1a.Objectives (from AD-416)
The goal of this research is to identify the major genes involved in Al tolerance in rice and provide a better understanding of the physiological mechanisms of Al tolerance. Our preliminary work demonstrates that as a species, rice is capable of growing at Al3+ activities that are between 5-15 times higher than that for maize, sorghum, and wheat, leading us to hypothesize that rice may be a source of novel Al tolerance genes.
1b.Approach (from AD-416)
1. Characterize T-DNA knockouts for candidate AltSB MATE homologs in rice for physiological function and involvement in Al tolerance and quantification of the role of these candidate MATE genes in rice Al tolerance.
2. Fine map and/or clone the gene(s) underlying the novel major Al resistance QTL we recently identified on rice chr 12.
3. Complete the whole genome mapping for rice Al tolerance using the OryzaSNP II chip (44k SNP chip).
4) Initiate development of Al tolerance near isogenic lines (NILs) based on identified QTLs and also newly mapped loci from whole genome association mapping to quantify the contribution of individual loci to Al tolerance and as a resource for breeding for rice Al tolerance.
In the first year of this project, we developed new techniques for the more physiologically appropriate hydroponic growth of rice under aluminum toxic conditions. This involved the development of a new hydroponic media that allowed us to impose reproducible Al stress. Also, because of the fine and fibrous nature of rice roots, we had to develop new root digital imaging and quantification techniques to quantify growth of the entire rice root system under +/-Al conditions.
Research conducted under this agreement was monitored via regular meetings, emails and teleconferences between the ADODR and the Cooperators.