title: Expression of expansin genes in the pulp and the dehiscence zone of ripening durian (Durio zibethinus) fruit.
abstract: Durian (Durio zibethinus) fruit was harvested at the commercially mature stage and stored at 25°C. Durian fruit have 3-5 longitudinal dehiscence zones (DZs) in the peel, which are up to 40cm long and 2cm thick in large fruit. Dehiscence started a week after harvest, was hastened by exogenous ethylene, and delayed by 1-methylcyclopropene (1-MCP), showing that it is regulated by endogenous ethylene. Three genes encoding α-expansins (DzEXP1-3) were isolated. In the expression of these genes increased, prior to dehiscence. Pulp firmness decreased during storage. The decrease was hastened by ethylene and delayed by 1-methylcyclopropene (1-MCP). Exogenous ethylene promoted gene expression of DzEXP1 both in the DZs and in the pulp. It had a smaller effect on DzEXP2 in the zones and pulp, but did not affect DzEXP3 expression. 1-MCP inhibited the expression of DzEXP1 and, somewhat less, of DzEXP2, but did not affect DzEXP3 expression, both in DZs and pulp. It is concluded that the close relationship between expression of DzEXP1 and DzEXP2 and both dehiscence and fruit softening suggests that these genes are involved in both processes.
authors.affiliation: Division of Agriculture Technology, Faculty of Science and Arts, Burapha University, Chanthaburi Campus, Chanthaburi 22170, Thailand.
authors.forename: Yossapol
authors.initials: Y
authors.lastname: Palapol
authors.affiliation: Mahidol University, Amnatcharoen Campus, Amnatcharoen 37000, Thailand.
authors.forename: Sutin
authors.initials: S
authors.lastname: Kunyamee
authors.affiliation: Department of Horticulture, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand.
authors.forename: Monthatip
authors.initials: M
authors.lastname: Thongkhum
authors.affiliation: Department of Horticulture, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand; Postharvest Technology Innovation Center, Commission on Higher Education, Bangkok 10400, Thailand; Academy of Science, The Royal Society of Thailand, Dusit, Bangkok 10300, Thailand. Electronic address: agrsck@ku.ac.th.
authors.forename: Saichol
authors.initials: S
authors.lastname: Ketsa
authors.affiliation: The New Zealand Institute for Plant and Food Research Ltd., Private Bag 92 169, Auckland, New Zealand.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Ferguson
authors.affiliation: Mann Laboratory, Department of Plant Sciences, University of California, Davis, CA 95616, USA.
authors.forename: Wouter G
authors.initials: WG
authors.lastname: van Doorn
mesh_terms: D035161:Bombacaceae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D003521:Cyclopropanes / Q000494:pharmacology; D005030:Ethylenes / Q000494:pharmacology; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D003521:Cyclopropanes; D005030:Ethylenes; D010937:Plant Growth Regulators; D010940:Plant Proteins; C095825:expansin protein, plant; C036216:ethylene; C412563:1-methylcyclopropene
keywords: 1-Methylcyclopropene; Ethylene; Expansin; Ripening; Softening