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以京白梨为试材,测定贮藏期间果实多聚半乳糖醛酸酶(PG)、糖苷酶(β-Gal、α-L-Af)及脂氧合酶(LOX)活性及其基因表达变化及对1-MCP和低温的响应。结果表明,果实软化呈慢(3d内)、快(3～9d)、慢(9d后)的变化趋势;PG、β-Gal、α-L-Af和LOX活性及其基因表达量均随果实软化呈不同程度增加,且β-Gal和LOX的活性均在果实采收后3d内上升快,其基因的表达量亦迅速增加,由此认为β-Gal和LOX可能在果实软化早期起着更为重要的作用。经1-MCP处理和冷藏后,β-Gal、α-L-Af、LOX和PG的活性及基因表达显著受抑,延缓了果实软化进程,且1-MCP对β-Gal和LOX的抑制作用最强烈,尤其在处理前期。在果实冷藏过程中PG和β-Gal活性基本维持原有水平,其基因表达在贮藏前期受到抑制,LOX活性和基因表达均维持在极低水平,说明LOX对低温较其它酶敏感。因此认为,PG、β-Gal、α-L-Af和LOX均不同程度地参与了京白梨果实的后熟软化,在早期软化阶段β-Gal和LOX可能起着更为重要的作用,1-MCP对β-Gal和LOX活性和基因表达具有更显著的调控作用,而低温可能主要是通过抑制LOX活性和基因表达来抑制果实软化。
The effects of polygalacturonase (PG), glycosidase (β-Gal, α-L-Af) and lipoxygenase (LOX) And response to 1-MCP and hypothermia. The results showed that the fruit softening showed a trend of slow (3d), fast (3 ~ 9d) and slow (9d). The activity and gene expression of PG, β-Gal, The results showed that the β-Gal and LOX activities increased rapidly in the 3d days after harvest, and the expression of β-Gal and LOX also increased rapidly. Therefore, β-Gal and LOX may play a more important role in the early fruit softening For the important role. The activity and gene expression of β-Gal, α-L-Af, LOX and PG were significantly inhibited after 1-MCP treatment and refrigeration, delayed the process of fruit softening, and the inhibitory effect of 1-MCP on β-Gal and LOX The most intense, especially in the pre-treatment. During the fruit freezing process, the activity of PG and β-Gal basically remained the same, and their gene expression was inhibited in the early storage stage. LOX activity and gene expression were kept at extremely low levels, indicating that LOX was more sensitive to hypothermia than other enzymes. Therefore, PG, β-Gal, α-L-Af and LOX are involved in the post-ripening softening of Jingbai pear to varying degrees. Β-Gal and LOX may play a more important role in the early softening stage.1 -MCP has more significant regulation of β-Gal and LOX activity and gene expression, while low temperature may inhibit fruit softening primarily by inhibiting LOX activity and gene expression.