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

期刊论文
发表日期：

2024年5月27日

查看全文

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

摘要

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-D^In, disrupting TaHKT1;5-D repression exhibited by TaSPL6-D^Del. Overexpressing TaSPL6-D^Del, but not TaSPL6-D^In, led to inhibited TaHKT1;5-D expression and increased salt sensitivity. Knockout of TaSPL6-D^Del 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-D^In was mainly present in landraces, and molecular-assisted introduction of TaSPL6-D^In 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.