Exogenous ethylene influences flower opening of cut roses (Rosa hybrida) by regulating the genes encoding ethylene biosynthesis enzymes.
The purpose of this paper is to investigate the differential responses of flower opening to ethylene in two cut rose cultivars, 'Samantha', whose opening process is promoted, and 'Kardinal', whose opening process is inhibited by ethylene. Ethylene production and 1-aminocyclopropane-1-carboxylate (ACC) synthase and oxidase activities were determined first. After ethylene treatment, ethylene production, ACC synthase (ACS) and ACC oxidase (ACO) activities in petals increased and peaked at the earlier stage (stage 3) in 'Samantha', and they were much more dramatically enhanced and peaked at the later stage (stage 4) in 'Kardinal' than control during vasing. cDNA fragments of three Rh-ACSs and one Rh-ACO genes were cloned and designated as Rh-ACS1, Rh-ACS2, Rh-ACS3 and Rh-ACO1 respectively. Northern blotting analysis revealed that, among three genes of ACS, ethylene-in- duced expression patterns of Rh-ACS3 gene corresponded to ACS activity and ethylene production in both cultivars. A more dramatic accumulation of Rh-ACS3 mRNA was induced by ethylene in 'Kardinal' than that of 'Samantha'. As an ethylene action inhibitor, STS at concentration of 0.2 mmol/L generally inhibited the expression of Rh-ACSs and Rh-ACO in both cultivars, although it induced the expression of Rh-ACS3 transiently in 'Kardinal'. Our results suggests that 'Kardinal' is more sensitive to ethylene than 'Samantha'; and the changes of Rh-ACS3 expression caused by ethylene might be related to the acceleration of flower opening in 'Samantha' and the inhibition in 'Kardinal'. Additional results indicated that three Rh-ACSs genes were differentially associated with flower opening and senescence as well as wounding
Ma
Nan
N
Department of Ornamental Horticulture and Landscape Architecture, China Agricultural University, Beijing 100094, China.
Cai
Lei
L
Lu
Wangjin
W
Tan
Hui
H
Gao
Junping
J
D000594:Amino Acid Oxidoreductases / Q000096:biosynthesis / Q000235:genetics*; D005030:Ethylenes / Q000096:biosynthesis* / Q000494:pharmacology; D035263:Flowering Tops / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D035264:Flowers / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006131:Growth Inhibitors / Q000096:biosynthesis* / Q000502:physiology; D008190:Lyases / Q000096:biosynthesis / Q000235:genetics*; D005810:Multigene Family; D010937:Plant Growth Regulators / Q000096:biosynthesis / Q000502:physiology*; D027826:Rosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D013045:Species Specificity; D013885:Thiosulfates / Q000494:pharmacology
D005030:Ethylenes; D006131:Growth Inhibitors; D010937:Plant Growth Regulators; D013885:Thiosulfates; C095213:silver thiosulfate; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase