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Christopher Vincent; Tripti Vashisth; Mongi Zekri; Ute Albrecht. 2021–2022 Florida Citrus Production Guide: Grove Planning and Establishment. EDIS 2021, 1 .
AMA StyleChristopher Vincent, Tripti Vashisth, Mongi Zekri, Ute Albrecht. 2021–2022 Florida Citrus Production Guide: Grove Planning and Establishment. EDIS. 2021; ():1.
Chicago/Turabian StyleChristopher Vincent; Tripti Vashisth; Mongi Zekri; Ute Albrecht. 2021. "2021–2022 Florida Citrus Production Guide: Grove Planning and Establishment." EDIS , no. : 1.
Florida citrus production has declined severely due to huanglongbing (HLB; “citrus greening disease”) caused by Candidatus Liberibacter asiaticus (CLas), a phloem-limited bacterium transmitted by the Asian citrus psyllid (ACP; Diaphorina citri Kuwayama). Kaolin particle films are a tool used to repel insect pests and improve growth. The film covers the natural color of the leaves, which attracts ACP. Kaolin, naturally white in color, has been found to reduce ACP in citrus plantings. Previous research suggests adding a red dye might lead to further ACP reductions by reducing ultraviolet and blue light that attract ACP. We implemented a field experiment to test the effects of white and red-dyed particle films on ACP pressure, CLas infection, and citrus growth over the course of a two-year field study. In this study, white and red-dyed kaolin particle films were applied in young, non-bearing ‘Hamlin’ sweet orange (Citrus x sinensis) trees. The white and red-dyed kaolin treatments reduced ACP pressure and delayed HLB infection, and the red-dyed kaolin particle film was more effective in reducing ACP and in delaying CLas infection. Trees in both the white and red kaolin treatments had greater relative growth rate of trunk cross-sectional area (TCSA) than controls. This effect was observed regardless of CLas infection. Both particle film treatments resulted in greater final TCSA. Our results suggest particle films are an effective alternative to insecticide-based management of ACP and have the added benefit of increasing citrus tree growth under HLB pressure.
Myrtho O. Pierre; JuanPablo Salvatierra-Miranda; Monique J. Rivera; Edgardo Etxeberria; Pedro Gonzalez; Christopher I. Vincent. White and red-dyed kaolin particle films reduce Asian citrus psyllid populations, delay huanglongbing infection, and increase citrus growth. Crop Protection 2021, 150, 105792 .
AMA StyleMyrtho O. Pierre, JuanPablo Salvatierra-Miranda, Monique J. Rivera, Edgardo Etxeberria, Pedro Gonzalez, Christopher I. Vincent. White and red-dyed kaolin particle films reduce Asian citrus psyllid populations, delay huanglongbing infection, and increase citrus growth. Crop Protection. 2021; 150 ():105792.
Chicago/Turabian StyleMyrtho O. Pierre; JuanPablo Salvatierra-Miranda; Monique J. Rivera; Edgardo Etxeberria; Pedro Gonzalez; Christopher I. Vincent. 2021. "White and red-dyed kaolin particle films reduce Asian citrus psyllid populations, delay huanglongbing infection, and increase citrus growth." Crop Protection 150, no. : 105792.
Huanglongbing (HLB), caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (CaLas), is the primary biotic stress causing significant economic damage to the global citrus industry. Among the abiotic stresses, salinity affects citrus production worldwide, especially in arid and coastal regions. In this study, we evaluated open-pollinated seedlings of the S10 (a diploid rootstock produced from a cross between two siblings of the Hirado Buntan Pink pummelo (Citrus maxima (Burm.) Merr.) with the Shekwasha mandarin (Citrus reticulata Blanco)) for their ability to tolerate HLB and salinity stresses. In a greenhouse study, ‘Valencia’ sweet orange (either HLB-positive or negative) was grafted onto six clonally propagated lines generated from the screened seedlings in the greenhouse and the trees were irrigated with 150 mM NaCl after eight months of successful grafting and detection of CaLas in the leaf petioles. Cleopatra mandarin was used as a salt-tolerant and HLB-sensitive rootstock control. CaLas infection was monitored using a quantitative polymerase chain reaction before and after NaCl treatments. Following three months of NaCl treatment, ‘Valencia’ leaves on the S10 rootstock seedlings recorded lower levels of chlorophyll content compared to Cleopatra under similar conditions. Malondialdehyde content was higher in HLB-infected ‘Valencia’ grafted onto Cleopatra than in the S10 lines. Several plant defense-related genes were significantly upregulated in the S10 lines. Antioxidant and Na+ co-transporter genes were differentially regulated in these lines. Based on our results, selected S10 lines have potential as salt-tolerant rootstocks of ‘Valencia’ sweet orange under endemic HLB conditions. However, it is necessary to propagate selected lines through tissue culture or cuttings because of the high percentage of zygotic seedlings derived from S10.
Lamiaa Mahmoud; Patrick Huyck; Christopher Vincent; Frederick Gmitter; Jude Grosser; Manjul Dutt. Physiological Responses and Gene Expression Patterns in Open-Pollinated Seedlings of a Pummelo-Mandarin Hybrid Rootstock Exposed to Salt Stress and Huanglongbing. Plants 2021, 10, 1439 .
AMA StyleLamiaa Mahmoud, Patrick Huyck, Christopher Vincent, Frederick Gmitter, Jude Grosser, Manjul Dutt. Physiological Responses and Gene Expression Patterns in Open-Pollinated Seedlings of a Pummelo-Mandarin Hybrid Rootstock Exposed to Salt Stress and Huanglongbing. Plants. 2021; 10 (7):1439.
Chicago/Turabian StyleLamiaa Mahmoud; Patrick Huyck; Christopher Vincent; Frederick Gmitter; Jude Grosser; Manjul Dutt. 2021. "Physiological Responses and Gene Expression Patterns in Open-Pollinated Seedlings of a Pummelo-Mandarin Hybrid Rootstock Exposed to Salt Stress and Huanglongbing." Plants 10, no. 7: 1439.
Huanglongbing (HLB) is a phloem-affecting disease of citrus that reduces growth and has impacted citrus production in most global production regions. HLB is caused by a phloem-limited bacterium (Candidatus Liberibacter asiaticus; CLas). By inhibiting phloem function, HLB stunts sink growth, including reducing production of new shoots and leaves, and induces hyperaccumulation of foliar starch. Despite evidence that HLB induces feedback inhibition of photosynthesis by reducing foliar carbohydrate export, its effects on net CO2 assimilation (A net) have not been reported. In this work we assessed the relationship of bacterial distribution within the foliage, foliar starch accumulation, and A net. Because HLB impacts canopy morphology, we developed a chamber to measure whole shoot A net, and tested the effects of HLB at both leaf and shoot levels. Starch accumulation was correlated with bacterial population, and starch was negatively correlated with A net at the leaf but not at the shoot level. Starch increased between the uninfected group and the shortest duration of infection, then decreased progressively with increasing length of infection. HLB infection reduced A net at the leaf level, but increased it at the whole shoot level. We attribute this enhancement of whole shoot A net to the increased contribution of stem photosynthesis due to the altered shoot morphology induced by the disease. Despite the increased photosynthetic efficiency, total carbon fixation per shoot decreased because shoot size and leaf area were reduced. Overall, our results indicate a localized relationship of CLas distribution with negative impacts on foliar carbohydrate export and photosynthesis. Additionally, starch accumulation and A net acclimate over time at the shoot level to the localized impacts of the disease. Stems contribute important proportions of whole shoot A net, and these contributions are likely increased by the morphological acclimation induced by HLB. This study highlights the importance of temporal and spatial scale in assessing photosynthesis.
Mark Keeley; Diane Rowland; Christopher Vincent. Citrus photosynthesis and morphology acclimate to phloem-affecting huanglongbing disease at the leaf and shoot levels. 2021, 1 .
AMA StyleMark Keeley, Diane Rowland, Christopher Vincent. Citrus photosynthesis and morphology acclimate to phloem-affecting huanglongbing disease at the leaf and shoot levels. . 2021; ():1.
Chicago/Turabian StyleMark Keeley; Diane Rowland; Christopher Vincent. 2021. "Citrus photosynthesis and morphology acclimate to phloem-affecting huanglongbing disease at the leaf and shoot levels." , no. : 1.
Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), is a phloem-limited disease which disrupts citrus production in affected areas. In HLB-affected plants, phloem sieve plate pores accumulate callose, and leaf carbohydrate export is reduced. However, whether HLB causes a reduction in carbohydrate phloem translocation speed, and the quantitative relationships among callose, CLas population, and phloem translocation are still unknown. In this work, a procedure was developed to concurrently measure sugar transport, callose deposition, and relative pathogen population at different locations throughout the stem. Increasing quantities of CLas genetic material were positively correlated with quantity and density of callose deposits, and negatively correlated with phloem translocation speed. Callose deposit quantity was site- and rootstock dependent, and were negatively correlated with phloem translocation speed, suggesting a localized relationship. Remarkably, callose accumulation and phloem translocation disruption in the scion was dependent on rootstock genotype. Regression results suggested that the interaction of Ct values and number of phloem callose depositions, but not their size or density, explained the effects on translocation speed. Sucrose, starch, and sink 14C label allocation data support the interpretation of a transport pathway limitation by CLas infection. This work shows that the interaction of local accumulation of callose and CLas affect phloem transport. Further, the extent of this accumulation is attenuated by the rootstock and provides important information about the disease mechanism of phloem-inhabiting bacteria. Together, these results constitute the first example of a demonstrated transport limitation of phloem function by a microbial infection.
Stacy Welker; Myrtho Pierre; James P. Santiago; Manjul Dutt; Christopher Vincent; Amit Levy. Phloem transport limitation in Huanglongbing affected sweet orange is dependent on phloem-limited bacteria and callose. 2021, 1 .
AMA StyleStacy Welker, Myrtho Pierre, James P. Santiago, Manjul Dutt, Christopher Vincent, Amit Levy. Phloem transport limitation in Huanglongbing affected sweet orange is dependent on phloem-limited bacteria and callose. . 2021; ():1.
Chicago/Turabian StyleStacy Welker; Myrtho Pierre; James P. Santiago; Manjul Dutt; Christopher Vincent; Amit Levy. 2021. "Phloem transport limitation in Huanglongbing affected sweet orange is dependent on phloem-limited bacteria and callose." , no. : 1.
Overstory shade enhances photochemical performance of feral citrus trees and reduces transmission of an invasive vectored pathogen. Feral citrus trees growing under forest overstory appeared healthy and showed no symptoms of huanglongbing (HLB; citrus greening disease), despite high infection rates and obvious symptoms in open plantings. We undertook a survey in a natural ecosystem area with abundant understory feral citrus (Citrus × paradisi Macfad.) trees to understand how natural understory conditions affect distribution of the HLB causal bacterium, Candidatus Liberibacter asiaticus, and its vector, the Asian citrus psyllid (Diaphorina citri Kuwayama). Citrus also undergoes high irradiance-induced photoinhibition which is exacerbated by HLB. We hypothesized that the understory environment would minimize photodamage and improve photochemical functions. We examined sixty citrus trees, across a high-low overstory density (gap fraction, GF) gradient, for photochemical performances and other key leaf traits associated with disease symptoms or shade acclimation. We did not detect any psyllids in the understory during early summer when peak outbreak of the vector population was expected, and only a few trees were infected with Ca. L. asiaticus. Leaf pigment stoichiometry and photosystem-II functions showed strong acclimation to overstory GF. Photochemical performance improved with decreasing overstory GF due to increased electron transport efficiencies from donor to acceptor sites. No difference in measured leaf biochemical traits and photosystem-II performances was observed between infected and uninfected understory trees, though the number of infected trees was small. We conclude that the naturally shaded understory environment greatly inhibits the HLB pathosystem by deterring the arrival of the vector and significantly improves the photosystem-II performance of citrus, making the shaded environment advantageous for the feral citrus population.
Christopher Vincent; Anirban Guha; Nabil Killiny; Lauren Diepenbrock. Understory environment promotes photosynthetic efficiency and mitigates severity and function of an introduced, vectored pathosystem: a study of a feral citrus population in central Florida. Trees 2021, 1 -15.
AMA StyleChristopher Vincent, Anirban Guha, Nabil Killiny, Lauren Diepenbrock. Understory environment promotes photosynthetic efficiency and mitigates severity and function of an introduced, vectored pathosystem: a study of a feral citrus population in central Florida. Trees. 2021; ():1-15.
Chicago/Turabian StyleChristopher Vincent; Anirban Guha; Nabil Killiny; Lauren Diepenbrock. 2021. "Understory environment promotes photosynthetic efficiency and mitigates severity and function of an introduced, vectored pathosystem: a study of a feral citrus population in central Florida." Trees , no. : 1-15.
The green leaves of plants are optimized for carbon fixation and the production of sugars, which are used as central units of carbon and energy throughout the plant. However, there are physical limits to this optimization that remain insufficiently understood. Here, quantitative anatomical analysis combined with mathematical modeling and sugar transport rate measurements were employed to determine how effectively sugars are exported from the needle‐shaped leaves of conifers in relation to leaf length. Mathematical modeling indicated that phloem anatomy constrains sugar export in long needles. However, we identified two mechanisms by which this constraint is overcome, even in needles longer than 20 cm: i) the grouping of transport conduits, and ii) a shift in the diurnal rhythm of sugar metabolism and export in needle tips. The efficiency of sugar transport in the phloem can have a significant influence on leaf function. The constraints on sugar export described here for conifer needles are likely to also be relevant in other groups of plants, such as grasses and angiosperm trees.
Johannes Liesche; Christopher Vincent; Xiaoyu Han; Maciej Zwieniecki; Alexander Schulz; Chen Gao; Rodrigue Bravard; Sean Marker; Tomas Bohr. The mechanism of sugar export from long conifer needles. New Phytologist 2021, 230, 1911 -1924.
AMA StyleJohannes Liesche, Christopher Vincent, Xiaoyu Han, Maciej Zwieniecki, Alexander Schulz, Chen Gao, Rodrigue Bravard, Sean Marker, Tomas Bohr. The mechanism of sugar export from long conifer needles. New Phytologist. 2021; 230 (5):1911-1924.
Chicago/Turabian StyleJohannes Liesche; Christopher Vincent; Xiaoyu Han; Maciej Zwieniecki; Alexander Schulz; Chen Gao; Rodrigue Bravard; Sean Marker; Tomas Bohr. 2021. "The mechanism of sugar export from long conifer needles." New Phytologist 230, no. 5: 1911-1924.
The final fruit yield and, ultimately, returns a grower receives from any given harvest is directly related to the number of viable flowers that are generated and the proportion of those flowers that produce fruit. A grower can improve the ability for their trees to consistently produce a profitable crop of fruit by understanding the steps involved in flowering and controlling the transition to reproductive growth. This new 6-page publication of the UF/IFAS Horticultural Sciences Department was written by Leigh Archer, Miurel Brewer, Bikash Adhikari, Eduardo Esteves, Christopher Vincent, and Tripti Vashisth.https://edis.ifas.ufl.edu/hs1399
Leigh Archer; Miurel Brewer; Bikash Adhikari; Eduardo Esteves; Christopher Vincent; Tripti Vashisth. Management Options for Improving Flowering in Citrus Production. EDIS 2021, 2021, 6 -6.
AMA StyleLeigh Archer, Miurel Brewer, Bikash Adhikari, Eduardo Esteves, Christopher Vincent, Tripti Vashisth. Management Options for Improving Flowering in Citrus Production. EDIS. 2021; 2021 (1):6-6.
Chicago/Turabian StyleLeigh Archer; Miurel Brewer; Bikash Adhikari; Eduardo Esteves; Christopher Vincent; Tripti Vashisth. 2021. "Management Options for Improving Flowering in Citrus Production." EDIS 2021, no. 1: 6-6.
Our study aimed to evaluate the physiological responses following salinity treatment of three putatively salt-tolerant Citrus rootstocks recently developed by the University of Florida’s Citrus breeding program. Four-month-old seedlings from each of the three rootstocks (HS1, HS17, and HC15) were irrigated with 0, 60, 80, and 100 mm NaCl solution. The seedlings were evaluated together with the salt-tolerant Cleopatra mandarin as a positive control, Volkamer lemon as a moderately salt-tolerant rootstock, and the salt-sensitive Carrizo rootstock as a negative control. Our results demonstrated that chlorophyll content, net CO2 assimilation rate (A), transpiration rate (E), and stomatal conductance (gsw ) significantly decreased in response to salinity. Na+ and Cl− levels were higher in leaf tissues than in the roots. Relatively little damage to the cellular membrane was recorded in HC15 and Cleopatra rootstocks under the 100 mm NaCl treatment, along with high accumulation of total phenolic content (TPC), while HS17 had the highest proline levels. Our results indicate that HC15 and HS17 rootstocks exhibited salt tolerance capacity via different strategies under salt stress and could be suitable replacements to the commercially available, salt-tolerant Cleopatra rootstock.
Lamiaa Mahmoud; Manjul Dutt; Christopher Vincent; Jude Grosser. Salinity-Induced Physiological Responses of Three Putative Salt Tolerant Citrus Rootstocks. Horticulturae 2020, 6, 90 .
AMA StyleLamiaa Mahmoud, Manjul Dutt, Christopher Vincent, Jude Grosser. Salinity-Induced Physiological Responses of Three Putative Salt Tolerant Citrus Rootstocks. Horticulturae. 2020; 6 (4):90.
Chicago/Turabian StyleLamiaa Mahmoud; Manjul Dutt; Christopher Vincent; Jude Grosser. 2020. "Salinity-Induced Physiological Responses of Three Putative Salt Tolerant Citrus Rootstocks." Horticulturae 6, no. 4: 90.
Candidatus Liberibacter asiaticus (CLas) is the predominant causal agent of citrus huanglongbing (HLB). The pathogen population size in local tissues and the whole plant are critical for the development of disease symptoms via pathogenicity factors and causing metabolic burden to the host. However, the total population size of CLas in a whole plant and the ratio of CLas vs. citrus cells in local tissues have not been addressed previously. The total CLas population size for 2.5-year-old Valencia sweet orange trees was quantified using quantitative PCR to be approximately 1.74 x 109, whereas that of 7 and 20-year-old sweet orange trees were estimated to be 4.3 x 1010, and 6.0 x 1010, respectively. The majority of CLas cells were distributed in the leaf tissues (55.58%), followed by that in the branch tissues (36.78%), feeder roots (4.75%), trunk (2.39%), and structural root (0.51%) tissues. The ratios of citrus cells vs. CLas cells for branch, leaf, trunk, feeder root, and structural root samples were approximately 39, 44, 153, 191, and 561, respectively, representing the metabolic burden of CLas in different organs. Approximately 0.01% of the total citrus phloem volume was estimated to be occupied by CLas. The CLas titer inside the leaf was estimated to be approximately 1.64 x 106 cells/leaf or 9.2 x 104 cells cm-2 in leaves, approximately 104 times less than that of typical apoplastic bacterial pathogens. This study provides quantitative estimates of phloem colonization by bacterial pathogens and further understands the biology and virulence mechanism of CLas.
Fernanda N.C. Vasconcelos; Jinyun Li; Zhiqian Pang; Christopher Vincent; Nian Wang. The total population size of Candidatus Liberibacter asiaticus inside the phloem of citrus trees and the corresponding metabolic burden related to Huanglongbing disease development. Phytopathology® 2020, 1 .
AMA StyleFernanda N.C. Vasconcelos, Jinyun Li, Zhiqian Pang, Christopher Vincent, Nian Wang. The total population size of Candidatus Liberibacter asiaticus inside the phloem of citrus trees and the corresponding metabolic burden related to Huanglongbing disease development. Phytopathology®. 2020; ():1.
Chicago/Turabian StyleFernanda N.C. Vasconcelos; Jinyun Li; Zhiqian Pang; Christopher Vincent; Nian Wang. 2020. "The total population size of Candidatus Liberibacter asiaticus inside the phloem of citrus trees and the corresponding metabolic burden related to Huanglongbing disease development." Phytopathology® , no. : 1.
Antibiotics have been successfully used to control plant diseases for more than fifty years. Recently, oxytetracycline and streptomycin have been approved for the treatment of Huanglongbing, which is threatening the citrus industry in many regions. Because the efficiency of antibiotics in planta is highly affected by their movement and distribution, understanding the mechanism of antibiotics’ uptake and distribution could lead to a better control of plant pathogens. Herein, we investigated the movement of oxytetracycline within citrus plants. Oxytetracycline was applied by root drenching to both girdled and non-girdled citrus seedlings. In addition, oxytetracycline was applied by trunk injection to girdled and non-girdled citrus trees. After the exposure time (24 h), citrus seedlings were dissected and the levels of oxytetracycline in the different tissues were measured using an oxytetracycline ELISA kit. Upon root application (laboratory experiment), oxytetracycline was detected in the inner part of the stem (xylem-associated tissue), cortex (phloem-associated tissue), and leaves above and below the girdled area. Likewise, oxytetracycline was also detected in leaves of trunk-injected field trees (girdled and non-girdled) three days post treatment. Interestingly, cortex girdling did not affect the distribution and translocation of oxytetracycline, indicating that the xylem is the main path for oxytetracycline translocation. Taken together, our results indicate that oxytetracycline translocation mainly occurs via xylem vessels, and that movement into the phloem occurs subsequent to xylem translocation. Our findings also clearly demonstrated that upon trunk injection, only trace levels of oxytetracycline reached the roots, minimizing its therapeutic value there. Thus, our recommendation is to time tree injections to coincide with the flushing periods when the bacteria are moving into new shoots to maximize the efficiency of oxytetracycline.
Faraj Hijaz; Yasser Nehela; Fuad Al-Rimawi; Christopher I. Vincent; Nabil Killiny. The Role of the Xylem in Oxytetracycline Translocation within Citrus Trees. Antibiotics 2020, 9, 691 .
AMA StyleFaraj Hijaz, Yasser Nehela, Fuad Al-Rimawi, Christopher I. Vincent, Nabil Killiny. The Role of the Xylem in Oxytetracycline Translocation within Citrus Trees. Antibiotics. 2020; 9 (10):691.
Chicago/Turabian StyleFaraj Hijaz; Yasser Nehela; Fuad Al-Rimawi; Christopher I. Vincent; Nabil Killiny. 2020. "The Role of the Xylem in Oxytetracycline Translocation within Citrus Trees." Antibiotics 9, no. 10: 691.
Recently in Florida, foliar treatments using products with the antibiotics oxytetracycline and streptomycin have been approved for the treatment of citrus Huanglongbing (HLB), which is caused by the putative bacterial pathogen ‘Candidatus Liberibacter asiaticus’. Herein, we assessed the levels of oxytetracycline and ‘Ca. L. asiaticus’ titers in citrus trees upon foliar applications with and without a variety of commercial penetrant adjuvants and upon trunk injection. The level of oxytetracycline in citrus leaves was measured using an oxytetracycline ELISA kit and ‘Ca. L. asiaticus’ titer was measured using quantitative PCR. Low levels of oxytetracycline were taken up by citrus leaves after foliar sprays of oxytetracycline in water. Addition of various adjuvants to the oxytetracycline solution showed minimal effects on its uptake by citrus leaves. The level of oxytetracycline in leaves from trunk‐injected trees was higher than those treated with all foliar applications. The titer of ‘Ca. L. asiaticus’ in the midrib of leaves from trees receiving oxytetracycline by foliar application was not affected after four days and thirty days of application, whereas the titer was significantly reduced in oxytetracycline‐injected trees thirty days after treatment. Investigation of citrus leaves using microscopy showed that they are covered by a thick lipidized cuticle. Perforation of citrus leaf cuticle with a laser significantly increased the uptake of oxytetracycline, decreasing the titer of ‘Ca. L. asiaticus’ in citrus leaves upon foliar application. Taken together, our findings indicate that trunk injection is more efficient than foliar spray even after the use of adjuvants. Our conclusion could help in setting useful recommendations for the application of oxytetracycline in citrus to improve tree health, minimize the amount of applied antibiotic, reduce environmental exposure, and limit off‐target effects.
Nabil Killiny; Faraj Hijaz; Pedro Gonzalez-Blanco; Shelley E. Jones; Myrtho O. Pierre; Christopher I. Vincent. Effect of Adjuvants on Oxytetracycline Uptake upon Foliar Application in Citrus. Antibiotics 2020, 9, 677 .
AMA StyleNabil Killiny, Faraj Hijaz, Pedro Gonzalez-Blanco, Shelley E. Jones, Myrtho O. Pierre, Christopher I. Vincent. Effect of Adjuvants on Oxytetracycline Uptake upon Foliar Application in Citrus. Antibiotics. 2020; 9 (10):677.
Chicago/Turabian StyleNabil Killiny; Faraj Hijaz; Pedro Gonzalez-Blanco; Shelley E. Jones; Myrtho O. Pierre; Christopher I. Vincent. 2020. "Effect of Adjuvants on Oxytetracycline Uptake upon Foliar Application in Citrus." Antibiotics 9, no. 10: 677.
Citrus is most important fruit crop of the world grown throughout the subtropics and semi-arid to humid tropics. Water deficit and high temperature are two major abiotic stresses that affect the plant physiology negatively and ultimately reduced crop yield and performance. The objective of this study was to evaluate the responses of ten genetically diverse citrus selections against the water deficit, heat, and their combinations. Treatments consisted of moderate and high heat (38 °C and 46 °C), water deficit (50% and 25% field capacity) and combined (38 °C with 50% field capacity and 46 °C with 25% field capacity) stress. We measured the effects of water potential, moisture contents and gas exchange on the expression of heat shock proteins (HSPs) and major intrinsic proteins (MIPs). Brazilian sour orange (Citrus aurantium L.) and Keen sour orage (C. aurantium L) performed well by avoiding desiccation and maintaining photosynthesis, stomatal conductance, water potential and moisture content under high temperature and low soil moisture. While, Savage citrange (Poncirus trifoliata × Citrus sinensis) proved the most sensitive to all stress conditions. Genome wide analysis indicated that CsHsp70 had NBD sugar kinase actin Hsp70 protein and molecular charpones Dnak, while CsHsp70.1 had chloroplast protein with Dnak and CsHsp90 had Hsp90 protein. Brazilian sour orange expressed HSPs under heat, MIPs under water deficit and both under combined stress conditions. CsHsp70, CsHsp70.1 and CsHsp90 showed high expression from 1.5 to 6.0 h and then gradually decreased till 24.0 h under heat and combined stress in Brazilian sour orange. CsHsp70 in Savage citrange exhibited slight expression under heat and combined stress after 6.0 h. High expression of CsTIP2 and CsTIP1 was observed from 1.5 to 24.0 h under water deficit, whereas CsTIP1 expressed under heat and combined stress after 1.5 h. Whereas, Savage citrange exhibited little expression of the same genes under stress. It was concluded that the differences among these varieties are in tolerance to heat and water deficit is associated with capacity for upregulation of HSPs and MIPs.
Waqar Shafqat; Muhammad Jafar Jaskani; Rizwana Maqbool; Waqas Shafqat Chattha; Zulfiqar Ali; Summar Abbas Naqvi; Muhammad Salman Haider; Iqrar A Khan; Christopher I Vincent. Heat shock protein and aquaporin expression enhance water conserving behavior of citrus under water deficits and high temperature conditions. Environmental and Experimental Botany 2020, 181, 104270 .
AMA StyleWaqar Shafqat, Muhammad Jafar Jaskani, Rizwana Maqbool, Waqas Shafqat Chattha, Zulfiqar Ali, Summar Abbas Naqvi, Muhammad Salman Haider, Iqrar A Khan, Christopher I Vincent. Heat shock protein and aquaporin expression enhance water conserving behavior of citrus under water deficits and high temperature conditions. Environmental and Experimental Botany. 2020; 181 ():104270.
Chicago/Turabian StyleWaqar Shafqat; Muhammad Jafar Jaskani; Rizwana Maqbool; Waqas Shafqat Chattha; Zulfiqar Ali; Summar Abbas Naqvi; Muhammad Salman Haider; Iqrar A Khan; Christopher I Vincent. 2020. "Heat shock protein and aquaporin expression enhance water conserving behavior of citrus under water deficits and high temperature conditions." Environmental and Experimental Botany 181, no. : 104270.
This document synthesizes information about the warm season cover crop sunn hemp. The question-and-answer format addresses frequently asked questions for growers with answers that summarize the growing body of sunn hemp research. The information is provided so that growers in Florida can learn about up-to-date cultivation and management options for sunn hemp as well as better understand its practical uses. This document is a follow-up to the following: Wang, Qingren, Yuncong Li, Waldemar Klassen, and Edward Hanlon. 2015. “Sunn Hemp : A Promising Cover Crop in Florida”. EDIS 2015 (7), 4. https://doi.org/10.32473/edis-tr003-2015. Wang, K., and Robert McSorley. 2004. “Management of Nematodes and Soil Fertility With Sunn Hemp Cover Crop”. EDIS 2004 (18). https://journals.flvc.org/edis/article/view/114109.
Thioro Fall; Ariel Freidenreich; Stacy Swartz; Christopher Vincent; Yuncong Li; Zachary Brym. Questions and Answers for Using Sunn Hemp (Crotalaria juncea L.) as a Green Manure Cover Crop. EDIS 2020, 2020, 4 -4.
AMA StyleThioro Fall, Ariel Freidenreich, Stacy Swartz, Christopher Vincent, Yuncong Li, Zachary Brym. Questions and Answers for Using Sunn Hemp (Crotalaria juncea L.) as a Green Manure Cover Crop. EDIS. 2020; 2020 (5):4-4.
Chicago/Turabian StyleThioro Fall; Ariel Freidenreich; Stacy Swartz; Christopher Vincent; Yuncong Li; Zachary Brym. 2020. "Questions and Answers for Using Sunn Hemp (Crotalaria juncea L.) as a Green Manure Cover Crop." EDIS 2020, no. 5: 4-4.
A/Ci curves are an important gas-exchange-based approach to understanding the regulation of photosynthesis, describing the response of net CO2 assimilation (A) to leaf internal concentration of CO2 (Ci). Low stomatal conductance species pose a challenge to the measurement of A/Ci curves by reducing the signal-to-noise ratio of gas exchange measures. Additionally, the stomatal attenuation effect of elevated ambient CO2 leads to further reduction of conductance and may lead to erroneous interpretation of high Ci responses of A. Rapid A/Ci response (RACiR) curves offer a potential practice to develop A/Ci curves faster than the stomatal closure response to elevated CO2. We used the moderately low conductance Citrus to compare traditional steady state (SS) A/Ci curves with RACiR curves. SS curves failed more often than RACiR curves. Overall parameter estimates were the same between SS and RACiR curves. When low stomatal conductance values were removed, triose-phosphate utilization (TPU) limitation estimates increased. Overall RACiR stomatal conductance values began and remained higher than SS values. Based on the comparable resulting parameter estimates, higher likelihood of success and reduced measurement time, we propose RACiR as a valuable tool to measure A/Ci responses in low conductance species.
Christopher Vincent; Myrtho O Pierre; Joseph Ronald Stinziano. Racing against stomatal attenuation: rapid CO2 response curves more reliably estimate photosynthetic capacity than steady state curves in a low conductance species. 2020, 1 .
AMA StyleChristopher Vincent, Myrtho O Pierre, Joseph Ronald Stinziano. Racing against stomatal attenuation: rapid CO2 response curves more reliably estimate photosynthetic capacity than steady state curves in a low conductance species. . 2020; ():1.
Chicago/Turabian StyleChristopher Vincent; Myrtho O Pierre; Joseph Ronald Stinziano. 2020. "Racing against stomatal attenuation: rapid CO2 response curves more reliably estimate photosynthetic capacity than steady state curves in a low conductance species." , no. : 1.
Christopher Vincent; Tripti Vashisth; Mongi Zekri; Ute Albrecht. 2020–2021 Florida Citrus Production Guide: Grove Planning and Establishment. EDIS 2020, 1 .
AMA StyleChristopher Vincent, Tripti Vashisth, Mongi Zekri, Ute Albrecht. 2020–2021 Florida Citrus Production Guide: Grove Planning and Establishment. EDIS. 2020; ():1.
Chicago/Turabian StyleChristopher Vincent; Tripti Vashisth; Mongi Zekri; Ute Albrecht. 2020. "2020–2021 Florida Citrus Production Guide: Grove Planning and Establishment." EDIS , no. : 1.
Optimizing plant physiological function is essential to maintaining crop yields under water scarcity and in developing more water-efficient production practices. However, the most common strategies in addressing water conservation in agricultural production have focused on water-efficient technologies aimed at managing water application or on improving crop water-use efficiency through breeding. Few management strategies explicitly consider the management or manipulation of plant physiological processes, but one which does is termed primed acclimation (PA). The PA strategy uses the physiological processes involved in priming to pre-acclimate plants to water deficits while reducing irrigation. It has been shown to evoke multi-mechanistic responses across numerous crop species. A combination of existing literature and emerging studies find that mechanisms for pre-acclimating plants to water deficit stress include changes in root:shoot partitioning, root architecture, water use, photosynthetic characteristics, osmotic adjustment and anti-oxidant production. In many cases, PA reduces agricultural water use by improving plant access to existing soil water. Implementing PA in seasonally water-limited environments can mitigate yield losses to drought. Genotypic variation in PA responses offers the potential to screen for crop varieties with the greatest potential for beneficial priming responses and to identify specific priming and acclimation mechanisms. In this review we: 1) summarize the concept of priming within the context of plant stress physiology; 2) review the development of a PA management system that utilizes priming for water conservation in agroecosystems; and 3) address the future of PA, how it should be evaluated across crop species, and its utility in managing crop stress tolerance.
Christopher Vincent; Diane Rowland; Bruce Schaffer; Elias Bassil; Kelly Racette; Brendan Zurweller. Primed acclimation: A physiological process offers a strategy for more resilient and irrigation-efficient crop production. Plant Science 2019, 295, 110240 .
AMA StyleChristopher Vincent, Diane Rowland, Bruce Schaffer, Elias Bassil, Kelly Racette, Brendan Zurweller. Primed acclimation: A physiological process offers a strategy for more resilient and irrigation-efficient crop production. Plant Science. 2019; 295 ():110240.
Chicago/Turabian StyleChristopher Vincent; Diane Rowland; Bruce Schaffer; Elias Bassil; Kelly Racette; Brendan Zurweller. 2019. "Primed acclimation: A physiological process offers a strategy for more resilient and irrigation-efficient crop production." Plant Science 295, no. : 110240.
We aimed to determine the rate of Candidatus Liberibacter asiaticus (CLas) DNA disappearance from Huanglongbing (citrus greening disease)-affected citrus trees after bacterial death from heat treatment. Using the leaf disc sampling method, we followed CLas qPCR Ct values in leaves of potted ‘Valencia’ orange trees after a heat-treatment that eliminated viable CLas. Although titer declined, CLas remained detectable 5 months after treatment. These results warn caution in interpreting experiments that use CLas titer to assess effects therapeutic treatments on diseased plants. Residual DNA may be detectable for 6 months, but the time to decay depends on pretreatment titer.
Ed Etxeberria; Pedro Gonzalez; Christopher Vincent; Arnold Schumann. Extended persistence of Candidatus Liberibacter asiaticus (CLas) DNA in Huanglongbing-affected citrus tissue after bacterial death. Physiological and Molecular Plant Pathology 2019, 106, 204 -207.
AMA StyleEd Etxeberria, Pedro Gonzalez, Christopher Vincent, Arnold Schumann. Extended persistence of Candidatus Liberibacter asiaticus (CLas) DNA in Huanglongbing-affected citrus tissue after bacterial death. Physiological and Molecular Plant Pathology. 2019; 106 ():204-207.
Chicago/Turabian StyleEd Etxeberria; Pedro Gonzalez; Christopher Vincent; Arnold Schumann. 2019. "Extended persistence of Candidatus Liberibacter asiaticus (CLas) DNA in Huanglongbing-affected citrus tissue after bacterial death." Physiological and Molecular Plant Pathology 106, no. : 204-207.
The mechanisms for tolerance of various abiotic stresses in plants are often considered to be similar, but there are also specific traits responsible for acclimation that differ according to the type and extent of stress. Water-deficit priming is the imposition of a period of moderate drought stress to induce tolerance to a subsequent stress. We hypothesized that priming improves papaya (Carica papaya L.) response to high light intensity. We tested the effects of water-deficit priming on photoinhibition upon shade removal. We assessed morphological and physiological variables associated with priming responses. Priming reduced the intensity and duration of photoinhibition upon shade removal and increased mean leaf area compared to non-primed plants. Photochemical responses to priming included reduced absorption and increased efficiencies of electron transfer from plastoquinone through photosystem I. Photosynthetic responses included upregulation of Rubisco and Ribulose 1,5-bisphosphate regeneration. Morphological responses included increased stomatal density and size. Anti-oxidant capacity was not affected by priming or prior shade treatment. We conclude that water-deficit priming improves papaya response to high light by different physiological mechanisms than shade-to-light acclimation itself. Rather than anti-oxidant upregulation, priming reduces energetic bottlenecks, thereby reducing oxidative stress during shade-to-high-light transitions.
Christopher Vincent; Bruce Schaffer; Diane Rowland. Water-deficit priming of papaya reduces high-light stress through oxidation avoidance rather than anti-oxidant activity. Environmental and Experimental Botany 2018, 156, 106 -119.
AMA StyleChristopher Vincent, Bruce Schaffer, Diane Rowland. Water-deficit priming of papaya reduces high-light stress through oxidation avoidance rather than anti-oxidant activity. Environmental and Experimental Botany. 2018; 156 ():106-119.
Chicago/Turabian StyleChristopher Vincent; Bruce Schaffer; Diane Rowland. 2018. "Water-deficit priming of papaya reduces high-light stress through oxidation avoidance rather than anti-oxidant activity." Environmental and Experimental Botany 156, no. : 106-119.
Christopher Vincent; Bruce Schaffer; Diane L. Rowland; Kati Migliaccio; Jonathan H. Crane; Yuncong Li. Sunn hemp intercrop and mulch increases papaya growth and reduces wind speed and virus damage. Scientia Horticulturae 2017, 218, 304 -315.
AMA StyleChristopher Vincent, Bruce Schaffer, Diane L. Rowland, Kati Migliaccio, Jonathan H. Crane, Yuncong Li. Sunn hemp intercrop and mulch increases papaya growth and reduces wind speed and virus damage. Scientia Horticulturae. 2017; 218 ():304-315.
Chicago/Turabian StyleChristopher Vincent; Bruce Schaffer; Diane L. Rowland; Kati Migliaccio; Jonathan H. Crane; Yuncong Li. 2017. "Sunn hemp intercrop and mulch increases papaya growth and reduces wind speed and virus damage." Scientia Horticulturae 218, no. : 304-315.