Interaction ofPseudostellaria heterophyllawith Quorum Sensing and Quorum Quenching Bacteria Mediated by Root Exudates in a Consecutive Monoculture System.
Many plant-pathogenic bacteria are dependent on quorum sensing (QS) to evoke disease. In this study, the population of QS and quorum quenching (QQ) bacteria was analyzed in a consecutive monoculture system ofPseudostellaria heterophylla. The isolated QS strains were identified asSerratia marcescenswithSwrIR-type QS system and exhibited a significant increase over the years of monoculture. Only one QQ strain was isolated from newly planted soil sample and was identified asBacillus thuringiensis, which secreted lactonase to degrade QS signal molecules. Inoculation ofS. marcescenstoP. heterophyllaroot could rapidly cause wilt disease, which was alleviated byB. thuringiensis. Furthermore, the expression of lactonase encoded by theaiiAgene inS. marcescensresulted in reduction of its pathogenicity, implying that the toxic effect ofS. marcescenson the seedlings was QS-regulated. Meanwhile, excess lactonase inS. marcescensled to reduction in antibacterial substances, exoenzymes, and swarming motility, which might contribute to pathogensis on the seedlings. Root exudates and root tuber extracts ofP. heterophyllasignificantly promoted the growth ofS. marcescens, whereas a slight increase ofB. thuringiensiswas observed in both samples. These results demonstrated that QS-regulated behaviors inS. marcescensmediated by root exudates played an important role in replanting diseases ofP. heterophylla.
Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea.|Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Liaoyuan
L
Zhang
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Zewang
Z
Guo
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Huifang
H
Gao
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Xiaoqian
X
Peng
College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Yongyu
Y
Li
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Shujing
S
Sun
Department of Chemical Engineering, Konkuk University, Seoul 05029, Republic of Korea.
Jung-Kul
JK
Lee
Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, College of Life Sciences, Gutian Edible Fungi Research Institute, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province, 350002, P.R. China.
Wenxiong
W
Lin
D001413:Bacillus thuringiensis / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D029748:Caryophyllaceae / Q000378:metabolism / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000382:microbiology*; D053147:Plant Exudates / Q000378:metabolism*; D018517:Plant Roots / Q000382:microbiology*; D053038:Quorum Sensing; D012706:Serratia marcescens / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*
D053147:Plant Exudates
P. heterophylla; consecutive monoculture; interaction; quorum quenching; quorum sensing; root exudates