title: Low-temperature-modulated fruit ripening is independent of ethylene in 'Sanuki Gold' kiwifruit.
abstract: Fruit ripening in response to treatments with propylene, 1-methycyclopropene (1-MCP), and low temperature was characterized in 'Sanuki Gold' kiwifruit, Actinidia chinensis Planch. Propylene treatment immediately induced rapid fruit softening, increased AC-PG (polygalacturonase) and AC-EXP (expansin) mRNA accumulation, and stimulated an increase in the soluble solid concentration (SSC) and a decrease in titratable acidity (TA). After 3 d exposure to propylene, ethylene production and AC-PL (pectate lyase) mRNA accumulation were observed. 1-MCP treatment after 24 h exposure to propylene eliminated AC-PG mRNA accumulation and suppressed continued changes in SSC and TA. Application of 1-MCP at the start of the treatment, followed by continuous propylene exposure, markedly delayed fruit softening, and the expression of the cell wall-modifying genes, and changes in the SSC and TA, indicating that kiwifruit become insensitive to ethylene at least for 3 d following 1-MCP exposure. Surprisingly, significant fruit softening, mRNA accumulation of AC-PG, AC-PL, and AC-EXP, and decreased TA were observed without ethylene production in intact fruit stored at low temperature for 1 month, but not in fruit stored at room temperature. Repeated 1-MCP treatments (twice a week) failed to inhibit the changes that occurred in low temperature storage. These observations indicate that low temperature modulates the ripening of kiwifruit in an ethylene-independent manner, suggesting that kiwifruit ripening is inducible by either ethylene or low temperature signals.
authors: Laboratory of Postharvest Agriculture, Faculty of Agriculture, Okayama University, Tsushima, Okayama, 700-8530, Japan.
authors: Eric G
authors: EG
authors: Mworia
authors: Takashi
authors: T
authors: Yoshikawa
authors: Nadiah
authors: N
authors: Salikon
authors: Chisato
authors: C
authors: Oda
authors: William O
authors: WO
authors: Asiche
authors: Naoki
authors: N
authors: Yokotani
authors: Daigo
authors: D
authors: Abe
authors: Koichiro
authors: K
authors: Ushijima
authors: Ryohei
authors: R
authors: Nakano
authors: Yasutaka
authors: Y
authors: Kubo
mesh_terms: D029042:Actinidia / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D000475:Alkenes / Q000494:pharmacology; D003080:Cold Temperature; D003521:Cyclopropanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D005030:Ethylenes / Q000032:analysis / Q000378:metabolism*; D005638:Fruit / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics; D011096:Polygalacturonase / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D000475:Alkenes; D003521:Cyclopropanes; D018076:DNA, Complementary; D005030:Ethylenes; D010940:Plant Proteins; D012333:RNA, Messenger; C095825:expansin protein, plant; C036216:ethylene; C013658:propylene; D011096:Polygalacturonase