《植物生理学报》 2022, 58(4): 654-666

外源海藻糖影响甜高粱幼苗抗旱性的生理生化机制

王志恒¹，赵延蓉¹，黄思麒^1,2，王悦娟¹，起金娥¹，魏玉清^1,*

¹北方民族大学生物科学与工程学院, 国家民委黄河流域农牧交错区生态保护重点实验室, 银川750021；²云南大学生态与环境学院, 昆明650500

通信作者：魏玉清；E-mail: weiyuqing@126.com

摘　要：

为探究外源海藻糖影响植物抗旱性的机理, 以‘辽甜1号’甜高粱幼苗为试验材料, 水培条件下, 分别以不同浓度海藻糖(0.1、0.3、0.5 mmol·L−1)喷施受到干旱胁迫(150 g·L−1 PEG-6000模拟)的幼苗叶片。通过相关性分析、主成分分析和冗余分析等方法, 研究了外源海藻糖对干旱胁迫下甜高粱幼苗生物量、光合作用、活性氧积累、抗氧化酶活性、渗透调节物质含量以及海藻糖代谢相关酶活性的影响。结果表明,适宜浓度的外源海藻糖可以缓解干旱胁迫对甜高粱幼苗的伤害, 提高其抗旱性; 干旱胁迫下喷施外源海藻糖对甜高粱幼苗抗旱性存在浓度效应; 中低浓度的海藻糖通过调节内源海藻糖代谢维持较高的光合作用强度, 增加叶片渗透调节物质的积累以提高吸水能力, 以及诱导抗氧化酶活性的增加以清除多余活性氧并减轻脂质过氧化程度, 从而提高甜高粱幼苗的抗旱性。0.3 mmol·L−1是海藻糖处理的最佳浓度, 而0.5mmol·L−1的海藻糖处理会加重干旱胁迫对甜高粱幼苗的伤害。这可能是外源海藻糖减轻干旱胁迫对甜高粱幼苗生长发育影响的生理机制。

关键词：甜高粱; 海藻糖; 干旱胁迫; 渗透调节; 抗氧化酶

收稿：2021-10-18   修定：2022-01-07

资助：国家自然科学基金(31960387)和北方民族大学高层次人才项目(2019BJLZ02)

Physiological and biochemical mechanism of exogenous trehalose on drought resistance in sweet sorghum seedlings

WANG Zhiheng¹, ZHAO Yanrong¹, HUANG Siqi^1,2, WANG Yuejuan¹, QI Jin'e¹, WEI Yuqing^1,*

¹Key Laboratory of Ecological Protection of Agro-Pastoral Ecozones in the Yellow River Basin, National Ethnic Affairs Commission, School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China; ²College of Ecology & Environmental Science, Yunnan University, Kunming 650500, China

Corresponding author: WEI Yuqing; E-mail: weiyuqing@126.com

Abstract:

In order to explore the effects of exogenous trehalose on plant drought resistance, the leaves of sweet sorghum cultivar ‘Liaotian No.1’ were sprayed with trehalose in different concentrations (0.1, 0.3, 0.5 mmol·L−1) under drought stress (150 g·L−1 PEG-6000 solution simulated) in hydroponic conditions. The effects of exogenous trehalose on the biomass, photosynthesis, reactive oxygen species accumulation, antioxidant enzyme activity, osmotic regulatory substance content and trehalose metabolism related enzyme activity of sweet sorghum seedlings under drought stress were studied with correlation analysis, principal component analysis and redundancy analysis. The results showed that the appropriate concentration of exogenous trehalose could alleviate the damage of drought stress to sweet sorghum seedlings and improve their drought resistance. Moreover, it was found that spraying trehalose on sweet sorghum seedlings under drought stress had concentration effect on their drought resistance. Trehalose of low and moderate concentration can maintain higher photosynthesis intensity by adjusting the metabolism of endogenous trehalose, improve water absorption ability by increasing the accumulation of leaf osmotic regulation substances, remove excess reactive oxygen species and reduce the degree of lipid peroxidation by inducing the increase of antioxidant enzyme activities, so as to improve the drought resistance of sweet sorghum seedling. It was found that 0.3 mmol·L−1 was the optimal concentration of trehalose treatment, while 0.5 mmol·L−1 trehalose treatment aggravated the damage of drought stress on sweet sorghum seedlings. These may be the physiological mechanism of exogenous trehalose for alleviating the effects of drought stress on the growth and development of sweet sorghum seedlings.

Key words: sweet sorghum; trehalose; drought stress; osmoregulation; antioxidant enzyme