抄録
Rice is the most Al-tolerant species among small-grain cereal crops. Recent identification of a C2H2-type zinc finger transcription factor ART1 for Al tolerance has revealed that multiple genes are implicated in high Al tolerance in rice. Here, we functionally characterized one of downstream genes of ART1, named OsCDT3. OsCDT3 encodes a predicted peptide of 53 amino acid residues, of which 14 (26.4%) are cysteine residues. OsCDT3 was mainly expressed in the roots and its expression was specifically induced by Al exposure. Furthermore, the Al-induced expression was not observed in art1 mutant. Analysis with transgenic plants carrying pOsCDT3::GFP showed that the signal was observed in all cells of the root tips. Both transient expression of GFP-OsCDT3 in onion epidermal cells and western blot analysis in rice roots showed that OsCDT3 was mainly localized to the plasma membrane. Knockdown of OsCDT3 resulted in increased sensitivity to Al in rice. Yeast expressing OsCDT3 showed increased tolerance to Al and decreased accumulation of Al, but the tolerance to Cd was not altered. Our results indicate that OsCDT3 is one of the components required for high Al tolerance in rice.
