The role of cell wall mechanic properties in the response of maize leaf growth to drought stress.

Drought is the most limiting factor for crop yield and ecosystem productivity and is predicted to become more prevalent in light of global climate change. One of the first responses of the plant to drought is an inhibition of leaf growth. This is the result of an inhibition of the growth of cells in the growth zone of the leaves. The growth of cells is a driven by a hydrostatic pressure (turgor) generated inside the cells, but is largely controlled by varying the reversible (plastic) and irreversible (elastic) extensibility of the wall. This project aims to further our understanding of the regulation of this crucial process. To this end, we developed a new assay where we measure the extension dynamics in different parts of the growth zone of control and drought stressed leaves after increasing the turgor. Additionally, we determine turgor in unperturbed segments using Psychometry. The extensibility measurements will be validated by independent methods: Atomic Force Microscopy to determine turgor and cell wall elasticity and extensiometry to determine cell wall plasticity. The assays use live tissues in a watery solution. Therefore, we can add putative regulatory substances, H2O2, Abscisic acid, sugars and change the pH to test their effect. These substances are of interest as we have shown that their levels in the growth zone are strongly affected by drought and they have been linked in the literature with the regulation of cell expansion. This project will yield a clear insight in the mechanistic basis of the drought response and its regulation, providing a basis to develop more tolerant crop varieties.

Keywords:CELL WALL, MAÏS BLADGROEI, DROUGHT STRESS

Disciplines:Plant biology