Stress-related proteins are specifically expressed under non-stress conditions in the overwinter buds of the gentian plant Gentiana triflora

• Published in: Breeding Science Vol. 56; no. 1; pp. 39 - 46
• Main Authors: Takahashi, M.(Iwate Univ., Morioka (Japan). Faculty of Agriculture), Hikage, T, Yamashita, T, Saitoh, Y, Endou, M, Tsutsumi, K
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese Society of Breeding 2006; Japan Science and Technology Agency
• Subjects: ACIDE AMINE; AMINO ACIDS; AMINOACIDOS; BUD INITIATION; COLD STRESS; cold tolerance; ESTERASAS; ESTERASE; ESTERASES; ESTRES DE FRIO; GENTIANA; Gentiana triflora; INICIACION DE LA YEMA; INITIATION DU BOURGEON; MUTANT; MUTANTES; MUTANTS; overwinter bud; PROTEINAS; PROTEINE; PROTEINS; RESISTANCE A L'HIVER; RESISTENCIA INVERNAL; STRESS DU AU FROID; stress-related proteins; WINTER HARDINESS; α/β hydrolase
• ISSN: 1344-7610; 1347-3735
• DOI: 10.1270/jsbbs.56.39

The overwinter bud of the gentian plant, Gentiana triflora, is an organ that develops from the basal tuber in late spring and becomes dormant and freezing-tolerant for overwintering. Here, proteins specifically enriched in the overwinter buds were identified using two-dimensional polyacrylamide gel electrophoresis followed by amino acid sequencing. Enriched proteins included those so far identified as stress- and cold-inducible in other plants, i.e., two isoforms of ethylene-induced esterase, a dehydration-induced protein, glyoxalase I, thioredoxin peroxidase, two isoforms of ascorbate peroxidase and a membrane pore protein. Interestingly, the stress-related proteins had already accumulated in the overwinter buds under non-stress conditions in early summer. Accumulation of these proteins was also examined in a mutant gentian, which developed overwinter buds but lacked cold tolerance and died under conditions below 3 deg C. In this mutant, several proteins including one of the putative esterase, enolase and ascorbate peroxidase were absent or greatly decreased. Thus, it appears that these stress-related proteins are expressed under non-stress conditions to aquire cold tolerance before overwintering.