Effects Of Petroleum Pollution On Mirabilis Jalapa And The Rhizosphere Microorganism Population Diversity

With a large number of petroleum mining applications, petroleum pollution is also increasing, caused by human concern. This paper is based on the research of the rhizosphere soil of Mirabilis jalapa under the condition of petroleum pollution treatment. By using the methods of traditional and modern molecular biology, the activities changes of CAT, PPO and Urease in the soil surrounding the roots of Mirabilis jalapa were studied at different time and different petroleum contaminated soil. Furthermore, diversity changes of bacterium were also assayed by high throughput sequencing. By high throughput sequencing of the V4 region of 16S RNA of soil bacteria, the diversity of the community structure of the soil bacteria in the rhizosphere of Mirabilis jalapa was analyzed, and provides theoretical support for the bioremediation of Mirabilis jalapa, also provides the basis for the study of plants microorganism combined remediation mechanism, the results are shown as follows:1. Petroleum pollution can affect the growth of Mirabilis jalapa and Orychophragmus violaceus. In the process of seed germination, the germination rate of Mirabilis jalapa was greater than that of the Orychophragmus violaceus seed germination rate, and the germination rate of the two plants showed a downward trend. In the seedling stage (15 d), high concentration of petroleum pollution (10 g/kg and 15 g/kg) had a promotion effect on the two kinds of plants. In the later stage of the experiment, the petroleum significantly inhibited the growth of Orychophragmus violaceus. Petroleum pollution concentration increased gradually Mirabilis root length and root fresh weight increased, while Orychophragmus violaceus length and root fresh weight was significantly reduced.2. Monitoring the change of enzyme activity in the rhizosphere soil of Mirabilis jalapa. The experimental petroleum treatment concentration is 0 g/kg、5 g/kg、10 g/kg and 15 g/kg, Samples were sampled at 15 days,30 days,45 days, and 60 days. In low concentration treatment, catalase activity was the lowest, then slightly restored, but the difference was not significant. The changes of enzyme activities in different time treatment groups increased slightly, but not significantly. In the petroleum concentration, the activity of polyphenol oxidase increased and then decreased slowly. When petroleum pollution concentrations is 15 g/kg, the maximum value of PPO activity is reached the experiment at 30 d. The effect of petroleum pollution on the activity of polyphenol oxidase in the rhizosphere soil of Mirabilis jalapa was explained. The law of urease and polyphenol oxidase is the same. With the increase of petroleum concentration, urease activity increased and then decreased. The values of ck in the control group were observed, and the activity of urease was less than that of the samples, and the change was obvious with the increase of time. Petroleum pollutants can produce different effects on different enzymes, and the response time of the enzyme is slightly different.3. Petroleum pollution has an impact on the diversity of Mirabilis jalapa rhizosphere microbial populations. From the OTU Venn diagram found an increase in the number of OUT in the presence of petroleum pollution. According to the determination of the number of rhizosphere microorganisms in the clean soil of Orychophragmus violaceus and Mirabilis jalapa show:the number of microorganisms in the rhizosphere of Orychophragmus violaceus was more than that of the Mirabilis jalapa rhizosphere microorganisms, and both of them were more than ck group of soil microorganisms. The rhizosphere microorganisms of Mirabilis jalapa are more than the number of Orychophragmus violaceus in the petroleum pollution stress. It showed that the Mirabilis jalapa was more conducive to the growth of microorganisms in the petroleum stress than Orychophragmus violaceus. This may also indicate that the mechanism of the resistance to petroleum stress is more than that Orychophragmus violaceus. Through the bacterial population diversity was analyzed by the method of microbial V4 16S RNA region sequencing in the absence of processing plants. In case of petroleum pollution of soil microbial diversity was significantly reduced. Under the petroleum stress, planting Mirabilis jalapa can increase the rhizosphere microbial diversity of petroleum contaminated soil. Planting Mirabilis jalapa can increase the rhizosphere microbial diversity of petroleum contaminated soil. And the high abundance of bacterial species: Sphingobium, Opitutus, Actinocorallia, etc.