土壤与农业可持续发展国家重点实验室Meng Wang团队发现，TaSPL6-D变体通过激活TaHKT1;5-D使面包小麦产生耐盐性同时保留产量相关性状。2024年5月27日出版的《自然—遗传学》杂志发表了这项成果。

研究人员表示，通过Na⁺选择性转运体HKT1;5从地上组织排除Na⁺，是一种存在于农作物中的主要耐盐机制。

通过全基因组表达关联研究和酵母单杂交筛选，研究人员在面包小麦中发现了TaSPL6-D，它是TaHKT1;5-D的转录抑制因子。SPL6也是水稻和禾本科植物HKT1;5的靶点。在TaSPL6-D的第一个外显子中插入47-bp后会产生一个截短肽TaSPL6-D^In，从而破坏 TaSPL6-D^Del对TaHKT1;5-D的抑制作用。过表达TaSPL6-D^Del（而非TaSPL6-D^In）会抑制TaHKT1;5-D的表达并增加植物对盐的敏感性。

在两种小麦基因型中敲除 TaSPL6-D^Del会增强耐盐性，而进一步敲除TaHKT1;5-D则会减弱耐盐性。在Taspl6-dd突变体中，穗的发育可以保持，而在Taspl6-aabbdd突变体中则不能。TaSPL6-D^In主要存在于陆地小麦品种中，通过分子辅助将陆地小麦品种中的TaSPL6-D^In引入到主要栽培小麦品种中，成功提高了小麦在盐碱地种的产量。SPL6-HKT1;5模块为耐盐作物的分子育种提供了参考。

附：英文原文

Title: Variation in TaSPL6-D confers salinity tolerance in bread wheat by activating TaHKT1;5-D while preserving yield-related traits

Author: Wang, Meng, Cheng, Jie, Wu, Jianhui, Chen, Jiefei, Liu, Dan, Wang, Chenyang, Ma, Shengwei, Guo, Weiwei, Li, Guangjie, Di, Dongwei, Zhang, Yumei, Han, Dejun, Kronzucker, Herbert J., Xia, Guangmin, Shi, Weiming

Issue&Volume: 2024-05-27

Abstract: Na+ exclusion from above-ground tissues via the Na+-selective transporter HKT1;5 is a major salt-tolerance mechanism in crops. Using the expression genome-wide association study and yeast-one-hybrid screening, we identified TaSPL6-D, a transcriptional suppressor of TaHKT1;5-D in bread wheat. SPL6 also targeted HKT1;5 in rice and Brachypodium. A 47-bp insertion in the first exon of TaSPL6-D resulted in a truncated peptide, TaSPL6-DIn, disrupting TaHKT1;5-D repression exhibited by TaSPL6-DDel. Overexpressing TaSPL6-DDel, but not TaSPL6-DIn, led to inhibited TaHKT1;5-D expression and increased salt sensitivity. Knockout of TaSPL6-DDel in two wheat genotypes enhanced salinity tolerance, which was attenuated by a further TaHKT1;5-D knockdown. Spike development was preserved in Taspl6-dd mutants but not in Taspl6-aabbdd mutants. TaSPL6-DIn was mainly present in landraces, and molecular-assisted introduction of TaSPL6-DIn from a landrace into a leading wheat cultivar successfully improved yield on saline soils. The SPL6-HKT1;5 module offers a target for the molecular breeding of salt-tolerant crops.

DOI: 10.1038/s41588-024-01762-2

Source: https://www.nature.com/articles/s41588-024-01762-2