Abstract: This study explored the impact of water stress on the physiological responses ofMelica transsilvanicato endophytic fungal infection. Using both endophyte-infected (E+) and non-infected (E－) plants, a controlled water experiment with soil moisture levels of 60%－65% field water capacity (FWC) was set up for the control (CK), 85%－90% FWC for the high humidity treatment (W), and 15%－20% FWC for the drought treatment (D). The significant differences were found in proline content and superoxide dismutase (SOD) activity between E+ and E－ plants following 7 days of both high humidity and drought stress (P<0.05). After 14 days of stress, the significant differences were observed in chlorophyll, proline, malondialdehyde (MDA) content, SOD, peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) activities in E+ and E－ plants under the same conditions (P<0.05). After 21 days of stress, E+ plants had significantly increased MDA content and relative cell membrane permeability compared to E－ plants under both conditions (P<0.05). The results suggested that endophytic fungal infection enhanced the tolerance ofMelica transsilvanicato water stress.

Key words: water stress, endophytic fungi;Melica transsilvanica, physiological parameters, protective enzymes