Dynamic structural changes in wheat vegetative development as an adaptive response to drought stress

Background and Aims The objective of our research was to define the precise structural response in wheat seedlings correlated with the duration of drought stress. For this purpose, we selected structural components of the cell recognised by specific molecular probes, which are molecules involved in rapid spatial cellular rearrangements: hydroxyproline-rich glycoproteins, xylan, and pectic compounds. Methods Using basic molecular techniques, we identified the transformations occurring within the cell and elucidated the mechanism triggered by growth in the absence of water. Results Our general observations are as follows: 1) remodelling of the cell wall after just 5 days of drought conditions; 2) organ-specific responses for drought resistance; 3) drought triggers the aggregation or cross-linking of molecules in the cell wall (appearance of larger molecular mass fractions) and causes degradation or breakdown of cell wall components (appearance of low molecular masses); 4) changes in the elemental economy due to modifications in cellular assembly. Conclusion Our finding of the deposition of un- and esterified homogalacturonans (HGs) and AGPs indicates reconstruction of cell wall as a means of prevention of drought effects. A stress-induced higher level of unesterified HGs permits calcium cross-linking, which enhances cell wall rigidity and helps in intracellular water preservation. Highlight statement Dynamic changes in wheat as a response to drought include remodelling of the cell wall after 5 days of drought,modification in the elemental composition, deposition of HGs, xylan, and AGP.