The Art of Botany: The Effect of Drought on Plant Anatomy

Abstract

Plants are negatively affected by water deficiencies, and water stress is expected to increase due to more frequent and prolonged droughts from climate change. I investigated the effect of drought on the internal anatomy of the invasive Syzygium cumini plant. In the greenhouse, S. cumini plants were grown, such that half of the plants were watered daily, while the remaining number of plants did not receive any water for the entire experiment. After nine weeks, the base of the main stem was cut into thin disks, stained, and the center was viewed through a microscope for the pith cells that provide structural support, conduct water, and store starch. The regularly watered plants had circular shaped piths with expanded, rigid cells filled with water and starch, while the non-watered plants had pinched and elongated piths with shriveled cells filled with air, light staining, and a lack of starch. S. cumini demonstrated exceptional drought tolerance with no mortality and only slight wilting; however, the lack of water and the energy storage starch in the pith cells indicates that the plants were stressed. This experiment provides insight into the ability for the drought-tolerant S. cumini to become more invasive under climate change-induced drought in Hawai‘i.