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He is a Plant Biotechnologist, currently working as Scientist-Plant Transformation Specialist at the International Institute of Tropical Agriculture (IITA), hosted by Biosciences for east and central Africa/ International Livestock Research Institute (BecA/ILRI) hub, Nairobi, Kenya. He has earned over 20 years of research experience in biotechnological techniques such as plant tissue culture, genetic engineering, and genome editing of tropical crops, especially bananas, cassava, enset, and yam. His research interests are to develop diseases and pest-resistant crop varieties using modern biotechnological tools such as genetic modification and genome editing for important staple food crops. His focus is on modern scientific tools and engaging scientific discoveries to practical applications for the farmers in Africa to enhance food production for the growing population globally. His research findings have been published in 41 journal articles with a high impact like Nature Biotechnology, Plant Biotechnology Journal, Communications Biology, Scientific Reports, and several news articles and book chapters.
Sushma Naithani; Dhirendra Kumar; Jaindra Nath Tripathi. Towards improving agriculture productivity. Current Plant Biology 2021, 100218 .
AMA StyleSushma Naithani, Dhirendra Kumar, Jaindra Nath Tripathi. Towards improving agriculture productivity. Current Plant Biology. 2021; ():100218.
Chicago/Turabian StyleSushma Naithani; Dhirendra Kumar; Jaindra Nath Tripathi. 2021. "Towards improving agriculture productivity." Current Plant Biology , no. : 100218.
Yam (Dioscorea spp.) anthracnose, caused by Colletotrichum alatae, is the most devastating fungal disease of yam in West Africa, leading to 50%–90% of tuber yield losses in severe cases. In some instances, plants die without producing any tubers or each shoot may produce several small tubers before it dies if the disease strikes early. C. alatae affects all parts of the yam plant at all stages of development, including leaves, stems, tubers, and seeds of yams, and it is highly prevalent in the yam belt region and other yam-producing countries in the world. Traditional methods adopted by farmers to control the disease have not been very successful. Fungicides have also failed to provide long-lasting control. Although conventional breeding and genomics-assisted breeding have been used to develop some level of resistance to anthracnose in Dioscorea alata, the appearance of new and more virulent strains makes the development of improved varieties with broad-spectrum and durable resistance critical. These shortcomings, coupled with interspecific incompatibility, dioecy, polyploidy, poor flowering, and the long breeding cycle of the crop, have prompted researchers to explore biotechnological techniques to complement conventional breeding to speed up crop improvement. Modern biotechnological tools have the potential of producing fungus-resistant cultivars, thereby bypassing the natural bottlenecks of traditional breeding. This article reviews the existing biotechnological strategies and proposes several approaches that could be adopted to develop anthracnose-resistant yam varieties for improved food security in West Africa.
Valentine Otang Ntui; Edak Aniedi Uyoh; Effiom Eyo Ita; Aniedi‐Abasi Akpan Markson; Jaindra Nath Tripathi; Nkese Ime Okon; Mfon Okon Akpan; Julius Oyohosuho Phillip; Ebiamadon Andi Brisibe; Ene‐Obong Effiom Ene‐Obong; Leena Tripathi. Strategies to combat the problem of yam anthracnose disease: Status and prospects. Molecular Plant Pathology 2021, 1 .
AMA StyleValentine Otang Ntui, Edak Aniedi Uyoh, Effiom Eyo Ita, Aniedi‐Abasi Akpan Markson, Jaindra Nath Tripathi, Nkese Ime Okon, Mfon Okon Akpan, Julius Oyohosuho Phillip, Ebiamadon Andi Brisibe, Ene‐Obong Effiom Ene‐Obong, Leena Tripathi. Strategies to combat the problem of yam anthracnose disease: Status and prospects. Molecular Plant Pathology. 2021; ():1.
Chicago/Turabian StyleValentine Otang Ntui; Edak Aniedi Uyoh; Effiom Eyo Ita; Aniedi‐Abasi Akpan Markson; Jaindra Nath Tripathi; Nkese Ime Okon; Mfon Okon Akpan; Julius Oyohosuho Phillip; Ebiamadon Andi Brisibe; Ene‐Obong Effiom Ene‐Obong; Leena Tripathi. 2021. "Strategies to combat the problem of yam anthracnose disease: Status and prospects." Molecular Plant Pathology , no. : 1.
Banana (Musa spp.) is an important staple food crop and a source of income for resource‐poor farmers in more than 136 tropical and sub‐tropical countries with an annual production of 155 million tons (FAOSTAT, 2018). Many diseases severely constrain banana production, particularly where many pathogens co‐exist (Tripathi et al., 2020). Banana Xanthomonas wilt (BXW) caused by Xanthomonas campestris pv. musacearum (Xcm) is considered among the most destructive banana diseases in East and Central Africa (Tripathi et al., 2009). All the cultivated banana varieties are susceptible, and only the wild‐type progenitor, Musa balbisiana, is resistant to BXW disease (Tripathi et al., 2019). Overall economic losses from BXW were estimated at US$ 2‐8 billion over a decade. The use of disease‐resistant varieties is one of the most effective strategies to manage diseases. Recent advances in CRISPR/Cas‐based genome‐editing can accelerate banana improvement. The availability of reference genome‐sequences and the CRISPR/Cas9‐editing system has made it possible to develop disease‐resistant banana by precisely editing the endogenous genes (Ntui et al., 2020).
Jaindra N. Tripathi; Valentine O. Ntui; Trushar Shah; Leena Tripathi. CRISPR/Cas9‐mediated editing of DMR6 orthologue in banana ( Musa spp.) confers enhanced resistance to bacterial disease. Plant Biotechnology Journal 2021, 19, 1291 -1293.
AMA StyleJaindra N. Tripathi, Valentine O. Ntui, Trushar Shah, Leena Tripathi. CRISPR/Cas9‐mediated editing of DMR6 orthologue in banana ( Musa spp.) confers enhanced resistance to bacterial disease. Plant Biotechnology Journal. 2021; 19 (7):1291-1293.
Chicago/Turabian StyleJaindra N. Tripathi; Valentine O. Ntui; Trushar Shah; Leena Tripathi. 2021. "CRISPR/Cas9‐mediated editing of DMR6 orthologue in banana ( Musa spp.) confers enhanced resistance to bacterial disease." Plant Biotechnology Journal 19, no. 7: 1291-1293.
Dhirendra Kumar; Jaindra Nath Tripathi; Sushma Naithani. Plant genetics and genomics for building a sustainable agriculture system. Current Plant Biology 2021, 26, 100208 .
AMA StyleDhirendra Kumar, Jaindra Nath Tripathi, Sushma Naithani. Plant genetics and genomics for building a sustainable agriculture system. Current Plant Biology. 2021; 26 ():100208.
Chicago/Turabian StyleDhirendra Kumar; Jaindra Nath Tripathi; Sushma Naithani. 2021. "Plant genetics and genomics for building a sustainable agriculture system." Current Plant Biology 26, no. : 100208.
The banana aphid, Pentalonia nigronervosa, is the sole insect vector of banana bunchy top virus (BBTV), the causal agent of banana bunchy top disease. The aphid acquires and transmits BBTV while feeding on infected banana plants. RNA interference (RNAi) enables the generation of pest and disease-resistant crops; however, its effectiveness relies on the identification of pivotal gene sequences to target and silence. Acetylcholinesterase (AChE) is an essential enzyme responsible for the hydrolytic metabolism of the neurotransmitter acetylcholine in animals. In this study, the AChE gene of the banana aphid was targeted for silencing by RNAi through transgenic expression of AChE dsRNA in banana and plantain plants. The efficacy of dsRNA was first assessed using an artificial feeding assay. In vitro aphid feeding on a diet containing 7.5% sucrose, and sulfate complexes of trace metals supported aphid growth and reproduction. When AChE dsRNA was included in the diet, a dose of 500 ng/μL was lethal to the aphids. Transgenic banana cv. Cavendish Williams and plantain cvs. Gonja Manjaya and Orishele expressing AChE dsRNA were regenerated and assessed for transgene integration and copy number. When aphids were maintained on elite transgenic events, there was a 67.8%, 46.7%, and 75.6% reduction in aphid populations growing on Cavendish Williams, Gonja Manjaya, and Orishele cultivars, respectively, compared to those raised on nontransgenic control plants. These results suggest that RNAi targeting an essential aphid gene could be a useful means of reducing both aphid infestation and potentially the spread of the disease they transmit.
Temitope Jekayinoluwa; Jaindra Tripathi; Benjamin Dugdale; George Obiero; Edward Muge; James Dale; Leena Tripathi. Transgenic Expression of dsRNA Targeting the Pentalonia nigronervosa acetylcholinesterase Gene in Banana and Plantain Reduces Aphid Populations. Plants 2021, 10, 613 .
AMA StyleTemitope Jekayinoluwa, Jaindra Tripathi, Benjamin Dugdale, George Obiero, Edward Muge, James Dale, Leena Tripathi. Transgenic Expression of dsRNA Targeting the Pentalonia nigronervosa acetylcholinesterase Gene in Banana and Plantain Reduces Aphid Populations. Plants. 2021; 10 (4):613.
Chicago/Turabian StyleTemitope Jekayinoluwa; Jaindra Tripathi; Benjamin Dugdale; George Obiero; Edward Muge; James Dale; Leena Tripathi. 2021. "Transgenic Expression of dsRNA Targeting the Pentalonia nigronervosa acetylcholinesterase Gene in Banana and Plantain Reduces Aphid Populations." Plants 10, no. 4: 613.
Yam (Dioscorea spp.) is a multi‐species tuber crop providing food and income to millions of people worldwide, particularly in Africa (Price et al., 2016). The “yam belt” in West Africa, including Nigeria, Benin, Togo, Ghana and Côte d’Ivoire, accounts for 92% of 72.6 million tons of global yam production (FAOSTAT 2018). Despite the economic importance, yam cultivation is plagued by several biotic and abiotic factors.
Easter D. Syombua; Zhengzhi Zhang; Jaindra N. Tripathi; Valentine O. Ntui; Minjeong Kang; Obiero O. George; Nguu K. Edward; Kan Wang; Bing Yang; Leena Tripathi. A CRISPR/Cas9‐based genome‐editing system for yam ( Dioscorea spp.). Plant Biotechnology Journal 2020, 19, 645 -647.
AMA StyleEaster D. Syombua, Zhengzhi Zhang, Jaindra N. Tripathi, Valentine O. Ntui, Minjeong Kang, Obiero O. George, Nguu K. Edward, Kan Wang, Bing Yang, Leena Tripathi. A CRISPR/Cas9‐based genome‐editing system for yam ( Dioscorea spp.). Plant Biotechnology Journal. 2020; 19 (4):645-647.
Chicago/Turabian StyleEaster D. Syombua; Zhengzhi Zhang; Jaindra N. Tripathi; Valentine O. Ntui; Minjeong Kang; Obiero O. George; Nguu K. Edward; Kan Wang; Bing Yang; Leena Tripathi. 2020. "A CRISPR/Cas9‐based genome‐editing system for yam ( Dioscorea spp.)." Plant Biotechnology Journal 19, no. 4: 645-647.
Banana and plantain are among the foremost staple food crops providing food and livelihood to over 500 million people in tropical countries. Despite the importance, their production is hampered due to several biotic and abiotic stresses. Plant tissue culture techniques such as somatic embryogenesis and genetic transformation offer a valuable tool for genetic improvement. Identification and quantification of phytochemicals found in banana and plantain are essential in optimizing in vitro activities for crop improvement. Total antioxidants, phenolics, flavonoids, and tannins were quantified in various explants obtained from the field, as well as in vitro plants of banana and plantain cultivars. The result showed genotypic variation in the phytochemicals of selected cultivars. The embryogenic cell suspensions were developed for three farmer-preferred plantain cultivars, Agbagba, Obino l’Ewai, and Orishele, using different MS and B5-based culture media. Both culture media supported the development of friable embryogenic calli (FEC), while MS culture media supported the proliferation of fine cell suspension in liquid culture media. The percentage of FEC generated for Agbagba, Obino l’Ewai, and Orishele were 22 ± 24%, 13 ± 28%, and 9 ± 16%, respectively. Cell suspensions produced from FECs were successfully transformed by Agrobacterium-mediated transformation with reporter gene constructs and regenerated into whole plants.
Temitope Jekayinoluwa; Jaindra Nath Tripathi; George Obiero; Edward Muge; Leena Tripathi. Phytochemical Analysis and Establishment of Embryogenic Cell Suspension and Agrobacterium-mediated Transformation for Farmer Preferred Cultivars of West African Plantain (Musa spp.). Plants 2020, 9, 789 .
AMA StyleTemitope Jekayinoluwa, Jaindra Nath Tripathi, George Obiero, Edward Muge, Leena Tripathi. Phytochemical Analysis and Establishment of Embryogenic Cell Suspension and Agrobacterium-mediated Transformation for Farmer Preferred Cultivars of West African Plantain (Musa spp.). Plants. 2020; 9 (6):789.
Chicago/Turabian StyleTemitope Jekayinoluwa; Jaindra Nath Tripathi; George Obiero; Edward Muge; Leena Tripathi. 2020. "Phytochemical Analysis and Establishment of Embryogenic Cell Suspension and Agrobacterium-mediated Transformation for Farmer Preferred Cultivars of West African Plantain (Musa spp.)." Plants 9, no. 6: 789.
Banana bunchy top virus (BBTV) is one of the world’s invasive species. Banana aphid (Pentalonianigronervosa) is found in all banana producing areas and it is the insect pest known to transmit BBTV causing banana bunchy top disease (BBTD) in bananas and plantains (Musa spp.) and can cause a significant yield loss of up to 100% in severe cases. Controlling the spread of BBTD has been very challenging since there is no known endogenous gene in the Musa germplasm that could confer resistance to BBTV. Excessive dependence on insecticides for disease control is detrimental to the environment and off-target-organisms. The objective of this study was to use RNA interference (RNAi) targeting the acetylcholinesterase (AChE) gene in banana aphid to develop resistance against aphids in farmer preferred plantain cultivars. This could help sustain smallholder farmers in areas where BBTD is an epidemic. To achieve this, plantain cultivars were initiated using plant tissue culture techniques and rapidly multiplied using Temporary Immersion Bioreactor. This was followed by generation of embryogenic cell suspension (ECS), Agrobacterium-mediated transformation of banana and plantain ECS using a RNAi plasmid construct and molecular characterization of putative transgenic lines. Agro-infected ECS of banana and plantain cultivars were regenerated on selective medium and produced several transgenic lines. Molecular characterization confirmed the presence of transgene in about 80% transgenic lines. Preliminary glasshouse screening of transgenic lines showed reduction in population of banana aphids in comparison to control non-transgenic plants. This is the first report on using RNAi targeting AChE gene for developing transgenic plantain that are resistant to banana aphids.
Temitope Jekayinoluwa; Jaindra Nath Tripathi; George Obiero; Edward Muge; James Dale; Leena Tripathi. Developing Plantain for Resistance to Banana Aphids by RNA Interference. Proceedings 2020, 36, 54 .
AMA StyleTemitope Jekayinoluwa, Jaindra Nath Tripathi, George Obiero, Edward Muge, James Dale, Leena Tripathi. Developing Plantain for Resistance to Banana Aphids by RNA Interference. Proceedings. 2020; 36 (1):54.
Chicago/Turabian StyleTemitope Jekayinoluwa; Jaindra Nath Tripathi; George Obiero; Edward Muge; James Dale; Leena Tripathi. 2020. "Developing Plantain for Resistance to Banana Aphids by RNA Interference." Proceedings 36, no. 1: 54.
Enset (Ensete ventricosum), also known as Ethiopian banana, is a food security crop for more than 20 million people in Ethiopia. As conventional breeding of enset is very challenging, genetic engineering is an alternative option to introduce important traits such as enhanced disease resistance and nutritional value. Genetic transformation and subsequent regeneration of transgenic enset has never been reported mainly due to challenges in developing transformation protocols for this tropical species. Agrobacterium-mediated transformation could be a practical tool for the genetic improvement of enset. However, the efficiency of the transformation system depends on several parameters such as plant regeneration, genotype, explant, selection agent and Agrobacterium strains. As a first step towards the development of transgenic enset, a simple and rapid plant regeneration system was developed using multiple buds as explants. Induction and proliferation of multiple buds from shoot tip explants was achieved on Murashige and Skoog (MS) medium supplemented with 5 and 10 mg/l of 6-benzylaminopurine (BAP), respectively. Shoots were regenerated from multiple buds on MS media containing 2 mg/l BAP and 0.2% activated charcoal. Based on the optimized regeneration protocol, an Agrobacterium-mediated transformation method was developed using multiple buds as explants and the binary plasmid pCAMBIA2300-GFP containing the green florescent protein (gfp) reporter gene and neomycin phosphotransferase II (nptII) selection marker gene. Transgenic plantlets were obtained within 4 months at a frequency of about 1.25%. The transgenic lines were validated by PCR analysis using primers specific to the nptII gene. To obtain uniformly transformed plantlets, chimerism was diluted by subculturing and regenerating the transgenic shoots on a selective medium containing kanamycin (150 mg/l) for five cycles. The uniformity of the transgenic plants was confirmed by Southern blot hybridization and RT-PCR analyses on different tissues such as leaf, pseudostem and root of same transgenic plant. In the present study, we report a simple Agrobacterium-mediated transformation system for generating transgenic events of enset. To the best of our knowledge, this is the first report on the stable transformation and regeneration of transgenic events of enset. The transformation system established in this study can be used for the generation of transgenic enset with important traits such as disease resistance.
Jonathan Matheka; Jaindra Tripathi; Ibsa Merga; Endale Gebre; Leena Tripathi. A simple and rapid protocol for the genetic transformation of Ensete ventricosum. Plant Methods 2019, 15, 1 -17.
AMA StyleJonathan Matheka, Jaindra Tripathi, Ibsa Merga, Endale Gebre, Leena Tripathi. A simple and rapid protocol for the genetic transformation of Ensete ventricosum. Plant Methods. 2019; 15 (1):1-17.
Chicago/Turabian StyleJonathan Matheka; Jaindra Tripathi; Ibsa Merga; Endale Gebre; Leena Tripathi. 2019. "A simple and rapid protocol for the genetic transformation of Ensete ventricosum." Plant Methods 15, no. 1: 1-17.
The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system enables precision editing of the genome of many plant species. Developing robust gene editing tools in banana and plantain would pave the way for the improvement of these crops. Here, we developed efficient CRISPR/Cas9 genome editing protocol for banana and plantain using multiple gRNA targeting phytoene desaturase (PDS) gene. CRISPR/Cas9 construct containing two gRNAs was delivered into embryogenic cell suspension cultures of banana cultivar ‘Sukali Ndiizi’ and plantain cultivar ‘Gonja Manjaya’ by Agrobacterium-mediated transformation. The regenerated genome-edited events of ‘Sukali Ndiizi’ and ‘Gonja Manjaya’ showed albino and variegated phenotypes indicating mutations at the targeted sites disrupting the function of PDS gene. The majority of events (52/77 for ‘Sukali Ndiizi’ and 16/17 for ‘Gonja Manjaya’) were albino. Sequencing of the target sites confirmed presence of indels in all the 18 events sequenced demonstrating mutation efficiency of 100 % in both cultivars. The majority of events (6/8) of ‘Gonja Manjaya’ showed indels at both the target sites of PDS gene, however only 2/10 events of ‘Sukali Ndiizi’ showed indels at both sites, with one event (S24) having a knockout of large fragment (723 bp) indicating that both gRNAs were effective. Several of the albino events of both ‘Sukali Ndiizi’ and ‘Gonja Manjaya’ showed homozygous mutations. Further sequencing of four potential off-target sites in five events showed no mutations indicating CRISPR/Cas9 based editing in banana and plantain is targeted and precise with a very low probability of off-target sites. This study could provide a methodological framework for single or multiple knockouts in banana and plantain.
Valentine Otang Ntui; Jaindra Tripathi; Leena Tripathi. Robust CRISPR/Cas9 mediated genome editing tool for banana and plantain (Musa spp.). Current Plant Biology 2019, 21, 100128 .
AMA StyleValentine Otang Ntui, Jaindra Tripathi, Leena Tripathi. Robust CRISPR/Cas9 mediated genome editing tool for banana and plantain (Musa spp.). Current Plant Biology. 2019; 21 ():100128.
Chicago/Turabian StyleValentine Otang Ntui; Jaindra Tripathi; Leena Tripathi. 2019. "Robust CRISPR/Cas9 mediated genome editing tool for banana and plantain (Musa spp.)." Current Plant Biology 21, no. : 100128.
Banana Xanthomonas wilt disease, caused by Xanthomonas campestris pv. musacearum (Xcm), is a major threat to banana production in east Africa. All cultivated varieties of banana are susceptible to Xcm and only the progenitor species Musa balbisiana was found to be resistant. The molecular basis of susceptibility and resistance of banana genotypes to Xcm is currently unknown. Transcriptome analysis of disease resistant genotype Musa balbisiana and highly susceptible banana cultivar Pisang Awak challenged with Xcm was performed to understand the disease response. The number of differentially expressed genes (DEGs) was higher in Musa balbisiana in comparison to Pisang Awak. Genes associated with response to biotic stress were up-regulated in Musa balbisiana. The DEGs were further mapped to the biotic stress pathways. Our results suggested activation of both PAMP-triggered basal defense and disease resistance (R) protein-mediated defense in Musa balbisiana as early response to Xcm infection. This study reports the first comparative transcriptome profile of the susceptible and resistant genotype of banana during early infection with Xcm and provide insights on the defense mechanism in Musa balbisiana, which can be used for genetic improvement of commonly cultivated banana varieties.
Leena Tripathi; Jaindra Tripathi; Trushar Shah; Kariuki Samwel Muiruri; Manpreet Katari. Molecular Basis of Disease Resistance in Banana Progenitor Musa balbisiana against Xanthomonas campestris pv. musacearum. Scientific Reports 2019, 9, 1 -17.
AMA StyleLeena Tripathi, Jaindra Tripathi, Trushar Shah, Kariuki Samwel Muiruri, Manpreet Katari. Molecular Basis of Disease Resistance in Banana Progenitor Musa balbisiana against Xanthomonas campestris pv. musacearum. Scientific Reports. 2019; 9 (1):1-17.
Chicago/Turabian StyleLeena Tripathi; Jaindra Tripathi; Trushar Shah; Kariuki Samwel Muiruri; Manpreet Katari. 2019. "Molecular Basis of Disease Resistance in Banana Progenitor Musa balbisiana against Xanthomonas campestris pv. musacearum." Scientific Reports 9, no. 1: 1-17.
Banana is a major staple food crop feeding more than 500 million people in tropical and subtropical countries. Its production is largely constrained by diseases and pests in addition to other factors such as declining soil fertility, narrow genetic diversity in germplasm, and inadequate availability of clean planting material. The impact of climate change, particularly a rise in temperature and drought, is predicted to affect production adversely due to direct effect on plant agronomy and also influence on pathogens, pests, and their interactions with host plants. There is need to develop climate‐smart varieties of banana with multiple and durable resistance to combat abiotic stresses such as extreme temperature and drought, and biotic stresses such as pathogens and pests. Modern breeding tools, including genetic modification and genome editing, can be applied for the improvement of banana bypassing the natural bottlenecks of traditional breeding. Intensive efforts using genetic modification have been made to develop improved banana varieties with resistance to biotic stresses; however, these need to be coupled with tolerance to abiotic stresses. Genome editing, an emerging powerful tool, can be applied for developing sustainable solutions to adapt to climate change by resisting biotic and abiotic stresses. CRISPR/Cas9‐based genome editing has been lately established for banana, paving the way for functional genomics allowing identification of genes associated with stress‐tolerant traits, which could be used for the improvement of banana for adaptation to a changing climate. This article presents an overview of recent advancements and prospective on the application of genetic modification and genome editing for developing climate‐smart banana.
Leena Tripathi; Valentine Otang Ntui; Jaindra Nath Tripathi. Application of genetic modification and genome editing for developing climate‐smart banana. Food and Energy Security 2019, 8, 1 .
AMA StyleLeena Tripathi, Valentine Otang Ntui, Jaindra Nath Tripathi. Application of genetic modification and genome editing for developing climate‐smart banana. Food and Energy Security. 2019; 8 (4):1.
Chicago/Turabian StyleLeena Tripathi; Valentine Otang Ntui; Jaindra Nath Tripathi. 2019. "Application of genetic modification and genome editing for developing climate‐smart banana." Food and Energy Security 8, no. 4: 1.
Presence of the integrated endogenous banana streak virus (eBSV) in the B genome of plantain (AAB) is a major challenge for breeding and dissemination of hybrids. As the eBSV activates into infectious viral particles under stress, the progenitor Musa balbisiana and its derivants, having at least one B genome, cannot be used as parents for crop improvement. Here, we report a strategy to inactivate the eBSV by editing the virus sequences. The regenerated genome-edited events of Gonja Manjaya showed mutations in the targeted sites with the potential to prevent proper transcription or/and translational into functional viral proteins. Seventy-five percent of the edited events remained asymptomatic in comparison to the non-edited control plants under water stress conditions, confirming inactivation of eBSV into infectious viral particles. This study paves the way for the improvement of B genome germplasm and its use in breeding programs to produce hybrids that can be globally disseminated. Jaindra Tirpathi et al. report a strategy for inactivating endogenous banana streak virus sequences in the plantain B genome using CRISPR/Cas9. They show that three-quarters of edited plants had no viral symptoms under stress conditions, providing an improved B genome germplasm for plantain and banana breeding.
Jaindra Tripathi; Valentine O. Ntui; Mily Ron; Samwel K. Muiruri; Anne Britt; Leena Tripathi. CRISPR/Cas9 editing of endogenous banana streak virus in the B genome of Musa spp. overcomes a major challenge in banana breeding. Communications Biology 2019, 2, 1 -11.
AMA StyleJaindra Tripathi, Valentine O. Ntui, Mily Ron, Samwel K. Muiruri, Anne Britt, Leena Tripathi. CRISPR/Cas9 editing of endogenous banana streak virus in the B genome of Musa spp. overcomes a major challenge in banana breeding. Communications Biology. 2019; 2 (1):1-11.
Chicago/Turabian StyleJaindra Tripathi; Valentine O. Ntui; Mily Ron; Samwel K. Muiruri; Anne Britt; Leena Tripathi. 2019. "CRISPR/Cas9 editing of endogenous banana streak virus in the B genome of Musa spp. overcomes a major challenge in banana breeding." Communications Biology 2, no. 1: 1-11.
Pseudocercospora fijiensis, causal agent of the black Sigatoka disease (BSD) of Musa spp., has spread globally since its discovery in Fiji 1963 to all the banana and plantain growing areas across the globe. It is becoming the most damaging and economically important disease of this crop. The identification and characterization of genes that regulate infection processes and pathogenicity in P. fijiensis will provide important knowledge for the development of disease-resistant cultivars. In many fungal plant pathogens, the Fus3 and Slt2 are reported to be essential for pathogenicity. Fus3 regulates filamentous-invasion pathways including the formation of infection structures, sporulation, virulence, and invasive and filamentous growth, whereas Slt2 is involved in the cell-wall integrity pathway, virulence, invasive growth, and colonization in host tissues. Here, we used RNAi-mediated gene silencing to investigate the role of the Slt2 and Fus3 homologs in P. fijiensis in pathogen invasiveness, growth and pathogenicity. The PfSlt2 and PfFus3 silenced P. fijiensis transformants showed significantly lower gene expression and reduced virulence, invasive growth, and lower biomass in infected leaf tissues of East African Highland Banana (EAHB). This study suggests that Slt2 and Fus3 MAPK signaling pathways play important roles in plant infection and pathogenic growth of fungal pathogens. The silencing of these vital fungal genes through host-induced gene silencing (HIG) could be an alternative strategy for developing transgenic banana and plantain resistant to BSD.
Francis Onyilo; Geoffrey Tusiime; Jaindra Tripathi; Li-Hung Chen; Bryce Falk; Ioannis Stergiopoulos; Wilberforce Tushemereirwe; Jerome Kubiriba; Leena Tripathi. Silencing of the Mitogen-Activated Protein Kinases (MAPK) Fus3 and Slt2 in Pseudocercospora fijiensis Reduces Growth and Virulence on Host Plants. Frontiers in Plant Science 2018, 9, 291 .
AMA StyleFrancis Onyilo, Geoffrey Tusiime, Jaindra Tripathi, Li-Hung Chen, Bryce Falk, Ioannis Stergiopoulos, Wilberforce Tushemereirwe, Jerome Kubiriba, Leena Tripathi. Silencing of the Mitogen-Activated Protein Kinases (MAPK) Fus3 and Slt2 in Pseudocercospora fijiensis Reduces Growth and Virulence on Host Plants. Frontiers in Plant Science. 2018; 9 ():291.
Chicago/Turabian StyleFrancis Onyilo; Geoffrey Tusiime; Jaindra Tripathi; Li-Hung Chen; Bryce Falk; Ioannis Stergiopoulos; Wilberforce Tushemereirwe; Jerome Kubiriba; Leena Tripathi. 2018. "Silencing of the Mitogen-Activated Protein Kinases (MAPK) Fus3 and Slt2 in Pseudocercospora fijiensis Reduces Growth and Virulence on Host Plants." Frontiers in Plant Science 9, no. : 291.
Enset (Ensete ventricosum (Welw.) Cheesman) is an economically important staple food crop in Ethiopia, especially in the southern and southwestern regions. It is called “false banana” due to its resemblance to banana, but inability to produce any edible fruit. The crop is clonally propagated using field-grown suckers. This study reports the development of a robust regeneration technique to propagate large numbers of plantlets using corm discs containing intercalary meristematic tissues. Hundreds of shoot buds were induced from corm discs of enset cultivar ‘Bedadeti’ cultured on Murashige and Skoog (MS) medium supplemented with 1.5 mg L−1 2,4-dichlorophenoxyacetic acid, 0.216 mg L−1 zeatin, and 2 g L−1 activated charcoal. The shoot buds were regenerated into complete plantlets when transferred onto MS medium supplemented with 1 mg L−1 6-benzylaminopurine and 2 g L−1 activated charcoal. More than 100 plantlets were generated in 4 mo from corm discs isolated from a single in vitro mother plantlet. Well-rooted plantlets were acclimatized in soil with 100% success, and did not show any apparent phenotypic abnormalities under glasshouse conditions. This efficient regeneration system could be very useful for the rapid multiplication of clean pathogen-free planting material.
Jaindra Tripathi; Jonathan Matheka; Ibsa Merga; Endale Gebre; Leena Tripathi. Efficient regeneration system for rapid multiplication of clean planting material of Ensete ventricosum (Welw.) Cheesman. In Vitro Cellular & Developmental Biology - Animal 2017, 53, 624 -630.
AMA StyleJaindra Tripathi, Jonathan Matheka, Ibsa Merga, Endale Gebre, Leena Tripathi. Efficient regeneration system for rapid multiplication of clean planting material of Ensete ventricosum (Welw.) Cheesman. In Vitro Cellular & Developmental Biology - Animal. 2017; 53 (6):624-630.
Chicago/Turabian StyleJaindra Tripathi; Jonathan Matheka; Ibsa Merga; Endale Gebre; Leena Tripathi. 2017. "Efficient regeneration system for rapid multiplication of clean planting material of Ensete ventricosum (Welw.) Cheesman." In Vitro Cellular & Developmental Biology - Animal 53, no. 6: 624-630.
Black Sigatoka disease, caused by Pseudocercospora fijiensis is a serious constraint to banana production worldwide. The disease continues to spread in new ecological niches and there is an urgent need to develop strategies for its control. The high osmolarity glycerol (HOG) pathway in Saccharomyces cerevisiae is well known to respond to changes in external osmolarity. HOG pathway activation leads to phosphorylation, activation and nuclear transduction of the HOG1 mitogen-activated protein kinases (MAPKs). The activated HOG1 triggers several responses to osmotic stress, including up or down regulation of different genes, regulation of protein translation, adjustments to cell cycle progression and synthesis of osmolyte glycerol. This study investigated the role of the MAPK-encoding PfHog1 gene on osmotic stress adaptation and virulence of P. fijiensis. RNA interference-mediated gene silencing of PfHog1 significantly suppressed growth of P. fijiensis on potato dextrose agar media supplemented with 1M NaCl, indicating that PfHog1 regulates osmotic stress. In addition, virulence of the PfHog1-silenced mutants of P. fijiensis on banana was significantly reduced, as observed from the low rates of necrosis and disease development on the infected leaves. Staining with lacto phenol cotton blue further confirmed the impaired mycelial growth of the PfHog1 in the infected leaf tissues, which was further confirmed with quantification of the fungal biomass using absolute- quantitative PCR. Collectively, these findings demonstrate that PfHog1 plays a critical role in osmotic stress regulation and virulence of P. fijiensis on its host banana. Thus, PfHog1 could be an interesting target for the control of black Sigatoka disease in banana.
Francis Onyilo; Geoffrey Tusiime; Li-Hung Chen; Bryce Falk; Ioannis Stergiopoulos; Jaindra Tripathi; Wilberforce Tushemereirwe; Jerome Kubiriba; Charles Changa; Leena Tripathi. Agrobacterium tumefaciens-Mediated Transformation of Pseudocercospora fijiensis to Determine the Role of PfHog1 in Osmotic Stress Regulation and Virulence Modulation. Frontiers in Microbiology 2017, 8, 830 .
AMA StyleFrancis Onyilo, Geoffrey Tusiime, Li-Hung Chen, Bryce Falk, Ioannis Stergiopoulos, Jaindra Tripathi, Wilberforce Tushemereirwe, Jerome Kubiriba, Charles Changa, Leena Tripathi. Agrobacterium tumefaciens-Mediated Transformation of Pseudocercospora fijiensis to Determine the Role of PfHog1 in Osmotic Stress Regulation and Virulence Modulation. Frontiers in Microbiology. 2017; 8 ():830.
Chicago/Turabian StyleFrancis Onyilo; Geoffrey Tusiime; Li-Hung Chen; Bryce Falk; Ioannis Stergiopoulos; Jaindra Tripathi; Wilberforce Tushemereirwe; Jerome Kubiriba; Charles Changa; Leena Tripathi. 2017. "Agrobacterium tumefaciens-Mediated Transformation of Pseudocercospora fijiensis to Determine the Role of PfHog1 in Osmotic Stress Regulation and Virulence Modulation." Frontiers in Microbiology 8, no. : 830.
Banana is an important staple food crop feeding more than 100 million Africans, but is subject to severe productivity constraints due to a range of pests and diseases. Banana Xanthomonas wilt caused by Xanthomonas campestris pv. musacearum is capable of entirely destroying a plantation while nematodes can cause losses up to 50% and increase susceptibility to other pests and diseases. Development of improved varieties of banana is fundamental in order to tackle these challenges. However, the sterile nature of the crop and the lack of resistance in Musa germplasm make improvement by traditional breeding techniques either impossible or extremely slow. Recent developments using genetic engineering have begun to address these problems. Transgenic banana expressing sweet pepper Hrap and Pflp genes have demonstrated complete resistance against X. campestris pv. musacearum in the field. Transgenic plantains expressing a cysteine proteinase inhibitors and/or synthetic peptide showed enhanced resistance to a mixed species population of nematodes in the field. Here, we review the genetic engineering technologies which have potential to improve agriculture and food security in Africa.
Leena Tripathi; Howard Atkinson; Hugh Roderick; Jerome Kubiriba; Jaindra N. Tripathi. Genetically engineered bananas resistant to Xanthomonas wilt disease and nematodes. Food and Energy Security 2017, 6, 37 -47.
AMA StyleLeena Tripathi, Howard Atkinson, Hugh Roderick, Jerome Kubiriba, Jaindra N. Tripathi. Genetically engineered bananas resistant to Xanthomonas wilt disease and nematodes. Food and Energy Security. 2017; 6 (2):37-47.
Chicago/Turabian StyleLeena Tripathi; Howard Atkinson; Hugh Roderick; Jerome Kubiriba; Jaindra N. Tripathi. 2017. "Genetically engineered bananas resistant to Xanthomonas wilt disease and nematodes." Food and Energy Security 6, no. 2: 37-47.
Banana production is severely affected by bacterial diseases jeopardizing the food security of millions of inhabitants in countries where farmers depend upon banana as staple food. Bacterial diseases like Xanthomonas wilt, Moko, blood, and Bugtok are the most important diseases threatening banana cultivation in several tropical and subtropical countries. Genetic improvement of banana through classical breeding is difficult due to the lack of resistant germplasm, sterile nature, and long generation time. Transgenic technology can complement classical breeding for developing bacterial disease-resistant varieties. Some success has been achieved for developing host plant resistance in order to control banana Xanthomonas wilt (BXW) disease. Currently, the transgenic bananas expressing either sweet pepper Pflp or Hrap gene are under evaluation for resistance to Xanthomonas wilt disease in field trials in Uganda. Management of bacterial diseases through cultural practices like removal of male buds and use of pathogen-free seed material and disinfected cutting tools can contain outbreak of diseases although these are not absolute solutions for control of bacterial diseases. In this chapter, we have discussed various management practices as well as existing transgenic technologies to control bacterial diseases of banana.
Leena Tripathi; Jaindra Tripathi; Jerome Kubiriba. Transgenic Technologies for Bacterial Wilt Resistance. Banana: Genomics and Transgenic Approaches for Genetic Improvement 2016, 197 -209.
AMA StyleLeena Tripathi, Jaindra Tripathi, Jerome Kubiriba. Transgenic Technologies for Bacterial Wilt Resistance. Banana: Genomics and Transgenic Approaches for Genetic Improvement. 2016; ():197-209.
Chicago/Turabian StyleLeena Tripathi; Jaindra Tripathi; Jerome Kubiriba. 2016. "Transgenic Technologies for Bacterial Wilt Resistance." Banana: Genomics and Transgenic Approaches for Genetic Improvement , no. : 197-209.
Dioscorea rotundata, commonly known as white yam, is an important staple food crop widely cultivated in West Africa and provides food security to millions of people. Genetic improvements of this crop using the advanced biotechnology tools have been hampered hitherto by the recalcitrant nature of regeneration through somatic embryogenesis. Therefore, we have developed an efficient and reproducible system for plant regeneration via somatic embryogenesis. Explants of different types (immature leaf, node, stem internode, root segment, petiole, and axillary bud) of D. rotundata accession TDr 2436 were tested for their embryogenic potentials on Murashige and Skoog (MS) medium supplemented with various auxins (2,4-D, NAA, and picloram). Among all explants tested, axillary bud explants cultured on MS medium supplemented with picloram (0.5–12 mg/l) favored the production of calli. Maximum proliferation of calli (526 mg fresh weight/explant) was achieved on MS medium supplemented with picloram (0.5 mg/l), casein hydrolysate (600 mg/l), and proline (1 g/l). Histology analysis confirmed that the embryogenic calli produced on this medium were mixed with non-embryogenic calli. Transfer of calli on MS basal medium supplemented with activated charcoal (1 %) changed the color of calli to purple and promoted the production of somatic embryos (87 embryos/callus) as well as adventitious shoot buds. Furthermore, upon transfer to MS medium supplemented with BAP (0.4 mg/l), the embryos continued their differentiation and maturation and germinated into complete plantlets. The adventitious shoot buds produced multiple shoots on MS medium supplemented with BAP (0.4 mg/l). Well-developed germinated plantlets were acclimatized in the screen house with 90 % survivability. Histology studies confirmed that the regeneration of D. rotundata reported here followed dual regeneration pathways. The embryogenic calli regenerated through development of somatic embryos and germinated into complete plantlets, however non-embryogenic calli regenerated through organogenesis and developed multiple shoots. The developed protocol has potential for somatic hybridization, mass clonal propagation, and genetic transformation applications.
Rajesh Manoharan; Jaindra Tripathi; Leena Tripathi. Plant regeneration from axillary bud derived callus in white yam (Dioscorea rotundata). Plant Cell, Tissue and Organ Culture (PCTOC) 2016, 126, 481 -497.
AMA StyleRajesh Manoharan, Jaindra Tripathi, Leena Tripathi. Plant regeneration from axillary bud derived callus in white yam (Dioscorea rotundata). Plant Cell, Tissue and Organ Culture (PCTOC). 2016; 126 (3):481-497.
Chicago/Turabian StyleRajesh Manoharan; Jaindra Tripathi; Leena Tripathi. 2016. "Plant regeneration from axillary bud derived callus in white yam (Dioscorea rotundata)." Plant Cell, Tissue and Organ Culture (PCTOC) 126, no. 3: 481-497.
Banana production in Africa's great lakes region is threatened by the Banana Xanthomonas wilt (BXW) disease caused by Xanthomonas campestris pv. musacearum, a biotrophic pathogen. Transgenic banana plants, cv. “Gonja manjaya,” expressing stacked hypersensitive response-assisting protein gene (HRAP) and the plant ferredoxin-like protein gene (PFLP) were evaluated for resistance against BXW in comparison to transgenic lines having single gene. Transgenic lines with stacked gene as well as single gene had higher resistance to the pathogen than non-transgenic control plants indicated by either no symptom development or delayed symptoms for completely and partially resistant plants, respectively. Transgenic lines also produced more hydrogen peroxide due to pathogen infection and also had higher transcription of stress response genes encoding NPR1, a defense response co-transcriptor, the antimicrobial PR-3 and glutathione S-transferase. However, transcription of PR-1, an indicator for infection with a biotrophic pathogen, was not increased in both stacked and single transgenic lines, indicating a possible shift to infection with a necrotrophic pathogen in plants due to transgenes expression. Expression of stacked HRAP and PFLP genes in transgenic banana lines did not show higher or additive resistance levels against pathogen in comparison to individual genes; however, stacking might provide the benefit of durable resistance in case one transgene function is lost.
Abubaker Muwonge; Jaindra Tripathi; Karl Kunert; Leena Tripathi. Expressing stacked HRAP and PFLP genes in transgenic banana has no synergistic effect on resistance to Xanthomonas wilt disease. South African Journal of Botany 2016, 104, 125 -133.
AMA StyleAbubaker Muwonge, Jaindra Tripathi, Karl Kunert, Leena Tripathi. Expressing stacked HRAP and PFLP genes in transgenic banana has no synergistic effect on resistance to Xanthomonas wilt disease. South African Journal of Botany. 2016; 104 ():125-133.
Chicago/Turabian StyleAbubaker Muwonge; Jaindra Tripathi; Karl Kunert; Leena Tripathi. 2016. "Expressing stacked HRAP and PFLP genes in transgenic banana has no synergistic effect on resistance to Xanthomonas wilt disease." South African Journal of Botany 104, no. : 125-133.