title: Effect of nitric oxide on ethylene synthesis and softening of banana fruit slice during ripening.
abstract: The effects of nitric oxide (NO) on ethylene synthesis and softening of ripening-initiated banana slice were investigated. Fruit firmness, color, and contents of starch and acid-soluble pectin (ASP) were measured. In addition, ethylene production, 1-aminocyclopropane-1-carboxylic acid (ACC) content, expression and activities of ACC synthase (ACS) and ACC oxidase (ACO), and activities of cell-wall-modifying enzymes, polygalacturonase (PG), pectin methylesterase (PME), and endo-beta-1,4-glucanase, were analyzed. Application of NO reduced ethylene production, inhibited degreening of the peel and delayed softening of the pulp. The decrease of ethylene production was associated with the reduction in the activity of ACO and the expression of the MA-ACO1 gene. Moreover, the NO-treated fruit showed a lower expression of the MA-ACS1 gene but higher ACS activity and ACC content. In addition, NO treatment decreased the activities of PG, PME, and endo-beta-1,4-glucanase and maintained higher contents of ASP and starch, which may account for the delay of softening. We proposed that the inhibition of ACO activity and transcription of gene MA-ACO1 by NO resulted in decreased ethylene synthesis and the delay of ripening of banana slice.
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, People's Republic of China.
authors.forename: Guiping
authors.initials: G
authors.lastname: Cheng
authors.forename: En
authors.initials: E
authors.lastname: Yang
authors.forename: Wangjin
authors.initials: W
authors.lastname: Lu
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Jia
authors.forename: Yueming
authors.initials: Y
authors.lastname: Jiang
authors.forename: Xuewu
authors.initials: X
authors.lastname: Duan
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005030:Ethylenes / Q000096:biosynthesis*; D005638:Fruit / Q000737:chemistry / Q000254:growth & development* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D008190:Lyases / Q000235:genetics / Q000378:metabolism; D028521:Musa; D009569:Nitric Oxide / Q000494:pharmacology*; D010368:Pectins / Q000032:analysis; D013213:Starch / Q000032:analysis
chemical_list: D004791:Enzyme Inhibitors; D005030:Ethylenes; D009569:Nitric Oxide; D010368:Pectins; D013213:Starch; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase