Response to zinc deficiency of two rice lines with contrasting tolerance is determined by root growth maintenance and organic acid exudation rates, and not by zinc-transporter activity
Widodo, , Broadley, Martin R., Rose, Terry, Frei, Michael, Pariasca-Tanaka, Juan, Yoshihashi, Tadashi, Thomson, M. (Mike), Hammond, John P., Aprile, Alessio, Close, Timothy James, Ismail, Abdelbagi M. and Wissuwa, Matthias. (2010) Response to zinc deficiency of two rice lines with contrasting tolerance is determined by root growth maintenance and organic acid exudation rates, and not by zinc-transporter activity. New Phytologist, Vol.186 (No.2). pp. 400-414. ISSN 0028-646XFull text not available from this repository.
Official URL: http://dx.doi.org/10.1111/j.1469-8137.2009.03177.x
Zinc (Zn)-deficient soils constrain rice (Oryza sativa) production and cause Zn malnutrition. The identification of Zn-deficiency-tolerant rice lines indicates that breeding might overcome these constraints. Here, we seek to identify processes underlying Zn-deficiency tolerance in rice at the physiological and transcriptional levels.
A Zn-deficiency-tolerant line RIL46 acquires Zn more efficiently and produces more biomass than its nontolerant maternal line (IR74) at low [Zn](ext) under field conditions. We tested if this was the result of increased expression of Zn2+ transporters; increased root exudation of deoxymugineic acid (DMA) or low-molecular-weight organic acids (LMWOAs); and/or increased root production. Experiments were performed in field and controlled environment conditions.
There was little genotypic variation in transcript abundance of Zn-responsive root Zn2+-transporters between the RIL46 and IR74. However, root exudation of DMA and LMWOA was greater in RIL46, coinciding with increased root expression of putative ligand-efflux genes. Adventitious root production was maintained in RIL46 at low [Zn](ext), correlating with altered expression of root-specific auxin-responsive genes.
Zinc-deficiency tolerance in RIL46 is most likely the result of maintenance of root growth, increased efflux of Zn ligands, and increased uptake of Zn-ligand complexes at low [Zn](ext); these traits are potential breeding targets.
|Item Type:||Journal Article|
|Subjects:||Q Science > QK Botany
S Agriculture > SB Plant culture
|Divisions:||Faculty of Science > Life Sciences (2010- )
Faculty of Science > Life Sciences (2010- ) > Warwick HRI (2004-2010)
|Library of Congress Subject Headings (LCSH):||Rice -- Research, Rice -- Genetics, Plants -- Effect of zinc on, Rice -- Roots -- Growth, Exudation (Botany)|
|Journal or Publication Title:||New Phytologist|
|Publisher:||Wiley-Blackwell Publishing Ltd.|
|Official Date:||April 2010|
|Number of Pages:||15|
|Page Range:||pp. 400-414|
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