Variation in microbial CAZyme families across degradation severity in a steppe grassland in northern China

Abstract

Little is known about the effects of grassland degradation on the carbohydrate-active enzyme (CAZYme) genes responsible for C cycling. Here we used a metagenomic approach to reveal variation in abundance and composition of CAZyme genes in grassland experiencing a range of degradation severity (i.e., non-, light, moderately, and severely degraded) in two soil layers (0–10 cm, 10–20 cm) in a steppe grassland in northern China. We observed a higher CAZyme abundance in severely degraded grassland compared with the other three degradation severities. Glycoside hydrolase (GH) and glycosyltransferase (GT) were identified as the most abundant gene families. The Mantel test and variation partitioning suggested an interactive effect of degradation severity and soil depth with respect to CAZyme gene composition. Structural equation modeling indicated that total soil carbon, microbial biomass carbon and organic carbon were the three soil characteristics most important to CAZyme abundance, which suggests an interaction between degradation and soil carbon fractions in determining CAZyme gene composition. Both above- and below-ground factors linked to soil organic matter play a central role in determining the abundance of CAZyme gene families.

Response of Rice Grain Yield and Soil Fertility to Fertilization Management under Three Rice-Based Cropping Systems in Reclaimed Soil

“…To test this hypothesis, we performed an analysis comparing different treatments, examining the physicochemical properties of the soil, enzyme activity, and microbial factors related to carbohydrate-active enzymes (CAZymes). CAZymes encompass a variety of enzymes involved in carbohydrate synthesis and degradation, and their presence could potentially reflect the carbon cycling potential of the microbial community [31]. This research holds significant importance as it has the potential to provide valuable scientific insights and practical guidance for improving soil quality, enhancing crop production, and promoting sustainable agricultural practices in infertile or reclaimed soils.…”

Microbial carbohydrate-active enzymes influence soil carbon by regulating the of plant- and fungal-derived biomass decomposition in plateau peat wetlands under differing water conditions

“…However, the role of carbohydrate-activated enzymes (CAZyme) in the function of carbon cycling in high-altitude peatlands has not been reported, and the gene abundance of CAZyme interacts with the degree of degradation and soil depth, and the gene abundance of CAZyme is influenced by soil degradation and depth. It is also possible that they do not share the same water conditions, which then affect the dynamic changes of the enzyme to indirectly affect the carbon cycle ( Žifčáková et al, 2017 ; Zhang Q. et al, 2023 ). Different degrees of succession in peatlands caused by differences in soil water changes led to changes in enzyme activity and nutrient content ( Jing et al, 2022 ; Yu-ting et al, 2022 ) and plant litter, root secretions, and soil humus decomposition are all impacted by differences in soil water ( Chen et al, 2018 ; Zhang et al, 2020 ).…”