5-氨基乙酰丙酸对辣椒植株低温胁迫伤害的缓解效应

Mitigative Effect of 5-aminolevulinic Acid in Pepper under Low Temperature Stress

以‘超越五号’辣椒品种为试材,研究了低温胁迫期间及随后的常温恢复过程中5-氨基乙酰丙酸(ALA 25mg.L-1)处理对始花期辣椒植株生长量,叶片中脯氨酸、可溶性糖、可溶性蛋白含量,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性和电解质渗透率及丙二醛(MDA)含量的影响,以探讨ALA提高辣椒抗寒性的生理机制。结果表明,低温胁迫下叶面喷施25 mg.L-1的ALA可显著提高辣椒植株生长量,增加叶片中脯氨酸、可溶性糖及可溶性蛋白含量,增强其POD、CAT及APX活性,并显著降低辣椒叶片中SOD活性、电解质渗透率和MDA含量。叶面喷施ALA也显著降低了恢复过程中辣椒叶片中的渗透调节物质含量和抗氧化酶活性,使膜伤害基本恢复到对照水平。可见,外源ALA处理可通过提高低温胁迫下辣椒叶片的渗透调节能力和抗氧化能力,促进植株生长,缓解低温胁迫对植株的伤害。

Effect of 5-aminolevulinic acid（ALA 25 mg·L-1） on the growth,Pro,soluble sugar and soluble protein contents,the activities of superoxide dismutase（SOD）,peroxidase（POD）,catalase（CAT）,ascorbate peroxidase（APX） and electrolyte leakage（EL）,MDA contents of leaves was conducted with pepper variety ＇Chaoyue No.5＇ in flowering stage under low temperature stress and the subsequent recovery process.Preliminarily explore the physiological mechanisms of ALA on improving the chilling resistance of pepper.Results showed that 25 mg·L-1 ALA significantly increased the growth mass,Pro,soluble sugar and soluble protein contents and the activities of POD,CAT and APX,significantly decreased the EL and MDA content and the activities of SOD under the low temperature stress,while the content of osmotic adjustment,MDA and the activities of POD,CAT,APX decreased under the normal conditions.It indicates that exogenous ALA treatment could improve the growth and relieve chilling injury of pepper by increasing the content of osmotica and the activities of antioxidant enzymes.