AMF regulates cysteine and methionine metabolic pathways in continuous
cropped soybean roots by alleviating sulfur deficiency in soybean
Abstract
Abstracts: Soybean ( Glycine max L.), a vital widely
grown grain and oilseed crop in northeastern China, often suffers yield
and quality issues from sulfur deficiency due to continuous cropping and
its high sulfur demand, resulting in reduced soil sulfur content. This
study aimed to enhance soybean soil-available sulfur absorption by
inoculating with a clumping arbuscular mycorrhizal fungus (AMF),
specifically Funneliformis mosseae, to improve sulfur utilization
in the soybean root system and alleviate sulfur deficiency in
continuously cropped soybean. The experiment used the soybean variety
“Heinong 48” as the test material, and involved four treatments in
pots over three years, with soil inoculated with F. mosseae in
both non-continuous and continuous cropping systems. Physiological
indicators such as soybean mycorrhizal infestation rate, sulfur content,
cysteine (Cys), glutathione (GSH), and β-thioglucoside levels were
measured. Additionally, functional genes and differential metabolites
involved in sulfur metabolism within cysteine and methionine metabolism
pathways in soybean roots were analyzed using a combination of
transcriptomics and metabolomics methods. The results demonstrated that
inoculation with F. mosseae increased Cys, β-thioglucoside, GSH
and sulphur contents in soybean roots. It enhanced the enrichment of the
cysteine and methionine metabolism pathway and significantly
up-regulated the expression of key regulatory genes, such as
ACO1 and At5g53970, and the sulfur metabolite
5’-methylthioadenosine. Consequently, F. mosseae effectively
regulates cysteine and methionine metabolism in soybean roots,
promotes root sulfur uptake, and mitigates the sulfur deficiency barrier
in continuous soybean cropping. Therefore, this study provides a
theoretical basis for applying AMF microbial fungicidesin continuous
soybean cropping production.