Mechanical stress in plants may be created in nature by wind, rain, and through contact with animals. Wind stressed plants are typically physiologically dwarfed; characteristics include shorter (and often thicker) stems, reduced leaf surface area and changes in leaf angle. Growth responses to other mechanical stresses are similar, with exception to vibration stress, which may promote growth. This study shows that subjecting Arabidopsis plants to wind stress under experimental conditions results in the expected dwarfing of plants with respect to an unstressed control. In contrast, subjecting Arabidopsis seedlings to vibration stress promotes growth.
RT-PCR was used to look at gene expression in tissues sampled from plants subjected to wind and other mechanical stresses. Candidate wind/mechanical stress genes; genes encoding plant cell wall proteins, genes involved in lignin biosynthesis and those encoding cell signalling pathway intermediates were found to be differentially expressed in plants subjected to these stresses. Transgenic constructs for gene silencing of selected candidate wind/mechanical stress genes by RNA interference (RNAi) were designed with a view to analyzing the role of theses genes in the response and adaptation of plants to wind stress. RNAi constructs targeting Expansin 3, Cellulose synthase 3, Touch gene 4, Cinnamoyl CoA reductase 2, and the Cinnamoyl CoA reductase family of Arabidopsis were generated. Arabidopsis plants were transformed with these constructs; the phenotypes of the resulting transgenic lines and expression of the targeted wind/mechanical stress genes in these lines under mechanical stress are detailed.