Figure 4.

Transient moderate heat stress at the tetrad stage leads to reduced starch content and enzymatic activity in mature pollen. A, Total starch quantification of mature pollen subjected to heat stress at the tetrad stage and the nonstressed control pollen. B and C, Light microscopic images of nonstressed (B) and heat-stressed pollen (C). D, Quantification of enzymatic activity (D) in mature pollen stained with FDA in nonstressed (E) and heat-stressed pollen (F). Data are presented as the mean ± sd. Scale bars = 10 μm (B and C) and 20 μm (E and F).