硫化氢与一氧化氮的交互作用诱导采后香蕉果实耐冷性的机制研究

Banana fruit are susceptible to chilling injury (CI) during storage at low temperature, which result in decrease in storage period and quality extremely. Along with nitric oxide (NO), hydrogen sulfide (H2S) is considered as a new emerging cell signal molecule involved in in various plant developmental processes and stress responses. H2S plays an important role in the response to the chilling stress, but its role in the acquisition of cold resistance in postharvest products remains to be further investigated. In order to understand the possible mechanism of exogenous H2S on acquisition of chilling tolerance in banana fruit under cold stress, physical quality, endogenous H2S and NO metabolism, carbon metabolism, mitochondrial function, energy metabolism, accumulation of secondary metabolites such as phenolics, proline, polyamine and GABA, as well as antioxidant capacity will be investigated in this proposal. With RNA sequencing technology, the full response view of H2S and NO processed banana gene transcriptional levels would be obtained to analyze the relationship between gene expression changes and induction of cold tolerance in banana fruit. Research results will not only help to further clarify the mechanism of H2S and its interaction with NO in cold resistance acquisition and signal transduction pathways, but also provide the reference for postharvest quality control of banana fruit and other cold-sensitive fruits and vegetables.

香蕉在低温贮藏下易发生冷害，对贮藏期和品质有极大影响。硫化氢（H2S）作为一种细胞信号分子，同NO一样广泛参与植物的生长发育以及胁迫响应等生理过程。H2S在低温胁迫响应中发挥着重要作用，但它在诱导采后耐冷性机制中的角色尚不明确。本文以香蕉为材料，研究H2S和NO的交互作用对低温贮藏下香蕉的生理品质、内源H2S和NO代谢、碳代谢、线粒体功能、能量代谢、次生产物代谢（酚类、脯氨酸、多胺和γ-氨基丁酸）和抗氧化系统等的影响，结合转录组测序分析技术，得到H2S与NO处理后香蕉基因转录水平的响应全景图像，分析基因表达变化与诱导香蕉耐冷性的关系，构建H2S和NO的交互作用诱导耐冷性的信号转导通路，为香蕉及其它冷敏型果蔬采后品质调控提供理论依据。

本研究以香蕉果实为原料，研究H2S和NO的交互作用对低温贮藏下香蕉的生理生化、转录水平、代谢水平的影响，利用转录组-代谢组联合分析的方法揭示了采后香蕉对H2S和NO的响应机制，研究H2S和NO的交互作用对采后香蕉耐冷性形成的调控作用。通过对不同处理香蕉基因表达及代谢物含量的差异进行分析，探讨在香蕉耐冷性形成过程中发挥重要作用的基因及生理过程，进一步明确了H2S和NO气体信号分子在抗氧化及次生代谢产物合成等方面的信号转导机制，为其在果蔬保鲜贮藏方面的应用提供了理论依据，对香蕉及其它冷敏型果蔬采后品质调控具有一定指导意义。