Abstract
The crop lodging resistance is a primary breeding target for stable high yield. Although reducing plant height has been extensively used as a predominat strategy to improve the lodging resistance, decrease in plant height also causes reduced biomass and crop yeild. To assess a new strategy for lodging resistance, we studied a new rice mutant, thick strong culm1 (tsc1) that strengthens the lodging resistance by producing the thick culm. In addition to the thick culm, the tsc1 mutant developed the thick leaves and roots by increased cell number and the reduced cell expansion. We further demonstrated that the expression of TSC1 encoding an AP2-type transcriptional factor is induced by the exogenous auxin treatment, and a auxin response element (AuxRE) of TSC1 promoter acts as a cis-motif. The microarray and ChIP experiments revealed that TSC1 regulates the expression of many cell-division related genes directly. We conclude that TSC1 is involved in controling the cell proliferation in the auxin signaling pathway for lodging resistance. This work was supported by a grant from the Ministry of Agriculture, Forestry and Fisheries of Japan (Genomics for Agricultural Innovation, IPG0003).
