Genome-Wide Identification, Evolutionary Analysis, and Expression Profiling of the β-D-Xylosidase Gene Family in Cotton (Gossypium hirsutum) Under PEG-Simulated Osmotic and Salt Stress
Simple Summary Cotton is one of the world’s most important fiber and oil crops, but drought and salty soils strongly reduce its growth and yield. Enzymes of the BXL family help remodel plant cell walls and are thought to contribute to a plant’s ability to cope with environmental stress. In this study, we searched the cotton genome and identified 25 BXL genes, and we examined their evolutionary relationships, gene structures, and the regulatory regions that control their activity. We then tested how these genes respond when cotton seedlings are exposed to drought-like and salt-like conditions. Several BXL genes were strongly activated under both treatments, and three in particular were identified as central “hub” genes within networks of stress-responsive genes. These results indicate that specific BXL genes may help cotton survive dry or salty conditions, and they provide candidate targets for future efforts to improve cotton’s tolerance to drought and salinity. Such improvements could help stabilize cotton production under increasingly challenging environmental conditions.