Cytochemical Localization Of H~+-ATPase In Root Of Puccinellia Tenuiflora Under Saline-alkali Stress

Puccinellia tenuiflora is gramineous, perennial, and herbaceous species. It has a strong salt-resistant ability and can live in circumstance of pH 9-10. Plant cell plasma membrane and vacuolar membrane H+-ATPase consumes ATP energy establishment of transmembrane proton electrochemical potential gradient, promoting a variety of ions and small molecule metabolites to transmembrane transport. Under stress conditions, the plasma membrane H+-ATPase activity changes and its regulation can response of the reasons environmental factors harm plants in a certain extent, which have an important value on revealing the mechanism of plant stress resistance. In this research, we adopted four stresses (Na2CO3, NaCl,PEG and NaHCO3 stress) and ten methods of treatment, the specific treatment methods are as follows:use 0.4%,1.0% Na2CO3 culture solution being osmotic potential and ion concentration as standards, respectively, separating two treatment:(1) 0.4%Na2CO3,0.277%NaCl,9.82% PEG solution treatment and 1.0% Na2CO3, 0.781% NaCl,19.721% PEG solution treatment; (2) 0.4%Na2CO3,0.184% NaCl,0.448% NaHCO3 solution treatment and 1.0% Na2CO3,0.395% NaCl,1.054% NaHCO3 solution treatment. The purpose was to investigate H+-ATPase histochemical localization in roots cells from P. tenuiflora seedlings under iso-osmotic stress and iso-natrium ionic stress, and discuss the H+-ATPase activity change and their effect on the physiological mechanism in P. tenuiflora in response to salt-tolerant.By determination of osmotic potential value, electrolysis leakage rate and relative content of Na+, K+ in root of P. tenuiflora seedings, we found that P. tenuiflora seedings could maintain the appropriate Na+/K+ ration though discharge Na+ or isolation Na+ to reduce the stress damage roots under high salt environment. Furthermore, using phosphate precipitation technique, we make H+-ATPase ultracytochemical localization of P. tenuiflora seeding root cells. Under the transmission electron microscopy study, we can clearly seen the black dot linear or lead phosphate precipitation on the roots of P. tenuiflora seedlings cortex parenchyma cells, cortical cells, phloem cells, and the pericycle cells. The number of phosphate precipitation on cortical parenchyma cells was most significantly, and the cortical parenchyma cell prone to deformation in the sample preparation. Mature cortex cells in the root of P. tenuiflora were five surfaces thicken shape, horseshoe shape, the number of phosphate precipitation in cortex cells was significantly less than the cortical parenchyma cells, and the number of phosphate precipitation in pericycle cells and phloem cells were also significantly less than in the cortical parenchyma cells. We didn't observe black phosphate precipitation in xylem cells in the roots of P. tenuiflora seedlings.