Genome-Wide Identification and Expression Pattern of the SPP Gene Family in Cotton (Gossypium hirsutum) Under Abiotic...

Sucrose metabolism plays a crucial role in plant responses to abiotic stresses such as drought and high temperatures, significantly influencing plant growth and yield formation. In higher plants, the second step in sucrose bioconversion involves sucrose phosphate phosphatase (SPP) hydrolyzing sucrose-6-phosphate to form sucrose. This study determined the number of SPP gene family members in upland cotton (Gossypium hirsutum), systematically analyzed their fundamental characteristics, physicochemical properties, phylogenetic relationships, chromosomal localization, and expression patterns across different tissues and under various abiotic stresses.

The SPP gene family in hirsutum was identified using Hidden Markov Models (HMMER) and the NCBI Conserved Domain Database (NCBI CDD), and its physico-chemical properties were analyzed via the SOPMA online analysis website. Phylogenetic relationships were determined using MEGA 12.0 software. Promoter regions were analyzed with PlantCARE, sequence patterns were identified via MEME, and transcriptome data were downloaded from the CottonMD database.

This study identified four members of the hirsutum SPP gene family, with amino acid lengths ranging from 335 to 1015, molecular weights between 38.38 and 113.28 kDa, and theoretical isoelectric points (pI) between 5.39 and 6.33. These genes are localized across four chromosomes. The SPP gene family in hirsutum exhibits closer phylo-genetic relationships with SPP genes in Arabidopsis thaliana and Chenopodium quinoa. Their promoter regions are rich in cis-elements associated with multiple abiotic stress resistance functions, and their expression patterns vary across different tissues and under different abiotic stress conditions.

The GhSPP gene may play an important role in the growth and development of upland cotton and its responses to salt stress and drought. Therefore, it could be considered as a candidate gene for future functional analysis of cotton resistance to salt and drought stress.