บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Expression analysis of genes encoding cell wall modifying enzymes during the postharvest period in fig fruit (Ficus carica cv. masui dauphine)

Willis Omondi Owino, Hideki Yuge, Ryohei Nakano, Yasutaka Kubo and Akitsugu Inaba

Acta Hort. (ISHS) 632:265-269

2002

บทคัดย่อ

Expression Analysis of Genes Encodeing Cell Wall Modifying Enzymes During The Postharvest Period in Fig Fruit (Ficus Carica cv. Masui Dauphine)

The fig fruit undergoes simultaneous ripening and increase in fruit size during its final stage of maturation. In an effort to understand the molecular basis of postharvest softening in figs, we isolated cDNAs responsible for cell wall expansion and disasembly, basically two cDNAs encoding two divergent Endo-1, 4-b-glucanases (FC-Cel2, respectively) and two cDNAs encoding xyloglucan endotransglycosylase (FC-XET1) and FC-XET1 and FC-XET2 exist as single copy genes, while FC-Cel2 exists as a two-copy gene in the fig fruit genome. Northern analysis showed that FC-Cel1 mRNA accumulated in the control fruit at harvest but gradually decreased to undetectable levels.FC-Cel1 mRNA accumulation was induced by propylene, however the stimulated expression was observed only after 24 h propylene exposure, but later declined to undetectable levels. FC-Cel1 mRNA accumulation was completely inhibited by 1-MCP, in dicating that this gene is positively regulated by ethylene. FC-Cel2 mRNA accumulation increased gradually from the day of harvest and high level accumulation was observed at the later stages of softening in both control and treated frutis. FC-Cel2 mRNA was unaffedted by either 1-MCP or propylene indicating that this gene is ethylene-idenpendent. FC-XET1 mRNA accumulation was only detected in the 1-MCP treated fruit suggesting that this gene is negatively regulated by ethylene. Low level accumulation of FC-XET2 was detected at the later stages of softening in all treatments even though relatively high level accumualtion of FC-XET2 was detected in the 1-MCP treated fruit. The overlapping expression and differential regulation by ethylene suggest that the Endo-1, 4-b-glucanases and the xyloglucan endotransglycosylases operate in a coordinate manner in the hemicellulose network during postharvest softening in fig fruit.