向日葵HaOSCA1.2基因克隆及表达特性分析OA

The hyperosmolarity-gated calcium-permeable channel family genes(OSCA)play a key regulatory role in plant responses to abiotic stresses.To clarify the molecular characteristics of sunflower HaOSCA1.2 and its response mecha-nism to stresses,this study cloned the HaOSCA1.2 gene.The coding sequence(CDS)of HaOSCA1.2 is 2 322 bp in length,encoding 773 amino acids.The relative molecular weight of the encoded protein is 88 430,with a theoretical isoe-lectric point of 8.81.It contains the RSN1_7TM conserved domain and is a hydrophobic transmembrane protein,whose sec-ondary structure is dominated by α-helices.Evolutionary analysis revealed that HaOSCA1.2 shared high amino acid se-quence similarity(88.93％-89.13％)with OSCA proteins from Tanacetum cinerariifolium,Arctium lappa,and Lactuca sativa,indicating a close phylogenetic relation-ship.Tissue-specific expression analysis revealed that the expression level of HaOSCA1.2 in sunflower leaves was significantly higher than that in roots and stems(P＜0.05).Analysis of abiotic stress response showed that the HaOSCA1.2 gene exhibited rapid and upregulated expres-sion under drought,high salt,and mixed saline-alkali stresses.Protein-protein interaction prediction indicated that HaOSCA1.2 potentially interacted with two members of the DnaJ heat shock protein(HSP40)family.This study clarifies the molecular characteristics and abiotic stress response pat-terns of the sunflower HaOSCA1.2 gene,providing a theoretical basis and genetic resources for analyzing the molecular mechanisms of sunflower stress resistance and for breeding stress-resistant varieties.