Cloning,Identification And Expression Analysis Of Chalcone Synthase Gene From Dianthus Chinensis

Chalcone synthase（CHS）is a key enzyme in the synthesis of anthocyanidins.Dianthus chinensis is widely used in flower beds and ground covers due to its numerous flower colors and strong resistance.VIGS（virus-induced gene silencing）can quickly and effectively identify plant gene function.Obtaining the genes related to Dianthus chinensis colors will be beneficial to genetic improvement in flower colors of Dianthus.In our study,the specific primers were designed according to CHS gene（accession number:Z67982）of carnation,and then DcCHS was cloned from Dianthus chinensis by RT-PCR and 3’-RACE.Its function was verified by VIGS,and its expression was analyzed.The main findings are as follows:1.The DcCHS（KX893854）with a fragment size of 898 bp was cloned.2.The q RT-PCR analysis of the Dc CHS showed that its expression increased with the colors in petals of Dianthus chinensis,indicating that the DcCHS may be related to colors of Dianthus.3.Different fragments of DcCHS were amplified by RT-PCR with different gene specific primers.Two TRV2 recombinant vectors were constructed.The flower buds infiltrated with GV3101 containing p TRV2/DcCHS₄₀₇ appeared white or light-colored.Meanwhile,their expression levels of CHS decreased.However,the silencing phenotypes were not obvious as flower buds were infiltrated with GV3101 containing pTRV2/DcCHS₄₁₂.It shows that DcCHS is related to the colors of Dianthus,but the fragments amplified from the different positions lead to different silencing effects by VIGS.4.QRT-PCR analysis found that the expression of DcCHS was highest in the early stage of flower buds,and was significantly higher than that in the middle stage and pre-florescence stage.The expression of DcCHS in the middle stage was not significant different to that in the pre-florescence stage.It showed that the expression levels of DcCHS decreased with the development stages of buds.