Figure 1.

Impact of Water Depletion on Leaf Development and Rate of Photosynthesis.

(A) Two leaf surfaces of the maize inbred line B73 are shown at the same developmental stage. The left leaf of a daily watered plant is fully expanded. The leaf at the right from a plant that was depleted of water for 10 d contains a smaller leaf surface area and less chlorophyll, stomata are closed, and leaf margins are curled to avoid water loss. Watering of plants at this stage leads to full recovery.

(B) Soil moisture continuously decreases after water depletion. Below a critical moisture of ∼15% (4th to 5th day after water depletion) rates of photosynthesis and transpiration drop dramatically to ∼10% of well-watered rates. (Figure courtesy of Manfred Gahrtz.)