背景回顾：Climate change negatively affects crop yield, which hinders efforts to reach agricultural sustainability and food security.

主要发现：Here, we show that a previously unidentified allele of the nitrate transporter gene OsNRT2.3 is required to maintain high yield and high nitrogen use efficiency under high temperatures. 

结果：We demonstrate that this tolerance to high temperatures in rice accessions harboring the HTNE-2 (high temperature resistant and nitrogen efficient-2) alleles from enhanced translation of the OsNRT2.3b mRNA isoform and the decreased abundance of a unique small RNA (sNRT2.3-1) derived from the 5′ untranslated region of OsNRT2.3. sNRT2.3-1 binds to the OsNRT2.3a mRNA in a temperature-dependent manner.

结论：Our findings reveal that allelic variation in the 5′ untranslated region of OsNRT2.3 leads to an increase in OsNRT2.3b protein levels and higher yield during high-temperature stress. 

展望：Our results also provide a breeding strategy to produce rice varieties with higher grain yield and lower N fertilizer input suitable for a sustainable agriculture that is resilient against climate change.

The schematic diagram of the mechanism by which OsNRT2.3 regulates NUE and yield at nighttime high temperature.

气候变化负调控作物的产量，阻碍了实现农业可持续性和食物安全的进程。本文中，作者发现一个硝酸盐转运蛋白编码基因OsNRT2.3对于高温条件下，维持水稻高产和高氮利用效率是必须的。作者发现，含有HTNE-2等位基因的水稻材料之所有具有对高温的耐受性，是因为OsNRT2.3b mRNA剪切体异构体的翻译增强以及来自OsNRT2.3基因5′-UTR的小RNA sNRT2.3-1的丰度减少。sNRT2.3-1可以以一种温度依赖性的方式，结合OsNRT2.3a基因的mRNA。本文的发现揭示了OsNRT2.3基因的5′-UTR等位基因变异导致高温条件下OsNRT2.3b蛋白水平的增加以及水稻的高产。同时，本文的研究结果还为创制具有更高产量和更低氮肥消耗的水稻新品种提供了一个育种策略，适合未来气候变化下的可持续农业的实现。

The simple structure diagram of two OsNRT2.3 alternative spliced proteins, OsNRT2.3a and OsNRT2.3b, under high nighttime.

** 范晓荣 **