ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Up-regulation of two cDNA clones encoding metallothionein-like proteins in apple fruit during cool storage.

Reid, S. J.; Ross, G. S.;

Physiologia Plantarum Year: 1997 Vol: 100 Issue: 1 Pages: 183-189 Ref: 32 ref.

1997

บทคัดย่อ

Two independent cold-regulated clones (pAMT1 and pAMT2) were isolated from a cDNA library derived from cool-stored apple cv. Granny Smith fruit. These clones share only 27% amino acid identity with each other, but both show high similarity to plant metallothionein (MT)-like proteins. The polypeptide encoded by pAMT1 shares similarity with type 2 MT-like sequences, while that encoded by pAMT2 is similar to others which share a different distribution of cysteine residues. It is suggested that these form a type 3 group of MT-like clones. Genomic Southern analysis confirmed that there is a family of MT-like genes in apples. There are differing patterns of pAMT1 and pAMT2 expression during apple fruit development. amt1 RNA was abundant in flowers and during the early stages of development, and decreased as the fruit approached maturity, while amt2 RNA was barely detectable in flowers and young fruit and accumulated with fruit development. In ripe fruit, amt1 expression was up-regulated, while amt2 ex

pression was down-regulated. In leaves, both genes showed increased expression with leaf age. In Granny Smith, Cox's Orange Pippin and Braeburn apple cultivars, both genes were up-regulated in cool-stored fruit. In Granny Smith cortical tissue, amt RNA levels were elevated within the first 45 min at both 0.5 and 4 deg C, but not at 12.5 deg C. The different patterns of amt1 and amt2 expression during fruit development and in different tissues suggest that the respective genes have distinct controlling elements and may be functionally different.