Pollination-induced ethylene promotes the early phase of pollen tube growth in Petunia inflata.
In Petunia inflata, a species with gametophytic self-incompatibility, pollination triggers two phases of ethylene production by the pistil, the first of which peaks 3 hours after pollination with compatible or incompatible pollen. To investigate the physiological significance of the first phase of ethylene production, pollinated flowers were treated with 2,5-norbornadiene (NBD), an inhibitor of ethylene action. Treatment with NBD reduced pollen tube growth in a dose-dependent manner during the first six hours after pollination; however, pollen tube growth was insensitive to NBD if the treatment was applied 6 hours or more after pollination. Simultaneous application of exogenous ethylene substantially offset the inhibitory effects of NBD in flowers pollinated for 4 hours. Another inhibitor of ethylene action, 1-methylcyclopropene (1-MCP), also produced a strong inhibition of pollen tube growth during the first six hours of pollination. The experiments with 1-MCP pretreatment indicate that pistil tissues are the primary target of the pollination-induced ethylene.
Biology Department, Western Washington University, Bellingham, WA 98225, USA.
Margaret J
MJ
Holden
Jerry A
JA
Marty
Anu
A
Singh-Cundy
D046508:Culture Techniques; D003521:Cyclopropanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005030:Ethylenes / Q000096:biosynthesis* / Q000494:pharmacology; D005298:Fertility / Q000187:drug effects / Q000502:physiology; D035264:Flowers / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009636:Norbornanes / Q000494:pharmacology*; D032306:Petunia / Q000187:drug effects / Q000254:growth & development*
D003521:Cyclopropanes; D005030:Ethylenes; D009636:Norbornanes; C036216:ethylene; C412563:1-methylcyclopropene; C048294:2,5-norbornadiene