【摘要】 番茄的多聚半乳糖醛酸是一种在果实成熟阶段特异性表达的酶。为了研究它在果实成熟中的作用，将其ｃＤＮＡ与花椰菜花叶病毒３５５启动子嵌合后，以反义基因的形式经农杆菌介导导入番茄植株，进一步分析了反义基因的整合与表达。结果表明，在转基因番茄中，反义基因的表达能明显抑制果实内源多聚半乳糖醛酸酶的活性。更多还原

【Abstract】 Ripening is a complex developmental process involving changes in the biochemistry, physiology and geneexpression of the fruit. Tomato polygalacturonase (PG;E.C.3. 2. 1.15)is expressed only during the ripening stage0 of fruit development and has a major role in cell wall degradation.To demonstrate the function ofPG in the fruit ripening,a chimaeric gene containing the cauliflower mosaic virus 35S promoter and a fulllength PG 1. 9kb cDNA in reverse orientation was constructed.The construct was integrated into thetomato genome by Agrobacterium-mediated transformation. Examination by PCR showed that the chimaeric antisense PG gene was stably integrated into the transgenic tomato chromosome. Furthermore,analysis of transcription in the mature transgenic tomato fruits indicated the expression of the antisense PGgene and a remarkable reduction in PG mRNA. These results demonstrated the ability of antisense PGgene to inhibit fruit endogenous PG gene expression in the whole tomato plants.The function of PG in thefruit softening was discussed. The approach which we have used to study fruit ripening will have generalapplicability in agricultural production.更多还原