The Effect Of Nodulation To The Tobacco Cell Structure And Calcium Distributing

More and more concern was focused on nitrogen fixation because of sustainable development. It isThe regenerated tobacco K326 plantlets were disposed in such condition: 0.3mg/L 2,4-D and 5×108/L rhizobium ; 0.3mg/L2,4-D rhizobium only ; 5×108/L rhizobium only; native Jesen Non-nitrogen medium. Cell structure and plant physiology of nodule-induced tobacco were analyzed as well.There are many proteome in apical cells, most of which localize in meristematic cells. Something with large scale of high-density electron appear in plasta , but its configure character physiology function, composition and mechanism of conformation are still unknown.paranudule in tobacco has similar ultrastucture with apical cells, but some difference was also found recently: 1) paranudule in tobacco has more mitochondrion , mitochondrion is larger in scale , cristern developed better than those of in apical cell, which provide plenty of energy for all kinds of physiology activity, substrate transport between cells and nitrogen fixation. 2) most of proteomes in paranudule were found in effete cell, forming gridding-like figure, however, proteomes in apical cell localized in apical cell, floccule, agglomeration and strict sphere are the most formsthat can be found. Different forms may exist in apical cells and paranudule .There are abundant chloroplasts in mesophyll cell cultured in Jesen non-nitrogen medium, they connected tightly or were separated by lots of mitochondrion. Member of most shuttle-like chloroplasts are slippery, and amount of layer system in chloroplasts is fairy small. Little plastoglobuli were found in chloroplast. Though plenty of nutrient exist in medium, and the plant is still young, which may be the main reason for poor photosynthesis in the cell.Tobacco treated with rhizobium alone is charactered with flourish root system, tall and straight stem, verdure leaves, without paranudule in the root except some brown speckles; Tobacco treated with rhizobium and 2, 4-D together growed not so well, some buff nodule appeared on roots, fibre became thickset and amount decreased sharply; the effect of tobacco treated with 2, 4-D alone is most serious, having the character of dwarfish stem, yellow and smallish leaves, nodules on the roots, and sparse fibre. It is obvious that 2, 4-D alone does harm to the growth of tobacco, but rhizobium alone , rhizobium and 2,4-D(0. 3mg/L) together can benefit to the growth of tobacco.Calcium ion is important for the expression of nodule factor, oxygen-protecting for nitrogenase and signal transduction of Nod factors. Several conclusions were drawn in the article: 1) concentration of calcium in the roots treated with rhizobium and 2, 4-D increased sharply during two periods, because plenty of calcium ion is necessary for nodule-forming and nitrogen fixation. However, concentration of calcium in leaves and stems increased only after maturation of paranudule , the reasons of which are that activities of many enzymes increased distinctly and the frequency of metabolism and cell communication were much higher. 2) the concentration of calcium ion growed clearly in all developing cells except some dividing cells in paranudule , which may be the result of invasion of rhizobium inducing early nodulation and nitrogen fixation subsequently.Concentration of calcium ion changed with the development of paranudule, expression of nitrogen fixation-genes, and hoist of nitrogenase activity.So such conclusion may be drawn that it is feasible to break the barrier by phytohormone(2, 4-D etc.) when rhizobium invade nonleguminous plants.