Biochemical responses of hairgrass (Deschampsia caespitosa) to hydrological change

Qiaoyu Luo; Yonggui Ma; Zhi Chen; Huichun Xie; Yanlong Wang; Lianyu Zhou; Yushou Ma

doi:10.3389/fpls.2022.987845

Biochemical responses of hairgrass (Deschampsia caespitosa) to hydrological change

Front Plant Sci. 2022 Sep 26:13:987845. doi: 10.3389/fpls.2022.987845. eCollection 2022.

Authors

Qiaoyu Luo^{1

2

3

4}, Yonggui Ma^{1

2

3}, Zhi Chen^{1

2

3}, Huichun Xie^{1

2

3}, Yanlong Wang⁴, Lianyu Zhou^{1

2

3}, Yushou Ma⁴

Affiliations

¹ School of Life Sciences, Qinghai Normal University, Xining, China.
² Qinghai Provincial Key Laboratory of Medicinal Plant and Animal Resources of Qinghai-Tibet Plateau, Qinghai Normal University, Xining, China.
³ Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, China.
⁴ College of Agriculture and Animal Husbandry, Qinghai University, Xining, China.

Abstract

Plant growth and development are closely related to water availability. Water deficit and water excess are detrimental to plants, causing a series of damage to plant morphology, physiological and biochemical processes. In the long evolutionary process, plants have evolved an array of complex mechanisms to combat against stressful conditions. In the present study, the duration-dependent changes in ascorbate (AsA) and glutathione (GSH) contents and activities of enzymes involved in the AsA-GSH cycle in hairgrass (Deschampsia caespitosa) in response to water stress was investigated in a pot trial using a complete random block design. The treatments were as follows: (1) heavily waterlogging, (2) moderate waterlogging, (3) light waterlogging, (4) light drought, (5) moderate drought, (6) heavily drought, and (7) a control (CK) with plant be maintained at optimum water availability. The hairgrass plants were subjected to waterlogging or drought for 7, 14, 21 and 28 days and data were measured following treatment. Results revealed that hairgrass subjected to water stress can stimulate enzymatic activities of ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR) and L-galactono-1, 4-lactone dehydrogenase (GalLDH), switched on the ascorbate-glutathione (AsA-GSH) cycle and the L-galactose synthesis, up-regulated the contents of AsA and GSH, and maintained higher ratios of ascorbate to dehydroascorbate (AsA/DHA) and reduced glutathione to oxidized glutathione (GSH/GSSG) to alleviate potential oxidative damage. However, the light waterlogging did not induce hairgrass under stress to switch on the AsA-GSH pathway. In general, the critic substances and enzyme activities in AsA-GSH metabolic pathway increased as the increase of water stress intensity. As the increase of exposure duration, the critic antioxidant substances content and enzyme activities increased first and then maintained a relatively stable higher level. Our findings provide comprehensive information on biochemical responses of hairgrass to hydrological change, which would be a major step for accelerating ecological restoration of degradation alpine marshes in the Qinghai-Tibetan Plateau.

Keywords: Deschampsia caespitosa; antioxidant substance and enzyme; ascorbate-glutathione cycle; drought; stress durations; water-logging control.