Bacterial community structure and diversity in rhizospheric soil and in stalk of healthy and black shank disease-infected tobacco plants
XIANG Ligang1,2, WANG Hancheng2,3, GUO Hua3,4, ZHOU Hao1,2, XIE Honglian2, CAI Liuti2, DING Wei3, YU Zhihe1
1 College of Life Sciences, Yangtze University, Jingzhou 434025, China; 2 Guizhou Academy of Tobacco Science, Guiyang 550081, China; 3 College of Plant Protection, Southwest University, Chongqing 400715, China; 4 Guizhou Center for Disease Control and Prevention, Guiyang 550004, China
Abstract Black shank is a common soil-borne disease in tobacco. When environmental conditions are appropriate, the pathogens present in soil will penetrate into tobacco plant, and eventually lead to disease of tobacco plant. To understand the changes of bacterial community structure and diversity in rhizosphere soil, diseased stem tissue and symptomatic-asymptomatic junction stem tissue of black shank infected tobacco plants, the hypervariable V3-V4 region of 16S rRNA gene was amplified by PCR, and the amplified fragments were sequenced using Illumina Miseq high-throughput sequencing technology. Bacterial communities structure and diversity in different parts of healthy and black shank infected tobacco plants were analyzed. The richness of bacterial community in rhizosphere soil of black shank infected tobacco plants were higher than that of healthy tobacco plants, while the bacterial diversity was slightly lower than that of healthy tobacco plants. The richness and diversity of diseased stem and symptomatic-asymptomatic junction stem were higher than that of healthy stem, and the increase of symptomatic-asymptomatic junction stem was significant. At phylum level, Proteobacteria, Acidobacteria and Actinobacteria were the dominant phyla in rhizosphere soil. There was no significant difference in relative abundance of dominant phyla between healthy and diseased groups. Proteobacteria and Cyanobacteria were dominant bacteria in stem samples. The relative abundance of Proteobacteria and Cyanobacteria in the symptomatic-asymptomatic junction stem was significantly different from that of healthy stem and diseased stem. At genus level, the main bacteria in rhizosphere soil were Candidatus_solibacter, Gemmatimonas and Sphingomonas, norank_c_Cyanobacteria and Ralstonia were the dominant bacteria in all stem samples. The relative abundance of norank_c_Cyanobacteria in symptomatic-asymptomatic junction stem was significantly different from that in healthy stem and diseased stem. After infected with black shank, the bacterial community structure changed and the diversity of bacterial community increased. The pathogen of bacterial wilt, Ralstonia solanacearum, was detected in all samples, which indicated that there was a possibility of mixed occurrence of tobacco black shank and bacterial wilt. It is therefore necessary to strengthen control of tobacco bacterial wilt while controlling tobacco black shank disease.
XIANG Ligang, WANG Hancheng, GUO Hua, ZHOU Hao, XIE Honglian, CAI Liuti, DING Wei, YU Zhihe. Bacterial community structure and diversity in rhizospheric soil and in stalk of healthy and black shank disease-infected tobacco plants[J]. Acta Tabacaria Sinica, 2020, 26(1): 100-108.