Study On The Change Characteristics And Function Of NO In The Process Of Soybean And Soybean Mosaic Virus Interactions

Our study is carried out with the combination of soybean Jidou-7and soybean mosaicvirus(SMV) strain N3, as the resisting combination(or incompatible combination), and thecombination of Jidou-7and SMV strain SC-8, as the susceptible combination(orcompatible combination). With the measurement of dot vaccination and frictionvaccination, Generation of Callose and nitrogen monoxidum is observed usingFluorescence microscopy and Confocal fluorescence microscopy after Aniline bluestaining and DAF-FMDA incubation proformed on leaves of soybean with different pointof time after vaccination, so as to discuss the function of nitrogen monoxidum on theprocedure of SMV resistance in soybean. The main results are as follows:1. A weak fluorescence of NO is observed at2hours after vaccination on theincompatible combination. The fluorescence shows obvious tendency of enhancement withthe Extension of time after vaccination, the area of NO fluorescence is also expanding, butalways be limited to the internal and surrounding necrotic spots; whereas only a very weakfluorescence in the compatible combination could be observed early after vaccination(2-24hours), after that period, no fluorescence of NO could be observed.2. Similar trend of enzymatic active of NR(Nitrate reductase) and NOS(Nitric oxidesynthase) is obtained, with a rapid upstroke at2-120hours after vaccination, maintaining ahigh level of steady state, then a Sharp decline at240h or264h after vaccination; in thecompatible combination, however, trend of enzymatic active of these two enzymes isunclear, and similar to the control group with vaccination simulation.3. Nitrogen monoxidum induced by early Virus Infection could be eliminated byc-PTIO Pre-injection, besides, Pre-injection of NR Inhibitor or NOS Inhibitor can alsolead to the reduction of NO in early Virus Infection. Fluorescence observation on thecallose in the Interaction process of the incompatible combination, showed whether toeliminate or to decline NO in the early process of Interaction, are making callose formationpostponed, leading to virus induced system infection, gene product of CP could bedetected in unvaccinated upper leaves.As our previous work has demonstrated, callose deposition in Plasmodesmata iscrucial for soybean to resist infestation of SMV. Combining results we discussed above, webelieve that in the process of incompatible soybean and SMV interaction, generation of NO and deposition of callose are induced by the infestation of SMV, the generation of NO isregulated by both NR and NOS enzymatic pathways, and the deposition procedure ofcallose in Plasmodesmata is mediated by NO.