PLASTOCHRON1 regulates rice leaf inclination through brassinolide pathway

Leaf inclination directly affects the plant architecture of rice (Oryza sativa), which in turn, affects the photosynthetic efficiency of the leaves and grain yield. Researchers have identified many mutants that exhibit various degrees of leaf inclination. Based on this, regulators have been cloned and functionally analyzed, but the regulation of leaf inclination is still unclear. Therefore, the discovery and cloning of novel genes that regulate leaf inclination has important theoretical and practical applications for improvement of yield in rice.

In an article recently published in Crop Science, scientists identified a mutant, s544, which contains a new allele mutant of PLASTOCHRON1 (PLA1), characterized by enhanced leaf inclination as well as small aerial organs. Quantitative polymerase chain reaction (qPCR) revealed that s544 has other genes that positively regulate brassinolide signal introductions and showed significantly increased expression. This mutant shows higher sensitivity to exogenous brassinolide. The results indicate that PLA1 may be involved in the brassinolide pathway to regulate development of the plant architecture of rice, especially leaf inclination. Additionally, s544 displays a beautiful plant phenotype and longer growing period—it may be a great candidate for balcony scenery in the city.