Title: Found: genes controlling the nutrient content of the rice grain Authors
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2012
Publication Date: October 21, 2012
Repository URL: http://a-c-s.confex.com/crops/2012am/webprogram/Paper73378.html
Citation: Pinson, S.R., Tarpley, L., Yeater, K.M., Yan, W., Guerinot, M., Salt, D.E. 2012. Found: genes controlling the nutrient content of the rice grain. ASA-CSSA-SSSA Annual Meeting Abstracts. Agronomy Abstracts Oct. 21-24, 2012 Cincinnati, OH. Paper number: 376-2. Technical Abstract: Biofortification refers to nutrient enhancement of the grain/food product through traditional breeding. Since it does not require genetic engineering, it is acceptable to many consumers, and is compatible with organic labeling. Enhancing the nutritional value of rice is of particular interest because rice is a primary dietary component for more than half of the world’s population, and especially so in underdeveloped parts of the world that have higher rates of malnutrition. New marketing strategies could be employed in developed countries as well for value-added products naturally high in consumer-desired minerals such as calcium, potassium, and iron; or strategically low in undesirable elements such as arsenic or cadmium. The first step toward targeted breeding is the identification of genes responsible for orchestrating desirable concentrations of various elements in the grain. Here we report the identification of quantitative trait loci (QTLs) affecting the concentrations of 16 elements in brown rice grain (dehusked but unmilled) that are important to human and plant nutrition. Genetic loci were mapped among several progeny populations from biparental crosses as well as among a set of diverse rice accessions. To increase opportunity to detect and characterize grain-element QTLs, the study populations were grown under two contrasting field redox conditions, flooded (reduced soil chemistry) and unflooded (flush-irrigated to maintain aerated soil chemistry while preventing water stress). Soil redox is known to alter mineral availability, and so was expected to affect grain mineral concentrations. ICP-MS was used to analyze the harvested brown rice for variation in accumulation of 16 elements, namely Mg, P, K, S, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, and Cd. Correlations among the individual elements and between each element with grain shape, plant height, and time of heading were also studied. Many of the grain element QTLs were significantly associated with multiple elements, supporting the concept of element physiological networks within plants, and indicating the importance of studying multiple elements at a time. Grain shape, heading time and plant height proved to have much less direct influence on rice grain mineral concentrations than was anticipated.