ALA对辣椒低温胁迫下伤害的缓解效应

为了探明5-氨基乙酰丙酸(ALA)对缓解辣椒不同低温胁迫下伤害的作用及其机制,以较耐低温的辣椒品种超越五号为试材,研究了叶面喷施ALA对冬春季不同低温胁迫下辣椒花期植株叶片中渗调物质含量、超氧阴离子(O.2-)产生速率、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、电解质渗透率(EL)、丙二醛(MDA)含量、植株光合特性及生长的影响。结果表明,叶面喷施25 mg/L ALA后,明显提高了低温胁迫下辣椒叶片脯氨酸、可溶性蛋白质和可溶性糖的含量以及SOD、POD、CAT的活性;同时ALA也提高了低温胁迫下辣椒叶片叶绿素含量、净光合速率以及植株生长量,显著降低了叶片中电解质渗透率和MDA含量以及O.2-的产生速率。说明,ALA通过提高低温胁迫下植株叶片中渗透调节物质含量和抗氧酶活性,从而降低植株叶片中活性氧的含量,维持膜系统的稳定性;同时通过促进叶绿素的合成,增强植株叶片的光合作用,促进植株生长,从而缓解了辣椒受到的低温伤害。但不同低温胁迫下ALA的缓解程度有显著差异,并且随着温度的降低,其缓解程度降低。

Mitigative effect of 5-aminolevulinic acid on chilling injuries in pepper

In order to elucidate the mitigative effect of 5-aminolevulinic acid(ALA) on chilling injuries in pepper and the mechanisms,foliage spray of ALA was conducted,and the contents of osmoregulation substance,the production rate of active oxygen(O2 ·-),the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT),electrolyte leakage(EL),malondialdehyde(MDA) content,the photosynthetic characteristics and the growth of plant were investigated with pepper variety Chaoyue No.5 during flowering under chilling stress in winter and spring.Results showed that 25 mg/L ALA obviously increased the proline,soluble sugar and soluble protein contents,the activities of SOD,POD,CAT,the chlorophyll contents,the net photosynthetic rate and plant growth,and decreased the EL and MDA content and the production rate of O2 ·-,which indicated that exogenous ALA treatment could relieve chilling injury of pepper by increasing the content of osmotica and the capacity of antioxidant enzymes,decreasing the production rate of O2 ·-,and maintaining the stability of the membrane system.Exogenous ALA application improved the photosynthesis and the plant growth by promoting the synthesis of chlorophyll.There was significant differences in response to different degrees of low temperature stress,and the mitigation weakened with the drop of temperature.