LAUSR

UGD gene encodes UDP-glucose dehydrogenase (UGD) which is a key enzyme in the biosynthesis of cell wall, and it catalyses the irreversible oxidation of UDP-glucose (UDP-Glc) into UDP-glucuronic acid (UDP-GlcA). In cucumber, the expression level of CsUGD2 genes was higher in phloem tissues of pedicel and fruit than that in stalk. This study investigated the function of CsUGD2 in cucumber by different methods. Structure analysis indicated that CsUGD2 gene only has an exon with a length of 1,443 bp. Protein alignment suggested that UGD protein was highly conservative in different species. Phylogenetic analysis showed that CsUGD2 protein and CmoUGD2 protein form a same clade which is far away from UGDs in Arabidopsis. Real-time fluorescence quantitative analysis of CsUGD2 in different tissues of cucumber in the same period showed that CsUGD2 expressed highest in the root of cucumber. When we transformed CsUGD2 into wild type Arabidopsis, the roots of transgenic plants were shorter and the flowering time was delayed.  These results suggested that CsUGD2 may play an important role in the development of cucumber roots and only act on the development of cucumber fruit when compared with other plants fruits. However, the role of CsUGD2 in regulating the growth and development process of cucumber need to further study.