采后嘎拉苹果果实细胞壁代谢及关键酶基因表达特性研究

以嘎拉苹果为试材,研究其果实细胞壁代谢及关键酶基因表达特性及受1-MCP、乙烯利和低温的影响效应。结果表明,常温下,嘎拉果实硬度变化与WSP显著正相关,与CSP和半纤维素显著负相关,与ISP的关系不大;1-MCP和低温处理显著抑制了WSP含量上升,减缓了CSP和半纤维素降解。嘎拉果实细胞壁酶中,β-Gal活性最高、增加最快,其基因表达亦迅速增加,α-L-Af活性和基因表达虽增加速率低于β-Gal,但二者变化规律相似,均显著受到1-MCP和0℃低温的抑制;PG和PME活性和基因表达量亦呈增加趋势,但未能完全被1-MCP处理和0℃低温所抑制;相关性分析表明,其细胞壁酶活性变化均与硬度呈显著负相关性,并显著受到1-MCP和低温的影响。但是,乙烯利处理虽对嘎拉果实软化有一定的促进作用,但效果不显著。

The Characteristics of Cell Wall Metabolism and Key Enzyme Genes Expression in Postharvest Gala Apple Fruit

Fruit of apple(Malus domestica Borkh.cv.Gala) was used to analyses cell wall metabolism and the related enzymes gene expression and the regulation by 1-MCP,ethephon and cold storage.The results indicated that fruit firmness had significantly correlated with cell wall components,which was positive to WSP and negative to CSP and hemi-cellulose,but little relationship with ISP during fruit softening in Gala apple.Both 1-MCP treatment and cold storage significantly inhibited the increase in WSP content,prevented CSP and hemi-cellulose from degradation.Among the cell wall enzymes,β-Gal activity was the highest and rapidly increased,and its gene expression also sharply enhanced during fruit softening.Although the increase rate in α-L-Af was no more than β-Gal,both two enzymes had a similar trend in activity and gene expression and strongly inhibited by 1-MCP treatment and cold storage.However,PG and PME activity and gene expression could not be completely inhibited by 1-MCP treatment and cold storage though they were showed an increase trend.The cell wall enzyme activity had significant negative correlation with fruit softening in Gala apple,and their correlation was dramatically affected by 1-MCP and low temperature.Otherwise,the promotion by ethephon treatment was no more than the inhibition by 1-MCP treatment and cold storage in cell wall enzymes activity and gene expression in Gala apple fruit.