Publications of NIPGR Scientists

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Author: search.filters.author.Yadav, ShaliniStart date: 2023

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    CBL1/9-CIPK6 complex negatively regulates respiratory burst oxidase homolog D in Arabidopsis thaliana
    (John Wiley & Sons, 2026) Vishwakarma, Niraj Kumar; Yadav, Shalini; Sardar, Atish; Choudhary, Megha; Chattopadhyay, Debasis
    Plant innate immune response is a well-balanced process with positive and negative regulations for the plants to survive. Calcium signaling is essential for pathogen-associated molecular pattern (PAMP)-driven respiratory burst oxidase homolog D (RBOHD)-mediated reactive oxygen species (ROS) burst. We show that calcium sensors calcineurin B like protein 1 (CBL1) and CBL9 and their interacting protein kinase CIPK6 negatively regulate RBOHD activity and immune response in Arabidopsis thaliana. Arabidopsis mutant cbl1cbl9, like cipk6, exhibited enhanced resistance and ROS production when infected with the bacterial pathogen Pseudomonas syringae pv. tomato (Pst). CBL1 and CBL9 enhanced kinase activity of CIPK6. CBL1/9-CIPK6 module interacts with RBOHD at the plasma membrane. CIPK6 along with CBL1 reduces RBOHD activity in planta. CIPK6 phosphorylates the N-terminal cytoplasmic domain of RBOHD at a non-conserved (S33) and a conserved (S39) serine residue. While S39 phosphorylation increased RBOHD activity, S33 phosphorylation drastically reduced it and superseded the effect of S39 phosphorylation. We propose a model that CIPK6 phosphorylates RBOHD at S33 to suppress its activity to balance ROS generation in post-PTI situation in Arabidopsis. Our study reports a direct mechanism of negative regulation of ROS production and plant immune response by a calcium-signaling module in Arabidopsis thaliana.
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    MicroRNA397 regulates tolerance to drought and fungal infection by regulating lignin deposition in chickpea root
    (John Wiley & Sons, 2023) Sharma, Nilesh Kumar; Yadav, Shalini; Gupta, Santosh Kumar; Irulappan, Vadivelmurugan; Francis, Aleena; Senthil-Kumar, Muthappa; Chattopadhyay, Debasis
    Plants deposit lignin in the secondary cell wall as a common response to drought and pathogen attacks. Cell wall localised multicopper oxidase family enzymes LACCASES (LACs) catalyse the formation of monolignol radicals and facilitate lignin formation. We show an upregulation of the expression of several LAC genes and a downregulation of microRNA397 (CamiR397) in response to natural drought in chickpea roots. CamiR397 was found to target LAC4 and LAC17L out of twenty annotated LACs in chickpea. CamiR397 and its target genes are expressed in the root. Overexpression of CamiR397 reduced expression of LAC4 and LAC17L and lignin deposition in chickpea root xylem causing reduction in xylem wall thickness. Downregulation of CamiR397 activity by expressing a short tandem target mimic (STTM397) construct increased root lignin deposition in chickpea. CamiR397-overexpressing and STTM397 chickpea lines showed sensitivity and tolerance, respectively, towards natural drought. Infection with a fungal pathogen Macrophomina phaseolina, responsible for dry root rot (DRR) disease in chickpea, induced local lignin deposition and LAC gene expression. CamiR397-overexpressing and STTM397 chickpea lines showed more sensitivity and tolerance, respectively, to DRR. Our results demonstrated the regulatory role of CamiR397 in root lignification during drought and DRR in an agriculturally important crop chickpea.
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    Lignin: the building block of defense responses to stress in plants
    (Springer Nature Publishing AG, 2023) Yadav, Shalini; Chattopadhyay, Debasis
    Lignin is a complex aromatic biopolymer important for providing mechanical strength to the cell wall and resistance against both biotic and abiotic stresses. It helps in plant growth by providing physical strength and helping in long distance transport of water and minerals. Lignin biosynthetic genes are known to be induced under both biotic and abiotic stresses, and perturbations in lignin biosynthesis has shown to result in changes in plants defense responses against these stresses. It’s important to understand how these sophisticated mechanisms are employed by the plants to adapt to the adverse climatic conditions and develop more resilient plant varieties. In this review, we try to deliver a thorough comprehension of how lignin biosynthesis is altered under various environmental conditions. We believe this information will be useful in understanding the role of diferent lignin biosynthetic genes in conferring resistance against diferent stresses.