مشخصات پژوهش

Background Sunfower (Helianthus annuus L.) is widely planted as an oilseed crop worldwide. Salt stress is one of the major abiotic stresses that negatively afect crop growth and productivity. To counter the negative impact of salt stress, plants have developed avoidance and tolerance mechanisms. Developing salt-tolerant genotypes requires understanding the molecular basis of adaptive mechanisms in depth. Although using model plants i.e., Arabidopsis has improved our understanding of salt tolerant mechanisms, the relative impotence and regulation mechanisms vary among plant species due to diferences in genetic and metabolic backgrounds. On the other hand, sunfower is a highly polymorphic plant due to its cross-pollinated behavior which provides diferent salt-tolerant genotypes available for comparative analyses. Methodsand results In order to gain a better view of molecular mechanismsinvolved in salt tolerance in sunfower, RNA sequencing analysis was realizedby evaluating a tolerant genotype (AS5305)with two biological replicates under control and salt stressconditions in a controlled environment. Salinity stress wasapplied from NaCl resource at the 8-leaf stage and samplings were done at 24 h postsalt stress application. Sequencing data were analyzed using tuxedo software suite. Blast2GO software and theKEGG database were used to identify the functional tasks of each of theassembled transcripts. Analysis of genes with robust expression (i.e., with FPKM>1in at least one sample) revealed a total of 121 signifcantly expressed genesbetween the saline-stressed and control samples. The diferential expression of11 genes was confrmed by real-time PCR. In the following, the cDNA of MYB44as one of the selected candidate genes involved in salt tolerance was isolated,cloned, and sequenced forcomparison. Conclusions Overall, the results of the current study may pave the way for the accurateselection of genes involved in salinity to be used inmolecular-genetics-assisted breeding