Study On The Fusarium Graminearum Toxin Impact On Wild Soybean Seedlings

Fusarium is one of the advantages of pathogenic bacteria in the soil, which can infect many kindsof plants, Causing plants dried up and wilting, has brought great damage to the production of agriculture.The Fusarium graminearum is One of the most important pathogenic bacteria, it not only can invadingmany different crops in different parts, causing seed, root and ear rot and so on, resulting in loss ofproduction, but also produce the toxins in the process of infection, bring a serious threat to human andanimal health. Along with the reform of farming system and the global warming, F. graminearum infectionof expanded, and more and more damage to crops. Studies have been reported that F. graminearum is oneof the pathogens of soybean root rot, the toxins which Produced by F. graminearum have certain inhibitoryeffect on the development of the growth of soybean. Wild soybean is wild species of cultivated soybean,Which has good Stress tolerance and disease resistance.In this paper, F. graminearum as materials, comparison of different extraction methods of F.graminearum toxin and its activity; selected the active carbon adsorption is the better extraction methods oftoxin; F. graminearum toxin was studied in the toxicity of wild soybean (X11) seedlings; under the toxinstress, the changes have been studied in metabolic activity of Wild soybean (X11) seedlings and the cellapoptosis induction effect of wild soybean (X11) root tip, and bying the conservative sequence of NBS typeof resistance genes have been cloned plants designed primers, used to wild soybean disease resistance genehomologous sequence analysis and detection. The main results were as follows:Under the two liquid medium of PD and PSC, the inhibitory effect of crude toxin that formculture filtrate, mycelial extract on the growth of soybean radicle is different, and PD medium is moreconducive to F. graminearum hyphae growth and toxin production than PSC medium. Inhibition rate ofradicle growth between the different soybean varieties have reached significant difference level. It waspossibe that culture filtrate was used to identify resistivity of soybean varieties to root. Compered sixdifferent extract methods, show that the toxin extracted by activated carbon adsorption method had a higherinhibition rate, it can be used for the extraction of toxins. F. graminearum toxin solution has strong heatstability.F. graminearum toxin could be harmful to seedling root of wild soybean. The symptoms of thetoxin inducing lesion on root were similar to the syptoms caused by the pathogen after inoculation. After soybean roots were inoculated by toxin, The inhibition rate and recovery ability of radicle growth havesignificant inhibite effection.After treatment with toxin reduced the root activity, affect the normalmetabolism of root.Within24h after25%and50%toxin treatment, protein content decreased in wild soybeanseedlings roots, the change is relatively stable in leaves, after24h protein content have a bigger rise. Afterwild soybean seedlings inoculated by toxin filtrate, root, stems and leaves showed increased first and thendecreased. The content of MDA in seedling showed up-down trend. After toxin treatment, PPO and PALactivity in wild soybean seedling roots, stems and leaves have increased, and appeared a trend of bimodaltype change. The activity of POD increased firstly and then decreased, the twists and turns of the upwardtrend.After Toxin treatment the the death rate of root cap cell was on the increase with the increase ofconcentration of toxin, indicating that F. graminearum toxin has induced apoptosis effect on wild soybeanroot cap cells. Appropriate concentration of F. graminearum toxin stress can induce root tip cellprogrammed cell death, after12h toxin treatment, cells DNA in degradation, the brightness and width ofDNA ladder bands gradually weakened with increasing treatment intensity, the final degradation for smallfragments. After induction by toxins, the NBS stripe disease resistance genes could be amplified from wildsoybean DNA and RNA, this shows that wild soybean be likely to contain potential resistance genes.