Does Puccinelia tenuiflora have the ability of salt exudation?

The leaves surface of Puccinelia tenuiflora seedling under stress of different concentration of Na(2)CO(3) was observed with scanning electron microscopy and X-ray electron probe micro analyzer. All the results indicated that varied salts crystalline distributing in stomatal apparatus on P. tenuiflora leaves surface could be observed by means of frozen-dried sampling. In the case of no stress, these leaves had many kinds of sediments such as Na, K, Ca, Mg, Zn, Cu, Cl, P, S, Si on their surface. When there was stress of Na(2)CO(3), the percentage content of each sediment would have an non-linear relationship to stress. As the concentration of Na(2)CO(3) increased, the percentage contents of Na, Cu, Zn, P, S generally decreased while that of K, Ca, Mg, Si generally increased. The ratio of K/Na also changed the same way as the later. From these results, we concluded, under stress of alkali and salts, P. tenuiflora leaves could exude salts through their stomata or together with wax secretion and these ways might participate many regulation process of P. tenuiflora leaves cells, for example in ion balancing, osmosis regulating and water metabolizing.