Browsing by Author "S.R. Prabhukarthikeyan"

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Deciphering environmental factors and defense response of rice genotypes against sheath blight disease
(Academic Press, 2022) R. Naveenkumar; A. Anandan; Vineeta Singh; S.R. Prabhukarthikeyan; C. Parameswaran; G. Sangeetha; A. Mahender; U. Keerthana; P.K. Singh; B.C. Patra; Jauhar Ali
Sheath blight (ShB) is one of the most serious diseases in rice, leading to severe yield losses globally. In our study, we evaluated a total of 63 rice genotypes for resistance against sheath blight disease by artificial inoculation over two seasons under field conditions and studied the weather parameters associated with disease incidence. Based on two years of testing, 23 genotypes were found moderately resistant, 38 were moderately susceptible, and 2 exhibited a susceptible reaction to sheath blight disease. Among the specific four genotypes (IC283139, IC283041, IC283038, and IC283023) of the moderately resistant group exhibited less disease reaction in comparison with check variety Tetep. Further, the correlation of percent disease index (PDI) with weather parameters revealed negative associations between PDI and maximum temperature, minimum temperature, low rainfall and the positive association with maximum relative humidity (RH) suggest that very low temperature or high precipitation might have a negative impact on pathogen establishment. In addition, the sheath blight-linked SSRs were assessed using distance and model-based approaches, results of both the models revealed that genotypes distinguished the resistant population from the susceptible one. From the output of two years of principal component analysis, two genotypes from each group of moderately resistant, moderately susceptible and susceptible were studied for their biochemical reaction against the sheath blight pathogen. The biochemical study revealed that the accumulation of defense and antioxidant enzymes, namely, polyphenol oxidase, peroxidase, total phenol, phenylalanine ammonia-lyase, catalase, and superoxide dismutase, were higher in moderately resistant genotypes, but was observed to be lower in moderately susceptible and susceptible genotypes. The statistical analysis revealed the enzyme activities (defense and antioxidant) exhibited a strong negative correlation with area under the disease progress curve (AUDPC) and influence of weather parameter RH. This demonstrates that the environment factor RH plays a major role in imparting the resistance mechanism by decreasing the enzymes activities and increasing PDI. This study found that the identified novel resistant genotype (IC283139) with purple stem base demonstrated improved resistance against sheath blight infection through a defense response and the use of antioxidant machinery. © 2022 The Authors
Pseudomonas and Bacillus: A biological tool for crop protection
(Elsevier, 2022) A. Muthukumar; T. Suthin Raj; S.R. Prabhukarthikeyan; R. Naveen; U. Keerthanab
The problems caused by soil-borne pathogens in crop production worldwide include reduced crop performance, decreased yield, and higher production costs. The threats of soil-borne disease epidemics in crop production, high cost of chemical fungicides and development of fungicide resistance, climate change, new disease outbreaks and increasing concerns regarding environmental as well as soil health are becoming increasingly evident. Research in the past few years has clearly shown that selected strains of bacteria (Pseudomonas spp. and Bacillus spp.) provide an eco-friendly well balanced plant health management system through systemic resistance to diseases of biotic and a biotic nature. Pseudomonas can also synthesize enzymes which may modulate the plant hormone levels, limit the available iron by production of siderophores and can also kill the pathogen by producing antibiotics such as Phenazine, 2, 4-diacetylphloroglucinol (DAPG), Phenazine carboximide, Pyoluteorin and Pyrrolnitrin, volatile compounds such as hydrogen cyanide (HCN), siderophores and biofilms mainly responsible for the inhibition of pathogens. Pseudomonas might have stimulated the plant growth by improving uptake of minerals into the host plants particularly phosphate production of IAA, production of cytokinin, regulating ethylene production in roots and solubilizing nutrients such as phosphorus. Likewise, Bacillus produced several kinds of antimicrobial peptide substances such as subtilin, bacilysin, mycobacillisyn, iturin, oligomycin A, kanosamine and zwittermicin A, which may be responsible for the inhibition of pathogen. It also play an important role in plant growth promotion by production of GA3 and IAA, production of cytokinin, synthesize various types of lipopeptides and zinc solubilization. Both powder and liquid formulations of Pseudomonas and Bacillus have been successfully used for the control of foliar and soil-borne diseases. Bio-fungicidal association also stimulated plant defensive mechanisms induction of resistance metabolism similar to the hypersensitive response, systemic acquired resistance and induced systemic resistance in plants. Nowadays, there is a growing demand for biologically based soil-borne pathogen management practices. © 2022 Elsevier Inc. All rights reserved.
Understanding the plant-microbe interactions in crispr/cas9 era: Indeed a sprinting start in marathon
(Bentham Science Publishers, 2020) S.R. Prabhukarthikeyan; C. Parameswaran; U. Keerthana; Basavaraj Teli; Prasanth Tej Kumar Jagannadham; B. Cayalvizhi; P. Panneerselvam; Ansuman Senapati; K. Nagendran; Shweta Kumari; Manoj Kumar Yadav; S. Aravindan; S. Sanghamitra
Plant-microbe interactions can be either beneficial or harmful depending on the nature of the interaction. Multifaceted benefits of plant-associated microbes in crops are well documented. Specifically, the management of plant diseases using beneficial microbes is considered to be eco-friendly and the best alternative for sustainable agriculture. Diseases caused by various phytopathogens are responsible for a significant reduction in crop yield and cause substantial economic losses globally. In an ecosystem, there is always an equally daunting challenge for the establishment of disease and development of resistance by pathogens and plants, respectively. In particular, comprehending the complete view of the complex biological systems of plant-pathogen interactions, co-evolution and plant growth promotions (PGP) at both genetic and molecular levels requires novel approaches to decipher the function of genes involved in their interaction. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 (CRISPR-associated protein 9) is a fast, emerging, precise, ecofriendly and efficient tool to address the challenges in agriculture and decipher plant-microbe interaction in crops. Nowadays, the CRISPR/Cas9 approach is receiving major attention in the field of functional genomics and crop improvement. Consequently, the present review updates the prevailing knowledge in the deployment of CRISPR/Cas9 techniques to understand plant-microbe interactions, genes edited for the development of fungal, bacterial and viral disease resistance, to elucidate the nodulation processes, plant growth promotion, and future implications in agriculture. Further, CRISPR/Cas9 would be a new tool for the management of plant diseases and increasing productivity for climate resilience farming. © 2020 Bentham Science Publishers.