Meta-analysis and dose-response analysis of low-temperature stress effects on rice yield and physiological responses

Low-temperature stress is a major environmental constraint on rice yield stability, considerable variation remains in the reported direction and magnitude of these effects. In this study, we conducted a systematic meta-analysis combined with dose-response analysis to evaluate the effects of low-temperature stress on rice yield formation, photosynthetic capacity, and physiological responses. The results showed that low-temperature stress significantly reduced yield-related traits in rice, with yield per plant and pollen viability decreasing by 10.58% and 21.75%, respectively. Photosynthetic performance was also markedly affected, as net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) decreased by 26.67%, 10.93%, and 31.00%, respectively, while intercellular CO₂ concentration (Ci) increased by 5.75%. Low-temperature stress also significantly induced the accumulation of osmotic regulatory substances and aggravated oxidative damage. Subgroup analysis and meta-regression indicated that the effects of low-temperature stress were jointly regulated by growth stage, stress temperature, and stress duration. Specifically, yield responses were more sensitive at the booting stage and heading-flowering stage, while Pn showed more pronounced responses to severe low temperature and prolonged stress. Dose-response analysis showed that most traits exhibited response turning points around 24 °C. Overall, this study quantitatively revealed the associations among yield reduction, photosynthetic inhibition, and physiological homeostasis imbalance in rice under low-temperature stress, providing comprehensive evidence for understanding the response patterns of rice to low temperature.