Ethylene receptor degradation controls the timing of ripening in tomato fruit.
Fruit ripening in tomato requires the coordination of both developmental cues and the phytohormone ethylene. The multigene ethylene receptor family has been shown to negatively regulate ethylene signal transduction and suppress ethylene responses. Here we demonstrate that reduction in the levels of either of two family members, LeETR4 or LeETR6, causes an early-ripening phenotype. We provide evidence that the receptors are rapidly degraded in the presence of ethylene, and that degradation probably occurs through the 26S proteasome-dependent pathway. Ethylene exposure of immature fruits causes a reduction in the amount of receptor protein and earlier ripening. The results are consistent with a model in which receptor levels modulate timing of the onset of fruit ripening by measuring cumulative ethylene exposure.
Kevany
Brian M
BM
Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32611-0690, USA.
Tieman
Denise M
DM
Taylor
Mark G
MG
Cin
Valeriano Dal
VD
Klee
Harry J
HJ
D005030:Ethylenes / Q000378:metabolism*; D005638:Fruit / Q000254:growth & development / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000254:growth & development / Q000378:metabolism*; D005810:Multigene Family; D010940:Plant Proteins / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D016372:RNA, Antisense; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013997:Time Factors
D005030:Ethylenes; D010940:Plant Proteins; D016372:RNA, Antisense; D011956:Receptors, Cell Surface; C083750:ethylene receptors, plant; C036216:ethylene; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease