Soil applied Ca, Mg and B altered phyllosphere and rhizosphere bacterial microbiome and reduced Huanglongbing incidence in Gannan Navel Orange

Yingjie Zhou; Yanni Tang; Chengxiao Hu; Ting Zhan; Simin Zhang; Miaomiao Cai; Xiaohu Zhao

doi:10.1016/j.scitotenv.2021.148046

Soil applied Ca, Mg and B altered phyllosphere and rhizosphere bacterial microbiome and reduced Huanglongbing incidence in Gannan Navel Orange

Sci Total Environ. 2021 Oct 15:791:148046. doi: 10.1016/j.scitotenv.2021.148046. Epub 2021 May 26.

Authors

Yingjie Zhou¹, Yanni Tang¹, Chengxiao Hu¹, Ting Zhan¹, Simin Zhang¹, Miaomiao Cai¹, Xiaohu Zhao²

Affiliations

¹ College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for New-Type Fertilizer, Wuhan 430070, China; Research Center of Trace Elements, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China.
² College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Hubei Provincial Engineering Laboratory for New-Type Fertilizer, Wuhan 430070, China; Research Center of Trace Elements, Wuhan 430070, China; Hubei Key Laboratory of Soil Environment and Pollution Remediation, Wuhan 430070, China. Electronic address: xhzhao@mail.hzau.edu.cn.

PMID: 34118675
DOI: 10.1016/j.scitotenv.2021.148046

Abstract

Huanglongbing (HLB) caused by 'Ca. Liberibacter. Asiaticus (Clas)' is one of the destructive diseases for citrus, threatening the development of citrus industry. Adopting a proper fertilization method instead of using pesticides seems particularly important, which would contribute to a sustainable development of orchard. In this study, the impact of soil application of nutrients combined with foliar spray of macro- and micro-nutrients on the incidence of HLB and the phyllosphere and rhizosphere bacterial microbiome was investigated in Gannan Navel Orange orchard from 2015 to 2018. Compared with the control (T1), the yield of Gannan Navel Orange in all other treatments applied with macro- and micro-nutrients increased significantly in 2018 (by 20.5%-45.8%), but not in the first two years (2016-17). Among treatments, Ca + Mg + B application in soil (T2) showed the highest yield and lowest HLB incidence. According to the PCR results, CLas was negative in T2 but positive in the control, which directly proved HLB incidence was reduced with Ca + Mg + B application in soil. Moreover, 16S rRNA sequencing was used to characterize rhizosphere and phyllosphere microbial communities. Results showed that microbial biodiversity was increased and microbial community structure was altered in T2 treatment, of which the beneficial bacteria were enriched in phyllosphere and rhizosphere. The results of PICRUSt showed that in T2 treatment, rhizosphere microbe contained more membrane transport (ABC transporters) genes, while, carbohydrate metabolism genes were enriched in the control rhizosphere due to HLB obstruct the photosynthetic metabolite transport. In summary, results indicated that macro- and micro-nutrients application improved the yield of Gannan Navel Orange and soil application of Ca + Mg + B reduced HLB incidence by altering microbial community structure and increasing microbial biodiversity. This study developed an environment-friendly way to reduce HLB incidence and improve the yield of citrus.

Keywords: Gannan Navel Orange; Huanglongbing; Macro- and micro-nutrients; Phyllosphere microbe; Rhizosphere microbe.

MeSH terms

Citrus*
Incidence
Microbiota*
Plant Diseases
RNA, Ribosomal, 16S
Rhizobiaceae* / genetics
Rhizosphere
Soil

Substances

RNA, Ribosomal, 16S
Soil