OsCOPT7 is involved in copper accumulation and transport through xylem.

Copper (Cu) is an essential micronutrient for humans, but excessive Cu in rice grains causes health risks. Currently, the mechanisms underlying Cu accumulation in rice are unclear. Here, we identified a novel member of the high-affinity copper transporter (Ctr)-like (COPT) protein family in rice, OsCOPT7, which controls Cu accumulation in rice grains. Mutation in the coding sequence of OsCOPT7 (mutant lc1) leads to inhibition of Cu transport through the xylem, contributing to lower Cu concentrations in the grain of lc1. Knockout or modulation of the expression of OsCOPT7 significantly impacts Cu transportation in the xylem and its accumulation in rice grains. OsCOPT7 localizes at the multi-pass membrane in the cell and the gene is expressed in the exodermis and stele cells, facilitating Cu loading into the xylem. OsCOPT7 expression is upregulated under Cu deficiency and in various organs, implying its contribution to Cu distribution within the rice plant. The variable expression pattern of OsCOPT7 suggests that OsCOPT7 expression responds to Cu stress in rice. Moreover, assays reveal that OsCOPT7 expression level is suppressed by the SQUAMOSA promoter-binding protein-like 9 (OsSPL9) and that OsCOPT7 interacts with Antioxidant Protein1 (OsATX1). This study elucidates the involvement of OsCOPT7 in Cu loading into the xylem, its subsequent distribution within the rice plant, and the potential of this protein in reducing the risk of high Cu concentrations in rice grain grown on Cu-contaminated soil.

[Inhibitory effect against the gastric carcinoma cell growth by the combination of the survivin antisense oligonucleotide and P53 gene].

OBJECTIVE: To investigate the inhibitory effect and mechanism against the growth of human gastric carcinoma cell line HS-746T by the combination of the survivin antisense oligonucleotide (ASODN) and P53 gene and its mechanism. METHODS: Gastric carcinoma cell line HS-746T was treated by P53 gene and survivin antisense oligonucleotide was designed. There were four regimen groups treated by different agents:ASODN alone, P53 gene alone and the combination of ASODN and P53 gene, blank control. Cell proliferative ability and cell growth were determined by cells counting and MTT. The expression of survivin mRNA and protein was detected by RT-PCR and Western blot respectively. Cell apoptotic index was detected by TUNEL. RESULTS: ASODN alone, P53 alone and the combination of ASODN and P53 could inhibit not only the growth of gastric carcinoma cell, but also down-regulate the survivin mRNA and protein expression. The inhibitory effect was stronger, and the apoptosis index was higher in the combined transfection group than those in the other two single transfection groups. CONCLUSION: The combination of survivin ASODN and P53 gene is more efficient to inhibit cell growth and induce apoptosis than that of agent alone.