Abiotic stress tolerance has been significantly weakened in modern crops during the domestication process. Regaining tolerance has become a critical task in light of current climate trends and their impact on global food security. Abiotic stress tolerance is an extremely complex trait and is conferred at various levels of plant functional organization and developmental stages, with regulatory mechanisms operating across multiple scales, from individual cells to tissues and the entire plant. The emergence of advanced molecular tools such as single-cell RNA sequencing and spatial omics technologies has revolutionized the field, advancing our understanding of plant responses to hostile environments. However, the implementation of this knowledge in crop breeding programmes is handicapped by the lack of appropriate phenotyping platforms. Here, we argue that current phenotyping methods may be excellent tools for functional validation of previously discovered traits but have limited predictive value in stress biology. We also propose that bridging the mismatch between omics technologies and phenotyping is the only way to account for cell-specific operation of key genes conferring stress tolerance and implementing them in breeding programmes. Some practical examples using cell-based phenotyping tools such as fluorescence dyes or electrophysiological methods are given, and current limitations and prospects of cell-based phenotyping are discussed.
Sergey Shabala, Ping Yun, Zhong-Hua Chen et al.· New Phytologist· 0 citations
Water-saving cultivation practices, such as intermittent irrigation, are essential for sustainable rice production but often exacerbate grain cadmium (Cd) accumulation due to aerobic-soil-induced increases in Cd bioavailability. Uncoupling this trade-off is a critical challenge for global food safety. Here, we identify the transcription factor OsNAC4 as a key positive regulator of Cd uptake. Loss-of-function osnac4 mutants significantly reduce grain Cd accumulation by 30%-50% across diverse genetic backgrounds without compromising grain yield or agronomic traits. Mechanistically, we reveal that the drought/abscisic acid (ABA)-activated kinase OsSAPK2 interacts with and phosphorylates OsNAC4, thereby stabilizing the protein and enhancing its transcriptional activation of the Cd transporter gene OsNRAMP1. This signaling cascade establishes a direct molecular link whereby environmental water stress signaling cascades effectively "hijack" the basal Cd uptake machinery. Crucially, multi-location field trials demonstrate that osnac4 mutation effectively suppresses the aerobic-induced Cd elevation typically observed under water-saving regimes. Our findings elucidate the molecular mechanism underlying the conflict between water conservation and Cd accumulation, providing a robust genetic resource for breeding safe, climate-resilient rice varieties suitable for water-limited agriculture.
Xiao-Fang Zhu, Fangwei Yu, Changzhao Chen et al.· Current Biology· 0 citations
