LAZY2 controls rice tiller angle through regulating starch biosynthesis in gravity-sensing cells

Area of Science:

• Plant Biology
• Genetics
• Biochemistry

Background:

• Rice tiller angle is crucial for optimal plant architecture and grain yield.
• The molecular mechanisms controlling rice tiller angle are not fully understood.

Purpose of the Study:

• To identify and characterize the gene responsible for regulating rice tiller angle.
• To elucidate the molecular mechanism of tiller angle regulation by the identified gene.

Main Methods:

• Map-based cloning to isolate the causative gene.
• Biochemical, molecular, and genetic analyses to understand gene function.
• Characterization of a novel mutant, lazy2 (la2).

Main Results:

• The gene LA2 was identified as the cause of the la2 mutant phenotype (large tiller angle).
• LA2 encodes a chloroplastic protein interacting with OspPGM, regulating starch biosynthesis in gravity-sensing cells.
• LA2 mediates lateral auxin transport, impacting shoot gravitropism and tiller angle.

Conclusions:

• LA2 is a novel regulator of rice tiller angle, specifically impacting starch biosynthesis in gravity-sensing cells.
• A starch-statolith-dependent pathway for tiller angle regulation in rice has been established.
• This research provides new insights into the regulatory network governing rice plant architecture.