Abstract
Opportunities exist for promoting plant nutrient uptake through genetic manipulation of rhizosphere processes. An assessment of the genotypic differences in plants such as in the excretion of nod-gene inducers by symbiotic legumes, the release of protons and phytosiderophores by crop varieties suffering from iron (Fe) and zinc (Zn) deficiencies, the extrusion of organic acid anions under aluminium (Al) and phosphorus (P) stress, and the release of root border cells and/or enzymes (phosphatases and phytases) concerned with P nutrition, is essential for identifying crop cultivars adapted to low-nutrient conditions. Approaches for creating nutrient-efficient crops suitable for low-nutrient environments include: (1) the screening of adapted landraces for a better understanding of the genetic basis of root exudation, (2) the selection of plants with enhanced symbiotic performance when infected with stem/root nodule bacteria (rhizobia) and/or vesicular arbuscular (VA) mycorrhizae, (3) increased experimentation on ion-channels, transporter genes and the promoters controlling their expression, and (4) the use of molecular markers to select useful plant traits. Additionally, we need to understand the operational relationship of these various genes to other processes involved with mineral nutrition, and to integrate the latter with such whole-plant processes as photosynthesis in order to obtain higher crop yields in low-nutrient environments. But the real challenge with these low-nutrient environments lies in the production of food crops with clinically acceptable levels of nutrients and vitamins that, when consumed by humans, do not cause malnutrition. Breeding for micro-nutrient enriched crops could be one way to produce foods that meet the dietary requirements of human nutrition. This summary presents the tools currently available for manipulating rhizosphere processes and plant genes for increased nutrient uptake and assimilation in low-nutrient environments.
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References
Ae N and Shen R-F 2002 Root cell-wall properties are proposed to contribute to phosphorus (P) mobilization by groundnut and pigeonpea. Plant Soil 245, 95–103.
Brame) P J 2002 Assessing germplasm collections for traits useful in plant nutrition. In Food Security in Nutrient-Stressed Environments: Exploiting Plants’ Genetic Capabilities, Proceedings of an International Workshop, 27–30 September 1999, Patancheru, India. Developments in Plant and Soil Sciences, Volume 95. Ed. J J Adu-Gyamfi. pp 193–200. Kluwer Academic Publishers, Dordrecht, The Netherlands.
Chrispeels M, Crawford N M and Schroeder J 1999 Proteins for transport of water and mineral nutrients across the membranes of plant cells. Plant Cell I I, 661–675.
Dakora F D and Phillips D A 2002 Root exudates as mediators of mineral acquisition in low nutrient environments. Plant Soil 245, 35–47.
Dakora F D, Lawlor D W and Sibuga K P 1999 Assessment of symbiotic nitrogen nutrition in marama bean (Tylosema esculentum L.), a tuber-producing underutilized grain legume. Symbiosis (in press).
Drake B G, Gonzalez-Meler M A and Long S P 1997 More efficient plants: a consequence of rising atmospheric CO2? Annu. Rev. Plant Physiol. Mol. Biol. 48, 609–639.
Dunlop J and Phung T 2002 Transporter genes to enhance nutrient uptake: opportunities and challenges. In Food Security in Nutrient-Stressed Environments: Exploiting Plants’ Genetic Capabilities, Proceedings of an International Workshop, 27–30 September 1999, Patancheru, India. Developments in Plant and Soil Sciences, Volume 95. Ed. J J Adu-Gyamfi. pp 227–234. Kluwer Academic Publishers, Dordrecht, The Netherlands.
Fox T C and Guerinot M L 1998 Molecular biology of cation transport in plants. Ann. Rev. Plant Physiol. Plant Mol. 49, 669–696.
Hawes M C, Brigham L A, Wen F, Woo H H and Zhu Y 1998 Functions of root border cells in plant health: pioneers in the rhizosphere. Ann. Rev. Phytopathol. 36, 311–327.
Hoffland E, van den Boogaard R, Nelemans J and Findenegg G 1992 Biosynthesis and root exudation of citric and malic acids in phosphate-starved rape plants. New Phytol. 122, 675–680.
Johansen C, Subbarao G V, Lee K K and Sharma K K 1995 Genetic manipulation of crop plants to enhance integrated nutrient management in cropping systems — the case of phosphorus. In Genetic Manipulation of Crop Plants to Enhance Integrated Nutrient Management in Cropping Systems — 1. Phosphorus. Eds. C Johansen, K K Lee, K K Sharma, G V Subbarao and E A Kueneman. pp 9–29. International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Andhra Pradesh, India.
Maranville J W and Madhavan S 2002 Physiological adaptations for nitrogen use efficiency in sorghum. Plant Soil 245, 25–34.
Phillips D A 1992 Flavonoids: Plant signals to soil microbes. In Phenolic Metabolism in Plants. Eds. H A Stafford and R K Ibrahim. Plenum Press, New York. Rec. Adv. Phytochem. 26, 201–231.
Rengel Z 2002a Breeding for better symbiosis. Plant Soil 245, 147–162.
Rengel Z 2002b Genetic control of root exudation. Plant Soil 245, 59–70.
Welch R M and Graham R D 2002 Breeding crops for enhanced micronutrient content. Plant Soil 245, 205–214.
Zhu Y-G, Huang C, Howes N K and Smith S E 2002 Breeding for low-nutrient environments. Ln Food Security in Nutrient-Stressed Environments: Exploiting Plants’ Genetic Capabilities, Proceedings of an International Workshop, 27–30 September 1999, Patancheru, India. Developments in Plant and Soil Sciences, Volume 95. Ed. J J Adu-Gyamfi. pp 47–57. Kluwer Academic Publishers, Dordrecht, The Netherlands.
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Dakora, F.D., Sinclair, T.R. (2002). Genetic approaches for manipulating crop plants to enhance root exudation and access low nutrients in the rhizosphere. In: Adu-Gyamfi, J.J. (eds) Food Security in Nutrient-Stressed Environments: Exploiting Plants’ Genetic Capabilities. Developments in Plant and Soil Sciences, vol 95. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-1570-6_28
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DOI: https://doi.org/10.1007/978-94-017-1570-6_28
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