The metalloid arsenic (As) and the hevy metal cadmium (Cd) are ubiquitously found at low concentrations in the earth, while high concentrations of the both elements in soil and crop are severe dangerous to human health. We have tried to retrieve RING E3 ligase gene, which is believed to regulate substrate proteins in As or Cd uptake via ubiquitin 26S proteasome pathway, related to inhibit metal ion transport system. A total of 48 rice RING E3 ligases were randomly selected and then conducted semi-quantitative RT-PCR for their expression patterns as exposed to As and Cd treatments. We discovered one gene, Oryza sativa heavy metal induced RING E3 ligase 1 (OsHIR1) that was significantly up-regulated against both treatments. A total of 31 positive interaction clones with OsHIR1 were screened depending on their strong α-galactosidase activity via yeast-two hybrid screen. Bimolecular fluorescence complementation analysis evidenced that the OsHIR1 protein was clearly interacted with each of six partner protein including aquaporin tonoplast intrinsic protein 4;1 (OsTIP4;1) in the plasma membrane. Protein degradation assay showed that OsHIR1 strongly degraded the protein level of OsTIP4;1 via ubiquitin 26S proteasome system. Heterogeneous overexpression of OsHIR1 in Arabidopsis showed As- and Cd-insensitive phenotype. In addition, the transgenic plant showed low levels of As and Cd accumulation than the control plant in leaf and root. Here, we report the novel finding that OsHIR1 E3 ligase positively regulates OsTIP4;1 related to As and Cd uptake.

A recombinant inbred lines (RILs) consisting of 231 lines, derived from a japonica (Suweon365) and a japonica (Chu-cheongbyeo) rice, was used to investigate the genetic factors affecting cooking and eating quality of rice. Alkali digestion valueloci (QTLs

The elite rice cultivar, Suweon365, shows high level of leaf blast resistance. The number and chromosomal locations of genes conferring the resistance were detected by linkage analysis using DNA markers in the RILs from the cross between Suweon365 and Chu

Genetic diversity of 94 japonica rice was assessed using 81 simple sequence repeat (SSR). All 81 SSR markers generated a total of 351 alleles. The number of alleles ranged from 1 to 16 with a mean of 4.3 alleles per SSR marker. Six of 81 SSR markers showe