JXB Advance Access originally published online on March 29, 2005
Journal of Experimental Botany 2005 56(415):1397-1407; doi:10.1093/jxb/eri141
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Published by Oxford University Press [2005] on behalf of the Society for Experimental Biology.
RESEARCH PAPER |
Regulation of flooding tolerance of SAG12:ipt Arabidopsis plants by cytokinin
1Department of Horticulture and Crop Science, Ohio State University, Columbus, OH 43210, USA
2USDA-ARS-Soil Drainage Research Units, Columbus, OH 43210, USA
3USDA-ARS National Forage Seed Production Research Center, Corvallis, OR 97331, USA
* To whom correspondence should be addressed. Fax: +1 301 838 0208. E-mail: tvantoai{at}tigr.org
A SAG12:ipt gene construct, which increases cytokinin biosynthesis in response to senescence, was introduced into Arabidopsis plants to delay senescence induced by flooding stress. Two forms of flooding stress, including total submergence and root waterlogging, were applied to SAG12:ipt (IPT) and wild-type (WT) plants for 1, 3, and 5 d. A separate experiment compared the recovery of WT and IPT plants subjected to flooding stress. Biomass accumulation, carbohydrate and chlorophyll contents, and cytokinin and abscisic acid were quantified to compare genotypic responses to flooding stress and post-flooding recovery. Real-time RT-PCR studies were performed to quantify ipt and SAG12 gene expression. IPT plants exposed to waterlogging accumulated greater quantities of cytokinins more rapidly than WT plants or those exposed to total submergence. Cytokinin accumulation was accompanied by phenotypic adaptations, including chlorophyll retention and increased biomass and carbohydrate content relative to WT plants. Abscisic acid accumulated rapidly in WT and IPT plants under waterlogging stress but remained low in all genotypes exposed to total submergence. IPT plants showed improved recovery after waterlogging stress was removed. Expression of ipt in submerged plants did not result in cytokinin accumulation until submergence stress was removed. At that point, IPT plants accumulated greater quantities of cytokinin and recovered to a greater extent than WT plants. This study established the relationship between flooding tolerance and cytokinin accumulation in IPT plants and suggested that translation of ipt transcripts and subsequent cytokinin accumulation were delayed under submergence stress.
Key words: Abiotic stress, abscisic acid, cytokinin, ipt gene, real-time RT-PCR, SAG12 gene, submergence, waterlogging
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  B. Sykorova, G. Kuresova, S. Daskalova, M. Trckova, K. Hoyerova, I. Raimanova, V. Motyka, A. Travnickova, M. C. Elliott, and M. Kaminek Senescence-induced ectopic expression of the A. tumefaciens ipt gene in wheat delays leaf senescence, increases cytokinin content, nitrate influx, and nitrate reductase activity, but does not affect grain yield J. Exp. Bot., February 10, 2008; (2008) erm319v1. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H. Kingston-Smith, T. E. Davies, J. E. Edwards, and M. K. Theodorou From plants to animals; the role of plant cell death in ruminant herbivores J. Exp. Bot., February 4, 2008; (2008) erm326v1. [Abstract] [Full Text] [PDF]
|
|