Evaluation of salinity tolerance and analysis of allelic function of HvHKT1 and HvHKT2 in Tibetan wild barley

• DOI: 10.1007/s00122-010-1479-2
• Publication Date: 2010-10-27T06:32:27Z
• Authors: Long Qiu; Dezhi Wu; Shafaqat Ali; Shengguan Cai; Fei Dai; Xiaoli Jin; Feibo Wu; Guoping Zhang
• Keywords: Salinity Tolerance; Nursing; Sodium Chloride; Wild Barley; Tibet; Salt Stress; Plant Roots; Polymorphism, Single Nucleotide; 630; 03 medical and health sciences; Gene Expression Regulation, Plant; Biomass; Alleles; Plant Proteins; 2. Zero hunger; 0303 health sciences; Nucleotides; Reverse Transcriptase Polymerase Chain Reaction; Barley Genotype; Sodium; Hordeum; Salt Tolerance; 15. Life on land; Organ Specificity; Potassium; Plant Shoots

Tibetan wild barley is rich in genetic diversity with potential allelic variation useful for salinity-tolerant improvement of the crop. The objectives of this study were to evaluate salinity tolerance and analysis of the allelic function of HvHKT1 and HvHKT2 in Tibetan wild barley. Salinity tolerance of 189 Tibetan wild barley accessions was evaluated in terms of reduced dry biomass under salinity stress. In addition, Na(+) and K(+) concentrations of 48 representative accessions differing in salinity tolerance were determined. Furthermore, the allelic and functional diversity of HvHKT1 and HvHKT2 was determined by association analysis as well as gene expression assay. There was a wide variation among wild barley genotypes in salt tolerance, with some accessions being higher in tolerance than cultivated barley CM 72, and salinity tolerance was significantly associated with K(+)/Na(+) ratio. Association analysis revealed that HvHKT1 and HvHKT2 mainly control Na(+) and K(+) transporting under salinity stress, respectively, which was validated by further analysis of gene expression. The present results indicated that Tibetan wild barley offers elite alleles of HvHKT1 and HvHKT2 conferring salinity tolerance.