Field Crop 2024, Vol.7, No.1, 9-16 http://cropscipublisher.com/index.php/fc 13 key role in regulating plant response to drought, low temperature and saline-alkali stress, and enhances plant adaptation by activating downstream stress response gene expression (Garrett et al., 2017). CBL/CIPK signaling system plays an important role in maintaining electrolyte balance and improving salt and drought tolerance in plant cells through its unique ion regulation mechanism. Members of the LEA protein gene family play a protective role in plant resistance to drought and low temperature stress, and reduce the damage under adverse conditions by maintaining the water content of cells and the stability of biological macromolecules. In rice, the study of OsNHX1 gene reveals how plants respond to salt stress by regulating Na+/H+ exchange, which provides an important reference for the study of salt tolerance in other crops. The proline synthesis pathway involved in AtP5CS gene also shows its importance in plant resistance to drought and salt stress. By increasing proline synthesis, plants are able to enhance their osmoregulatory capacity and thus enhance stress tolerance. 3 Application of GWAS in the Study of Barley Resistance 3.1 A case study of barley drought tolerance tolerance by GWAS In one study, scientists collected several barley germplasm resources and evaluated their phenotypic performance under drought conditions, including drought response traits such as leaf water potential, yield, and root structure. Illumina 9k single nucleotide polymorphism (SNP) chips were used for genome-wide SNP analysis of these barley germplasm. Through GWAS analysis, the researchers identified multiple gene loci associated with drought tolerance in barley. These gene loci are located in different regions of the barley genome, some of which are associated with genes related to stress response such as root growth and ABA signaling pathways, and through further functional validation experiments, the researchers confirmed the importance of some candidate genes for drought tolerance in barley (Sallam et al., 2019). The results of this study show that GWAS technology can help identify key genetic factors in barley drought tolerance and provide potential candidate genes for the future development of more drought-tolerant barley varieties, and the study also provides important clues for further understanding of barley drought response mechanisms. This case study shows that GWAS techniques have great potential for studying drought tolerance in barley and provide an important scientific basis for addressing environmental stress challenges such as drought. It is important to note that the GWAS findings require further validation and functional analysis to confirm the exact mechanism of action of candidate genes on drought tolerance in barley. 3.2 A case study of barley salt stress tolerance by GWAS To carry out the GWAS study of salt tolerance in barley, the scientists collected a number of barley germplasm resources, which included barley species of different geographical origin and cultivation purposes. By conducting multiple phenotypic assessments under salt stress, such as growth indicators, biomass, ion concentration, etc., the researchers determined the level of tolerance of barley under salt stress. A high density single nucleotide polymorphism (SNP) chip was used to analyze the whole genome SNP of these barley germplasm. Through GWAS analysis, the researchers found multiple gene loci related to barley salt stress tolerance, which were distributed in different regions of the barley genome (Fan et al., 2016), and through further functional verification experiments, the researchers identified some candidate genes. These genes are involved in stress response pathways related to salt stress response, ion balance and osmotic regulation. This case study shows that GWAS techniques can help reveal the genetic basis of salt stress tolerance in barley and provide important clues for the future development of barley varieties with greater salt stress tolerance. The study also provides an important scientific basis for further understanding of barley's adaptation to salt stress, but the GWAS findings require further validation and functional analysis to confirm the exact mechanism of action of candidate genes on barley salt stress tolerance.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==