外源5-氨基乙酰丙酸对盐胁迫下黄连种子萌发及幼苗生理特性的影响

目的 本研究通过对黄连种子萌发及幼苗生理特性的研究,旨在寻找提高黄连种子及幼苗在盐胁迫条件下抗性能力的途径.方法 用100 mmol/L的NaCl模拟盐胁迫,在外源5-氨基乙酰丙酸(ALA)处理后,对黄连种子的各萌发指标及黄连幼苗叶片细胞质膜透性、超氧阴离子产生速率,过氧化氢(H₂O₂)量,可溶性糖、可溶性蛋白、游离脯氨酸及丙二醛(MDA)量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性进行测定.结果 NaCl胁迫下的黄连种子萌发受到显著抑制,但是在经过不同浓度的ALA处理后,发芽势、发芽率、发芽指数和活力指数等萌发指标均有升高.外源ALA处理显著提高了盐胁迫下黄连幼苗叶片可溶性糖、可溶性蛋白和脯氨酸量,不同程度的提高了叶片超SOD、POD和CAT活性,显著降低了MDA量、质膜透性、超氧阴离子产生速率及H₂O₂量.结论 外源ALA通过提高黄连种子的萌发指数,提高渗透调节物质含量及抗氧化酶活性,降低细胞质膜氧化程度,有效地减缓NaCl 胁迫对黄连种子及幼苗产生的伤害,提高了种子及幼苗的抗盐能力.

Effect of exogenous 5-aminolevulinic acid on seed germination and seedlings physiological characteristics of Coptis chinensis under NaCl stress

Objective To find get the method of alleviating salinity damage to Coptis chinensis under NaCl stress by studying the seed generation and seedling physiological nature. Methods Several physiological indexes such as germination vigor, germination rate, germination index, and vigor parameters of C. chinensis were measured after treated by 5-aminolevulinic acid (ALA) under salt stress (NaCl with the concentration of 100 mmol·L^-1 NaCl). And other parameters such as memberane permeability, H₂O₂ content, production rate of superoxide anion, contents of soluble surge, soluble protein, free proline, and malondialdehyde (MDA), and activities of superoxide (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were also measured. Results The seed germination indexes of C. chinensis under NaCl stress have an obvious inhibition. But after the treatment of ALA, germination indexes were all increased. The results also showed that the treatment of exogenous ALA obviously increased the contents of soluble sugars, free proline, and soluble protein, decreased the contents of MDA, H₂O₂, and production rate of superoxide anion. Meanwhile, the results also indicated that ALA could improve the activities of SOD, POD, CAT, and APX. Conclusion Exogenous ALA with appropriate concentration could significantly alleviate the damages to the seeds and seedlings of C. chinensis under NaCl stress and promote the salt resistance of the seeds and seedlings through improving the germination indexes and activities of anti-oxidase, decreasing the memberane permeability, and so on.