Institutional Publications

Permanent URI for this collectionhttps://ndkr-library.nipgr.ac.in/handle/123456789/11

Browse

Start date: 2022Subject: search.filters.subject.MPK3

Search Results

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    KRP3 stability controls rice plant architecture and productivity via MPK3-mediated phosphorylation
    (John Wiley & Sons, 2026) Banerjee, Gopal; Jonwal, Sarvesh; Rengasamy, Balakrishnan; Pal, Uttam; Singh, Dhanraj; Mohit, Mohit; Sinha, Alok Krishna
    Yield is a critical agronomic trait in cereal crops, shaped by factors like tiller and seed number, and seed weight. Understanding the factors governing these traits will help in improving the yield of plants. In this study, we identified an orphan gene, KRP3, belonging to cereal crops as a key regulator of rice plant architecture. Altered KRP3 protein homeostasis affected plant height, tiller number, and seed production, highlighting its role in maintaining rice plant vigor and productivity. The stability of the KRP3 protein is positively regulated by MPK3-mediated phosphorylation, as unphosphorylated KRP3 is targeted for degradation via the ubiquitin-proteasome pathway. Our findings reveal that the identified MPK3-KRP3 module operates as an S-phase checkpoint, modulating the pace of cell division in the actively dividing zones and maintaining a balance between cell division and elongation. These findings provide valuable insights for improving plant growth and grain yield in rice.
  • Thumbnail Image
    Item
    Regulation of photosynthesis by mitogen-activated protein kinase in rice: antagonistic adjustment by OsMPK3 and OsMPK6
    (Springer Nature Publishing AG, 2023) Jonwal, Sarvesh; Rengasamy, Balakrishnan; Sinha, Alok Krishna
    Photosynthesis is the basis of almost all life on earth and is the main component of crop yield that contributes to the carbohydrate partitioning to the grains. Maintaining the photosynthetic efficiency of plants in challenging environmental conditions by regulating the associated factors is a potential research arena which will help in the improvement of crop yield. Phosphorylation is known to play a pivotal role in the regulation of photosynthesis. Mitogen Activated Protein Kinases (MAPKs) cascade although known to regulate a diverse range of processes does not have any exact reported function in the regulation of photosynthesis. To elucidate the regulatory role of MAPKs in photosynthesis we investigated the changes in net photosynthesis rate and related parameters in DEX inducible over-expressing (OE) lines of two members of MAPK gene family namely, OsMPK3 and OsMPK6 in rice. Interestingly, significant changes were found in net photosynthesis rate and related physiological parameters in OsMPK3 and OsMPK6-OE lines compared to its wild-type relatives. OsMPK3 and OsMPK6 have regulatory effects on nuclear-encoded photosynthetic genes. Untargeted metabolite profiling reveals a higher accumulation of sugars and their derivatives in MPK6 overexpressing plants and a lower accumulation of sugars and organic acids in MPK3 overexpressing plants. The accumulation of amino acids was found in abundance in both MPK3 and MPK6 overexpressing plants. Understanding the effects of MPK3 and MPK6 on the CO2 assimilation of rice plants under normal growth conditions, will help in devising strategies that can be extended for crop improvement.
  • Thumbnail Image
    Item
    Rice Mitogen-Activated Protein Kinase regulates serotonin accumulation and interacts with cell cycle regulators under prolonged UV-B exposure
    (Elsevier B.V., 2023) Banerjee, Gopal; Singh, Dhanraj; Pandey, Chandana; Jonwal, Sarvesh; Basu, Udita; Parida, Swarup K.; Pandey, Ashutosh; Sinha, Alok Krishna
    Stress conditions such as UV-B exposure activates MAPKs in Arabidopsis and rice. UV-B radiation is hazardous to plant as it causes photosystem disruption, DNA damage and ROS generation. Here we report its effect on biological pathways by studying the global changes in transcript profile in rice seedling exposed to UV-B radiation for 1 h and 16 h. Short UV-B exposure (1 h) led to moderate changes, while a drastic change in transcript landscape was observed after long term UV-B exposure (16 h) in rice seedlings. Prolonged UV-B exposure negatively impacts the expression of cell cycle regulating genes and several other metabolic pathways in developing seedlings. MAP kinase signaling cascade gets activated upon UV-B exposure similar to reports in Arabidopsis indicating conservation of its function in both dicot and monocot. Expression analysis in inducible overexpression transgenic lines of MPK3 and MPK6 shows higher transcript abundance of phytoalexin biosynthesis gene like Oryzalexin D synthase and Momilactone A synthase, along with serotonin biosynthesis genes. An accumulation of serotonin was observed upon UV-B exposure and its abundance positively correlates with the MPK3 and MPK6 transcript level in the respective over-expression lines. Interestingly, multiple cell cycle inhibitor proteins including WEE1 and SMR1 interact with MPK3 and MPK6 thus, implying a major role of this pathway in cell cycle regulation under stress condition. Overall overexpression of MPK3 and MPK6 found to be detrimental for rice as overexpression lines shows higher cell death and compromised tolerance to UV-B.
  • Thumbnail Image
    Item
    Arabidopsis MPK3 and MPK6 regulates D-Glucose signaling and interacts with G-Protein, RGS1
    (Elsevier B.V., 2022) Bhagat, Prakash Kumar; Sharma, Deepika; Verma, Deepanjali; Singh, Kirti; Sinha, Alok Krishna
    Sugar as a signaling molecule has attracted lots of attention. Even though several kinases have been shown to play a crucial role in the sugar signaling and response to exogenous D-glucose (Glc), the information on the involvement of MAP kinase cascade in sugar signaling has remain largely unexplored. In this report we demonstrate that MAP kinase signaling is essential for sensitivity to higher concentrations of D-Glc in Arabidopsis. We found that D-Glc activates MAP kinases, MPK3 and MPK6 in a concentration and time-dependent manner. The mutants of mpk3 and mpk6 display hyposensitivity to 6% D-Glc during seed germination, cotyledon greening and root growth. Interestingly, the altered sensitivity to increased D-Glc is severely enhanced by addition of 1% Sucrose in the media. Our study also deciphered the role of one of the Glc sensor proteins, RGS1 that interacts and gets phosphorylated at its C-terminal domain by MPK3 and MPK6. Overall our study provides a new insight on the involvement of MAP kinases in association with G-proteins that might regulate sugar signaling and sugar responsive growth and development in Arabidopsis.
  • Thumbnail Image
    Item
    Dynamic phosphorylation of miRNA biogenesis factor HYL1 by MPK3 involving nuclear–cytoplasmic shuttling and protein stability in Arabidopsis
    (MDPI AG, 2022) Bhagat, Prakash Kumar; Verma, Deepanjali; Singh, Kirti; Badmi, Raghuram; Sharma, Deepika; Sinha, Alok Krishna
    MicroRNAs (miRNAs) are one of the prime regulators of gene expression. The recruitment of hyponastic leaves 1 (HYL1), a double-stranded RNA binding protein also termed as DRB1, to the microprocessor complex is crucial for accurate primary-miRNA (pri-miRNA) processing and the accumulation of mature miRNA in Arabidopsis thaliana. In the present study, we investigated the role of the MAP kinase-mediated phosphorylation of AtHYL1 and its sub-cellular activity. AtMPK3 specifically phosphorylates AtHYL1 at the evolutionarily conserved serine-42 present at the Nterminal regions and plays an important role in its nuclear–cytosolic shuttling. Additionally, we identified that AtHYL1 is cleaved by trypsin-like proteases into an N-terminal fragment, which renders its subcellular activities. We, for the first time, report that the dimerization of AtHYL1 not only takes place in the nucleus, but also in the cytosol, and the C-terminal of AtHYL1 has a role in regulating its stability, as well as its subcellular localization. AtHYL1 is hyper-phosphorylated in mpk3 mutants, leading to higher stability and reduced degradation. Our data show that AtMPK3 is a negative regulator of AtHYL1 protein stability and that the AtMPK3-induced phosphorylation of AtHYL1 leads to its protein degradation.