As global temperatures steadily increase, the frequent occurrence of extreme high-temperature events has significantly hampered peanut ( L.) production in low-latitude regions. Previously, 24-epibrassinolide (EBR) was identified as a substance capable of mitigating abiotic stress damage in plants. However, it remains unclear whether and by what mechanisms EBR can diminish the yield loss caused by heat stress in peanuts. During the flowering phase, two distinct peanut cultivars, (heat-resistant type) and (heat-sensitive type) were exposed to a 10-day heat stress treatment (+4.2 ℃). EBR or water was sprayed on the 1st, 3rd, and 5th days of heating, and water-sprayed natural peanuts was used as control, to assess the effect of EBR on antioxidant capacity, photosynthetic performance, and yield in heat-stressed peanuts. EBR application increased activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in heat-stressed peanut leaves. Simultaneously, EBR decreased hydrogen peroxide and superoxide anion production, along with a reduction in malondialdehyde content. Additionally, EBR notably alleviated the oxidation damage to chloroplast membranes and grana lamella under heat stress. Thus, an increase in maximum photochemical efficiency, comprehensive performance index, rubisco activity, net photosynthetic rate, and biomass accumulation was observed in heat-stress peanuts. Synergistic enhancement provided by EBR on antioxidant capacity and photosynthetic performance resulted in improved plant growth, kernel weight, and effective pods per plant, led to a reduction in yield loss for heat-stressed cultivars and by 26.92 % and 55.18 %, respectively. The application of EBR enhanced the antioxidant capacity of peanut leaves. This, in turn, mitigated oxidative damage to chloroplast membranes, resulting in improved photosynthetic performance. Ultimately, this intervention led to a reduction in yield loss for heat-stressed peanuts, achieved through an increase in kernel weight. The foliar spraying of EBR holds significant promise in crop production, offering a broad application prospect. This practice is beneficial for enhancing the heat resistance of peanuts and potentially other field crops, equipping them to better withstand the increasingly severe climate challenges anticipated in the future.

中文翻译：

---

减轻热引起的花生产量损失：深入了解 24-表油菜素内酯介导的抗氧化能力、光合作用和籽粒重量的改善


随着全球气温持续升高，极端高温事件频繁发生，严重制约了低纬度地区花生生产。此前，24-表油菜素内酯（EBR）被鉴定为能够减轻植物非生物胁迫损害的物质。然而，目前尚不清楚 EBR 是否以及通过什么机制可以减少花生热应激造成的产量损失。在开花期，对两个不同的花生品种（耐热型）和（热敏型）进行为期10天的热应激处理（+4.2℃）。在加热第1、3、5天喷洒EBR或水，并以喷水的天然花生为对照，评价EBR对热胁迫花生抗氧化能力、光合性能和产量的影响。 EBR 的施用增加了热应激花生叶片中超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过氧化物酶的活性。同时，EBR 减少了过氧化氢和超氧阴离子的产生，同时降低了丙二醛含量。此外，EBR 显着减轻了热应激下叶绿体膜和基粒片层的氧化损伤。因此，在热应激花生中观察到最大光化学效率、综合性能指数、Rubisco活性、净光合速率和生物量积累的增加。 EBR 对抗氧化能力和光合性能的协同增强作用提高了植物生长、籽粒重量和单株有效荚果的含量，使热应激品种的产量损失分别减少了 26.92% 和 55.18%。 EBR的应用增强了花生叶片的抗氧化能力。 这反过来又减轻了叶绿体膜的氧化损伤，从而提高了光合作用性能。最终，这种干预通过增加籽粒重量，减少了热应激花生的产量损失。 EBR叶面喷施在作物生产中具有广阔的应用前景。这种做法有利于增强花生和其他潜在大田作物的耐热性，使它们能够更好地抵御未来日益严峻的气候挑战。