Publications of NIPGR Scientists

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Author: search.filters.author.Achary, Rakesh KumarSubject: search.filters.subject.Rice

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    Rice PROTEIN L-ISOASPARTYL METHYLTRANSFERASES provides tolerance against sheath blight disease and repairs ALDH and PBZ1
    (Nature Publishing Group, 2026) Gautam, Shikha; Kamble, Nitin Uttam; Achary, Rakesh Kumar; Chandan, Ravindra Kumar; Varshney, Vishal; Hazra, Abhijit; Laha, Saroj; Mahawar, Shivangi; Mehandiratta, Sohela; Singh, Sarvanand; Jha, Gopaljee; Majee, Manoj
    Protein L-isoaspartyl methyltransferase (PIMT) regulates key seed traits and abiotic stress tolerance in plants by repairing isoaspartyl (isoAsp) damaged proteins. However, whether PIMT-mediated repair is induced and is required during biotic stress tolerance remains unknown. Using rice lines with OsPIMT overexpression, RNAi-mediated suppression, and genome editing, we show that PIMT enhances tolerance to sheath blight (ShB) caused by Rhizoctonia solani. OsPIMT restricts fungal penetration and colonization of rice sheaths. Co-immunoprecipitation coupled with LC-MS/MS identify various proteins including antioxidant proteins, aldehyde dehydrogenases (ALDH) and pathogenesis-related protein 10 (PBZ1), that undergo isoAsp modification during R. solani infection and interact with PIMT. We show that OsALDH and OsPBZ1 exhibit intrinsic antifungal activity against R. solani, but isoAsp modification impairs their activity, making PIMT mediated repair important. Further, OsALDH enhances tolerance to R. solani by inhibiting lipid peroxidation and ROS homeostasis in rice and fungus. Overall, our study reveals that PIMT enhances ShB tolerance through the repair of isoAsp-damaged proteins important for disease tolerance.
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    Methionine sulfoxide reductase B5 plays a key role in preserving seed vigor and longevity in rice (Oryza sativa)
    (John Wiley & Sons, 2022) Hazra, Abhijit; Varshney, Vishal; Verma, Pooja; Kamble, Nitin Uttam; Ghosh, Shraboni; Achary, Rakesh Kumar; Gautam, Shikha; Majee, Manoj
    Oxidation of methionine leads to the formation of methionine S-sulfoxide and methionine R-sulfoxide, which can be reverted by two types of Methionine Sulfoxide Reductase (MSR), MSRA and MSRB, respectively. Despite the role of MSR enzymes being elucidated in various physiological processes, regulation and implication of MSR in seeds remained poorly explored. In this study, through molecular, biochemical, and genetic studies using seed-specific overexpression and RNAi lines of OsMSRB5 in Oryza sativa, we demonstrate the role of OsMSRB5 in maintaining seed vigor and longevity. We show that age-induced reduced vigor and viability of seeds is correlated with reduced MSR activity and increased methionine sulfoxide (MetSO) formation. OsMSRB5 expression increases during seed maturation and predominantly localizes in the embryo. Further analyses on transgenic lines reveal the role of OsMSRB5 in modulating reactive oxygen species (ROS) homeostasis to preserve seed vigor and longevity. We show that ascorbate peroxidase (APX) and PROTEIN L-ISOASPARTYL METHYLTRANSFERASE (PIMT) undergo MetSO modification in seeds that affect their functional competence. OsMSRB5 physically interacts with these proteins and reverts this modification to facilitate their functions and preserve seed vigor and longevity of seeds. Our results thus illustrate the role of OsMSRB5 in preserving seed vigor and longevity by modulating ROS homeostasis in seeds.