Research Description:
Characterization of MAP70 family, a potential regulator for lateral root development
Plants can grow organs post-embryonically, requiring the orchestration of several processes that take place within immotile, interconnected, and pressurized cells. Cell division plane orientation regulation allows multicellular organisms to alter cellular topology during morphogenesis. The mechanism underlying the orientation of the division plane to enable 3-dimensional, differential growth deep within a tissue are largely unknown. Cortical microtubules (CMTs) affect the axes of cell elongation and impact the determination of the division plane During lateral root (LR) formation, the isotropy of CMTs within the primordium and neighboring endodermis changes, which is required for proper LR development. Interfering with CMT dynamics results in deformed primordia. A member of the MICROTUBULE-ASSOCIATED PROTEIN70 family, MAP70-5, was shown to be required for proper LR development and establishment of spatially distinctly organized CMT domains in the endodermis. Here we present the characterization of another member of the MAP70 family, MAP70-2, which is mainly expressed in the pericycle and the LR primordium. We are currently investigating the functional role of MAP70-2 during LR morphogenesis and root growth. Preliminary results support a role for MAP70-2 as an integrator of biochemical and mechanical signals during the early stages of LR development.
(Unpublished data)
Plants expressing the Citrine:MAP70-2 fusion exhibit cytoplasmic accumulation of MAP70-2 in the primary root tip. The initiation of MAP70-2 can be already observed at early stages of lateral root development (Stage I ). In stages II and onward, MAP70-2 localization is predominantly observed on the basal and apical sides of the central cells within the LRP, potentially indicating the sites of new cell division.