《双语版植物生理学》Chapter 1 Water metabolism of plants.pptx

植物的营养问题

(NutritionofPlants)

土壤营养：Water,Mineralelements

空气营养：Photosynthesis(光合作用);有收无收在于水!;1.1Theimportanceofwaterinplants

1.2Waterabsorptionbyindividualplantcell

1.3Waterabsorptionbywholeplant

1.4Watertransportationinplantbody

1.5Transpiration

1.6Physiologicalbasesofrationalirrigation;1.1Theimportanceofwaterinplants;Sameplantsunderdifferentenvironments:

Shadeandwet?——Sunnyanddry?;Freewater(自由水)：距离胶粒较远可以自由流动的水分。;Ratiooffreewater/boundwater:moreimportant

代谢旺盛细胞、组织、器官：高

休眠、越冬：低;Solventforsubstanceabsorptionandtransportation: 不能吸收固态物，物质（矿质、碳水化合物）要溶于水中才能运输。（施肥后淋水）;水是极性分子(polarmolecule);Highsurfacetension(表面张力)

air-waterinterface;

cohesion(内聚力):H2O-H2O

adhesion(粘着力):H2O-Solidphase(CW)

capillarity(毛细管作用);Cell:structuralandfunctionalunitofplantbody;concentrationgradient,diffusioncoefficient系数;Throughaquaporin水孔蛋白:waterchannelproteins

onplasmamembraneandtonoplast(液泡膜);Aquaporin+Pi;;Howtomeasurewaterenergyinasystem(cell)?;1.2.2.1Waterpotential(水势);Waterpotential(水势):ifthegivensubstanceis

water.J/mol;Theabsolutevalueofwaterpotentialisdifficulttodetermine.Inplantphysiology,thewaterpotentialofpurewaterissettobezero.纯水的水势为零！

纯水的自由能最大，水势也最高!?;1.2.2.2ComponentsofΨwofplantcells;衬质势(matricpotential)Ψm:细胞胶体物质亲水性和毛细管对自由水束缚而引起水势降低的值。Negativeorpositive?;细胞中的亲水胶体？Cellulose(纤维素)inCW,proteinsinprotoplast,starches(淀粉)incytoplasm。;水分移动需要能量，因此，水分一定是从高势区域顺着能量梯度（energygradient）流到低势区域，也就是说，水分由水势高处流到水势低处。;1.2.2.3Osmosis(渗透作用);Structureofplantplasmamembrane;; CW：全透性

Plasmamembrane：选择透性

Protoplastlayer：选择透性

Tonoplast：选择透性;H?flerdiagram;1.2.2.6Watermovementbetweencells;Back;;1.3.2Pathways;质外体途径;Casparianstrip

凯氏带;1.3.3Motivepower;Guttation吐水;?;Mechanismofrootpressure?;1.3.3.2Transpirationpull(蒸腾拉力);Intheso