外源神经酰胺处理对青椒果实抗冷性的影响

Effect of Exogenous Ceramide Treatment on Chilling Tolerance in Green Bell Pepper Fruits

摘要:

为研究外源物质处理对青椒果实抗冷性的影响，本试验采用不同浓度的外源神经酰胺(0、200、400 μmol/L)处理青椒果实，测定贮藏期间青椒果实冷害指数、相对电导率、MDA、叶绿素、Vc、可溶性蛋白含量、POD、CAT和APX等生理指标，探究外源神经酰胺处理对青椒果实抗冷性的影响。结果表明：在4 ℃贮藏条件下，外源神经酰胺处理可有效抑制青椒果实冷害的发生。200和400 μmol/L外源神经酰胺处理均有效抑制了青椒果实冷害指数的升高，延缓了相对电导率增加，抑制了青椒果实MDA含量的积累，维持了细胞膜的完整性；同时外源神经酰胺处理延缓了青椒果实叶绿素、Vc和可容性蛋白的降解，增强了POD、CAT和APX活性，增强了青椒果实的抗冷性，其中以400 μ mol/L外源神经酰胺处理的青椒果实抗冷性最好。

Abstract:

To study the effect of treatment with an exogenous substance on the chilling tolerance in green bell pepper fruits, different concentrations of exogenous ceramide solutions (0, 200, and 400 μmol/L) were used to treat pepper fruits. The chilling index, relative electrical conductivity, contents of malondialdehyde (MDA), chlorophyll, vitamin C (Vc), and soluble proteins, and the activities of peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) of pepper fruit, during storage, were determined. The results showed that exogenous ceramide treatment could effectively inhibit chilling injury in pepper fruits stored at 4 ℃. Both 200 and 400 μmol/L exogenous ceramide treatments effectively inhibited the increase of chilling index, delayed the increase of relative electrical conductivity, suppressed the accumulation of MDA content, and maintained the integrity of the cell membrane. At the same time, exogenous ceramide treatment delayed the degradations of chlorophyll, Vc, and soluble proteins, and enhanced the activities of POD, CAT, and APX, thereby increasing the chilling tolerance of pepper fruits. Among all the treatments, optimal chilling tolerance of pepper fruits was found in 400 μmol/L of ceramide treatment.