Transcriptome Analysis of Biochemistry Responses to Low-Temperature Stress in the Flower Organs of Five Pear Varieties

Using floral organs of five pear cultivars as materials, this study determined and compared physiological indices such as relative conductivity, superoxide dismutase (SOD), and malondialdehyde (MDA) of each cultivar’s floral organs under different low-temperature stress treatments, and evaluated the cold resistance of the five pear cultivars. Transcriptome sequencing analysis was performed on the floral organs of a new early-ripening pear cultivar called “Jinguang”, and 259 differentially expressed genes (DEGs) were identified, which were mainly enriched in pathways related to circadian rhythm and flavonoid biosynthesis. Weighted gene co-expression network analysis (WGCNA) showed that specific gene modules were significantly associated with MDA and soluble protein. Key enzymes such as NPC1(non-specific PLC, NPC), transcription factor MYB102, BBX19, and LHY (Late elongated hypocotyl) genes were located at the core of the constructed network, and may have important potential roles under low-temperature stress.