Studies On Cloning And Transformation Of The Rice (Oryza Sativa) WAX2 Homologous Genes

Drought is one of the main stresses that cause great loss in crop production. The aerial surfaces of plants are covered with a wax layer, which provides protection against water loss and other environmental stresses, such as UV, pathogens and insects. The ubiquitous presence of epicuticular wax is testimony to its essential function. The Arabidopsis WAX2 gene is the first reported gene involved in both cuticle membrane and epicuticular wax production. Leaf transpiration of the T-DNA insertion wax2 mutant plant is greatly increased, indicating that WAX2 may play important role against anti-transpiration. Studies on the function, expression and regulation of the rice WAX2 homologous genes will be helpful in illustrating the mechanism and practical prospect of WAX2 protein in anti-transpiration and pathogen resistance.Three rice homologous genes and proteins are found By BLAST search in the NCBI database using the Arabidopsis WAX2 gene and WAX2 protein sequences. These three rice homologous genes were named OsWAX2-1, OsWAX2-2, OsWAX2-3, and have 56. 0%, 55. 2% and 52. 0% homology to Arabidopsis WAX2 gene respectively. Homology of their coding proteins to Arabidopsis WAX2 protein were 61.5%,60.5% and 64.7% respectively. All the three proteins have four transmembrane domains and two conserved sterol desaturases, which suggest that the three proteins are transmembrane protein and are related to plant epicuticular wax biosynthesis.Full length cDNA sequences of the three rice WAX2 homologous genes were found in the rice full length cDNA database and the respective clones were obtained from the Rice Genome Resource Center. The coding sequences of the three cDNAs were amplified by PCR from the cDNA clones and digested with BamH I or Xba I , which restriction sites were produced by adding the restriction sites to the 5' end of the primers. The digested...