Functional Gene-mining For Salt-tolerance Genes With The Power Of Arabidopsis & The Isolation And Analysis Of Oxidative Stress Tolerant Mutant OT24-1

Using the plant transformation-ready expression library of salt cress that we previously constructed, a large-scale floral-dip transformation of Arabidopsis was carried out, and a large collection of 125, 000 independent transgenic lines was generated. Using a high-throughput genetic screen for salt-tolerant seedlings, the transgenic seed library was screened, and hundreds of putative salt-tolerance lines were isolated in the primary screen. A secondary screen was used to confirm the salt tolerance and a number of salt-tolerance lines were isolated. Analysis of the cDNAs from the salt tolerance lines revealed novel genes that confer salt tolerance when overexpressed in Arabidopsis. Three salt tolerant mutants ST5-18,ST103-2 and ST54-6 were isolated by this method and the inserted cDNAs identified. The Arabidopsis homologs of these genes were investigated and their importance in salt tolerance demonstrated. This functional gene-mining method may be applicable to the isolation of other abiotic stress-tolerance genes, as well as to biotic stress-resistance genes such as disease-resistance genes. Arabidopsis; oxidative tolerance; At1g66950; paraquat...