β-氨基丁酸诱导甜樱桃采后抗病性的细胞机制研究

Induced resistance by elicitors has been an interesting focus in the research of storage and preservation of fruit and vegetable. Fruit cell is the basic structure and function unit of physiological function in fruit, however, little information is known about the variation of fruit cell in the process of postharvest induced disease resistance. With sweet cherry fruit as test material, the variation of cell nucleus and mitochondria in fruit cell, histochemical analysis of cellular defense responses in cherry fruit, the change of molecule biology of hypersensitive response in sweet cherry fruit in the process of induced disease resistance by β-aminobutyric acid (BABA) are the core research content, combined with the research of the variation of cell morphology under observation of electron microscopy and extracellular N-acetyl glucosamine concentration in vitro test in the present study. The objectives of this study are to explore the inner connection and mode of action between the effects of BABA on pathogenic bacteria and fruit cell and inhibitions of postharvest diseases, to clarify the correlative mechanism of organelle variation of fruit cell in the process of induced disease resistance by BABA and postharvest disease resisitance. The results are expected to enrich the theory of postharvest physiology and storage and preservation of fruit and vegetable, and further to provide a scientific basis for controlling the decay development of harvested sweet cherry fruit.

通过激发子诱导提高果蔬采后抗病性成为国际上果蔬贮藏保鲜技术研究的热点。果实细胞是果实实现生理功能的基本结构和功能单位，然而对于果蔬产生诱导抗病性过程中果实细胞的变化规律知之甚少。本项目拟以甜樱桃为试材，以β-氨基丁酸（BABA）诱导提高甜樱桃采后抗病性过程中，果实细胞内细胞核和线粒体等主要细胞器的变化、果实细胞抗性响应的组织化学分析和超敏反应的分子生物学变化为核心研究内容，结合体外BABA抑制病原菌的过程中，电镜观察BABA对病原菌细胞形态的影响和胞外N-乙酰葡萄糖胺含量的变化，探索BABA在甜樱桃果实体内对病原菌和果实细胞的影响与抑制采后病害之间的内在联系和作用方式，揭示BABA诱发甜樱桃果实抗病响应过程中各细胞器的变化与采后抗病性的关联机制。研究成果可丰富果实采后生理和贮运保鲜技术的理论，进而为控制甜樱桃果实采后的腐烂提供科学依据。

水果采后真菌病害对水果产业造成了严重的危害，在众多的防治方法中，通过激发子诱导提高果蔬采后抗病性成为国际上果蔬贮藏保鲜技术研究的热点。本项目以甜樱桃为研究对象，探讨了β-氨基丁酸（BABA）诱导提高甜樱桃对青霉病和灰霉病抗性提高过程中，甜樱桃果实细胞的变化。开展的主要研究内容如下：（1）通过浸泡和穿刺接种的方式筛选出抑制甜樱桃采后青霉病和灰霉病的最合理BABA浓度，基于在甜樱桃果实上抑菌最佳浓度，研究后续离体条件下BABA与病原菌之间的互作；（2）应用荧光显微镜观察了碘化丙啶染色后病原菌孢子的完整性，并测定了病原菌细胞培养液中N-乙酰葡萄糖胺含量的变化，结果表明BABA可以造成质膜完整性的下降，并破坏青霉和灰霉病原菌的细胞结构；（3）分析了BABA在提高甜樱桃诱导抗性过程中，果肉组织细胞中相关的活性氧种类、活性氧清除能力（超氧阴离子清除能力、DPPH清除能力、羟基自由基清除能力等）、能量水平和能量代谢相关酶活性的变化和相关基因的表达，说明BABA在抑制甜樱桃采后青霉病和灰霉病的过程中通过调控果肉细胞中的抗氧化状态和能量状态来发挥作用；（4）利用石蜡切片的技术观察了甜樱桃果实细胞壁和细胞核形态的变化，发现处理组果实的细胞壁能够维持较好的形态，但细胞核的观察不是很明显；（5）应用扫描电镜和透射电镜观察了甜樱桃果实病健交界处果实细胞与霉菌菌丝表观形态和超微结构的变化，研究了甜樱桃果实细胞之间的木质素、酚类化合物、胼胝质等抗病相关物质的含量，以及相关的酶活性。研究成果丰富了果实采后生理和贮运保鲜技术的理论，为减少甜樱桃果实采后青霉病和灰霉病的腐烂提供了理论依据。