Ph.D. Student University of Calgary Calgary, Alberta, Canada
Body of Abstract: The Mitogen-Activated Protein Kinase (MAPK) cascade is a critical signaling pathway that regulates several cellular processes in plants. While the downstream pathway of YODA, a MAPK kinase kinase and a key component of various responses, has been extensively studied in dicots, its role in mediating similar responses in monocots has remained relatively unexplored. In this study, we investigated the YODA signaling pathway in Brachypodium distachyon, a model monocot plant, specifically focusing on its role in stomatal development. Previous research has demonstrated the significance of YODA genes in promoting normal stomatal spacing patterns in both Arabidopsis and Brachypodium. However, the underlying molecular mechanisms and interactions within the YODA pathway in monocots are poorly understood. Therefore, our study aimed to shed light on the downstream players in the YODA signaling cascade in Brachypodium and their involvement in stomatal development. To investigate this, we utilized constitutively active phospho-mimic mutants of BdMKK4 and BdMKK5, modified in the conserved YODA phosphorylation sites based on the dicot studies. Our findings revealed that the active MKK4 and MKK5 interact with MPK3 and MPK6 in vitro, two key MAP kinases involved in various signaling cascades. These interactions suggest the conservation of YODA signaling components between dicots and monocots. We aim to further evaluate the involvement of the downstream kinases in stomatal development. By unraveling the putative downstream elements of YODA pathway in Brachypodium, our study will provide valuable insights into the molecular mechanisms underlying stomatal development in monocot plants. Understanding these processes will contribute to a broader understanding of plant biology and may have implications for crop improvement strategies in the future.