Abstract：
Kiwifruit ripening and senescence after harvesting are closely related to its economic value. Transcriptome analysis and biochemical parameters were used to investigate the differences in gene expression levels and the potential regulation of cell wall metabolism in kiwifruit treated with ozone, thereby regulating fruit softening and prolonging postharvest life. Compared to the control group, the activities of the cell wall modification enzyme were lower under ozone treatment, the content of polysaccharide in the cell wall of primary pectin and cellulose was higher, and the content of soluble pectin was lower. Meanwhile, ozone treatment delayed the degradation of the cell wall mesosphere during storage. A total of 20 pectinesterase (PE)-related genes were identified by sequencing analysis. The data analysis and quantitative polymerase chain reaction results confirmed that cell wall modifying enzyme genes played an important role in softening and senescence after harvesting, which may reduce or induce the expression of certain genes affecting cell wall metabolism. Ozone treatment not only regulates active genes such as xyloglucan endo glycosyltransferase/hydrolase, cellulose synthase, polygalacturonase, and PE to maintain the quality of fruit after harvest but also acts synergically with cell wall modifying enzymes to inhibit the degradation of cell wall, resulting in changes in the ultrastructure of cell wall, thereby reducing the hardness of kiwifruit. In addition, according to the results of cis-acting elements, cell wall degradation is also related to downstream hormone signaling, especially PE-related genes. These results provide a theoretical basis for studying the mechanism of firmness and cell wall metabolism difference of kiwifruit and also lay a good foundation for further research.
摘要：
猕猴桃采后的成熟和衰老与其经济价值密切相关。转录组分析和生化参数用于研究臭氧处理的猕猴桃基因表达水平的差异和细胞壁代谢的潜在调节，从而调节果实软化和延长采后寿命。与对照组相比,在臭氧处理下，细胞壁修饰酶的活性较低，细胞壁中初级果胶和纤维素的多糖含量较高，可溶性果胶含量较低。同时,臭氧处理延迟了储存过程中细胞壁中间层的降解。通过测序分析鉴定了总共20个果胶酯酶(PE)相关基因。数据分析和定量聚合酶链反应结果证实，细胞壁修饰酶基因在采后软化和衰老中起着重要作用，可以减少或诱导某些影响细胞壁代谢的基因的表达。臭氧处理不仅调节活性基因，如木葡聚糖内切糖基转移酶/水解酶，纤维素合酶，多聚半乳糖醛酸酶，和PE，以保持果实采后的质量，但也与细胞壁修饰酶协同作用，以抑制细胞壁的降解，导致细胞壁超微结构的变化，从而降低猕猴桃的硬度。此外,根据顺式作用元素的结果，细胞壁降解也与下游激素信号有关，尤其是与PE相关的基因。这些结果为研究猕猴桃硬度和细胞壁代谢差异的机理提供了理论依据，也为进一步研究奠定了良好的基础。
