Polymorphic analysis of the exon 1 region of OsHKT1;5 gene in Kien Giang seasonal rice salt tolerance

Abstract

The increasing risk of saltwater intrusion due to climate change is a serious threat to rice production in the Mekong Delta. In order to address this issue, a study was conducted to evaluate the salt tolerance of 16 local seasonal rice varieties collected from Kien Giang province. These varieties were compared to the well-known salt-tolerant varieties Pokkali and RC222. The aim was to identify rice varieties with varying levels of salt tolerance. In addition, the study also analyzed the exon 1 region of the OsHKT1;5 gene in these varieties using sequencing techniques. The results of the phenotypic evaluation revealed that 7 of the rice varieties showed different levels of salt tolerance. These included Lua Chuoi, FL478, and Pokkali (which showed good tolerance), as well as Nang Trich, Trang Tep, Ba Bui, and Mot Bui (which showed intermediate salt tolerance). However, RC222 was found to be sensitive to salinity. Further analysis of the exon 1 region of the OsHKT1;5 gene identified 3 SNP markers at G382A, C418G, and G551A nucleotide positions. These markers were found to be non-synonymous mutations, resulting in changes in the amino acids D128N, P140A, and R184H, respectively.