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为探讨外源ABA调控姜干旱胁迫的生理机制,以‘莱芜大姜’为试材,采用砂培,通过模拟干旱(5%PEG)和根系外施ABA(0.05 mmol·L~(-1)),研究ABA对姜叶片活性氧代谢的影响。结果表明,外源ABA显著增加了姜叶片内源ABA含量,且以干旱胁迫下增加量为最多;同时,外源ABA亦有利于保持姜叶片较高的相对含水量。姜根系外施ABA早期,植株叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)活性均增强,进而显著降低了叶片中超氧阴离子()产生速率及过氧化氢(H_2O_2)含量,延缓了膜脂过氧化产物丙二醛(MDA)含量的增加;虽外源ABA处理后期,随干旱胁迫时间的延长,外施ABA处理植株叶片抗氧化酶活性有所降低,但其活性氧水平及MDA含量仍显著低于单一的干旱胁迫处理。表明外施0.05 mmol·L~(-1)ABA有利于维持姜叶片活性氧代谢的正常进行,降低膜脂过氧化水平,增强植株抗干旱能力。
In order to investigate the physiological mechanism of exogenous ABA regulating ginger drought stress, we used ’Laiwu ginger’ as test material, sand culture, simulated drought (5% PEG) and ABA (0.05 mmol·L -1) ) To study the effects of ABA on reactive oxygen species metabolism in ginger leaves. The results showed that exogenous ABA significantly increased the content of endogenous ABA in ginger leaves, and the increase was highest under drought stress. At the same time, exogenous ABA was also helpful to maintain the higher relative water content of ginger leaves. At the early stage of ABA application to ginger roots, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in plant leaves were enhanced, and the production of superoxide anion () in leaves was significantly reduced The content of malondialdehyde (MDA) in membrane lipid peroxidation was slowed down by increasing the content of H 2 O 2 and the content of H 2 O 2. Under the condition of exogenous ABA treatment, with the prolongation of drought stress, Activity decreased, but the level of reactive oxygen species and MDA content was still significantly lower than the single drought stress treatment. The results showed that application of 0.05 mmol·L -1 ABA was beneficial to maintain the normal oxygen metabolism of ginger leaves, reduce membrane lipid peroxidation and enhance drought tolerance of plants.