Adaption Mechanism Of Structure, Physiological, And Comparative Proteomic Analysis Of Leaf Of Polygonum Viviparum Form Different Altitudes

Ecological environment of alpine is a kind of extremely unfavorable conditions forplant survival. Apline plants often encounter strong radiation, low temperature, low airpressure, wind, snow and poor soil environment. Under extreme environment, aplineplants have evolved adaptation strategies which inclosed morphology, physiology andbiochemistry meachanisms. Investiagation the adaption mechanisms will not only revealthe new strategy on alpine plants survive, but also can provide theoretical basis foreconomic changes in alpine region.In this study, the leaves of Polygonum viviparum growth in2300，3200，3900m ofQilian Mountain were collected. The structure of leaves, chloroplast ultrastructure, lowerepidermal surface and some secondary metabolites were determined. The chlorophyllfluorescence parameters and gas exchange rate were measured on sampling sites. Thetwo-dimensional gel electrophresis and fluorescence difference electrophresis were usedto analsis comparative proteome of leaves of Polygonum viviparum from differentaltitudes. The main results of the research were listed as follow:1. The thickness of leaf reached maximum at3200m altitude. It was increased by40.3%and54.7%, respectively, compared to the thickness of leaf at2300m and3900maltitude. With the altitude increase, the mesophyll cells were tighter and the volume ofinterecellular space was increased. The number of thylakoids was decreased as altitudeincreased. The density of leaf stomata was increased and the dimter of stomata of back三leaves was diminished as altitude increased.2. Both the maximum quantum efficiency (Fv/Fm) and light capture efficiency(F’v/F’m) both decreased with the altitude increased from2300m to3200m and thendecreased at3900m. The actual PSII efficiency (ФPSII) decreased, whereasnon-photochemical quenching coefficient (NPQ) increased significantly as altitudeincreased. The non-photochemical quenching (qn) increased by114%and87%in3900m,respectively, compared to2300m and3200m altitude. The photochemical quenchingcoefficient (qp) slightly reduced with altitude increased. The net CO2assimilation (Pn) andtransparent rate (Tr) and stomatal conductance (Gs) were reached maxmum at3200m. Theintercellular CO2concentration (Ci) decreased the minimum level at3200m.3. The content of proline, soluble sugar, polysaccharide, simple phenol and mannitolwere increased as altitude increased. But, the content of tannic declined as altitudeincreased. The Linolenic acid (18:3), the main fatty acid, which relative contents was reached peak level by40.25%at3200m.4. The protein expression was examined by ues the two-dimensional gelelectrophresis and fluorescence difference electrophresis. Fifty nine proteins wereidentified from seventy difference spots on2D-DIGE map. The thirty-six proteins wereidentified from2-DE map. Those differentially expressed proteins involved in differentpathways, including photosynthesis (46.32%), bioenergy and metabolism (7.37%), celldefense (10.53%), transport ATPases protein (7.37%), molecular chaperones (8.24%) andgene expressionregulation protein were (12.36%).Overall, alpine environment will damage the photosynthesis ability of PSII andreduce CO2assimilation rate. The changes of structural of leaves and chloroplast resultedin stable photosynthesis in P.viviparum. The membrane fluidity and function weremaintained by the trienoic fatty acid. The secondary metabolisms can scave the highlyreactive hydroxyl radical. The most comparative protein weer involved in photosynthesisand metabolism function stable.