances Wheat Head Blight Susceptibility by Suppressing Plant Immunity." Molecular Plant-Microbe Interactions® 32, no. 7: 888-898.
Rising atmospheric CO2 concentrations and associated climate changes are thought to have contributed to the steady increase of Fusarium head blight (FHB) on wheat. However, our understanding of precisely how elevated CO2 influences the defense response of wheat against Fusarium graminearum remains limited. In this study, we evaluated the metabolic profiles of susceptible (Norm) and moderately resistant (Alsen) spring wheat in response to whole-head inoculation with two deoxynivalenol (DON)-producing F. graminearum isolates (DON+), isolates 9F1 and Gz3639, and a DON-deficient (DON−) isolate (Gzt40) at ambient (400 ppm) and elevated (800 ppm) CO2 concentrations. The effects of elevated CO2 were dependent on both the Fusarium strain and the wheat variety, but metabolic differences in the host can explain the observed changes in F. graminearum biomass and DON accumulation. The complexity of abiotic and biotic stress interactions makes it difficult to determine if the observed metabolic changes in wheat are a result of CO2-induced changes in the host, the pathogen, or a combination of both. However, the effects of elevated CO2 were not dependent on DON production. Finally, we identified several metabolic biomarkers for wheat that can reliably predict FHB resistance or susceptibility, even as atmospheric CO2 levels rise.
Miroslava Cuperlovic-Culf; Martha M. Vaughan; Karl Vermillion; Anu Surendra; Jennifer Teresi; Susan McCormick. Effects of Atmospheric CO2 Level on the Metabolic Response of Resistant and Susceptible Wheat to Fusarium graminearum Infection. Molecular Plant-Microbe Interactions® 2019, 32, 379 -391.
AMA StyleMiroslava Cuperlovic-Culf, Martha M. Vaughan, Karl Vermillion, Anu Surendra, Jennifer Teresi, Susan McCormick. Effects of Atmospheric CO2 Level on the Metabolic Response of Resistant and Susceptible Wheat to Fusarium graminearum Infection. Molecular Plant-Microbe Interactions®. 2019; 32 (4):379-391.
Chicago/Turabian StyleMiroslava Cuperlovic-Culf; Martha M. Vaughan; Karl Vermillion; Anu Surendra; Jennifer Teresi; Susan McCormick. 2019. "Effects of Atmospheric CO2 Level on the Metabolic Response of Resistant and Susceptible Wheat to Fusarium graminearum Infection." Molecular Plant-Microbe Interactions® 32, no. 4: 379-391.
Surveys were conducted in commercial wheat and barley fields in the south central production regions of state of Paraná, Brazil, from 2011 to 2015. Spikes displaying visible Fusarium head blight symptoms were collected and the pathogen isolated from the tissues. The 754 Fusarium isolates recovered were identified by a high-throughput multilocus genotyping assay (MLGT) designed to identify trichothecene toxin–producing fusaria (i.e., formerly B-clade, but referred to here as F. sambucinum species complex lineage 1 [FSAMSC-1]) together with sequencing a portion of the translation elongation factor 1-α (TEF1) gene. One strain was discovered that appeared to be closely related to but phylogenetically distinct from F. praegraminearum based on the relatively low 97.7% TEF1 identity and positive genotype obtained with one of the two F. praegraminearum species–specific MLGT probes. Molecular phylogenetic analyses of a 10-gene data set resolved this novel FSAMSC-1 species and F. praegraminearum as sisters. Formally described herein as F. subtropicale, it is phenotypically distinct from the 22 other FSAMSC-1 species in that it produces mostly 1–3-septate macroconidia. Whole-genome sequence data were used to predict its potential to produce mycotoxins. Chemical analyses confirmed that F. subtropicale could produce the mycotoxins 4,15-diacetylnivalenol, butenolide, culmorin, and fusarin C in vitro, and the pathogenicity experiment revealed that F. subtropicale could infect but not spread in susceptible hard red spring wheat cultivar “Norm.”
Carolina B. Pereira; Todd J. Ward; Dauri J. Tessmann; Emerson M. Del Ponte; Imane Laraba; Martha M. Vaughan; Susan McCormick; Mark Busman; Amy Kelly; Robert H. Proctor; Kerry O’Donnell. Fusarium subtropicale, sp. nov., a novel nivalenol mycotoxin–producing species isolated from barley (Hordeum vulgare) in Brazil and sister to F. praegraminearum. Mycologia 2018, 110, 860 -871.
AMA StyleCarolina B. Pereira, Todd J. Ward, Dauri J. Tessmann, Emerson M. Del Ponte, Imane Laraba, Martha M. Vaughan, Susan McCormick, Mark Busman, Amy Kelly, Robert H. Proctor, Kerry O’Donnell. Fusarium subtropicale, sp. nov., a novel nivalenol mycotoxin–producing species isolated from barley (Hordeum vulgare) in Brazil and sister to F. praegraminearum. Mycologia. 2018; 110 (5):860-871.
Chicago/Turabian StyleCarolina B. Pereira; Todd J. Ward; Dauri J. Tessmann; Emerson M. Del Ponte; Imane Laraba; Martha M. Vaughan; Susan McCormick; Mark Busman; Amy Kelly; Robert H. Proctor; Kerry O’Donnell. 2018. "Fusarium subtropicale, sp. nov., a novel nivalenol mycotoxin–producing species isolated from barley (Hordeum vulgare) in Brazil and sister to F. praegraminearum." Mycologia 110, no. 5: 860-871.
Due to health risks and economic losses associated with mycotoxins produced by Fusarium species, there is a compelling need for an improved understanding of these fungi from across diverse perspectives and disciplinary approaches. In this article, we provide a transdisciplinary overview of: (i) Fusarium phylogenetics; (ii) linkages between mycotoxin biosynthetic gene clusters and chemical structures; (iii) biotransformation of mycotoxins to reduce toxicity; (iv) Fusarium population biology; (v) genomics of secondary metabolite production; and (vi) mycotoxigenic fusaria in a phytobiomes context. Phylogenetic studies have made tremendous progress in delineating the species that comprise the genus Fusarium, many of which are morphologically cryptic. Accurate species identification and a thorough understanding of the distribution of mycotoxin biosynthetic genes among those species will facilitate control of mycotoxin contamination. The biochemical pathways leading to the formation of several Fusarium mycotoxins have been elegantly linked with the genes responsible for each chemical transformation during synthesis, and for most structural differences among chemotypes. Screens for the biotransformation of mycotoxins have led to the description of chemical modifications that impact bioactivity and have implications for monitoring and testing of the food supply. Population biology studies have revealed the potential for introductions of foreign genotypes to alter regional populations of mycotoxigenic fusaria. Genomic analyses have begun to reveal the complex evolutionary history of the genes responsible for mycotoxin production, both across and within lineages. Improved understanding of how climate variability impacts plant–Fusarium interactions and mycotoxin accumulation is necessary for effective plant resistance. Additionally, improved understanding of interactions between Fusarium and other members of crop microbiomes is expected to produce novel strategies for limiting disease and mycotoxin accumulation.
Matthew G. Bakker; Daren W. Brown; Amy C. Kelly; Hye-Seon Kim; Cletus P. Kurtzman; Susan McCormick; Kerry L. O’Donnell; Robert H. Proctor; Martha M. Vaughan; Todd J. Ward. Fusarium mycotoxins: a trans-disciplinary overview. Canadian Journal of Plant Pathology 2018, 40, 161 -171.
AMA StyleMatthew G. Bakker, Daren W. Brown, Amy C. Kelly, Hye-Seon Kim, Cletus P. Kurtzman, Susan McCormick, Kerry L. O’Donnell, Robert H. Proctor, Martha M. Vaughan, Todd J. Ward. Fusarium mycotoxins: a trans-disciplinary overview. Canadian Journal of Plant Pathology. 2018; 40 (2):161-171.
Chicago/Turabian StyleMatthew G. Bakker; Daren W. Brown; Amy C. Kelly; Hye-Seon Kim; Cletus P. Kurtzman; Susan McCormick; Kerry L. O’Donnell; Robert H. Proctor; Martha M. Vaughan; Todd J. Ward. 2018. "Fusarium mycotoxins: a trans-disciplinary overview." Canadian Journal of Plant Pathology 40, no. 2: 161-171.
Plant defense research is facilitated by the use of genome-sequenced inbred lines; however, a foundational knowledge of interactions in commercial hybrids remains relevant to understanding mechanisms present in crops. Using an array of commercial maize hybrids, we quantified the accumulation patterns of defense-related metabolites and phytohormones in tissues challenged with diverse fungal pathogens. Across hybrids, Southern leaf blight (Cochliobolus heterostrophus) strongly elicited specific sesqui- and diterpenoid defenses, namely zealexin A4 (ZA4) and kauralexin diacids, compared with the stalk-rotting agents Fusarium graminearum and Colletotrichum graminicola. With respect to biological activity, ZA4 and kauralexin diacids demonstrated potent antimicrobial action against F. graminearum. Unexpectedly, ZA4 displayed an opposite effect on C. graminicola by promoting growth. Overall, a negative correlation was observed between total analyzed terpenoids and fungal growth. Statistical analyses highlighted kauralexin A3 and abscisic acid as metabolites most associated with fungal suppression. As an empirical test, mutants of the ent-copalyl diphosphate synthase Anther ear 2 (An2) lacking kauralexin biosynthetic capacity displayed increased susceptibility to C. heterostrophus and Fusarium verticillioides. Our results highlight a widely occurring defensive function of acidic terpenoids in commercial hybrids and the complex nature of elicited pathway products that display selective activities on fungal pathogen species.
Shawn A Christensen; James Sims; Martha M Vaughan; Charles Hunter; Anna Block; Denis Willett; Hans T Alborn; Alisa Huffaker; Eric A Schmelz. Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses in maize. Journal of Experimental Botany 2018, 69, 1693 -1705.
AMA StyleShawn A Christensen, James Sims, Martha M Vaughan, Charles Hunter, Anna Block, Denis Willett, Hans T Alborn, Alisa Huffaker, Eric A Schmelz. Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses in maize. Journal of Experimental Botany. 2018; 69 (7):1693-1705.
Chicago/Turabian StyleShawn A Christensen; James Sims; Martha M Vaughan; Charles Hunter; Anna Block; Denis Willett; Hans T Alborn; Alisa Huffaker; Eric A Schmelz. 2018. "Commercial hybrids and mutant genotypes reveal complex protective roles for inducible terpenoid defenses in maize." Journal of Experimental Botany 69, no. 7: 1693-1705.
Chemical isolation and NMR-based structure elucidation revealed a novel keto-acidic sesquiterpenoid, termed zealexin A4 (ZA4). ZA4 is elicited by pathogens and herbivory, but attenuated by heightened levels of CO 2 . The identification of the labdane-related diterpenoids, termed kauralexins and acidic sesquiterpenoids, termed zealexins, demonstrated the existence of at least ten novel stress-inducible maize metabolites with diverse antimicrobial activity. Despite these advances, the identity of co-occurring and predictably related analytes remains largely unexplored. In the current effort, we identify and characterize the first sesquiterpene keto acid derivative of β-macrocarpene, named zealexin A4 (ZA4). Evaluation of diverse maize inbreds revealed that ZA4 is commonly produced in maize scutella during the first 14 days of seedling development; however, ZA4 production in the scutella was markedly reduced in seedlings grown in sterile soil. Elevated ZA4 production was observed in response to inoculation with adventitious fungal pathogens, such as Aspergillus flavus and Rhizopus microsporus, and a positive relationship between ZA4 production and expression of the predicted zealexin biosynthetic genes, terpene synthases 6 and 11 (Tps6 and Tps11), was observed. ZA4 exhibited significant antimicrobial activity against the mycotoxigenic pathogen A. flavus; however, ZA4 activity against R. microsporus was minimal, suggesting the potential of some fungi to detoxify ZA4. Significant induction of ZA4 production was also observed in response to infestation with the stem tunneling herbivore Ostrinia nubilalis. Examination of the interactive effects of elevated CO2 (E-CO2) on both fungal and herbivore-elicited ZA4 production revealed significantly reduced levels of inducible ZA4 accumulation, consistent with a negative role for E-CO2 on ZA4 production. Collectively, these results describe a novel β-macrocarpene-derived antifungal defense in maize and expand the established diversity of zealexins that are differentially regulated in response to biotic/abiotic stress.
Shawn A. Christensen; Alisa Huffaker; James Sims; Charles T. Hunter; Anna Block; Martha M. Vaughan; Denis Willett; Maritza Romero; J. Erik Mylroie; W. Paul Williams; Eric A. Schmelz. Fungal and herbivore elicitation of the novel maize sesquiterpenoid, zealexin A4, is attenuated by elevated CO2. Planta 2017, 247, 863 -873.
AMA StyleShawn A. Christensen, Alisa Huffaker, James Sims, Charles T. Hunter, Anna Block, Martha M. Vaughan, Denis Willett, Maritza Romero, J. Erik Mylroie, W. Paul Williams, Eric A. Schmelz. Fungal and herbivore elicitation of the novel maize sesquiterpenoid, zealexin A4, is attenuated by elevated CO2. Planta. 2017; 247 (4):863-873.
Chicago/Turabian StyleShawn A. Christensen; Alisa Huffaker; James Sims; Charles T. Hunter; Anna Block; Martha M. Vaughan; Denis Willett; Maritza Romero; J. Erik Mylroie; W. Paul Williams; Eric A. Schmelz. 2017. "Fungal and herbivore elicitation of the novel maize sesquiterpenoid, zealexin A4, is attenuated by elevated CO2." Planta 247, no. 4: 863-873.
Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defence mechanism by attracting parasitoid wasps; yet little is known about the impact of climate change on this form of plant defence. To investigate how a central component of climate change affects indirect defence, we measured herbivore-induced volatile emissions in plants grown under elevated carbon dioxide (CO2). We found that S. exigua infested or elicitor-treated Z. mays grown at elevated CO2 had decreased emission of its major sesquiterpene, (E)-β-caryophyllene and two homoterpenes, (3E)-4,8-dimethyl-1,3,7-nonatriene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. In contrast, inside the leaves, elicitor-induced (E)-β-caryophyllene hyper-accumulated at elevated CO2, while levels of homoterpenes were unaffected. Furthermore, gene expression analysis revealed that the induction of terpene synthase genes following treatment was lower in plants grown at elevated CO2. Our data indicate that elevated CO2 leads both to a repression of volatile synthesis at the transcriptional level and to limitation of volatile release through effects of CO2 on stomatal conductance. These findings suggest that elevated CO2 may alter the ability of Z. mays to utilize volatile terpenes to mediate indirect defenses.
Anna Block; Martha M. Vaughan; Shawn A. Christensen; Hans T. Alborn; James H. Tumlinson. Elevated carbon dioxide reduces emission of herbivore‐induced volatiles in Zea mays. Plant, Cell & Environment 2017, 40, 1725 -1734.
AMA StyleAnna Block, Martha M. Vaughan, Shawn A. Christensen, Hans T. Alborn, James H. Tumlinson. Elevated carbon dioxide reduces emission of herbivore‐induced volatiles in Zea mays. Plant, Cell & Environment. 2017; 40 (9):1725-1734.
Chicago/Turabian StyleAnna Block; Martha M. Vaughan; Shawn A. Christensen; Hans T. Alborn; James H. Tumlinson. 2017. "Elevated carbon dioxide reduces emission of herbivore‐induced volatiles in Zea mays." Plant, Cell & Environment 40, no. 9: 1725-1734.
Reliable large-scale maize production is an essential component of global food security; however, sustained efforts are needed to ensure optimized resilience under diverse crop stress conditions. Climate changes are expected to increase the frequency and intensity of both abiotic and biotic stress. Protective phytochemicals play an important role in both abiotic stress resilience and resistance to biotic challenges, yet the concentration and composition of these phytochemicals are also dependent on climate variables. We review the research on the effects of climate change associated abiotic stresses on three classes of maize defense metabolites, including benzoxazinoids, volatile organic compounds, and terpenoid phytoalexins. Despite significant knowledge gaps that still exist, it is evident that climate change will influence maize phytochemicals associated with resilient productivity. While broad generalizations are not yet possible, climate induced changes in phytochemicals are context specific and dependent upon developmental stage and tissue type. Under conditions of drought, maize modulates different classes of defense phytochemicals to protect the above-and belowground tissues. Aboveground the benzoxazinoid defenses are stimulated, but belowground terpenoid phytoalexins are predominantly deployed. Changes in the allocation or distribution of the different classes of defense metabolites or signaling molecules have the potential to further shape the biodiversity and abundance of pests within the maize agroecosystem. A better understanding of the underlying genetics, biosynthetic pathways, regulation and precise biological roles of maize phytochemicals modulated by arrays of climatic conditions will be required to ensure optimal plant resilience and productivity in the face of combined biotic and abiotic stresses.
Martha M. Vaughan; Anna Block; Shawn A. Christensen; Leon Hartwell Allen; Eric A. Schmelz. The effects of climate change associated abiotic stresses on maize phytochemical defenses. Phytochemistry Reviews 2017, 17, 37 -49.
AMA StyleMartha M. Vaughan, Anna Block, Shawn A. Christensen, Leon Hartwell Allen, Eric A. Schmelz. The effects of climate change associated abiotic stresses on maize phytochemical defenses. Phytochemistry Reviews. 2017; 17 (1):37-49.
Chicago/Turabian StyleMartha M. Vaughan; Anna Block; Shawn A. Christensen; Leon Hartwell Allen; Eric A. Schmelz. 2017. "The effects of climate change associated abiotic stresses on maize phytochemical defenses." Phytochemistry Reviews 17, no. 1: 37-49.
Changes in climate due to rising atmospheric carbon dioxide concentration ([CO2]) are predicted to intensify episodes of drought, but our understanding of how these combined conditions will influence crop-pathogen interactions is limited. We recently demonstrated that elevated [CO2] alone enhances maize susceptibility to the mycotoxigenic pathogen, Fusarium verticillioides (Fv) but fumonisin levels remain unaffected. In this study we show that maize simultaneously exposed to elevated [CO2] and drought are even more susceptible to Fv proliferation and also prone to higher levels of fumonisin contamination. Despite the increase in fumonisin levels, the amount of fumonisin produced in relation to pathogen biomass remained lower than corresponding plants grown at ambient [CO2]. Therefore, the increase in fumonisin contamination was likely due to even greater pathogen biomass rather than an increase in host-derived stimulants. Drought did not negate the compromising effects of elevated [CO2] on the accumulation of maize phytohormones and metabolites. However, since elevated [CO2] does not influence the drought-induced accumulation of abscisic acid (ABA) or root terpenoid phytoalexins, the effects elevated [CO2] are negated belowground, but the stifled defense response aboveground may be a consequence of resource redirection to the roots.
Martha M. Vaughan; Alisa Huffaker; Eric Schmelz; Nicole J. Dafoe; Shawn A. Christensen; Heather J. McAuslane; Hans T. Alborn; Leon Hartwell Allen; Peter E. A. Teal. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides. PLoS ONE 2016, 11, e0159270 .
AMA StyleMartha M. Vaughan, Alisa Huffaker, Eric Schmelz, Nicole J. Dafoe, Shawn A. Christensen, Heather J. McAuslane, Hans T. Alborn, Leon Hartwell Allen, Peter E. A. Teal. Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides. PLoS ONE. 2016; 11 (7):e0159270.
Chicago/Turabian StyleMartha M. Vaughan; Alisa Huffaker; Eric Schmelz; Nicole J. Dafoe; Shawn A. Christensen; Heather J. McAuslane; Hans T. Alborn; Leon Hartwell Allen; Peter E. A. Teal. 2016. "Interactive Effects of Elevated [CO2] and Drought on the Maize Phytochemical Defense Response against Mycotoxigenic Fusarium verticillioides." PLoS ONE 11, no. 7: e0159270.
Maize (Zea mays) production, which is of global agro‐economic importance, is largely limited by herbivore pests, pathogens and environmental conditions, such as drought. Zealexins and kauralexins belong to two recently identified families of acidic terpenoid phytoalexins in maize that mediate defence against both pathogen and insect attacks in aboveground tissues. However, little is known about their function in belowground organs and their potential to counter abiotic stress. In this study, we show that zealexins and kauralexins accumulate in roots in response to both biotic and abiotic stress including, Diabrotica balteata herbivory, Fusarium verticillioides infection, drought and high salinity. We find that the quantity of drought‐induced phytoalexins is positively correlated with the root‐to‐shoot ratio of different maize varieties, and further demonstrate that mutant an2 plants deficient in kauralexin production are more sensitive to drought. The induction of phytoalexins in response to drought is root specific and does not influence phytoalexin levels aboveground; however, the accumulation of phytoalexins in one tissue may influence the induction capacity of other tissues.
Martha M. Vaughan; Shawn Christensen; Eric Schmelz; Alisa Huffaker; Heather J. McAuslane; Hans T. Alborn; Maritza Romero; Leon Hartwell Allen; Peter E. A. Teal. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance. Plant, Cell & Environment 2014, 38, 2195 -2207.
AMA StyleMartha M. Vaughan, Shawn Christensen, Eric Schmelz, Alisa Huffaker, Heather J. McAuslane, Hans T. Alborn, Maritza Romero, Leon Hartwell Allen, Peter E. A. Teal. Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance. Plant, Cell & Environment. 2014; 38 (11):2195-2207.
Chicago/Turabian StyleMartha M. Vaughan; Shawn Christensen; Eric Schmelz; Alisa Huffaker; Heather J. McAuslane; Hans T. Alborn; Maritza Romero; Leon Hartwell Allen; Peter E. A. Teal. 2014. "Accumulation of terpenoid phytoalexins in maize roots is associated with drought tolerance." Plant, Cell & Environment 38, no. 11: 2195-2207.
Maize is by quantity the most important C4 cereal crop; however, future climate changes are expected to increase maize susceptibility to mycotoxigenic fungal pathogens and reduce productivity. While rising atmospheric [CO2] is a driving force behind the warmer temperatures and drought, which aggravate fungal disease and mycotoxin accumulation, our understanding of how elevated [CO2] will effect maize defences against such pathogens is limited. Here we report that elevated [CO2] increases maize susceptibility to Fusarium verticillioides proliferation, while mycotoxin levels are unaltered. Fumonisin production is not proportional to the increase in F. verticillioides biomass, and the amount of fumonisin produced per unit pathogen is reduced at elevated [CO2]. Following F. verticillioides stalk inoculation, the accumulation of sugars, free fatty acids, lipoxygenase (LOX) transcripts, phytohormones and downstream phytoalexins is dampened in maize grown at elevated [CO2]. The attenuation of maize 13‐LOXs and jasmonic acid production correlates with reduced terpenoid phytoalexins and increased susceptibility. Furthermore, the attenuated induction of 9‐LOXs, which have been suggested to stimulate mycotoxin biosynthesis, is consistent with reduced fumonisin per unit fungal biomass at elevated [CO2]. Our findings suggest that elevated [CO2] will compromise maize LOX‐dependent signalling, which will influence the interactions between maize and mycotoxigenic fungi.
Martha M. Vaughan; Alisa Huffaker; Eric Schmelz; Nicole J. Dafoe; Shawn Christensen; James Sims; Vitor F. Martins; Jay Swerbilow; Maritza Romero; Hans T. Alborn; Leon Hartwell Allen; Peter E. A. Teal. Effects of elevated [CO2] on maize defence against mycotoxigenicFusarium verticillioides. Plant, Cell & Environment 2014, 37, 2691 -2706.
AMA StyleMartha M. Vaughan, Alisa Huffaker, Eric Schmelz, Nicole J. Dafoe, Shawn Christensen, James Sims, Vitor F. Martins, Jay Swerbilow, Maritza Romero, Hans T. Alborn, Leon Hartwell Allen, Peter E. A. Teal. Effects of elevated [CO2] on maize defence against mycotoxigenicFusarium verticillioides. Plant, Cell & Environment. 2014; 37 (12):2691-2706.
Chicago/Turabian StyleMartha M. Vaughan; Alisa Huffaker; Eric Schmelz; Nicole J. Dafoe; Shawn Christensen; James Sims; Vitor F. Martins; Jay Swerbilow; Maritza Romero; Hans T. Alborn; Leon Hartwell Allen; Peter E. A. Teal. 2014. "Effects of elevated [CO2] on maize defence against mycotoxigenicFusarium verticillioides." Plant, Cell & Environment 37, no. 12: 2691-2706.
Fusarium verticillioides is a widely distributed fungus that can associate with maize as a deleterious pathogen and an advantageous endophyte. Here, we show that seed treatment with live F. verticillioides enhances maize resistance to secondary stalk rot infection and further demonstrate that dead F. verticillioides is sufficient to equivalently reduce F. verticillioides biomass. Seed treatment with live or dead F. verticillioides primes maize plants, and upon subsequent stalk infection, terpenoid phytoalexins accumulate faster than control‐treated plants. Seed treatment did not constitutively activate plant defences nor did it impact plant growth. These results suggest that seed treatment with dead F. verticillioides can be used as a ‘vaccination’ method to decrease the severity of stalk rot and potentially pathogen infection throughout the plant.
Vitor F. Martins; Martha M. Vaughan; Alisa Huffaker; Eric Schmelz; Shawn Christensen; James Sims; Nicole D. Benda; Jay Swerbilow; Hans T Alborn; Peter E. Teal. Seed Treatment with Live or Dead Fusarium verticillioides Equivalently Reduces the Severity of Subsequent Stalk Rot. Journal of Phytopathology 2013, 162, 201 -204.
AMA StyleVitor F. Martins, Martha M. Vaughan, Alisa Huffaker, Eric Schmelz, Shawn Christensen, James Sims, Nicole D. Benda, Jay Swerbilow, Hans T Alborn, Peter E. Teal. Seed Treatment with Live or Dead Fusarium verticillioides Equivalently Reduces the Severity of Subsequent Stalk Rot. Journal of Phytopathology. 2013; 162 (3):201-204.
Chicago/Turabian StyleVitor F. Martins; Martha M. Vaughan; Alisa Huffaker; Eric Schmelz; Shawn Christensen; James Sims; Nicole D. Benda; Jay Swerbilow; Hans T Alborn; Peter E. Teal. 2013. "Seed Treatment with Live or Dead Fusarium verticillioides Equivalently Reduces the Severity of Subsequent Stalk Rot." Journal of Phytopathology 162, no. 3: 201-204.