Polyphenol oxidase in potato. A multigene family that exhibits differential expression patterns.

AUTOR(ES)

Thygesen, P W

RESUMO

Polyphenol oxidase (PPO) activity in potato (Solanum tuberosum) plants was high in stolons, tubers, roots, and flowers but low in leaves and stems. PPO activity per tuber continued to increase throughout tuber development but was highest on a fresh weight basis in developing tubers. PPO activity was greatest at the tuber exterior, including the skin and cortex tissue 1 to 2 mm beneath the skin. Flowers had high PPO activity throughout development, particularly in the anthers and ovary. Five distinct cDNA clones encoding PPO were isolated from developing tuber RNA. POT32 was the major form expressed in tubers and was found in all parts of the tuber and at all stages of tuber development. It was also expressed in roots but not in photosynthetic tissues. POT33 was expressed in tubers but mainly in the tissue near the skin. POT72 was detected in roots and at low levels in developing tubers. NOR333 was identical with the P2 PPO clone previously isolated from potato leaves (M.D. Hunt, N.T. Eannetta, Y. Haifeng, S.M. Newman, J.C. Steffens [1993] Plant Mol Biol 21: 59-68) and was detected in young leaves and in tissue near the tuber skin but was highly expressed in flowers. The results indicate that PPO is present as a small multigene family in potato and that each gene has a specific temporal and spatial pattern of expression.

Documentos Relacionados

• Differential expression of the multigene family encoding the soybean mitochondrial alternative oxidase.
• Differential Expression and Turnover of the Tomato Polyphenol Oxidase Gene Family during Vegetative and Reproductive Development.
• Expression patterns and promoter activity of the cold-regulated gene ci21A of potato.
• Tomato Polyphenol Oxidase (Differential Response of the Polyphenol Oxidase F Promoter to Injuries and Wound Signals).
• Spatial and temporal patterns of transcription of a wound-induced gene in potato.