AUTHOR=Zhang Fengjuan , Sun Jianru , Wang Chang , Li Chunying , Chen Fengxin , Xu Haiyun , Chen Xue 

TITLE=Bacillus benefits the competitive growth of Ambrosia artemisiifolia by increasing available nutrient levels

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1069016

DOI=10.3389/fpls.2022.1069016

ISSN=1664-462X

ABSTRACT=<p><italic>Bacillus</italic> can help plants to acquire nutrients either directly or indirectly. However, the role of <italic>Bacillus</italic> community on the competitive growth of invasive <italic>Ambrosia artemisiifolia</italic> is poorly understood. Native <italic>Setaria viridis</italic> is often found in areas that have been invaded by <italic>A. artemisiifolia</italic>. We sought to determine whether the quantitative and/or qualitative differences in the <italic>Bacillus</italic> community present on the invasive <italic>A. artemisiifolia</italic> and native <italic>S.viridis</italic> provide a competitive advantage to the invasive over native species. A field experiment was established to imitate the invasion of <italic>A. artemisiifolia</italic>. The 16S rRNA gene was commercially sequenced to identify the bacilli isolated from the rhizosphere soil of field-grown <italic>A. artemisiifolia</italic> and <italic>S. viridis</italic>. The <italic>Bacillus</italic> communities in their rhizosphere were compared, and their effects on the competitive growth of <italic>A. artemisiifolia</italic> and <italic>S. viridis</italic> were tested in the pot experiments. <italic>Bacillus</italic> in the rhizosphere soil of <italic>A. artemisiifolia</italic> significantly enhanced its intra-specific competitive ability. The relative abundance of <italic>B. megaterium</italic> in the rhizosphere soil of <italic>A. artemisiifolia</italic> was significantly higher than that of <italic>S. viridis</italic>. Inoculation with <italic>B. megaterium</italic> that was isolated from the rhizosphere soil of both <italic>A. artemisiifolia</italic> and <italic>S. viridis</italic> significantly enhanced the relative competitiveness of <italic>A. artemisiifolia</italic> and inhibited that of <italic>S. viridis</italic>. The higher abundance of <italic>B. megaterium</italic> in the rhizosphere of <italic>A. artemisiifolia</italic> creates higher levels of available nutrients than that in the native <italic>S. viridis</italic>, which enhance the competitive growth of <italic>A. artemisiifolia</italic>. The result helps to discover the mechanism of <italic>Bacillus</italic> community in the invasion of <italic>A. artemisiifolia</italic>.</p>