Effects Of Knocking Out Flowering Time Gene C220 On The Growth And Development In Tobacco

Near two-decade studies have suggested that there are four pathways for the genetic control of flowering time in Arabidopsis,namely:independent pathway,gibberelin pathway, photoperiod pathway and vernalization Pathway.Zheng Huiyong discovered(not published data)that the flowering time was delayed and the biological yield and seed yield greatly increased in comparison with the wildtype when a gene(named as C220 temporarily) controlling flowering time was deleted in Arabidopsis.Therefore,this gene is valuable not only in theoretical research,but also in application.In this study,an RNA interference vector of C220 gene was constructed using the C220 homologous gene(cDNA)previously cloned from tobacco and the Gateway technology and transferred the vector into tobacco via Agrobacterium.With PCR analysis on the total DNA and RT-PCR analysis on the total RNA extracted from the leaves of T₀ transgenic plants,some transgenic plants in which the RNAi expression frame had been inserted into the genome and could express to show efficient interference effect were identified.Phenotypic investigation indicated that the length between stem nodes of the transgenic plants was 2.32 cm on average,88.79%shorter than that of wildtype;the number of leaves of the transgenic plants is 60 on average,14 pieces more than that of wildtype;the 20-leave fresh weight and dry weight of the transgenic plants at the flowering stage were 1103g and 311g,respectively,increasing 144%and 130%compared with the wildtype;the leaf area(length×width)of the transgenic plants was 1450.20cm² on average,increasing 148%compared with the wildtype;the flowering time of the transgenic plants under the long day condition was 117d on average,19d later than that of the wildtype; the chlorophyll content of the transgenic plants was 1.722%on average,71.5%higher than that of the wildtype.These results suggest that the tobacco C220 homologous gene has the similar function to the Arabidopsis C220 gene.Since this gene can greatly increase the leaf yield when its expression is suppressed,it may probably have important application prospect in tobacco production.