By Stephanie Baum
Rapidly intensifying global climate instability is causing increasingly erratic temperature fluctuations. When sudden cold snaps strike during a crop's critical flowering window, they trigger irreversible pollen abortion, slashing yields of staple crops by 20% to 60%. Passive defenses offer minimal protection at a high cost, while breeding for continuous cold resistance often backfires by wasting vital energy under normal temperatures. Shifting the breeding paradigm toward "on-demand" climate resilience—maintaining high yields in favorable seasons while securing stable performance under stress—is critical.
In a study published in Nature, a team led by Prof. Xu Cao from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences has identified RGF as the first small peptide signal that senses cold during pollen development. Researchers uncovered an "on-demand" peptide-receptor-ion channel signaling axis, offering a powerful genetic strategy to shield crops from sudden climate shocks without compromising baseline yields.
By integrating techniques including multi-omics, gene editing and artificial intelligence, researchers uncovered the RGF gene, which has long been annotated as "function unknown" in the tomato genome. It encodes a tiny peptide of just 13 amino acids and remains silent at normal temperatures, preventing unnecessary energy drain. However, upon sudden cold stress, it sharply activates in anther tapetal cells during the tetrad stage of pollen development. This unique expression pattern—silent under normal conditions but activated during stress—explains why this gene has long eluded researchers.
Moreover, researchers found that the cold-induced RGF peptide is recognized by the cell-membrane receptor kinase SlRGFR6 and co-receptor SlSERK. This complex phosphorylates and activates the cyclic nucleotide-gated ion channels SlCNGC16/18, driving a rapid calcium influx. The calcium surge orchestrates the programmed cell death of the anther tapetum, ensuring it degrades on schedule to supply essential nutrients and energy for developing pollen. By preventing cold-induced pollen abortion, this cascade illustrates how plants deploy localized, precise defenses on demand during transient environmental stress.
Multi-year, multi-site field trials demonstrated that moderately activating this cold-induced RGF signaling recovered 33.9% to 52.2% of cold-induced yield losses in tomatoes. This signaling axis is highly conserved across both dicots and monocots. Upregulating RGF in commercial rice cultivars salvaged roughly 18% of yield losses during cold shocks. Currently, researchers are expanding this strategy to soybeans and maize.
Nature reviewers have praised the study as "an outstanding achievement and a significant breakthrough in the field of cold tolerance research," noting that it seamlessly connects basic mechanistic insights with real-world agronomic gains.
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