The cold tolerance of rice at the booting stage is a main factor determining sustainability and regional adaptability. However, relatively few cold tolerance genes have been identified that can be effectively used in breeding programmes. Here, we show that a point mutation in the low-temperature tolerance 1 (LTT1) gene improves cold tolerance by maintaining tapetum degradation and pollen development, by activation of systems that metabolize reactive oxygen species (ROS). Cold-induced ROS accumulation is therefore prevented in the anthers of the ltt1 mutants allowing correct development. In contrast, exposure to cold stress dramatically increases ROS accumulation in the wild type anthers, together with the expression of genes encoding proteins associated with programmed cell death and with the accelerated degradation of the tapetum that ultimately leads to pollen abortion. These results demonstrate that appropriate ROS management is critical for the cold tolerance of rice at the booting stage. Hence, the ltt1 mutation can significantly improve the seed setting ability of cold-sensitive rice varieties under low-temperature stress conditions, with little yield penalty under optimal temperature conditions. This study highlights the importance of a valuable genetic resource that may be applied in rice breeding programmes to enhance cold tolerance.

中文翻译：

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LTT1的一个点突变增强了水稻在孕穗期的耐寒性。

水稻在孕穗期的耐寒性是决定可持续性和区域适应性的主要因素。但是，已经鉴定出相对较少的耐寒基因，可以有效地用于育种程序。在这里，我们表明低温耐受性1（LTT1）基因中的点突变通过维持代谢活性氧（ROS）的系统来维持绒毡层降解和花粉发育，从而提高了耐寒性。因此，可以防止在ltt1突变体的花药中冷诱导的ROS积累，从而可以正确发育。相反，暴露于冷胁迫下会大大增加野生型花药中的ROS积累，连同编码与程序性细胞死亡相关的蛋白质的基因的表达以及与绒毡层的加速降解，最终导致花粉流产。这些结果表明，适当的ROS处理对于孕穗期水稻的耐寒性至关重要。因此，ltt1突变可显着提高低温胁迫条件下冷敏水稻品种的结实能力，而在最佳温度条件下收成损失很小。这项研究强调了宝贵的遗传资源的重要性，该遗传资源可用于水稻育种计划中以增强耐寒性。ltt1突变可显着提高低温胁迫条件下冷敏水稻品种的结实能力，在最佳温度条件下收成损失很小。这项研究强调了宝贵的遗传资源的重要性，该遗传资源可用于水稻育种计划中以增强耐寒性。ltt1突变可显着提高低温胁迫条件下冷敏水稻品种的结实能力，在最佳温度条件下收成损失很小。这项研究强调了宝贵的遗传资源的重要性，该遗传资源可用于水稻育种计划中以增强耐寒性。