The Influence Of Elicitor Of The MTs Patterns And Cytosolic Ca～(2+) In Mesophyll Protoplast Of Wheat

In this paper, wheat cultivars Lovrin 10 (resistant) and 5389 (susceptible) were selected as materials in this system. The mesophyll protoplasts of wheats (MPW) were isolated using cellulase and pectolase digestion. By the indirect immune fluorescent labeling, Microtubules (MTs) pattern in MPW were showed clearly under the confocal laser scanning microscope (CLSM). The influent factors were discussed in this paper. The results showed that MTs in MPW distributed throughout the whole cytoplasm in a form of network. The higher concentration of extracellular calcium could influent the stability of microtubules in protoplast. MTs in the protoplasts would depolymerize when the extracellular calcium concentration was rising up to lOmmoI/L.The intercellular washing fluid (IWF) of wheat-leaf rust fungus interaction which contains elicitor were used as stimulator to interact with the protoplast of cv. Lovrin 10 and cv. 5389. By using this system, following questions were investigated: the change of the pattern of microtubules when treated with IWF; the change of cytosolic calcium levels in the protoplasts when treated with IWF and the influence of microtubule depolymerization prior to IWF treatment on the levels of cytosolic calcium.The results are as follows:(1) When the protoplasts of cv. Lovrin 10 had treated with IWF for 15 minutes, the microtubules in the protoplasts began to depolymerize, this mainly showed in forms that the MT bundles cleaved, the quantity of MTs reduced and the density of MTs decreased. Along with time extended in treatment with IWF, the depolymerization of MTs aggravated and the MTs completely depolymerized till 120 minutes. The MTs in protoplast of cv. 5389 also depolymerized when treated with IWF for 60 and 120 minutes, but the depolymerization was much less than that of cv. Lovrin 10.(2) When treated with IWF, the cytosolic calcium in the protoplasts from the two cultivars both increasing. But it increased significantly in the protoplasts of cv. Lovrin 10 than in cv. 5389. In the protoplasts which MTs were depolymerized by oryzalin prior to IWF treatment, the increase of cytosolic calcium was even more high that in the one which were not depolymerized. These results mean the depolymerization of MTs caused52by the increasing influx of extracellular calcium. MTs may participate in the signal transduction which are mediated by the calcium ion in the elicitation of plant defense response.In brief, MTs may participate in the plant disease resistant response. There must be some relationships between MTs and calcium. They may affect each other and play important roles in plant disease resistant response.