Abstract
Soil salinity has a major impact on rice seed germination,severely limiting rice production.Herein,a rice germination defective mutant under salt stress(gdss)was identified by using chemical mutagenesis.The GDSS gene was detected via MutMap and shown to encode potassium transporter OsHAK9.Phenotypic analysis of complementation and mutant lines demonstrated that OsHAK9 was an essential regulator responsible for seed germination under salt stress.OsHAK9 is highly expressed in germinating seed embryos.Ion contents and non-invasive micro-test technology results showed that OsHAK9 restricted K+efflux in salt-exposed germinating seeds for the balance of K+/Na+.Disruption of OsHAK9 significantly re-duced gibberellin 4(GA4)levels,and the ger-mination defective phenotype of oshak9a was partly rescued by exogenous GA3 treatment under salt stress.RNA sequencing(RNA-seq)and real-time quantitative polymerase chain reaction analysis demonstrated that the dis-ruption of OsHAK9 improved the GA-deactivated gene OsGA2ox7 expression in germinating seeds under salt stress,and the expression of OsGA2ox7 was significantly in-hibited by salt stress.Null mutants of Os-GA2ox7 created using clustered,regularly in-terspaced,short palindromic repeat(CRISPR)/CRISPR-associated nuclease 9 approach dis-played a dramatically increased seed germina-tion ability under salt stress.Overall,our results highlight that OsHAK9 regulates seed germi-nation performance under salt stress involving preventing GA degradation by mediating Os-GA2ox7,which provides a novel clue about the relationship between GA and OsHAKs in rice.
基金项目
国家自然科学基金(32272169)
国家自然科学基金(32000377)
国家自然科学基金(32172037)
国家自然科学基金(31601387)
广东省自然科学基金(2022A1515110449)
Hainan Yazhou Bay Seed Laboratory(B21HJ1002)
万方数据