Assessing the contributions of lateral roots to element uptake in rice using an auxin-related lateral root mutant
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Background and aims
The role of lateral roots in the acquisition of nutrients and contaminants from the soil may vary between mobile and immobile solutes. The aim of the present study was to quantify the contributions of lateral roots to growth and elemental uptake under different conditions.
A lateral rootless mutant of rice (Oryza sativa) with a gain-of-function mutation in OsIAA11 was compared with its wild-type (WT) in hydroponic, pot and field conditions. Three soils varying in the P availability were used in the pot experiment. Synchrotron fast X-ray fluorescence (XRF) was used to map the distribution of trace elements in fresh hydrated roots.
The Osiaa11 mutant grew smaller compared with the WT in all three experiments, especially in the field. The difference was larger in a P-sufficient soil than in P-deficient soils in the pot experiment. Elemental concentrations in the roots and shoots were affected differently by the mutation, depending on the elements and the growth media. The apparent contributions of lateral roots to elemental uptake varied from 2.7 to 82.5% in the hydroponic experiment, from −19.8 to 76.4% in the pot experiment, and from 30 to 76% in the field experiment. In general, the apparent contributions to the uptake of P, Mn, Zn, Cu and As were larger than that for the biomass, whereas for N, S and K the apparent contributions were smaller than or similar to the effect on plant biomass. Synchrotron XRF revealed strong accumulation of Mn, Zn, Cu, As and Se in the lateral roots of the WT.
Lateral roots play an important role in the acquisition of less mobile elements such as P, Mn, Zn, Cu and As, but have relatively small effects on the acquisition of mobile elements such as N, S and K.
KeywordsLateral roots OsIAA11 Auxin signalling pathway Nutrient uptake Rice
This research was supported by the Ministry of Science and Technology of the People’s Republic of China (grant number 2010DFA31080), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and the 111 project (B12009). Part of this research was undertaken on the X-ray fluorescence microscopy beamline at the Australian Synchrotron, Victoria, Australia.
- Barber SA (1984) Soil nutrient bioavailability, a mechanistic approach. Wiley, New YorkGoogle Scholar
- Fukaki H, Okushima Y, Tasaka M (2007) Auxin-mediated lateral root formation in higher plants. Inter Rev Cytol 256:111–137Google Scholar
- Kirkham R, Dunn PA, Kuczewski AJ, Siddons DP, Dodanwela R, Moorhead GF, Ryan CG, De Geronimo G, Beuttenmuller R, Pinelli D (2010) The Maia spectroscopy detector system: engineering for integrated pulse capture, low-latency scanning and real-time processing. AIP Conf Proc 1234:240–243Google Scholar
- Kitomi Y, Inahashi H, Takehisa H, Sato Y, Inukai Y (2012) OsIAA13-mediated auxin signaling is involved in lateral root initiation in rice. Plant Sci 190:116–122Google Scholar
- Kopittke PM, de Jonge M, Menzies NW, Wang P, Donner E, McKenna BA, Paterson D, Howard DL, Lombi E (2012) Examination of the distribution of arsenic in hydrated and fresh cowpea roots using two- and three-dimensional techniques. Plant Physiol 159:1149–1158Google Scholar
- Lombi E, de Jonge MD, Donner E, Ryan CG, Paterson D (2011) Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors. Anal Bioanal Chem 400:1637–1644Google Scholar
- Paterson DJ, Boldeman JW, Cohen DD, Ryan CG (2007) Microspectroscopy beamline at the Australian synchrotron. In: Choi JY, Rah S (eds) The ninth international conference on Synchrotron Radiation Instrumentation (SRI 2006), vol 879. AIP Conf Proc, Daegu, South Korea, pp 864–867Google Scholar
- Ryan CG (2000) Quantitative trace element imaging using PIXE and the nuclear microprobe. Inter J Imaging System Technol 11:219–230Google Scholar
- Ryan CG, Jamieson DN (1993) Dynamic analysis: on-line quantitative PIXE microanalysis and its use in overlap-resolved elemental mapping. Nucl Instr Meth Physics Res B 77:203–214Google Scholar
- Tinker PB, Nye PH (2000) Solute movement in the rhizosphere. Oxford University Press, New YorkGoogle Scholar
- White PJ (2012) Ion uptake mechanisms of individual cells and roots: short-distance transport. In: Marschner P (ed) Marschner’s mineral nutrition of higher plants. Elsevier, Amsterdam, pp 7–47Google Scholar