Auxin response factor 2 (ARF2) plays a major role in regulating auxin-mediated leaf longevity
SCIE
SCOPUS
- Title
- Auxin response factor 2 (ARF2) plays a major role in regulating auxin-mediated leaf longevity
- Authors
- Lim, PO; Lee, IC; Kim, J; Kim, HJ; Ryu, JS; Woo, HR; Nam, HG
- Date Issued
- 2010-03
- Publisher
- OXFORD UNIV PRESS
- Abstract
- Auxin regulates a variety of physiological and developmental processes in plants. Although auxin acts as a suppressor of leaf senescence, its exact role in this respect has not been clearly defined, aside from circumstantial evidence. It was found here that ARF2 functions in the auxin-mediated control of Arabidopsis leaf longevity, as discovered by screening EMS mutant pools for a delayed leaf senescence phenotype. Two allelic mutations, ore14-1 and 14-2, caused a highly significant delay in all senescence parameters examined, including chlorophyll content, the photochemical efficiency of photosystem II, membrane ion leakage, and the expression of senescence-associated genes. A delay of senescence symptoms was also observed under various senescence-accelerating conditions, where detached leaves were treated with darkness, phytohormones, or oxidative stress. These results indicate that the gene defined by these mutations might be a key regulatory genetic component controlling functional leaf senescence. Map-based cloning of ORE14 revealed that it encodes ARF2, a member of the auxin response factor (ARF) protein family, which modulates early auxin-induced gene expression in plants. The ore14/arf2 mutation also conferred an increased sensitivity to exogenous auxin in hypocotyl growth inhibition, thereby demonstrating that ARF2 is a repressor of auxin signalling. Therefore, the ore14/arf2 lesion appears to cause reduced repression of auxin signalling with increased auxin sensitivity, leading to delayed senescence. Altogether, our data suggest that ARF2 positively regulates leaf senescence in Arabidopsis.
- Keywords
- Ageing; Arabidopsis; ARF2; auxin; leaf longevity; leaf senescence; SENESCENCE-ASSOCIATED GENES; ARABIDOPSIS-THALIANA; OXIDATIVE STRESS; TRANSCRIPTION; EXPRESSION; PATHWAYS; PROTEIN; IDENTIFICATION; CYTOKININ; AUX/IAA
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/26337
- DOI
- 10.1093/JXB/ERQ010
- ISSN
- 0022-0957
- Article Type
- Article
- Citation
- JOURNAL OF EXPERIMENTAL BOTANY, vol. 61, no. 5, page. 1419 - 1430, 2010-03
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