Characteristics of Rhizosphere Microbiome, Soil Chemical Properties, and Plant Biomass and Nutrients in <i>Citrus reticulata</i> cv. Shatangju Exposed to Increasing Soil Cu Levels
Xiaorong Mo,
Qichun Huang,
Chuanwu Chen,
Hao Xia,
Muhammad Riaz,
Xiaomin Liang,
Jinye Li,
Yilin Chen,
Qiling Tan,
Songwei Wu,
Chengxiao Hu
Affiliations
Xiaorong Mo
Guangxi Key Laboratory of Marine Environment Change and Disaster in Beibu Gulf, College of Resources and Environment, Beibu Gulf University, Qinzhou 535011, China
Qichun Huang
Guangxi Academy of Agricultural Sciences, Nanning 530007, China
Chuanwu Chen
Guangxi Laboratory of Germplasm Innovation and Utilization of Specialty Commercial Crops in North Guangxi, Guangxi Academy of Specialty Crops, Guilin 541004, China
Hao Xia
Tobacco Research Institute, Anhui Academy of Agricultural Sciences (AAAS), Hefei 230001, China
Muhammad Riaz
College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
Xiaomin Liang
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
Jinye Li
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
Yilin Chen
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
Qiling Tan
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
Songwei Wu
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
Chengxiao Hu
Microelement Research Center, Hubei Provincial Engineering Laboratory for New Fertilizers, Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, China
The prolonged utilization of copper (Cu)-containing fungicides results in Cu accumulation and affects soil ecological health. Thus, a pot experiment was conducted using Citrus reticulata cv. Shatangju with five Cu levels (38, 108, 178, 318, and 388 mg kg−1) to evaluate the impacts of the soil microbial processes, chemistry properties, and citrus growth. These results revealed that, with the soil Cu levels increased, the soil total Cu (TCu), available Cu (ACu), organic matter (SOM), available potassium (AK), and pH increased while the soil available phosphorus (AP) and alkali-hydrolyzable nitrogen (AN) decreased. Moreover, the soil extracellular enzyme activities related to C and P metabolism decreased while the enzymes related to N metabolism increased, and the expression of soil genes involved in C, N, and P cycling was regulated. Moreover, it was observed that tolerant microorganisms (e.g., p_Proteobacteria, p_Actinobacteria, g_Lysobacter, g_Sphingobium, f_Aspergillaceae, and g_Penicillium) were enriched but sensitive taxa (p_Myxococcota) were suppressed in the citrus rhizosphere. The citrus biomass was mainly positively correlated with soil AN and AP; plant N and P were mainly positively correlated with soil AP, AN, and acid phosphatase (ACP); and plant K was mainly negatively related with soil β−glucosidase (βG) and positively related with the soil fungal Shannon index. The dominant bacterial taxa p_Actinobacteriota presented positively correlated with the plant biomass and plant N, P, and K and was negatively correlated with plant Cu. The dominant fungal taxa p_Ascomycota was positively related to plant Cu but negatively with the plant biomass and plant N, P, and K. Notably, arbuscular mycorrhizal fungi (p_Glomeromycota) were positively related with plant P below soil Cu 108 mg kg−1, and pathogenic fungi (p_Mortierellomycota) was negatively correlated with plant K above soil Cu 178 mg kg−1. These findings provided a new perspective on soil microbes and chemistry properties and the healthy development of the citrus industry at increasing soil Cu levels.
