干旱和盐胁迫下百子莲的抗逆生理研究

Physiology of stress resistance of Agapanthus praecox under drought and salt stress

以蓝色大花百子莲实生苗作为材料进行干旱和盐处理,从抗逆生理层面探索其在干旱和盐胁迫下的耐受能力,为其在干旱和盐碱环境下的园林应用提供科学的指导依据。研究结果表明,园土培养下百子莲能够完全耐受约30 d的断水干旱胁迫;盐处理下的半致死NaCl浓度为1.29%。生理指标测定结果显示,干旱和盐胁迫提高了百子莲叶片的细胞膜透性、丙二醛(MDA)与总可溶性蛋白(TSP)含量。干旱胁迫下叶绿素(Chl)含量先升后降,盐胁迫下维持稳定。干旱胁迫下,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性在胁迫30 d时显著(P<0.05)升高而后下降,过氧化氢酶(CAT)活性持续下降;盐胁迫下3种抗氧化酶均表现为由高活性降低的趋势。基因表达结果显示,两种胁迫下百子莲的抗氧化基因响应有所差异,Cu/Zn-SOD、POD、APX和GPX积极响应干旱胁迫信号,Cu/Zn-SOD、POD和GPX参与响应盐胁迫信号。主成分分析结果表明,可从膜脂过氧化程度、抗氧化酶活性、渗透调节物质含量来评价百子莲对干旱的耐受能力,从抗氧化酶活性评价百子莲对高盐的耐受能力。

Agapanthus praecox ssp.orientalis Big Blue was taken as the experimental material under drought and salt treatments,to explore the tolerance to drought and salt stress at the level of resistance physiology to provide scientific guidance for its application under drought and salt stress treatments.Results showed that A.praecox could have resistance for about 30 d under drought stress.The semi-lethal NaCl concentration was about 1.29%.The results of physiological indexes showed that the cell membrane permeability,malondialdehyde content and total soluble protein content continued to rise under both stress treatments.The chlorophyll content under drought stress firstly increased and then decreased.Under drought stress,the activities of superoxide dismutase(SOD)and peroxidase(POD)increased under 30-day drought stress and then decreased,while catalase(CAT)activity continued to decrease.Under salt stress,the activities of three antioxidant enzymes all showed a downward trend.qRT-PCR results showed distinctive results that Cu/Zn-SOD,POD,APX and GPX responded to the drought stress,while Cu/Zn-SOD,POD and GPX were involved in responding to the salt stress.The results of the principal component analysis indicated that membrane lipid peroxidation,antioxidant enzyme activity and osmoregulatory substance content of A.praecox can evaluate the tolerance to drought,while antioxidant enzyme activity indicated the tolerance to salt.