Signal There is a growing body of knowledge about how mechanoreceptors in plant cells receive information about a mechanical stimulation, but there are many gaps in the current understanding. While a complete model cannot yet be formed, we do know much of what is happening at the plasma membrane. The plasma membrane is full of membrane proteins and ion channels. One type of ion channel are Mechanosensitive (MS) ion channels. MS channels are different from other membrane proteins in that their primary gating stimulus is force, such that they open conduits for ions to pass through the membrane in response to mechanical stimuli. This system allows physical force to create an
ion flux, which then results in signal integration and response (as detailed below). MS channels are hypothesized to be the working mechanism in the perception of gravity, vibration, touch, hyper-osmotic and hypo-osmotic stress, pathogenic invasion, and interaction with commensal microbes. MS channels have been discovered across a diverse array of genera as well as in different plant organs, like leaves and stems, and localize to diverse cellular membranes. Not only can mechanoreceptors be present within the plasma membrane of cells, but they can also exist as whole cells whose primary purpose is to detect mechanical stimuli. A well known example is the trigger hairs on the venus fly trap . When repeatedly touched within a certain time span, the plant will snap shut, entrapping and digesting its prey.
Integration and response Once the plant perceives a mechanical stimulus via mechanoreceptor cells or mechanoreceptor proteins within the plasma membrane of a cell, the resulting ion flux is integrated through signaling pathways resulting in a response. The signaling cascade (integration) and response is dependent on the type of stimulus and the particular species. For instance, it can manifest as a change in turgor pressure resulting in movement, secretion of defense chemicals, and the closing of stomata. == Examples ==