南方红壤侵蚀区芒萁对聚乙二醇6000模拟干旱胁迫的响应

Responses of Dicranopteris pedata to Simulated Drought Stress with Polyethylene Glycol 6000 in the Red Soil Erosion Area of Southern China

利用聚乙二醇(PEG)6000模拟干旱胁迫,探讨了芒萁对干旱胁迫的响应。结果显示,干旱胁迫显著提高了芒萁的超氧化物歧化酶(SOD)、脯氨酸(Pro)、相对电导率(REC)和丙二醛(MDA)水平。过氧化物酶(POD)活性在10%PEG 6000浓度下显著提高,但在较高浓度时下降。随着PEG 6000浓度的增加,过氧化氢酶(CAT)活性先降低后升高。通过相关分析和主成分分析发现,在30%PEG 6000浓度时芒萁表现出较强的抗旱性。综上,较高的SOD和CAT活性以及较高的Pro浓度共同提高了芒萁的抗旱性,是协助芒萁抵御季节性土壤干旱的主要因子,而极端干旱仍会破坏芒萁的抗旱生理活动。

This research investigated the response of D.pedata to drought stress using polyethylene glycol(PEG)6000.We examined several parameters such as superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),proline(Pro),relative electrical conductivity(REC),and malondialdehyde(MDA)of D.pedata under drought stress induced by PEG 6000.Exposure to drought stress significantly increased SOD,Pro,PEC,and MDA levels in D.pedata.POD expression was remarkably upregulated at 10%PEG 6000 concentration but decreased at higher concentrations.CAT activity decreased at first but increased later as the concentration of PEG 6000 increased.Strong drought resistance was observed at 30%PEG 6000 concentration by principal component analysis and correlation analysis.Pro was shown to perform a critical role in the response of D.pedata to drought stress.The results suggest that the higher activities of SOD and CAT and higher Pro concentration,which work together to improve the drought resistance,are the main components that facilitate the survival of D.pedata under seasonal drought environment and play a vital role in soil and water conservation.Nevertheless,extremely severe drought still destroys the physiological activities of D.pedata further weakens its drought resistance.