Researchers Unlock Water-Saving Potential of Wheat With TabHLH27 Balancing Stress and Growth

By Zhang Nannan

Wheat plays a critical role in global food security, but water scarcity in arid and semi-arid regions hinders its efficient production, suggesting significant opportunities for water saving. Therefore, understanding the genes that control wheat's drought tolerance and water use efficiency is critical for improving genetic resilience and breeding water-efficient varieties.

In a recent study led by Prof. Xiao Jun from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences, researchers have shown how TabHLH27, a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat, enhances wheat's drought tolerance and water use efficiency by balancing stress and growth.

The study, published in Journal of Integrative Plant Biology, sheds light on the multifaceted regulation of TabHLH27.

The researchers identified a shared genetic locus associated with drought tolerance at both the seedling and mature stages, pinpointing TabHLH27-A1 as a key candidate through expression profile analysis. Knocking out TabHLH27 significantly reduced wheat drought tolerance, spikelet number per spike, grain yield, and water use efficiency.

The role of TabHLH27 involves dual transcriptional activity, activating stress response genes while repressing developmental genes, possibly through interactions with co-factors like TabZIP62-D1 and TaABI3-D1. Its dynamic expression under drought stress, rapidly induced but declining over time, suggests a nuanced response for enhanced adaptation. Interaction with transcription factors like TaNAC29-A1 forms a hierarchical regulatory network crucial for wheat's response to water-limited environments.