reported that excess Zn2+ could
affect stomatal density, size and shape, and conductance in sugar beet
plants. The decrease in stomatal density and size could promptly reduce
the rate of transpiration and photosynthesis. In young bean plants, Zn2+
could disturb water uptake, inhibiting photosynthesis, transpiration, and
stomatal conductance, which could decrease the fresh leaf mass and area
(Vassilev et al., 2011).