Effects of Temperature and Nitrogen Application on Carbon and Nitrogen Accumulation and Bacterial Community Composition in Apple Rhizosphere Soil

Abstract

Malus sieversii grows on the slopes of the Tianshan Mountains in Xinjiang where the difference in daily temperature is significant. In recent years, the rhizosphere soil health of Malus sieversii has been severely impacted by anthropogenic disturbance and pathogenic infestation. The soil nutrient content and soil microorganism diversity are the main components of soil health. Low temperature has negative effects on soil bacterial community structure by inhibiting the accumulation of carbon and nitrogen. However, the effects of temperature and nitrogen application on soil carbon and nitrogen accumulation and the bacterial community composition in the rhizosphere soil of Malus sieversii are unclear. We set two temperature levels, i.e., low temperature (L) and room temperature (R), combined with no nitrogen (N0) and nitrogen application (N1) to explore the response of plant carbon and nitrogen uptake, rhizosphere soil carbon and nitrogen accumulation and bacterial community composition to temperature and nitrogen fertilization. At the same temperature level, plant 13C abundance (P-Atom13C), plant 15N absolute abundance (P-Con15N), soil 15N abundance (S-Atom15N) and soil urease, protease and glutaminase activities were significantly higher under nitrogen application compared with the no-nitrogen application treatment. The bacterial community diversity and richness indices of the apple rhizosphere soil in the N1 treatment were higher than those in the N0 treatment. The relative abundances of Actinobacteria, Rhodopseudomonas, and Bradyrhizobium were higher in the LN1 treatment than in the LN0 treatment. Redundancy analysis (RDA) showed that plant 13C absolute abundance (P-Con13C) and plant 15N absolute abundance (P-Con15N) were the main factors affecting the soil bacterial community composition. In summary, Nitrogen application can alleviate the effects of low temperature stress on the soil bacterial community and is of benefit for the uptakes of carbon and nitrogen in Malus sieversii plants.

The response of nutrient cycle, microbial community abundance and metabolic function to nitrogen fertilizer in rhizosphere soil of Phellodendron chinense Schneid seedlings

“…N is a crucial element in soil, with substantial effects on physicochemical properties, enzyme activities, and the relative expression abundances of genes related to nutrient element metabolism ( Cardinale et al, 2020 ; Chen et al, 2021 ; Zhang H. et al, 2022 ). Previous studies showed that N addition significantly decreased the soil pH value and SOC content, but increased the contents of soil NO 3 − -N, TN and available N in soil of wheat and Cunninghamia lanceolata forests, suggesting that N input regulated rhizosphere soil physicochemical properties by promoting soil acidification ( Liu et al, 2022 ; Xu et al, 2022 ).…”

Impacts of Oak Mulch Amendments on Rhizosphere Microbiome of Citrus Trees Grown in Florida Flatwood Soils

“…Additionally, the CCA infers that the rhizosphere bacterial communities were also significantly correlated with the soil temperature between the oak mulch and the controltreated soils in April 2021 (Figure 8) and October 2021 (Figure 9). When examining the effects of temperature on the rhizosphere bacterial communities of wild apple trees (Malus sieversii), [51] found a positive correlation between the soil temperature and community structure and diversity. Soil temperature is known as a soil-limiting factor that can impact the establishment and respiration of soil microorganisms, enzyme dynamics, and plant development [52], likely playing a role in the observed differences in the rhizosphere community composition between the oak mulch and control-treated soils of the citrus trees (Figure 6B).…”

Elevational patterns of microbial species richness and evenness across climatic zones and taxonomic scales

“…The diversified evenness–elevation patterns in soil bacterial community were consistent with that of aquatic bacteria across different climatic regions (Nogues‐Bravo et al, 2008 ). One possible explanation for the contrast elevational patterns in climatic zones is the effects of temperate on the distribution and abundance of soil bacterial communities (Zhang et al, 2022 ). For instance, in the tropical forest, the high temperature and precipitation levels may favor certain bacterial taxa that are adapted to such conditions, resulting in a more even distribution of species across the elevation gradient.…”