SHANGHAI, Dec. 3 (Xinhua) -- Chinese scientists have identified key genes and molecular pathways that enable rice to sense and adapt to high temperatures, leading to the successful breeding of heat-tolerant rice lines.

This scientific advancement presents a promising strategy to enhance food security amid global warming.

The research, conducted collaboratively by the Center for Excellence in Molecular Plant Sciences of the Chinese Academy of Sciences, Shanghai Jiao Tong University and Guangzhou Laboratory, was published on Wednesday in the leading journal Cell.

Lin Hongxuan, the team's lead scientist, explained the mechanism through which rice senses and adapts to high temperatures. When exposed to heat, a key enzyme, diacylglycerol kinase 7 (DGK7), on the plant cell membrane becomes activated, producing the lipid messenger phosphatidic acid (PA), which acts as a "chemical alarm."

PA then activates the metal-dependent phosphodiesterase (MdPDE1), and they move to the nucleus, lowering cyclic adenosine monophosphate (cAMP) levels. This reduction reprograms gene expression, upregulating heat-protection genes that help cells maintain photosynthetic protein activity, repair oxidative damage and mount a comprehensive heat-response system.

After mapping the complete signaling pathway from membrane perception to gene regulation, the research team pinpointed DGK7 and MdPDE1 as precise breeding targets.

Field trials conducted under heat-mimicking conditions demonstrated that rice lines genetically modified with a single-gene in DGK7 or MdPDE1 yielded about 50 percent more than control plants. Notably, a double-gene line combining DGK7 with a known heat-tolerance gene (TT2) nearly doubled the yield, enhanced grain quality and maintained normal growth.

This study establishes a critical theoretical framework and genetic toolkit for developing heat-tolerant varieties of staple crops, including rice, wheat and corn. It opens a new avenue for designing tailored crops suited to diverse climate conditions, thereby bolstering global food security in a warming world, according to industry experts. ■