Physiological and metabolic changes in Selaginella tamariscina in response to desiccation and recovery

• Published in: Plant growth regulation 2024-12, Vol.104 (3), p.1535-1547
• Main Authors: Xi, Yi, Cai, Yiming, Li, Zhou
• Format: Article
• Language: English
• Subjects: Acids; Agriculture; Alanine; Antioxidants; Arabinose; Biomedical and Life Sciences; Catalase; Citric acid; Damage tolerance; Dehydration; Desiccation; Energy metabolism; Extreme values; Glycine; Lactic acid; Leaves; Life Sciences; Metabolites; Moisture content; Original Paper; Peroxidase; Photochemicals; Physiology; Plant Anatomy/Development; Plant layout; Plant Physiology; Plant Sciences; Recovery; Rehydration; Selaginella; Superoxide dismutase; Vanillic acid; Water content; γ-Aminobutyric acid
• ISSN: 0167-6903; 1573-5087
• DOI: 10.1007/s10725-024-01237-8

As a resurrection plant, Selaginella tamariscina exhibits remarkable desiccation tolerance and recovery capacity. However, the mechanisms of desiccation tolerance and recovery associated with the alteration of global organic metabolites in S. tamariscina have not been fully elucidated. Objectives of the study were to investigate desiccation tolerance and recovery capacity of S. tamariscina based on physiological response and to further reveal potential mechanisms of desiccation tolerance and recovery related to changes in antioxidant defense and differential metabolites under dehydration stress and after rehydration. Results showed that dehydration stress reduced leaf relative water content from 90 to 18%, resulting in extreme declines in chlorophyll content and photochemical efficiency as well as a significant increase in malondialdehyde content in leaves, but S. tamariscina plants could rapidly recover within 3 days of rehydration. Superoxide dismutase, peroxidase, and catalase were significantly activated by dehydration and rehydration. In addition, dehydration-induced accumulations of citric acid and ribitol could be maintained at higher levels in response to rehydration. Although most organic metabolites were not affected significantly by dehydration (lactic acid, ribonic acid, arabinitol, and erythritol) or decreased sharply under desiccation stress (glycine, alanine, γ-aminobutyric acid, proline, glyceric acid, vanillic acid, arabinose, and rhamnose), but S. tamariscia has the ability to quickly recover or increase the contents of these organic metabolites after rehydration. Current findings indicated that enhanced antioxidant defense system could be one of the main pathways for acquisition of desiccation tolerance and recovery capacity, thereby alleviating oxidative damage to S. tamariscina plants. The accumulation of various organic metabolites played critical roles in underlying mechanisms of desiccation tolerance and recovery due to their positive function associated with osmotic adjustment, osmoprotection, antioxidant, and energy metabolism.