Abstract：

 pPLA (patatin-related phospholipase A) is a key enzyme that catalyzes the initial step of lipid hydrolysis, which isinvolved in biological processes, such as drought, salt stress, and freezing injury. However, a comprehensive analysis of thepPLA gene family in cotton, especially the role of pPLA in the response to drought and salt tolerance, has not been reportedso far. A total of 33 pPLA genes were identified in this study using a genome-wide search approach, and phylogenetic analysisclassified these genes into three groups. These genes are unevenly distributed on the 26 chromosomes of cotton, and mostof them contain a few introns. The results of the collinear analysis showed that G. hirsutum contained 1–5 copies of eachpPLA gene found in G. arboreum and G. raimondii. The subcellular localization analysis of Gh_D08G061200 showed thatthe protein was localized in the nucleus. In addition, analysis of published upland cotton transcriptome data revealed thatsix GhPLA genes were expressed in various tissues and organs. Two genes (Gh_A04G142100.1 and Gh_D04G181000.1) were highly expressed in all tissues under normal conditions, showing the expression characteristics of housekeeping genes.Under different drought and salt tolerance stresses, we detected four genes with different expression levels. This study helpsto clarify the role of pPLA in the response to drought and salt tolerance.

KeyWords:

Cotton · Patatin-related phospholipase A gene family · Salt tolerance · Drought tolerance