| Abstract Detail
Conference Wide Jones, Matthew [1], Thompson, Andrew [2], Taylor, Ian [3]. Genetic manipulation of ABA biosynthesis in roots of the Solanaceae. THE plant hormone abscisic acid (ABA) regulates many aspects of plant development and mediates physiological responses to environmental stresses, particularly drought and salinity. ABA is synthesised from the breakdown of carotenoids, which are themselves produced from universal isoprenoid precursors. Our aim is to increase pathway flux to ABA in the roots and to enhance root-sourced ABA signals to the leaves. This project investigates the impact of the over expression of several genes from this pathway in tomato (Solanum lycopersicum) and tobacco (Nicotiana tobacum) roots. The three different genes to be overexpressed encode deoxy-D-xylulose phosphate synthase (LeDXS1), phytoene synthase (LePSY1) and 9-cis-epoxycarotenoid dioxygenase (LeNCED1). The latter has been well studied previously, and is rate-limiting for ABA biosynthesis in leaves where large pools of carotenoid precursors are present. Over-expression of LeNCED1 alone has a moderate effect on root ABA biosynthesis, presumably because carotenoid precursor supply becomes limiting in roots. We have isolated a novel root-specific tomato promoter for use in root-specific up-regulation of carotenoid and ABA pathways. Tomato plants constitutively expressing NCED have been re-transformed with LePSY1 under the control of both a constitutive promoter and the root specific promoter, and the effects on carotenoid and ABA content of roots will be discussed. In tobacco, a tetracycline-inducible system is being used. Plants have been produced that show inducible expression of both LeDXS2 and LeNCED1, and these will be used to further investigate the rate-limiting steps for ABA synthesis in roots.
Log in to add this item to your schedule
1 - University of Warwick, Warwick HRI, Wellesbourne, CV35 9EF, United Kindom
2 - Wariwck HRI, University of Warwick, Wellesbourne, Warwickshire, CV35 9EF, Uniket Kingdom
3 - Plant Science Division, School of BioSciences, The University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire, LE12 5RD, United Kingdom
Keywords:
ABA
Abscisic acid
guttation
carotenoid
tetracycline-inducible expression
water-use efficiency.
Session: Poster-136
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:342 |
