[Valve-like structures in motor cells of the leaf of Distichlis spicata "Yesen 4A" (Poaceae)]

The salt gland of the leaf of Distichlis directly contacts the cells of interfascicular aquiferous parenchyma (motor cells). The cytoplasmic strand of motor cells produce deep invaginations, which form with the participation of mitochondria. The constriction of the cytoplasmic strand at the site of the localization of mitochondria leads to the fusion of the tonoplast and plasmalemma with mitochondrial membranes and the formation of a thin one-layer plate, a valve. At this locus, vacuolar and apoplast spaces are separated only by a valve. The cytoplasm of motor cells is filled with electron dense granules, which are considered as contractile elements. It is assumed that the cytoplasmic strand is involved in the reduction of the volume, which results in the generation of pressure on the valve. This leads to the direct throw-in of water into the apoplast space adjacent to the salt gland.