5-氨基乙酰丙酸和钙离子对NaCl胁迫下当归种子萌发的影响及对高温下幼苗抗氧化酶的调节作用

Effects of 5-ALA and calcium ions on seed germination of Angelica sinensis under NaCl stress and the regulation of antioxidant enzyme in seedlings at high temperature

以当归为材料(Angelica sinensis),研究了不同浓度5-氨基乙酰丙酸(ALA)和外源Ca^2+对NaCl胁迫下当归种子萌发质量及相关生理指标的影响.此外,研究了不同浓度ALA和Ca^2+对当归幼苗所受高温胁迫的缓解作用.结果表明,25 mg·L^-1 ALA处理和10 mmol·L^-1 Ca^2+处理对NaCl胁迫下当归种子萌发的促进作用最强,外源Ca^2+在高于10 mmol·L^-1后萌发率和相关生理指标均有所下降,且在高于15 mmol·L^-1后对当归种子活力有抑制作用.当ALA浓度高于25 mg·L^-1时萌发率和相关生理指标均略下降,但仍呈现促进作用.在高温环境中,ALA和Ca^2+处理可以显著降低当归幼苗中丙二醛(MDA)含量,减轻逆境中幼苗膜脂的过氧化作用,增强对环境的适应性;除此之外,ALA和Ca^2+处理可以提高抗氧化酶活性,缓解高温对植物膜系统的破坏,同时增加叶片中叶绿素的含量,增强当归幼苗的光合作用与植株抗高温能力.

In this study,the effects of different concentrations of 5-aminolevulinic acid(ALA)and exogenous Ca^2+on the germination quality and related physiological indexes of Angelica sinensis seeds under NaCl stress are studied.In addition,the effects of different concentrations of ALA and Ca^2+on the high temperature stress of Angelica sinensis seedlings are investigated.The results show that the treatment with 25 mg·L^-1 ALA and 10 mmol·L^-1 Ca^2+has the strongest promoting effect on seed germination of Angelica sinensis under NaCl stress.When the concentration of exogenous Ca^2+is higher than 10 mmol·L^-1,the germination rate and related physiological indexes are decreased,and when it is higher than 15 mmol·L^-1,the vigor of Angelica sinensis seeds is inhibited.When the concentration of ALA is higher than 25 mg·L^-1,the germination rate and related physiological indexes are decreased slightly,but still promot performanc improved.At high temperature,the MDA content in Angelica sinensis seedlings and the peroxidation of seedling membrane lipids under the stress are reduced when treated with ALA and Ca^2+,which is enhanced the adaptability to the environment.Moreover,the activity of antioxidant enzymes is improved and thus the damage of plant membrane system by high temperature is alleviated while treated with ALA and Ca^2+.At the same time,the content of chlorophyll in leaves is increased,which is enhanced the photosynthesis of Angelica sinensis seedlings and the ability of plants to resist high temperature.