Identification and characterization of rice OsCIPK10 gene / 生物工程学报

The preliminary role of calcineurin B-like protein-interacting protein kinases (CIPKs) in stress response is defined but the exact function of OsCIPK10 gene in rice stress response and its expression pattern yet unclear. In this study we explored the possible functions of OsCIPK10 gene by reverse genetics approaches and also revealed its expression pattern by GUS staining. From the preliminary study of this gene we presumed its function to assist plant to resist stress but over-expressed OsCIPK10 rice transgenic lines showed no significant phenotypic differences from the wild type either under high salt or low potassium conditions, however the gene knockdown plants using inverted repeat strategy presented meaningful healthy plants compared to wild type under the stress of salt. Further we checked the expression profile under high salt and low potassium conditions in wild type and found that OsCIPK10 decreases under high salt and increases on low potassium conditions. So we speculate that OsCIPK10 is actually going to function in response to high salt and low potassium stress. We also explored the expression pattern of this gene using Gus staining and found that gene expresses in all plant tissues, the only exception observed was its higher expression in the vascular tissues.

Analysis of rice OsPLD3 and OsPLD4 genes and promoters / 生物工程学报

Phospholipase Ds (PLDs) exist in many plants. PLDs catalyse the hydrolysis of phospholipids (e.g. phosphatidylcholine) in cell membrane into phosphatidic acid (PA) and polar free heads (e.g. choline). Two PLD members from rice, OsPLD3 and OsPLD4, were studied by reverse genetics approaches. The results showed that the promoters of OsPLD3 and OsPLD4 could drive the expression of the reporter gene in various tissues of the rice flower organs at different levels. The expression of both genes was induced by wounding and methyl jasmonate (MeJA), but with different intensity at different time intervals. No prominent phenotypes were observed by RNA interference with the gene-specific artificial miRNAs or over-expression of the target genes in rice plants, implying the functional redundancy among different members of the rice PLD family.

Cloning and function analysis of the rice small GTP-binding protein gene OsPra2 / 生物工程学报

Gene expression in rice roots under nutritional stress was studied using micro array techniques. The results showed that when re-supplied with sufficient amounts of nutrition after nutrition stress, the expression of OsPra2 (a small G protein which is homologous with Pea Pra2 protein) decreased in the plants root tissue. The cDNA sequence of the OsPra2 gene and its promoter, which is about 1 kb upstream of the translation origin point, was obtained using RT-PCR and PCR approaches. The OsPra2 protein contains four conserved GTP/GDP binding domains and specific domain of Rab small G protein family. The expression of OsPra2 and GST fusion protein in onion epidermal cells showed that OsPra2 protein was localized in the membrane and nucleus of the cell. The fusion expression of OsPra2 promoter and GUS reporter gene in transgenic rice suggested that the OsPra2 promoter allowed GUS expression in coleoptiles and roots. Compared with wild type rice, OsPra2 over expressed transgenic rice showed an obvious dwarf phenotype which resembles the BR deficient rice.