| 1 | Author
| J.Christopher Hall, M. Ira Soni | Requires cookie* | | Title
| Antagonism by Clopyralid of Picloram-Induced Ethylene Biosynthesis in Rapeseed Plants  | | | Abstract
| The effect o f clopyralid pretreatment (500 g/ha) on picloram-induced ethylene, ACC (1-am inocyclopropane-l-carboxylic acid), and M ACC [l-(m alonylam ino)-cyclopropane-1-carboxylic acid] was measured in rapeseed plants that were treated with 50 or 100 g/ha o f picloram. In contrast to plants that did not receive a clopyralid pretreatment, ethylene biosyn thesis was significantly reduced in plants pretreated with clopyralid prior to picloram. Piclo ram-induced levels o f ACC also were significantly reduced in plants receiving pretreatment with clopyralid. In contrast, there was no difference between the levels o f M ACC in plants that were and were not pretreated with clopyralid. Therefore, the mechanism by which clopyralid pretreatment interferes with picloram-induced synthesis o f both ACC and ethylene may be manifested through the blocking o f de novo synthesis o f ACC synthase normally stimulated by picloram. The lack o f significant difference in M ACC levels between plants that were and were not pretreated with clopyralid precludes the stimulation o f enhanced ACC conversion to MACC as an exclusive mechanism o f clopyralid's antidoting activity. It is likely that the rate o f picloram-induced ACC synthesis by plants receiving pretreatment is within their capacity to convert ACC to M ACC, thereby limiting the substrate available for conversion to ethylene. In contrast, it appears that the extent o f ACC synthesis by plants receiving no pretreatment su persedes their capacity for conversion to M ACC. thereby resulting in greatly enhanced rates o f ethylene evolution and subsequent developm ent o f injury symptoms. | | |
Reference
| Z. Naturforsch. 46c, 957 (1991); received January 30 1991 | | |
Published
| 1991 | | |
Keywords
| Clopyralid, Picloram, Ethylene, Antagonism, Safener | | |
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| default:Reihe_C/46/ZNC-1991-46c-0957.pdf | | | Identifier
| ZNC-1991-46c-0957 | | | Volume
| 46 | |
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