Proteomic profile analysis of Pyropia haitanensis in response to high-temperature stress

High-temperature stress is a major abiotic stress that affects the yield and quality of Pyropia, which is produced for use as a nutrient. Pyropia haitanensis strain Z-61 is tolerant to high temperature and is widely cultivated in South China. Here, we conducted a comparative proteomic analysis of the blades of Z-61 strain at 29 °C. Changes in the proteome of the blades were analyzed every other day for 8 days at 29 °C. Approximately 1,000 protein species were reproducibly detected at all time points, whereas 87 protein spots were differentially expressed at least at one time point. Fifty-nine protein spots were successfully identified using liquid chromatography–tandem mass spectroscopy and database searching. The proteins were classified into nine functional categories: photosynthesis (27.12 %), energy metabolism (22.03 %), other metabolic pathways (11.86 %), redox homeostasis (11.86 %), response to stimuli (8.47 %), proteins involved in transcription and translation (6.78 %), cytoskeleton-related proteins (5.08 %), proteins that mediate signal transduction (1.69 %), and unknown proteins (5.08 %). These findings indicated that the blades of Z-61 resist high-temperature stress by inhibiting photosynthesis and other nonessential metabolic processes. In contrast, to increase energy metabolism, the expression of proteins related to redox homeostasis and response to stimuli were upregulated, thereby maintaining physiological balance during stress.