Abstract
When plant tissue receives mechanical stress, does occur water movement across cell membranes? If the water movement doesn't occur, the exogenous energy is conserved in the distortion of cells just as mechanical energy potential. On the other hand, when the water movement across cell membranes occurs, a part of the exogeous energy is transformed to water potential energy, and is conserved. This difference causes the fundamental difference in the strategy of plants against exogenous mechanical stress.
If the water movement across cell membranes occurs, participation of some aquaporins which locate on the cell membranes can be assumed. We performed flexural stress relaxation test using mercuric chloride which inhibits water transport through aquaporins. Mercuric chloride delayed the relaxation of flexural stress in living plant tissues, though it did not affect on the viscoelasticity of apoplast at all. This suggested that water movement in grass plants relieves exogenous mechanical stress.
