https://www.cas.cn/syky/202606/t20260604_5111793.shtml

https://www.nature.com/articles/s41586-026-10603-7

Scientists Uncover the “On-Demand Cold Resistance” Mechanism—A Masterstroke for Crops During Flowering

June 4, 2026 | Source: Institute of Genetics and Developmental Biology | [Font Size: Large | Medium | Small] | Audio Broadcast

Climate change is causing major staple crops worldwide to suffer from widespread fertilization impairments and reduced grain-setting rates. For a long time, research has focused primarily on the ability of crops to adapt to low temperatures during their seedling and vegetative growth stages. In contrast, fundamental research into the mechanisms of cold adaptation during the flowering stage—a critical period for reproductive success—has remained weak, and key genetic resources for cold resistance applicable to this stage have been extremely scarce.

The CAS Institute of Genetics and Developmental Biology has unveiled the spatiotemporally specific mechanisms underlying cold resilience during crop pollen development. The team identified RGF—the first known small peptide signal involved in sensing low temperatures during pollen development—and elucidated the “small peptide–receptor–ion channel” signaling axis and regulatory mechanisms that enable crops to mount an “on-demand” cold resistance response during flowering. Furthermore, the study confirmed the significant potential of this molecular pathway for practical applications in mitigating cold-induced crop damage and in precision breeding.

The research team overcame three major technical hurdles:

• the difficulty of sampling and analyzing pollen during specific developmental stages;
• the challenge of accurately replicating authentic agricultural low-temperature conditions in a controlled setting; and
• the difficulty of identifying the specific genes responsible for cold resilience.

By integrating sensing technologies, multi-omics analysis, gene editing, and artificial intelligence, the team pinpointed the *RGF* gene, a small peptide-encoding gene that had long been annotated in genomic databases as having “unknown function.” Under normal conditions, *RGF* expression is nearly undetectable; however, when the plant encounters low-temperature stress, the gene is significantly activated within the tapetal cells of the anther specifically during the tetrad stage of pollen development.

Further investigations revealed that the cold-induced RGF small peptide is secreted into the extracellular space, where it is recognized by the cell-surface receptor kinase SlRGFR6 and its co-receptor SlSERK, located on the anther cell membrane. This interaction leads to the formation of a receptor complex. Subsequently, this complex phosphorylates and activates the cyclic nucleotide-gated ion channels SlCNGC16 and SlCNGC18, triggering a rapid influx and rise in intracellular calcium ion concentrations. This cascade precisely regulates the process of programmed cell death (PCD) within the anther tapetum, ensuring that the tapetum degrades punctually at the appropriate developmental stage. By providing the necessary nutrients and energy for normal pollen development, this mechanism effectively prevents pollen abortion—a common failure caused by the delayed degradation of the tapetum. The RGF cold-signaling axis—formed by a novel molecular pathway mediated by small peptides, receptors, and ion channels—elucidates how plants execute precise and efficient localized defense through “on-demand stress resistance” when confronted with unpredictable, short-term cold damage.

Crop improvement efforts, coupled with multi-year, multi-site, and multi-variety field yield trials, have already demonstrated that activating the expression of these RGF small peptides can recover 33.9% to 52.2% of the yield losses caused by cold damage in tomatoes. The RGF cold-signaling axis is conserved across both dicotyledonous and monocotyledonous plants; upregulating the expression of RGF genes in rice significantly enhances pollen cold tolerance, thereby recovering approximately 18% of the yield losses caused by cold damage in currently dominant, high-yielding commercial rice varieties.

Scientists Uncover the “Secret Weapon” Mechanism Behind Crops’ “On-Demand Cold Resistance” During Flowering