A GH3-like gene, CcGH3, isolated from Capsicum chinense L. fruit is regulated by auxin and ethylene.
Auxin, which has been implicated in multiple biochemical and physiological processes, elicits three classes of genes (Aux/IAAs, SAURs and GH3s) that have been characterized by their early or primary responses to the hormone. A new GH3-like gene was identified from a suppressive subtraction hybridization (SSH) library of pungent pepper (Capsicum chinense L.) cDNAs. This gene, CcGH3, possessed several auxin- and ethylene-inducible elements in the putative promoter region. Upon further investigation, CcGH3 was shown to be auxin-inducible in shoots, flower buds, sepals, petals and most notably ripening and mature pericarp and placenta. Paradoxically, this gene was expressed in fruit when auxin levels were decreasing, consistent with ethylene-inducibility. Further experiments demonstrated that CcGH3 was induced by endogenous ethylene, and that transcript accumulation was inhibited by 1-methylcyclopropene, an inhibitor of ethylene perception. When over-expressed in tomato, CcGH3 hastened ripening of ethylene-treated fruit. These results implicate CcGH3 as a factor in auxin and ethylene regulation of fruit ripening and suggest that it may be a point of intersection in the signaling by these two hormones.
Liu
Kede
K
National Key Laboratory of Crop Genetic Improvement, Huazhong Agriculture University, 430070, Wuhan, Hubei Province, China.
Kang
Byoung-Cheorl
BC
Jiang
Hui
H
Moore
Shanna L
SL
Li
Hanxia
H
Watkins
Christopher B
CB
Setter
Tim L
TL
Jahn
Molly M
MM
D017360:Arabidopsis / Q000235:genetics; D015152:Blotting, Northern; D002212:Capsicum / Q000235:genetics* / Q000378:metabolism; D003521:Cyclopropanes / Q000494:pharmacology; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005030:Ethylenes / Q000494:pharmacology*; D005638:Fruit / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000235:genetics; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization / Q000379:methods; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D024363:Transcription Initiation Site; D014162:Transfection
D003521:Cyclopropanes; D018076:DNA, Complementary; D005030:Ethylenes; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C105498:1-methylcyclopropane; C036216:ethylene; D005966:Glucuronidase