Abstract
Ionomic analysis is one of the powerful tools for screening of mutants related to elemental transporting systems. Previously, molybdenum transporter gene MOT1 has been identified in our laboratory by comparison of multiple mineral elements between two Arabidopsis accessions, Col-0 and Ler. To expand this concept to the wide-range of gene resources, we performed a large-scale ionomic analysis by using approximately 3000 lines of N-methyl-N-nitrosourea treated rice mutants (cv. Taichung-65). To minimize the vexatious complication for sample preparation such as acid digestion, xylem sap was collected from individual rice mutant lines grown in the 128-well tray and directly analyzed by ICP-MS as a primary screening. Both aerial parts and seeds were also collected in a single cultivation period for second and third screenings. This method allows effective screening by monitoring both the root-to-shoot and shoot-to-seed transport of essential and non-essential nutrients. Currently, we obtained several mutants affected by Cd content in rice seeds. Further investigations are also in progress for isolation of other mutants possessed altered elemental transporting systems.
