Identification, gene expression and genetic polymorphism of zinc finger A20/AN1 stress-associated genes, HvSAP, in salt stressed barley from Kazakhstan

Abstract

Background A family of genes designated as the Zinc finger A20/AN1 Transcription factors encoding stress-associated proteins (SAP) are well described in Arabidopsis and rice, and include 14 AtSAP and 18 OsSAP genes that are associated with variable tolerances to multiple abiotic stresses. The SAP gene family displays a great diversity in its structure and across different plant species. The aim of this study was to identify all HvSAP genes in barley (Hordeum vulgare L.), to analyse the expression of selected genes in response to salinity in barley leaves and develop SNP marker for HvSAP12 to evaluate the association between genotypes of barley plants and their grain yield in field trials. Results In our study, 17 HvSAP genes were identified in barley, which were strongly homologous to rice genes. Five genes, HvSAP5, HvSAP6, HvSAP11, HvSAP12 and HvSAP15, were found to be highly expressed in leaves of barley plants in response to salt stress in hydroponics compared to controls, using both semi-quantitative RT-PCR and qPCR analyses. The Amplifluor-like SNP marker KATU-B30 was developed and used for HvSAP12 genotyping. A strong association (R2 = 0.85) was found between KATU-B30 and grain yield production per plant of 50 F3 breeding lines originating from the cross Granal × Baisheshek in field trials with drought and low to moderate salinity in Northern and Central Kazakhstan. Conclusions A group of HvSAP genes, and HvSAP12 in particular, play an important role in the tolerance of barley plants to salinity and drought, and is associated with higher grain yield in field trials. Marker-assisted selection with SNP marker KATU-B30 can be applied in barley breeding to improve grain yield production under conditions of abiotic stress.

Expression of Specific Alleles of Zinc-Finger Transcription Factors, HvSAP8 and HvSAP16, and Corresponding SNP Markers, Are Associated with Drought Tolerance in Barley Populations

“…Many genes are known to be involved in the determination of GY and its components, and it is important to determine those with a substantial and clear impact on the improvement of GY. In barley, HvSAP12 was associated with higher GY under salinity stress, as reported in our previous study [9], while over-expression of the rice transgene OsSAP5 in plants of A. thaliana resulted in a higher 1000 seed weight under heat stress [23].…”

“…Based on published data, SAP genes are very responsive to abiotic stresses in plants, including HvSAP in barley plants under salinity stress [9]. We show here that expression of HvSAP8 and HvSAP16 in response to drought stress follows a similar trend, but differences were genotype-dependent and strongly associated with identified SNPs in parents and selected breeding lines from two segregating barley populations, G×B and N×A.…”

“…Under salinity stress, HvSAP8 (incorrectly classified earlier as HvSAP5) was highly up-regulated (4-7 fold) after 7 days of growth in hydroponics with 150 mM NaCl. Transcript levels then returned to normal after 14 days [9]. Other barley genes, HvSAP6, HvSAP11, HvSAP12 and HvSAP15, showed similar expression profiles, but with variable magnitude and genotype-dependence.…”

“…Cultivated barley (Hordeum vulgare), a widely grown cereal crop, is genetically similar to both rice (Oryza sativa), and Brachypodium distachyon, allowing comparative sequence analysis of barley with these species. In total, 17 HvSAP barley genes were identified and described in our previous study, with two genes, HvSAP8 and HvSAP16, representing groups with A20/AN1 and AN1/two C2H2 domains, respectively [9]. Under salinity stress, HvSAP8 (incorrectly classified earlier as HvSAP5) was highly up-regulated (4-7 fold) after 7 days of growth in hydroponics with 150 mM NaCl.…”

“…Various molecular markers are used for MAS, but SNPs are most commonly used for genotyping (Reviewed in: [30]). Amplifluor-like [31] and the recently developed Allele-specific qPCR (ASQ) methods [32] are particularly suitable and non-expensive approaches for plant SNP genotyping, successfully used for this type of research in barley [9,32].…”