AUTHOR=Wu Hongmiao , Wu Linkun , Wang Juanying , Zhu Quan , Lin Sheng , Xu Jiahui , Zheng Cailiang , Chen Jun , Qin Xianjin , Fang Changxun , Zhang Zhixing , Azeem Saadia , Lin Wenxiong 

TITLE=Mixed Phenolic Acids Mediated Proliferation of Pathogens Talaromyces helicus and Kosakonia sacchari in Continuously Monocultured Radix pseudostellariae Rhizosphere Soil

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00335

DOI=10.3389/fmicb.2016.00335

ISSN=1664-302X

ABSTRACT=<p><italic>Radix pseudostellariae</italic> L. is a common and popular Chinese medication. However, continuous monoculture has increased its susceptibility to severe diseases. We identified two pathogenic microorganisms, <italic>Talaromyces helicus</italic> M. (KU355274) and <italic>Kosakonia sacchari</italic> W. (KU324465), and their antagonistic bacterium, <italic>Bacillus pumilus</italic> Z. in rhizosphere soil of continuously monocultured <italic>R. pseudostellariae</italic>. Nine types of phenolic acids were identified both in the rhizosphere soil and in culture medium under sterile conditions. A syringic acid and phenolic acid mixture significantly promoted the growth of <italic>T. helicus</italic> and <italic>K. sacchari</italic>. <italic>T. helicus</italic> could utilize eight types of phenolic acids, whereas <italic>K. sacchari</italic> could only use four phenolic acids. <italic>K. sacchari</italic> produced protocatechuic acid when consuming vanillin. Protocatechuic acid negatively affected the growth of <italic>B. pumilus</italic>. The 3A-DON toxin produced by <italic>T. helicus</italic> promoted the growth of <italic>K. sacchari</italic> and inhibited growth of <italic>B. pumilus</italic> at low concentrations. These data help explain why phenolic exudates mediate a microflora shift and structure disorder in the rhizosphere soil of continuously monocultured <italic>R. pseudostellariae</italic> and lead to increased replanting disease incidence.</p>