种胚特异性表达番茄SlABI3对水稻冈46B穗萌的抗性研究

【目的】利用水稻胚特异表达基因OsVP1的启动子驱动与OsVP1同源的番茄SlABI3在穗萌严重的水稻保持系冈46B中表达，以增强冈46B对穗萌的抗性，进而为改良水稻穗萌抗性的分子设计育种提供理论依据。【方法】构建SlABI3的胚特异表达载体pHB-OsVP1P::SlABI3，利用根癌农杆菌介导的遗传转化法将其导入籼稻冈46B中，通过研究转基因和野生型植株的穗萌差异，验证种胚特异表达的SlABI3在穗萌抑制中的生理功能。【结果】获得了pHB-OsVP1P::SlABI3转冈46B的转基因植株；转基因植株种子的萌发速率较野生型冈46B慢，并且萌发后第8天转基因植株的苗长、根长显著（P<0.05）短于野生型冈46B；此外，在不同浓度ABA处理的试验中，随着ABA浓度的升高，转基因和野生型种子的萌发速率都呈现下降的趋势，但转基因种子的萌发速率均比野生型种子慢。【结论】SlABI3在水稻胚中特异表达能够降低种子的萌发速率并且抑制穗萌发生。

Embyo-Specific Expression of Tomato S/AB/3 Results in Inhibition of Preharvest Sprouting in G46B of Rice

【Objective】In order to increase resistance to preharvest sprouting in maintain line G46B of rice,the promoter of rice OsVP1 was used to drive tomato SlABI3(homologous to OsVP1) expression in rice embryos.This will probably provide a theoretical basis of molecular design for improving preharvest sprouting resistance in hybrid rice【.Method】The expression vector containing the full-length coding region of SlABI3 whose expression is driven by the OsVP1 promoter was constructed and introduced into rice G46B by Agrobacterium-mediated genetic transformation.To further elucidate the physiological function of SlABI3 in inhibiting the pre-harvest sprouting,the phenotypic differences in germination between transgenic and wild-type seeds were observed.【Result】A number of transgenic plants containing pHB-OsVP1P::SlABI3 were obtained.Germination experiments showed that the percentage of geminated seeds from transgenic plants was lower than that of wild-type G46B plants,and that the shoot and root length of transgenic seedling was significantly shorter than that of wild-type seedlings 8 days after germination.In addition,in the experiment of using different concentrations of ABA treatments,although increasing ABA application resulted in decrease of germination rate in both the transgenic and wild-type seeds,germination velocity of the transgenic seeds was slower than that wild-type seeds.【Conclusion】 Embryo-specific expression SlABI3 in rice can reduce germination velocity of transgenic seeds and also inhibit the preharvest sprouting in hybrid rice lines.