In the heart of China’s rice-growing regions, scientists are uncovering a hidden mechanism that could help rice crops beat the heat, with significant implications for global food security and the agricultural sector. A recent study led by Qilin Mu from the MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River at Yangtze University has shed light on how certain rice varieties use transpirational cooling to combat heat stress during the critical grain-filling stage.
The research, published in the journal *Frontiers in Plant Science* (which translates to *Frontiers in Plant Science* in English), focused on 28 newly bred, high-quality rice varieties. The study found that high temperatures during grain filling can significantly reduce grain yield and quality, decreasing 1,000-grain weight by 1.6 grams and head rice rate by 6.7%, while increasing chalkiness by 3.3%. However, some varieties showed remarkable resilience.
Mu and his team discovered that heat-tolerant varieties maintained lower leaf and panicle temperatures by enhancing transpirational cooling. This process, driven by stomatal activity, allows the plant to cool itself down, much like sweating in humans. “Heat-tolerant varieties exhibited higher stomatal conductance, density, and total stomatal area, which helped them regulate the canopy microenvironment effectively,” Mu explained.
The study grouped the varieties into three categories based on their heat tolerance: tolerant, intermediate, and susceptible. The findings suggest that the ability to regulate stomatal activity could be a key factor in developing heat-resistant rice varieties. This could revolutionize rice farming in regions prone to high temperatures, ensuring better yields and quality.
The commercial implications are substantial. Rice is a staple food for more than half of the world’s population, and climate change is exacerbating heat stress in many rice-growing regions. By identifying and breeding heat-tolerant varieties, farmers could mitigate losses and improve food security. Additionally, understanding the role of stomatal regulation could lead to innovative agricultural practices and technologies aimed at enhancing crop resilience.
As Mu noted, “Our findings indicate that stomatal regulation of the canopy microenvironment may serve as a general physiological basis for varietal heat response in rice.” This insight could pave the way for future research and development in agritech, focusing on breeding and biotechnological approaches to enhance transpirational cooling in crops.
The study not only highlights the importance of transpirational cooling but also opens new avenues for improving rice cultivation under climate change. By leveraging these findings, the agricultural sector can develop more resilient crops, ensuring sustainable food production for a growing global population.