Rice, originating from tropical and subtropical regions, is highly sensitive to low temperatures. Cold stress, which occurs during the booting stage, severely affects rice production. Understanding the molecular mechanisms underlying cold tolerance and using molecular design methods to accelerate the development of new cold-tolerant varieties is an effective strategy to prevent cold injury at the booting stage. However, the known molecular mechanism of cold response in rice is very limited, which severely hinders the breeding of cold-tolerant varieties.
In a recent study published in
Plant Physiology, a research team led by Prof. CAO Xiaofeng from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences (CAS) has identified the crucial role of the acyl carrier protein OsMTACP2 in promoting anther and pollen grain development at low temperatures, thereby positively regulating cold tolerance at the booting stage.
In this study, OsMTACP2, which encodes a highly conserved acyl carrier protein, was identified as an essential gene for cold tolerance by genetic screening of an EMS-mutagenized M2 population in the background of the cold-tolerant japonica cultivar Longdao 5 (LD5). Loss of OsMTACP2 function impaired cold tolerance by disrupting anther cuticle and pollen wall development, resulting in abnormal anther morphology, reduced pollen fertility and seed setting.
Comparative transcriptomic analysis revealed differential expression of genes involved in lipid metabolism between the wild type and the Osmtacp2-1 mutant in response to cold. Further lipidomic analysis identified wax esters, the primary lipid components of the anther cuticle and pollen walls, as cold-responsive lipids.
These results highlight the essential role of OsMTACP2-mediated wax ester biosynthesis in rice’s cold tolerance during the booting stage.
This work was supported by the STI 2030 - Major Projects, the Strategic Priority Research Program of CAS, and the National Natural Science Foundation of China.
A proposed model explaining the function of OsMTACP2 in rice cold tolerance at the booting stage. (Image by IGDB)
