Effect of azoxystrobin on tobacco leaf microbial composition and diversity

Meili Sun; Hancheng Wang; Caihua Shi; Jianjun Li; Liuti Cai; Ligang Xiang; Tingting Liu; Paul H Goodwin; Xingjiang Chen; Ling Wang

doi:10.3389/fpls.2022.1101039

Effect of azoxystrobin on tobacco leaf microbial composition and diversity

Front Plant Sci. 2023 Feb 1:13:1101039. doi: 10.3389/fpls.2022.1101039. eCollection 2022.

Authors

Meili Sun^{1

2}, Hancheng Wang², Caihua Shi¹, Jianjun Li³, Liuti Cai², Ligang Xiang^{1

2}, Tingting Liu^{1

2}, Paul H Goodwin⁴, Xingjiang Chen², Ling Wang⁵

Affiliations

¹ College of Agriculture, Yangtze University, Jingzhou, Hubei, China.
² Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China.
³ College of Tropical Crops, Hainan University, Haikou, Hainan, China.
⁴ School of Environmental Sciences, University of Guelph, Guelph, ON, Canada.
⁵ Guizhou Bijie Tobacco Company, Bijie, Guizhou, China.

Abstract

Azoxystrobin, a quinone outside inhibitor fungicide, reduced tobacco target spot caused by Rhizoctonia solani by 62%, but also affected the composition and diversity of other microbes on the surface and interior of treated tobacco leaves. High-throughput sequencing showed that the dominant bacteria prior to azoxystrobin treatment were Methylobacterium on healthy leaves and Pseudomonas on diseased leaves, and the dominant fungi were Thanatephorous (teleomorph of Rhizoctonia) and Symmetrospora on healthy leaves and Thanatephorous on diseased leaves. Both bacterial and fungal diversity significantly increased 1 to 18 days post treatment (dpt) with azoxystrobin for healthy and diseased leaves. For bacteria on healthy leaves, the relative abundance of Pseudomonas, Sphingomonas, Unidentified-Rhizobiaceae and Massilia declined, while Methylobacterium and Aureimonas increased. On diseased leaves, the relative abundance of Sphingomonas and Unidentified-Rhizobiaceae declined, while Methylobacterium, Pseudomonas and Pantoea increased. For fungi on healthy leaves, the relative abundance of Thanatephorous declined, while Symmetrospora, Sampaiozyma, Plectosphaerella, Cladosporium and Cercospora increased. On diseased leaves, the relative abundance of Thanatephorous declined, while Symmetrospora, Sampaiozyma, Plectosphaerella, Cladosporium, Phoma, Pantospora and Fusarium, increased. Compared to healthy leaves, azoxystrobin treatment of diseased leaves resulted in greater reductions in Thanatephorous, Sphingomonas and Unidentified-Rhizobiaceae, a greater increase in Methylobacterium, and similar changes in Phoma, Fusarium, Plectosphaerella and Cladosporium. Azoxystrobin had a semi-selective effect altering the microbial diversity of the tobacco leaf microbiome, which could be due to factors, such as differences among bacterial and fungal species in sensitivity to quinone outside inhibitors, ability to use nutrients and niches as certain microbes are affected, and metabolic responses to azoxystrobin.

Keywords: azoxystrobin; high-throughput sequencing; leaf microorganisms; microbial composition; tobacco target spot.

Grants and funding

This study received funding from Guizhou Science Technology Foundation (No. ZK[2021]Key036), the National Natural Science Foundation of China (No. 32160522 and 31960550), China National Tobacco Corporation (No. 110202001035(LS-04), No. 110202101048(LS-08) and 110202101045(LS-05)), ‘Hundred’ Level Innovative Talent Foundation of Guizhou Province (No. GCC[2022]028-1), and Guizhou Tobacco Company (No. 2020XM22 and 2020XM03). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. All authors declare no other competing interests.