Preliminary Study Of PhDHS On Physiological Mechanism Of Leaves Color In Petunia

Petunia hybrida is a good material for plant molecular biology research.Virus-induced gene silencing(VIGS)is mainly used for gene function research.Deoxyhypusine synthase(DHS)catalyzes post-translational activation of the eukaryotic initiation factor 5A(eIF-5A).Our previous research showed that PhDHS silencing resulted in reduction of chlorophyll content and chloroplast number.These results indicate that PhDHS may be involved in the development of chloroplasts,and its mechanism requires further studies.Nl-guanyl-1,7-diaminoheptane(GC7)is a structural inhibitor of DHS that inhibits the activation of eIF5-A.Antisense RNA technology is one of the transgenic technologies and was used to identify plant gene function.A proteomic analysis of PhDHS-silenced chlorogenic leaves revealed that the protein levels of two proteins,ferredoxin-thioredoxin reductase(FTR)and Oxygen-evolving enhancer protein 1(OEE1),were significantly reduced.FTR is a key enzyme in the light-dependent enzyme regulatory system of oxygen-containing photosynthetic organisms,and OEE1 is component of the oxygen-releasing complex of photosynthetic system II(PS II).In this study,petunia seedlings were treated with GC7.PhDHS antisense expression vector was constructed.The PhFTR and PhOEE1 genes were silenced in petunia plants by VIGS technology.The main results were as follows:(1)Plants treated with GC7 showed chlorotic phenotype.(2)The growth of antisense PhDHS plants was accelerated.The leaves were yellow-green and mottled.(3)The fragments of PhFTR and PhOEE1 genes were successfully isolated and their VIGS vectors was constructed.(4)The leaves of PhFTR silencing were yellow at the base and partially necrotic.Theleaves of PhOEE1 silencing were yellow-green.The common features of the two genes silencing plant phenotypes were the reduction of chlorophyll content,leaf photosynthetic and the number of chloroplasts.In addition,the plant flowering was delayed.