Adequate water supply enhances seedling growth and metabolism in Festuca kryloviana: insights from physiological and transcriptomic analys

• Published in: BMC plant biology 2024-07, Vol.24 (1), p.714-15, Article 714
• Main Authors: Shi, Zhenghai, Liang, Guoling, Li, Sida, Liu, Wenhui
• Format: Article
• Language: English
• Subjects: Abscisic acid; Acidic soils; Amylases; Analysis; Antioxidant system; Antioxidants; Catalase; Chloroplasts; Climatic changes; Ecosystem management; Energy metabolism; Environmental aspects; Enzymes; Festuca kryloviana; Gene expression; Genes; Genetic aspects; Germination; Grasses; Grasslands; Growth; Indigenous species; Kinases; Lipid peroxidation; Metabolism; Metabolites; Methods; Moisture content; Peroxidase; Photosystem I; Photosystem II; Physiological effects; Physiology; Plant growth; Qinghai Lake region; Rainfall; Seedling development; Seedlings; Seeds; Signal transduction; Soil moisture; Soil stresses; Soil water; Sugar; Sugar metabolism; Superoxide dismutase; Transcriptomics; Trehalose; Trehalose-6-phosphate; Water; Water availability; Water content; Water management; Water stress; Water supply; α-Amylase
• ISSN: 1471-2229; 1471-2229
• DOI: 10.1186/s12870-024-05353-5

Festuca kryloviana is a significant native grass species in the Qinghai Lake region, and its low emergence rate is a primary factor limiting the successful establishment of cultivated grasslands. The region's arid and low-rainfall climate characteristics result in reduced soil moisture content at the surface. Despite the recognized impact of water availability on plant growth, the specific role of moisture in seedling development remains not fully elucidated. This study aims to investigate the germination rate and seedling growth velocity of F. kryloviana seeds under varying moisture conditions, and to integrate physiological and transcriptomic analyses of seedlings under these conditions to reveal the mechanisms by which water influences seedling development. The emergence rate of F. kryloviana seedlings exhibited an initial increase followed by a decrease with increasing moisture content. The highest emergence rate, reaching 75%, was observed under 20% soil moisture conditions. By the eighth day of the experiment, the lengths of the plumules and radicles under the optimal emergence rate (full water, FW) were 21.82% and 10.87% longer, respectively, than those under closely matching the soil moisture content during the background survey (stress water, SW). The differential development of seedlings under varying moisture regimes is attributed to sugar metabolism within the seeds and the accumulation of abscisic acid (ABA). At FW conditions, enhanced sugar metabolism, which generates more energy for seedling development, is facilitated by higher activities of α-amylase, sucrose synthase, and trehalose-6-phosphate synthase compared to SW conditions. This is reflected at the transcriptomic level with upregulated expression of the α-amylase (AMY2) gene and trehalose-6-phosphate synthase (TPS6), while genes associated with ABA signaling and transduction are downregulated. Additionally, under FW conditions, the expression of genes related to the chloroplast thylakoid photosystems, such as photosystem II (PSII) and photosystem I (PSI), is upregulated, enhancing the seedlings' light-capturing ability and photosynthetic efficiency, thereby improving their autotrophic capacity. Furthermore, FW treatment enhances the expression of the non-enzymatic antioxidant system, promoting metabolism within the seeds. In contrast, SW treatment increases the activity of the enzymatic antioxidant system, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), to