Proc Natl Acad Sci U S A
August 2025
The formation of a body axis is one of the fundamental steps in developmental patterning in multicellular organisms. Ectopic expression of the stomatal protein BASL (BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE) reveals a proximal-distal cell polarity field in the leaf and an apical-basal field in the hypocotyl and root of . This provides a framework for uncovering molecular components of body-axis cell polarity in higher plants.
View Article and Find Full Text PDFSeed germination is, a critical physiological process, is tightly regulated by the phytohormone abscisic acid (ABA). However, the cross talk between multiple regulatory pathways involved in seed germination remains poorly understood. Here, we show that ABA activates two MAP kinases, AtMPK3/AtMPK6, which interact with and phosphorylate AtABI5, a master regulator of ABA signaling.
View Article and Find Full Text PDFThe mitogen-activated protein kinase (MAPK) cascade is involved in several signal transduction processes in eukaryotes. Here, we report a mechanistic function of MAP kinase kinase kinase 20 (MKKK20) in light signal transduction pathways. We show that MKKK20 acts as a negative regulator of photomorphogenic growth at various wavelengths of light.
View Article and Find Full Text PDFSugar 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.
View Article and Find Full Text PDFMicroRNAs (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 . In the present study, we investigated the role of the MAP kinase-mediated phosphorylation of AtHYL1 and its sub-cellular activity.
View Article and Find Full Text PDFCross-talk between light and ABA signaling is mediated by physical interaction between HY5 and ABI5 Arabidopsis. Plants undergo numerous transitions during their life-cycle and have developed a very complex network of signaling to integrate information from their surroundings to effectively survive in the ever-changing environment. Light signaling is one of the crucial factors that govern the plant growth and development from the very first step of that is from seedling germination to the flowering.
View Article and Find Full Text PDFA dual-specificity phosphatase MKP1 negatively regulates the activity of MPK6 by dephosphorylating it and acts as a positive regulator of blue light (BL)-mediated photomorphogenic development in Arabidopsis. Reversible phosphorylation of proteins is one of the major post-translational modifications in nearly all signaling pathways in plants. MAP kinase phosphatases are very crucial in the regulation of MAPKs as they dephosphorylate both threonine (Thr) and tyrosine (Tyr) residues within the T-X-Y motif of active MAPKs.
View Article and Find Full Text PDFMYC2, a bHLH TF, acts as regulatory hub within several signaling pathways by integration of various endogenous and exogenous signals which shape plant growth and development. However, its involvement in salt stress regulation is still elusive. This study has deciphered a novel role of MYC2 in imparting salt stress intolerance by regulating delta1 -pyrroline-5-carboxylate synthase1 (P5CS1) gene and hence proline synthesis.
View Article and Find Full Text PDFSignalling pathways play vital roles as determinants of almost all the molecular processes inside a eukaryotic cell. They are more often considered to be the link between extracellular and intracellular environmental cues. Gene silencing pathways have emerged to be involved in regulation of stress responses and developmental processes.
View Article and Find Full Text PDFPlants confront multifarious environmental stresses widely divided into abiotic and biotic stresses, of which heavy metal stress represents one of the most damaging abiotic stresses. Heavy metals cause toxicity by targeting crucial molecules and vital processes in the plant cell. One of the approaches by which heavy metals act in plants is by over production of reactive oxygen species (ROS) either directly or indirectly.
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