Effects of different fertilization regimes on abundance and community structure of the nirKtype denitrifying bacteria in greenhouse vegetable soils. DREB Gene Expression in Leaves of Broussonetia papyrifera Seedlings under Salt Stress Detected by Real-Time Fluorescent Quantitative PCR Effect of Exogenous GA3 on Flowering Genes Expression of Betula platyphylla by Real-Time Fluorescent Quantitative PCR