Linking rhizosphere bacterial diversity and soil fertility in tobacco plants under different soil types and cropping pattern in Tanzania: A pilot study

Abstract

Tobacco ( Nicotiana tabacum L.), one of the major crop plants in Tanzania, cropping affects the level of soil fertility, but the reason has not been known. Plant rhizosphere plays an important role in affecting soil fertility through changing microbial composition. We planned a pilot study to understand the changes in microbial composition and soil nutrients in the rhizosphere soils of tobacco in three agro-ecological zone, namely Sikonge, Tabora and Urambo in Tanzania. This study assessed bacteriota composition using 16S rRNA sequencing and soil fertility in the rhizosphere of tobacco plants. The results showed that bacterial diversity in tobacco rhizosphere soils belonged to Proteobacteria phyla, associated significantly ( p < 0.05) with solubilization of insoluble P, K and S. The solubilization of P, K and S in soils facilitates the availability of these nutrients to the tobacco plants (a heavy feeder crop) allows low levels of these nutrients in the soils for the subsequent crop. The Proteobacteria phyla also associated with an increase in soil N content through fixation. Therefore, bacteria diversity in tobacco rhizosphere influence solubilities of macronutrients (P, K, S) and quickly up taken by the tobacco plant and reduces their levels in soils, some bacteria involved in fixing N and increases total N in the soil.

Effects of ecological environment and host genotype on the phyllosphere bacterial communities of cigar tobacco (Nicotiana tabacum L.)

“…For example, Proteobacteria and Actinobacteria participated in the P solubilization for the tobacco plants. Deficiency of P in the soil would limit soil bacterial diversity and abundance (Lisuma et al., 2020 ). The effect of soil nutrients on plant growth and the interactions between leaf mineral contents and phyllosphere bacterial communities are also well documented (Laforest‐Lapointe & Whitaker, 2019 ).…”

“…( 2018 ) also recommended that organic fertilizer application could influence the phyllosphere microbiome through recruiting the manure‐borne bacteria by air. Finally, factors such as chemical composition variations of leaves and leaf exposure to sun would also result in a high phyllosphere microbiome variability over individual plant of the same species (Chen et al., 2021 ; Lisuma et al., 2020 ; Truchado et al., 2017 ). These factors aggravate the exploration of bacterial community response to environmental factors.…”

“…Genotypes, geographical location, and land-use could affect the community of Proteobacteria; normally, we can see the significant different community composition among meadows and mown pastures (Wellner et al, 2011). Tobacco (Nicotiana tabacum L.) is an important agricultural nonfood crop and the main raw material of tobacco commodities worldwide (Chen et al, 2020;Lisuma et al, 2020). It is widely cultivated in South China, such as Hainan and Sichuan (Tang et al, 2020;Yuan et al, 2016;Zhao et al, 2007).…”

“…Tobacco ( Nicotiana tabacum L.) is an important agricultural nonfood crop and the main raw material of tobacco commodities worldwide (Chen et al., 2020 ; Lisuma et al., 2020 ). It is widely cultivated in South China, such as Hainan and Sichuan (Tang et al., 2020 ; Yuan et al., 2016 ; Zhao et al., 2007 ).…”

Genetically Modified Sugarcane Intercropping Soybean Impact on Rhizosphere Bacterial Communities and Co-occurrence Patterns

“…The introduction of drought-resistance genes has been shown to enhance the secretion of root exudates, which further shapes and influences the rhizosphere microbial community of intercropped soybean ( Chun-miao et al, 2015 ). Moreover, a higher diversity of bacterial species around or in the roots plays an important role in the recycling of soil nutrients, and thus, improves soil fertility ( Lisuma et al, 2020 ). Compared with WT sugarcane intercropping, the abundance of Actinobacteria was higher in Inter–Sug ( Figure 4A ), thus, contributing to higher nitrogen fixation, ferrite synthesis, phytohormone synthesis, and solubilization of minerals, which enhanced their availability to plants ( Barka et al, 2016 ).…”