石菖蒲形态和生理生化特性对干旱胁迫的响应

Response of morphological and physiological-biochemical characteristics of Acorus tatarinowii under drought stress

摘要:

【目的】探究干旱胁迫对石菖蒲生长及生理生化特性的影响,筛选石菖蒲的关键抗旱指标。【方法】采用0%、10%、20%、30%和40%聚乙二醇(PEG-6000)模拟干旱胁迫处理石菖蒲,研究不同干旱胁迫浓度和时长对三年生石菖蒲外观形态、叶片相对含水量、相对电导率以及光合色素、丙二醛、可溶性蛋白、可溶性糖、脯氨酸含量、超氧化物歧化酶活性的影响,并进行主成分分析。【结果】10%和20%浓度处理对石菖蒲的伤害不显著;随着干旱强度和时长增加,整体变化趋势为相对含水量降低,相对电导率、丙二醛、可溶性糖、脯氨酸含量上升,超氧化物歧化酶活性先升高后降低,可溶性蛋白含量先升高后降低再升高;叶绿素a、叶绿素b和类胡萝卜素含量随着干旱强度增加而升高,随着干旱时长增加呈“N”形变化。相关性分析和主成分分析表明,可溶性糖、脯氨酸含量、相对电导率、类胡萝卜素含量和超氧化物歧化酶活性5个指标可作为石菖蒲抗旱性的评价指标。【结论】石菖蒲能抵御10%和20%PEG-6000溶液引起的轻度干旱损伤,且主要通过增加渗透调节物质、光合色素含量和抗氧化酶活性来提高干旱适应性。

Abstract:

【Objective】To investigate the morphological and physiological responses of Acorus tatarinowii Schott to drought stress and to identify key drought resistance indices.【Method】Five different concentrations (0, 10%, 20%, 30%, 40%) were used to simulate drought stress in three-year-old A. tatarinowii. Morphology, leaf relative water content, relative electrolyte leakage, photosynthetic pigment content, soluble protein, soluble sugar, malondialdehyde, proline and superoxide dismutase activity were measured under different drought stress intensities and durations. Key drought-resistance indices were than identified by principal component analysis.【Result】Damage from 10% and 20% PEG-6000 was minor. As drought intensity and duration increased, the general trends were as follows: leaf relative water content (LRWC) decreased, relative electrolyte leakage (REL), malondialdehyde (MDA), soluble sugar (SS), and proline (PRO) increased; superoxide dismustase (SOD) activity first increased and then decreased; and soluble protein (SP) content followed an “up-down-up” pattern. Chlorophyll a, chlorophyll b, and carotenoid contents increased with drought intensity and showed an “N” shaped change with increasing stress duration. Correlation analysis and principal component analysis indicated that SS, PRO, REL, carotenoid (Car), and SOD can serve as key indices for evaluating drought stress in A. tatarinowii.【Conclusion】A. tatarinowii can withstand the damage caused by 10% and 20% PEG-6000 stress and improves its drought adaptability mainly by increasing osmotic regulators, photosynthetic pigments, and antioxidant enzymes.