华东师范大学：《植物生理学》课程资源（实验课教学课件）植物组织水势的测定——小液流法和质壁分离法 Water potential in the plant

Water potential in the plant Course: Plant Physiology Lab Experimental Teaching Centre Of Life Sciences

Water potential in the plant Course: Plant Physiology Lab Experimental Teaching Centre Of Life Sciences

The way of water absorbed by plant ■ Diffusion concentration gradient 简单扩散 浓度梯度 Mass flow- pressure gradient 集流 压力梯度 Osmosis- water potential gradient 渗透作用 水势梯度

The way of water absorbed by plant  Diffusion —— concentration gradient 简单扩散 浓度梯度  Mass flow —— pressure gradient 集流 压力梯度  Osmosis —— water potential gradient 渗透作用 水势梯度

Water Potential ■ Chemical potential -free energy per mole of substance Water Potential the chemical potential of water divided by the partial molal volume of water

Water Potential  Chemical Potential ——free energy per mole of substance  Water Potential —— the chemical potential of water divided by the partial molal volume of water w w w w w V V w 0 ( )         

Cell Water Potential Factors: concentration, pressure and gravity yw=ys typ tyg Water enters the cell along a water potential gradient Yw=ys+y 适用于有液泡的细胞或细胞群

Cell Water Potential  Factors: concentration, pressure and gravity  Water enters the cell along a water potential gradient 适用于有液泡的细胞或细胞群  w  s  p  g  w  s  p

(A)Pure water (B)Solution contalnlng 0. 1 M sucrose 0.1 M Sucrose solution Pure water Y。=0MPa s=-0.244MPa y =OMPa YeLp+ 0-0.244MPa =0 MPa -0 244 MPa (C)Flacdd cell dropped Into sucrose solution (D)Concentration of sucrose Increased Flaccid cell Turgid cell Yp =0MPa P=0.488 MPa s=-0.732MPa 中=-0.732MPa Yw=-0732 MPa Y.E-0.244 MPa 0.3 M Sucrose Cell after equilibrium solution Cell after equilibrium Yw=-0732 MPa P =0MPa Yw=-0 244 MPa 华s=-0732MPa 5=-0.732MPa Is =-0.732 MPa 鄄p=w-ys=0MPa Y=-0.732MPa Ww-ps=0.488 MPa (E)Pressure applled to cell Applied pressure squeezes out half the water, thus doubling ys from -0.732 to-1464 MPa 0. 1 M Sucrose solution ce‖ in initial state Cell in final state Fw=-0.244MP w=-0.244MPa 中s=-0.732MPa 华s=-1.464MPa Yn= Yw= ys=0488 MPa p=平w-Y=1.22MPa

Experient ■质壁分离法—测定细胞渗透势 质壁分离和质壁分离复原现象可证明植物细胞是 渗透系统。 小液流法——测定细胞水势 要求:叶片在蔗糖溶液中浸没的时间内不时振荡? 蔗糖溶液配制过程中充分混匀?

 质壁分离法——测定细胞渗透势 质壁分离和质壁分离复原现象可证明植物细胞是一 个渗透系统。  小液流法——测定细胞水势 要求：叶片在蔗糖溶液中浸没的时间内不时振荡？ 蔗糖溶液配制过程中充分混匀？ Experient

Thinking a As the soil dries, how to adjust water potential of the plant?

Thinking  As the soil dries, how to adjust water potential of the plant?