Browsing by Author "Patil, Mahesh"

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ath-miR164c influences plant responses to the combined stress of drought and bacterial infection by regulating proline metabolism
(Elsevier B.V., 2020) Gupta, Aarti; Patil, Mahesh; Qamar, Aarzoo; Senthil-Kumar, Muthappa
Plants under combined stresses exhibit a prominent shift in molecular responses compared with plants exposed to the same stresses independently. Profiling responses to individual and combined stressors at the gene expression level have identified several genes with intersecting responses to these stressors. However, the upstream regulators at the intersection of plant responses to individual and combined stresses are not known. Here, using the transcriptome of Arabidopsis thaliana under individual and combined drought and Pseudomonas syringae infection, we identified several genes whose expression overlaps between individual and combined stresses. To study the key regulator of such an overlapping gene, we predicted that the expression of 1-Pyrroline-5-carboxylate synthase 1 (AtP5CS1) is regulated by ath-miR164c at post-transcriptional level. Our results from the stem-loop RT-PCR based expression analysis revealed significant downregulation of ath-miR164c in response to P. syringae infection under both well-irrigated (pathogen only) and drought stress (combined stress) conditions. Furthermore, an Arabidopsis loss-of-function mutant of the miRNA ath-miR164c exhibited resistance to pathogen infection under combined stress, unlike the wild-type plants, implicating the role of ath-miR164c in regulating plant immunity. AtP5CS1 gene expression and proline accumulation were enhanced in the ath-miR164c mutant plants relative to the wild-type plants, demonstrating that ath-miR164c regulates AtP5CS1 of the proline biosynthesis pathway, which was also validated by 5’RLM-RACE results. This miRNA-mediated modulation of AtP5CS1 gene expression under combined stress fills crucial gaps in identifying the key convergent players in the current understanding of plant stress responses.
Role of plant kinases in combined stress
(John Wiley & Sons, 2021) Patil, Mahesh; Senthil-Kumar, Muthappa
Plants in nature are exposed to multiple stresses during their life cycle, affecting growth and productivity. Plants have evolved various molecular mechanisms to cope with stress by altering the protein and enzyme activity involved in cellular processes. Protein phosphorylation, catalyzed by kinase, is one of the critical regulatory mechanisms known to control protein and enzyme activity and its interaction with other proteins involved in the cellular signaling cascade. In eukaryotes, approximately 1–3% of functional genes encode protein kinases, implicating the relevance of kinases in cellular regulation and metabolism. Several past studies have shown the importance of protein phosphorylation by kinases under different stresses like drought, heat, high light, pathogen attack, and nutrient deprivation. However, the role of kinases under combined stresses has been elucidated for only a few. In this chapter, using publically available microarray data under combined stress, we have identified the protein kinases involved in different abiotic and biotic stress combinations. Further, an attempt has also been made to explain the possible function of the identified kinases through literature analysis and also to emphasize the need for functional validation of these kinases under combined stress for a better understanding of the stress tolerance mechanisms.
Stress combinations and their interactions in plants database: a one-stop resource on combined stress responses in plants
(John Wiley & Sons, 2023) Priya, Piyush; Patil, Mahesh; Pandey, Prachi; Singh, Anupriya; Babu, Vishnu Sudha; Senthil-Kumar, Muthappa
We have developed a compendium and interactive platform, named Stress Combinations and their Interactions in Plants Database (SCIPDb; http://www.nipgr.ac.in/scipdb.php), which offers information on morpho-physio-biochemical (phenome) and molecular (transcriptome and metabolome) responses of plants to different stress combinations. SCIPDb is a plant stress informatics hub for data mining on phenome, transcriptome, trait-gene ontology, and data-driven research for advancing mechanistic understanding of combined stress biology. We analyzed global phenome data from 939 studies to delineate the effects of various stress combinations on yield in major crops and found that yield was substantially affected under abiotic-abiotic stresses. Transcriptome datasets from 36 studies hosted in SCIPDb identified novel genes, whose roles have not been earlier established in combined stress. Integretome analysis under combined drought-heat stress pinpointed carbohydrate, amino acid, and energy metabolism pathways as the crucial metabolic, proteomic, and transcriptional components in plant tolerance to combined stress. These examples illustrate the application of SCIPDb in identifying novel genes and pathways involved in combined stress tolerance. Further, we showed the application of this database in identifying novel candidate genes and pathways for combined drought and pathogen stress tolerance. To our knowledge, SCIPDb is the only publicly available platform offering combined stress-specific omics big data visualization tools, such as an interactive scrollbar, stress matrix, radial tree, global distribution map, meta-phenome analysis, search, BLAST, transcript expression pattern table, Manhattan plot, and co-expression network. These tools facilitate a better understanding of the mechanisms underlying plant responses to combined stresses.
When two negatives make a positive: The favorable impact of the combination of abiotic stress and pathogen infection on plants
(Oxford University Press, 2024) Pandey, Prachi; Patil, Mahesh; Priya, Piyush; Senthil-Kumar, Muthappa
Combined abiotic and biotic stresses modify plant defense signaling, leading to either the activation or suppression of defense responses. Although the majority of combined abiotic and biotic stresses reduce plant fitness, certain abiotic stresses reduce the severity of pathogen infection in plants. Remarkably, certain pathogens also improve the tolerance of some plants to a few abiotic stresses. While considerable research focuses on the detrimental impact of combined stresses on plants, the upside of combined stress remains hidden. This review succinctly discusses the interactions between abiotic stresses and pathogen infection that benefit plant fitness. Here, we discuss various factors that govern the positive influence of combined abiotic stress and pathogen infection on plant performance. We also provide a brief overview of the role of pathogens, mainly viruses, in improving plant responses to abiotic stresses. We further highlight the critical nodes in defense signaling that guide plant responses during abiotic stress towards enhanced resistance to pathogens. Studies on antagonistic interactions between abiotic and biotic stressors can uncover candidates in host plant defense that may shield plants from combined stresses.