Arabidopsis Reduces Growth Under Osmotic Stress by Decreasing SPEECHLESS Protein

作者：Archana Kumari, Pawan Kumar Jewaria, Dominique C. Bergmann, Tatsuo Kakimoto · 发表于：Plant and Cell Physiology · 年份：2014 · DOI：10.1093/pcp/pcu159 · 被引用次数：55 · 研究领域：Plant Molecular Biology Research、Plant Stress Responses and Tolerance、Plant Reproductive Biology

Plants, which are sessile unlike most animals, have evolved a system to reduce growth under stress; however, the molecular mechanisms of this stress response are not well known. During programmed development, a fraction of the leaf epidermal precursor cells become meristemoid mother cells (MMCs), which are stem cells that produce both stomatal guard cells and epidermal pavement cells. Here we report that Arabidopsis plants, in response to osmotic stress, post-transcriptionally decrease the protein level of SPEECHLESS, the transcription factor promoting MMC identity, through the action of a mitogen-activated protein kinase (MAPK) cascade. The growth reduction under osmotic stress was lessened by inhibition of the MAPK cascade or by a mutation that disrupted the MAPK target amino acids in SPEECHLESS, indicating that Arabidopsis reduces growth under stress by integrating the osmotic stress signal into the MAPK-SPEECHLESS core developmental pathway.