Zebra leaf 15, a receptor-like protein kinase involved in moderate low temperature signaling pathway in rice

Abstract

Background: Zebra leaf mutants are an important resource for studying leaf colour in rice. In most such mutants, the zebra leaf phenotype results from defective chloroplast biogenesis. The molecular mechanism by which zebra leaves develop remains unclear, so additional zebra-leaf mutants need to be identified. Results: We isolated a novel rice zebra-leaf mutant, named zebra leaf 15 (z15), which showed transversely striped leaves with yellow-green or white-green sectors, in which chloroplast structure was disturbed. Transmission electron microscopy revealed that the structure of various organelles was impaired in yellow/white sectors. Z15, a single-copy gene in the rice genome, encodes a receptor-like protein kinase. Subcellular localization analysis indicates that Z15 and z15 are localized on the plasma membrane. The expression of Z15 is induced by moderate low temperature (18 °C). The mutation of Z15 influenced the expression of two downstream genes, OsWRKY71 and OsMYB4, that were responsive to moderate low temperature. The results show that Z15 plays a crucial role in the early stages of the response to moderate low temperature in rice. Conclusions: We identified a novel zebra-leaf mutant (z15) that impaired chloroplast structure in rice, LOC_Os05g12680, encoding a receptor-like protein kinase. Further study indiceted that Z15 plays a crucial role in the early stages of the response to moderate low temperature in rice.