Abstract
Shoot branching is a major determinant of the aerial architecture of plants. In rice, three types of branches develop through out the life time (i.e. tillers in the vegetative phase, panicle branches and spikelets in the reproductive phase). We previously identified LAX1 gene as a main regulator of axillary meristem (AM) formation in the reproductive phase of rice. The mRNAs locate in the boundary between SAM and the region of new AM formation suggests that LAX1 acts non-cell autonomously.
Here we demonstrate that LAX1 protein trafficked from boundary region to the AM cells at P4 stage, and this protein trafficking is required for LAX1 full function. Detailed analysis of lax1 mutants indicates that LAX1 is required for AM formation in both vegetative and reproductive phases. Together with results of in situ experiments, we propose that LAX1 regulates the activity of cell proliferation in the AM at P4 stage.
