Drought-Induced Changes in Leaf Morphology and Anatomy: Overview, Implications and Perspectives

The global climate change scenario intensified various environmental factors, especially in arid and semi-arid regions. Drought is one of the most severe environmental stresses affecting plant productivity. Plants in the Mediterranean climate zone are exposed to heat and drought in summer, and these conditions have a significant effect on plant growth and development. However, in this case, the entry of CO2 into mesophyll cells is prevented and therefore the rate of photosynthesis decreases which ultimately causes a reduction in plant growth. In order to acclimate to stressful environmental conditions, plants exhibit several structural modifications to cope with these harmful conditions. This review highlights some aspects of anatomical adaptive changes in plants under drought stresssuch as a reduction in leaf size and angle, stomatal position, epidermal thickness and deposition of the cuticle to prevent the loss of water from the leaf surface. Furthermore, it elaborates the role of buliform cells in leaf rolling, structural adaptation in the mesophyll cells, and the presence of trichomes. Mesophyll cells and bulliform cells provide easier rolling of leaves in case of intense drought. In arid conditions, the economical use of water by plants is possible by closing the stomata and reducing transpiration.