Functional Characterization Of PhCS In Petunia

Shikimate pathway is an important metabolic pathway and it’s the main bridge linking glucose metabolism and secondary metabolismin plants,fungi and microbes.Folate,as a major carbon unit donor,is widely involved in many important metabolic reactions.Chalismate synthase(CS)plays an important role in the shikimate pathway and folic acid-mediated carbon metabolism.CS is one of the key enzymes in the shikimate pathway.The genes encoding a lot of enzymes in the shikimate pathway have been cloned and studied,but the main function of the CS is not well known.We identified the function of Ph CS in petunia with the technology of VIGS.In order to further verify the function of Ph CS.The main results were as follows :(1)Ph CSprotein is predicted to encode439 amino acids and shares a high amino acid sequence identity with Sl CS.(2)The expressions of Ph CSwere present in the leaves and flowers of petunia,and in different site leaves,the expression of Ph CSwas different.Ph CS silencing plants showed a decreasing trend in the leaves,and during the development of flowers,the expression of Ph CSis firstly up-regulated and then down-regulated,whichincreased first and then decreased,and in the fourth stage of buds the expression is the highest.(3)VIGS-mediated Ph CSsilencing and the treatment with methotrexate resulted in yellow leaves,and young leaves were more obvious;Ph CSsilencing also resulted in deformedflowers,smallerpetals,and the flowers was pink.The results show that the Ph CS gene has the function of regulating the color of the leaf and.the flower.(4)Ph CSsilencing and the treatment with methotrexate resulted in the chlorophyll content of leaves and sepals reduced.Ph CSsilencing and the treatment with methotrexate resulted in anthocyaninscontent of petals decreased.(5)The folatecontent of the leaves were decreased;Ph CSsilencing thecontent of Met in leaves was decreased by 75.2%,and the contents of Ado Hcy and Ado Met increased by 27.1% and 25.9%,respectively.The results show that the function of Ph CS gene is related to the folate synthesis.(6)Ph CSsilencing and the treatment with methotrexate the expressions of Ph EPSPSand Ph CS was decreased;Ph CSsilencing and the treatment with methotrexate affects the expressionsof anthocyanin biosynthesis related genes,Ph CSshowed an increased trend in the bud stage of the Ph CSsilencing plantsand the treatment with methotrexateplants.