Development of "Multi-Resistance Rice" by Pyramiding of Insect (Cry1C) and Blast Resistance (Pi1 and Pi2) Genes

[Objective] The paper was to improve the blast resistance of insect-resistant transgenic rice. [Method] The Japonica rice variety Jikang10, a new transgenic variety with exogenous insect-resistant gene Cry1C, was used as the receptor, and Kongyu 131, a traditional breeding variety with broad-spectrum high blast resistance genes Pi1 and Pi2, was used as the donor to breeding new rice varieties. The genes were polymerized by hybridization and multi-generation backcrossing, and the offspring of each generation was screened by molecular marker assisted selection, field identification of multi-resistance against insect pests and diseases and agronomic trait selection. [Result] Four lines SK01, SK02, SK03 and SK04 with better resistances to insect pests and blast and outstanding agronomic traits in field were selected. [Conclusion] The results will lay foundations for breeding new multi-resistance rice varieties in Huanghuai rice region.

Recent progress in cationic polymeric gene carriers for cancer therapy

In recent years,various carriers for gene delivery nave been developed for biomedical applications.Among all kinds of gene carriers,cationic polymeric carriers for delivery therapeutic gene as non-viral carriers have received growing interests due to their improved high transfection efficiency with the relative safety.In particular,the advancement of novel polymeric gene carriers has gained much progress in the development of effective anticancer therapy.Herein,this review focused on the development of cationic polymeric carriers for cancer therapy,including polyethylenimine(PEI),polyamidoamine(PAMAM) dendrimers,polylysine(PLL),chitosan and modified cationic polymers.And recent progresses in the development of novel polymeric carriers for gene delivery,such as targeted gene carriers,responsive gene carriers and multifunctional gene carriers,were summarized.Finally,the future perspectives in the development of novel polymeric carriers for delivery gene were presented.

Polymeric prodrug for bio-controllable gene and drug co-delivery

A polymeric polyethylenimine(PEI)-based prodrug of anticancer doxorubicin(DOX)(PEI-hyd-DOX) was designed by attaching DOX to PEI via an acid-labile hydrazone bond, for the achievement of biocontrollable gene and drug co-delivery in response to the intracellular acid microenvironments in the late endosome/lysosome compartments. The cytotoxicity of PEI-hyd-DOX was evaluated by the MTT assay and the cellular uptake was monitored using confocal laser scanning microscopy. The polymeric prodrug can respond with a high sensitivity to the specific acid condition inside cells, thus permitting the precise biocontrol over intracellular drug liberation with high drug efficacy. The chemical attachment of drug molecules also led to the relatively reduced toxicity and the enhanced transfection efficiency compared with parent PEI. The resulting data adumbrated the potential of PEI-hyd-DOX to co-deliver DOX and therapeutic gene for the combination of chemotherapy and gene therapy.