1. Announcements For biotechnology lab –Labelling GUS stained seedlings –Hyperladder For water status lab 1 –Measurement of relative water content

2. Water Status Lab II

5. stomatal opening cell volume increase increased ψp /water uptake more negative guard cell ψs K + uptake Stomatal opening

6. ABA mediated stomatal closure mechanism: Water deficit → ABA → stomatal closure ABA → ROS → Ca 2+ ↑ → Cl - efflux/membrane potential depolarization → K + efflux/K + influx is blocked → ψ p decrease/water loss → volume reduction → stomatal closure ABA → NO/S1P → cADP ribose/IP3 → Ca 2+ → pm H + -ATPase inhibited → H + gradient dissipation (pH) → K + efflux

12. Introduction Observation of Stomatal Aperture Measurement of Stomatal Aperture Using a ImageJ Measurement of Leaf Water Potential (  w) Measurement of Water Loss Rate by Gravimetric Method Measurement of Leaf Area Calculation of Transpiration Rates and plotting graph w/o ABA & w/ ABA