Clone and Heterologous Expression of the Poly-γ-glutamic Acid Synthesis Gene pgsBCAE from Bacillus amyloliquefaciens C1 Characteristics of Transgenic Rice Overexpressing Maize Photosynthetic Enzymes for Breeding Two-line Hybrid Rice Effects of Exogenous Spermidine on Free Polyamine Content and Polyamine Biosynthesis Gene Expression in Cucumber Seedlings under Salt Stress Isolation and biological control effects of cotton Verticilium wilt antagonist