Expression of ethylene biosynthetic and receptor genes in rose floral tissues during ethylene-enhanced flower opening.
Ethylene production, as well as the expression of ethylene biosynthetic (Rh-ACS1-4 and Rh-ACO1) and receptor (Rh-ETR1-5) genes, was determined in five different floral tissues (sepals, petals, stamens, gynoecia, and receptacles) of cut rose (Rosa hybrida cv. Samantha upon treatment with ethylene or the ethylene inhibitor 1-methylcyclopropene (1-MCP). Ethylene-enhanced ethylene production occurred only in gynoecia, petals, and receptacles, with gynoecia showing the greatest enhancement in the early stage of ethylene treatment. However, 1-MCP did not suppress ethylene production in these three tissues. In sepals, ethylene production was highly decreased by ethylene treatment, and increased dramatically by 1-MCP. Ethylene production in stamens remained unchanged after ethylene or 1-MCP treatment. Induction of certain ethylene biosynthetic genes by ethylene in different floral tissues was positively correlated with the ethylene production, and this induction was also not suppressed by 1-MCP. The expression of Rh-ACS2 and Rh-ACS3 was quickly induced by ethylene in gynoecia, but neither Rh-ACS1 nor Rh-ACS4 was induced by ethylene in any of the five tissues. In addition, Rh-ACO1 was induced by ethylene in all floral tissues except sepals. The induced expression of ethylene receptor genes by ethylene was much faster in gynoecia than in petals, and the expression of Rh-ETR3 was strongly suppressed by 1-MCP in all floral tissues. These results indicate that ethylene biosynthesis in gynoecia is regulated developmentally, rather than autocatalytically. The response of rose flowers to ethylene occurs initially in gynoecia, and ethylene may regulate flower opening mainly through the Rh-ETR3 gene in gynoecia.
Xue
Jingqi
J
Department of Ornamental Horticulture, China Agricultural University, Beijing 100094, China.
Li
Yunhui
Y
Tan
Hui
H
Yang
Feng
F
Ma
Nan
N
Gao
Junping
J
D000594:Amino Acid Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways; D003521:Cyclopropanes / Q000494:pharmacology; D005030:Ethylenes / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000494:pharmacology; D035264:Flowers / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008190:Lyases / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018514:Plant Structures / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027826:Rosa / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity
D003521:Cyclopropanes; D005030:Ethylenes; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C083750:ethylene receptors, plant; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase; C412563:1-methylcyclopropene