Breeding beyond trade-offs

Abstract

In a recent study, Yibo Li and colleagues from Huazhong Agricultural University, China, identified a major rice locus, QT12, that encodes a putative Sec61 translocon β subunit and plays a critical role in regulating thermotolerance for grain quality. They demonstrated that QT12 negatively affects grain-quality stability under heat stress, particularly by promoting grain chalkiness, a key indicator of quality deterioration that reduces the nutritional value, cooking performance and market appeal of rice.

The study further revealed that QT12 expression is regulated by a natural on–off gene switch involving the nuclear factor Y (NF-Y) complex, which modulates its expression in response to rising temperatures. High temperature disrupts NF-Y interactions and activates the switch system, increasing QT12 expression and leading to grain quality deterioration and reduced thermotolerance in rice. Large-scale field trials showed that low-expression or non-functional QT12 can simultaneously improve grain yield and quality in elite varieties without compromising other agronomic traits, offering a promising strategy for climate-resilient rice breeding.