Metabolic Engineering On Biogenic Volaitle Organic Compounds Released From Plants(Ⅱ): Analysis And Manipulation On Volatile Terpenoid Flux Of Arabidopsis

Biogenic volatile organic compounds(BVOCs) released by plants play multiple roles in plant-plant, plant-insect and plant-environmental signaling. Volatile terpenoid mainly includes monoterpenes and sesquiterpenes based on their chemical structures. The elucidation of their metabolic pathways leads to the cloning and characterization of more than 40 terpene synthases(TPSs) from different kinds of species. All these results provide a new insight into engineering plant emissions by molecular gentic methods. In this thesis, we firstly presented a direct quantitative analysis method for monitoring BVOCs emitted from live Pelargonium hortorum in situ by mutiple headspace microextraction(HS-SPME) combined with a internal standard. Then, the influences derived from the overexpression of two terpene synthases(QH5 and QH6) and geranyl diphosphate sythase(GPPS) on Arabidopsis terpenoid flux were investigated.The results were listed as follows: 1. The chemical composition of emission from a live leaf of P.hortorum was determined by use of a single HS-SPME procedure. Seventeen kinds of terpnoid compounds were qualitatively characterized with senven monoterpen including α-pinene, myrcene, β-pinene, camphene, linalool, limonene) and a sesquiterpene as the main constitutes. 2. The calibration system provided the best performance when using hexane as the solvent with a 20min equilibrium time, good correlation coefficient(R2, 0.989~0.998) and relative standard deviation(RSD, 3~6%). 3. The multiple HS-SPME combined with an internal standards was employed to monitoring the absolute amounts of BVOCs from live leaf of P.hortorum.