Polycyclic Aromatic Hydrocarbons Effect on the phyllosphere bacterial community of Gliricidia sepium leaves

Abstract

Plants and microorganisms can coexist in such a way that each of these two heterospecific organisms benefit from this association. In the environment of plants there are several habitats of bacteria among them the phyllosphere which is the aerial part of the plant. The phyllosphere can be influenced by several factors including hydrocarbons. Thus, polycyclic aromatic hydrocarbons (PAHs) have been used to assess their influence on the phyllosphere microorganisms of the leaves of Gliricidia sepium. The results showed that the atmospheric concentrations of PAHs are rather high in rural areas. The spatial patterns of atmospheric concentrations of PAHs showed higher concentrations of naphthalene in the two experimental group due to the high road traffic. In the different experimental groups, 93626 and 96954 OTUs were identified in the leaves collected on the road (SR) and out of the road (SH), respectively. In this present study, the leaves harvested on the road which are more exposed to PAHs present a strongly elevated relative abundance of Actinobacteria and Bacilli. It can therefore easily deduce that these bacteria could have developed a kind of resistance to these road PAHs. On the other hand, bacteria belonging to the Alphaproteobacteria class are significantly less represented in this rural area.