Physiological and Transcriptomic Cooperative Regulatory Mechanisms of Cotinus coggygria in Response to Drought and Rewatering Processes

Background Global drought represents a pressing environmental challenge, necessitating a deeper comprehension of how plant species at various stages of drought response adapt to such stress. Cotinus coggygria, a deciduous tree species known for its autumn color transformation, holds significance for arid and semi-arid ecological contexts. Research investigating the detailed physiological and transcriptomic responses of C. coggygria to drought and subsequent rewatering is currently lacking. Results Seedlings of C. coggygria were subjected to five distinct drought durations (30, 50, 70, 90, and 110 days) followed by a 20-day rewatering period. Increasing drought severity led to reductions in seedling height, ground diameter, leaf water potential, and nitrogen and phosphorus contents across plant organs, while showing notable increases in stomatal traits, chlorophyll and carotenoid levels, as well as soluble protein and proline contents, ultimately bolstering the plant's ability to retain water. Towards the later stages of stress, heightened levels of hydrogen peroxide and malondialdehyde were observed, accompanied by diminished hydroxyl radical content, and augmented activities of peroxidase, catalase, and glutathione, indicative of antioxidant system modulation. Following short-term rewatering, most physiological parameters of C. coggygria did not fully recover to control levels. Transcriptomic analysis revealed 3443 up-regulated and 3891 down-regulated differentially expressed genes (DEGs) under 110 days of stress, and 1923 up-regulated and 1541 down-regulated DEGs following 20 days of rewatering, highlighting genes modulating phytohormone signaling pathways, metabolic pathways associated with key physiological indicators, and differentially expressed transcription factors. Conclusions The research revealed that C. coggygria demonstrated synchronized physiological and transcriptomic reactions to both drought stress and subsequent rehydration. These reactions encompassed alterations in growth metrics, nutrient levels, physiological characteristics, antioxidant system functionality, and gene expression profiles. The results offer significant understanding into the adaptive mechanisms of C. coggygria under drought stress conditions and may have implications for comprehending and mitigating drought effects on plant species in arid and semi-arid regions.