Difference between revisions of "IC4R006-Microarray-2014-24913626"
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==The Background of This Project== | ==The Background of This Project== | ||
* Root growth into hypoxic or anoxic waterlogged substrates relies on internal diffusion of oxygen (Armstrong, 1979). The roots of waterlogging-tolerant species, such as rice (Oryza sativa), typically contain a large volume of aerenchyma. The aerenchyma provides a low-resistance pathway for diffusion of oxygen from the shoot base to the root tip (Armstrong, 1979). The roots of some wetland species, including rice, also possess a barrier to radial oxygen loss (ROL) within the basal zones (Armstrong, 1971; Visser et al., 2000; Colmer, 2003a; Garthwaite et al., 2003; Garthwaite et al., 2008; Abiko et al., 2012), so that ROL occurs predominately from short lateral roots (Armstrong and Armstrong, 2005) and the apical few centimetres of the main axes of adventitious roots (Fig. 1A). A barrier to ROL prevents loss of oxygen from the basal part of roots, which can enhance oxygen transport via the aerenchyma to the root tip. In the roots with an ROL barrier, oxygen at the root tip can be maintained at a higher level to allow root elongation into hypoxic/anoxic soil. The barrier might also impede entry of phytotoxins from chemically reduced water- logged soil. | * Root growth into hypoxic or anoxic waterlogged substrates relies on internal diffusion of oxygen (Armstrong, 1979). The roots of waterlogging-tolerant species, such as rice (Oryza sativa), typically contain a large volume of aerenchyma. The aerenchyma provides a low-resistance pathway for diffusion of oxygen from the shoot base to the root tip (Armstrong, 1979). The roots of some wetland species, including rice, also possess a barrier to radial oxygen loss (ROL) within the basal zones (Armstrong, 1971; Visser et al., 2000; Colmer, 2003a; Garthwaite et al., 2003; Garthwaite et al., 2008; Abiko et al., 2012), so that ROL occurs predominately from short lateral roots (Armstrong and Armstrong, 2005) and the apical few centimetres of the main axes of adventitious roots (Fig. 1A). A barrier to ROL prevents loss of oxygen from the basal part of roots, which can enhance oxygen transport via the aerenchyma to the root tip. In the roots with an ROL barrier, oxygen at the root tip can be maintained at a higher level to allow root elongation into hypoxic/anoxic soil. The barrier might also impede entry of phytotoxins from chemically reduced water- logged soil. | ||
| + | * Another key feature contributing to waterlogging tolerance is aerenchyma formation. In rice roots, aerenchyma is formed constitutively, but the amount can be enhanced by soil water-logging (Armstrong, 1971; Pradhan et al., 1973; Jackson and Armstrong, 1999), low oxygen (Colmer et al., 2006), and ethylene (Justin and Armstrong, 1991; Colmer et al., 2006). On the other hand, the barrier to ROL is inducible in rice roots, forming in stagnant or waterlogged conditions, but not (or only weakly) in well-drained or aerated conditions (Colmer et al., 1998; Colmer, 2003a; Colmer et al., 2006; Insalud et al., 2006; Kotula et al., 2009; Shiono et al., 2011). Interestingly, low oxygen, ethylene, and elevated CO 2 , which arise from natural waterlogged soil, are not involved in triggering for- mation of the barrier to ROL in roots of rice (Colmer et al., 2006). | ||
| + | * The signal that triggers formation of the barrier to ROL is not known yet, but it may involve root exudates, cellular degradation products (Armstrong and Armstrong, 2001; Voesenek and Sasidharan, 2013) or phytotoxins present in chemically reduced waterlogged soils (e.g. Fe 2+ , sulphide, and microbial metabolites; Armstrong, 1979; Armstrong and Armstrong, 2005; Mongon et al., 2014). Aerenchyma and the barrier to ROL in roots are regarded as key features contrib- uting to long-distance oxygen transport and waterlogging tolerance in many wetland species (Armstrong, 1979; Jackson and Drew, 1984; Justin and Armstrong, 1987; Colmer, 2003b; Colmer and Voesenek, 2009; Nishiuchi et al., 2012). However, the molecular mechanism of ROL barrier formation is poorly understood (Shiono et al., 2008). | ||
== Labs working on this Project == | == Labs working on this Project == | ||
Revision as of 09:10, 22 June 2016
Contents
Project Title
Microarray analysis of laser-microdissected tissues indicates the biosynthesis of suberin in the outer part of roots during formation of a barrier to radial oxygen loss in rice (Oryza sativa)
The Background of This Project
- Root growth into hypoxic or anoxic waterlogged substrates relies on internal diffusion of oxygen (Armstrong, 1979). The roots of waterlogging-tolerant species, such as rice (Oryza sativa), typically contain a large volume of aerenchyma. The aerenchyma provides a low-resistance pathway for diffusion of oxygen from the shoot base to the root tip (Armstrong, 1979). The roots of some wetland species, including rice, also possess a barrier to radial oxygen loss (ROL) within the basal zones (Armstrong, 1971; Visser et al., 2000; Colmer, 2003a; Garthwaite et al., 2003; Garthwaite et al., 2008; Abiko et al., 2012), so that ROL occurs predominately from short lateral roots (Armstrong and Armstrong, 2005) and the apical few centimetres of the main axes of adventitious roots (Fig. 1A). A barrier to ROL prevents loss of oxygen from the basal part of roots, which can enhance oxygen transport via the aerenchyma to the root tip. In the roots with an ROL barrier, oxygen at the root tip can be maintained at a higher level to allow root elongation into hypoxic/anoxic soil. The barrier might also impede entry of phytotoxins from chemically reduced water- logged soil.
- Another key feature contributing to waterlogging tolerance is aerenchyma formation. In rice roots, aerenchyma is formed constitutively, but the amount can be enhanced by soil water-logging (Armstrong, 1971; Pradhan et al., 1973; Jackson and Armstrong, 1999), low oxygen (Colmer et al., 2006), and ethylene (Justin and Armstrong, 1991; Colmer et al., 2006). On the other hand, the barrier to ROL is inducible in rice roots, forming in stagnant or waterlogged conditions, but not (or only weakly) in well-drained or aerated conditions (Colmer et al., 1998; Colmer, 2003a; Colmer et al., 2006; Insalud et al., 2006; Kotula et al., 2009; Shiono et al., 2011). Interestingly, low oxygen, ethylene, and elevated CO 2 , which arise from natural waterlogged soil, are not involved in triggering for- mation of the barrier to ROL in roots of rice (Colmer et al., 2006).
- The signal that triggers formation of the barrier to ROL is not known yet, but it may involve root exudates, cellular degradation products (Armstrong and Armstrong, 2001; Voesenek and Sasidharan, 2013) or phytotoxins present in chemically reduced waterlogged soils (e.g. Fe 2+ , sulphide, and microbial metabolites; Armstrong, 1979; Armstrong and Armstrong, 2005; Mongon et al., 2014). Aerenchyma and the barrier to ROL in roots are regarded as key features contrib- uting to long-distance oxygen transport and waterlogging tolerance in many wetland species (Armstrong, 1979; Jackson and Drew, 1984; Justin and Armstrong, 1987; Colmer, 2003b; Colmer and Voesenek, 2009; Nishiuchi et al., 2012). However, the molecular mechanism of ROL barrier formation is poorly understood (Shiono et al., 2008).
Labs working on this Project
- Department of Bioscience, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjyojima, Eiheiji, Fukui 910-1195, Japan.
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
- Graduate School of Agriculture and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan.
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore.
- School of Plant Biology and Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
- National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
- Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, 1–308 Nonoichimachi, Ishikawa 921-8836, Japan.
Corresponding Author
Katsuhiro Shiono (email: shionok@fpu.ac.jp ) & Mikio Nakazono (email:nakazono@agr.nagoya-u.ac.jp)
