Identification, Phylogeny, and Expression Profiling of Pineapple Heat Shock Proteins (HSP70) Under Various Abiotic Stresses.

Pineapple ( (L.) Merr.) is an economically significant and delicious tropical fruit. Pineapple commercial production faces severe decline due to abiotic stresses, which affect the development and quality of pineapple fruit. Heat shock protein 70 (HSP70) plays an essential role in abiotic stress tolerance. However, the pineapple family identification and expression analysis in response to abiotic stresses has not been studied. To explore the functional role of , different abiotic stress treatments were applied to pineapple cultivar "Bali" seedlings. A total of 21 members were identified in the pineapple genome. The identified genes were classified into four subfamilies (I-IV) using phylogenetic analysis. The family is expressed under different stress conditions. Quantitative real time polymerase chain reaction (qRT-PCR) revealed the expression pattern of the family under cold, drought, salt, and heat stress. The expression level of genes such as increased under heat, cold, and drought stress, while the expression level of genes such as decreased under salt stress. Furthermore, the expression profile of s in different tissues and development stages was analyzed using transcriptome analysis. The genes exhibited unique expression patterns in pineapple tissue at different developmental stages. The study therefore provides a list of genes with substantial roles in abiotic stress response and valuable information for understanding functional characteristics during abiotic stress tolerance in pineapple.