西瓜脱落酸受体蛋白基因ClPYL8的克隆、亚细胞定位及表达分析OA

The abscisic acid(ABA)receptor protein PYL,as the initial component of ABA signaling transduc-tion,actively participated in ABA-mediated signaling transduction in plants and played a crucial role in regulating plant resistance to stress.In our previous study,based on transcriptome data,the gene Cla97C07G133100.1,which was negatively responsive to salt stress in watermelon,was screened out and named ClPYL8.To further explore the biological function of the watermelon ABA receptor ClPYL8,using watermelon TN07011 as the experimental materi-al,the structure and function of ClPYL8 were analyzed using bioinformatics,subcellular localization,and RT-qPCR methods.The results showed that the open reading frame of ClPYL8 gene was 702 bp,encoding 233 amino acids.Protein conserved domain prediction revealed that C1PYL8 contained the PYR/PYL/RCAR-like conserved domain,belonging to the SPRBCC superfamily.The promoter cis-acting element analysis indicated that the C1PYL8 promoter contained various elements responsive to stress,auxin,and light.The seamless cloning technique was used to con-struct the EGFP fusion expression vector,which was then transformed into tobacco.The results showed that C1PYL8 was localized in the nucleus and cell membrane.Tissue-specific(RT-qPCR)analysis revealed that the gene exhibi-ted the highest expression level in seeds and the lowest in fruits and female flowers;under salt stress,the expression of ClPYL8 showed a downregulation trend;under drought stress,the gene expression first decreased and then in-creased;under low-temperature stress,the gene expression first increased and then decreased.In conclusion,ClPYL8 actively responded to abiotic stress and might regulate watermelon's stress response through the ABA signaling path-way,suggesting a potential negative regulatory role in salt stress and positive regulatory roles in drought and low-temperature stress.