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作 者 ：Wei Yu-ning, Li Yao-dong, Ma Qing-hu and Song Yan-ru

Keywords:Polygalacturonase, Antisense RNA, Transgenic tomato, Homozygote,

Abstract:Authors have been transfered antisense polygalacturonase (PG, E, C, 3, 2, 1, 15) gene into two tomato cultivars (Lycopersicon esculentum cv. “Lichun” and “Qingfeng”) by Agrobacterium-mediated transformation and obtained homozygotes with expression of antisense PG gene. Analysis of Northern blot and PG activity showed that antisense PG gene had stably expressed in T0～T2 generations of transgenic tomatoes, and this expression could be inherited and enhanced in the progeny. For example, PG activity of To, T1 and T2 generation fruits in line T2-19 of"Lichun” was dropped to 27%, 20% and 4% respectively. But the remarkable decrement of PG activity did not have obvious inhibitory effect on normal fruit softening. The transgenic plants of T0～T2 generations grew and developed normally. Average yield per plant and average weight per fruit in these transgenic plants were a little more than those in nontransgenic control. The content determination of vitamin C, soluble sugar and soluble solid substances indicated that transgenic fruits kept the original texture and taste. The contents of vitamin C and soluble solid substances of “Lichun” T2-19 and soluble sugar of “Qingfeng” T2-46 were higher than those of the control. Stored in 28～32℃ for 30 days, all of nontransgenic fruits and about 50% of the transgenic ones were infected by pathologcal bacteria, a few of remainders could be perserved for 50 days. These evidences suggested that the resistance of the transgenic fruits to pathological bacteria during preservation has been strengthened. The approach which the authors used to study regulation of tomato fruit ripening will be desirable to improve the storability of certain famous and precious fruits.

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