Alfalfa modified the effects of degraded black soil cultivated land on the soil microbial community

Genome-wide Characterization of the MBF1 Gene Family and Its Expression Pattern in Different Tissues and Under Stresses in Medicago truncatula and Medicago sativa

Multiprotein bridging factor 1 (MBF1) is a transcription factor family playing crucial roles in plant development and stress responses. In this study, we analyzed MBF1 genes in Medicago truncatula and Medicago sativa under abiotic stresses, revealing evolutionary patterns and functional differences. Four MBF1 genes were identified in M. truncatula and two in M. sativa, with conserved MBF1 and HTH domains, similar exon/intron structures, and stress-related cis-elements in their promoters. Subcellular localization showed that MtMBF1a.1 is predominantly localized in the nucleus, while MtMBF1a.2, MtMBF1b, MtMBF1c, and MsMBF1a localize to both the nucleus and cytoplasm. In contrast, MsMBF1c is exclusively localized in the cytoplasm. An expression analysis revealed distinct stress responses: salt stress-induced MtMBF1b and MtMBF1c expression but repressed MsMBF1a and MsMBF1c. In contrast, PEG stress did not affect M. truncatula MBF1 genes but repressed both M. sativa MBF1 genes. These findings provide insights into MBF1-mediated stress adaptation and inform strategies for the molecular breeding of stress-tolerant alfalfa.

Arbuscular mycorrhizal fungi communities and promoting the growth of alfalfa in saline ecosystems of northern China

Arbuscular mycorrhizal fungi (AMF) are universally distributed in soils, including saline soils, and can form mycorrhizal symbiosis with the vast majority of higher plants. This symbiosis can reduce soil salinity and influence plant growth and development by improving nutrient uptake, increasing plant antioxidant enzyme activity, and regulating hormone levels. In this study, rhizosphere soil from eight plants in the Songnen saline-alkaline grassland was used to isolate, characterize, and screen the indigenous advantageous AMF. The promoting effect of AMF on alfalfa (Medicago sativa L.) under salt treatment was also investigated. The findings showed that 40 species of AMF in six genera were identified by high-throughput sequencing. Glomus mosseae (G.m) and Glomus etunicatum (G.e) are the dominant species in saline ecosystems of northern China. Alfalfa inoculated with Glomus mosseae and Glomus etunicatum under different salt concentrations could be infested and form a symbiotic system. The mycorrhizal colonization rate and mycorrhizal dependence of G.m inoculation were significantly higher than those of G.e inoculation. With increasing salt concentration, inoculation increased alfalfa plant height, fresh weight, chlorophyll content, proline (Pro), soluble sugar (SS), soluble protein (SP), peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity while decreasing the malondialdehyde (MDA) content and superoxide anion production rate. The results highlight that inoculation with G.m and G.e effectively alleviated salinity stress, with G.m inoculation having a significant influence on salt resistance in alfalfa. AMF might play a key role in alfalfa growth and survival under harsh salt conditions.

Arbuscular Mycorrhizal Fungi Selectively Promoted the Growth of Three Ecological Restoration Plants

Arbuscular mycorrhizal inoculation can promote plant growth, but specific research on the difference in the symbiosis effect of arbuscular mycorrhizal fungi and plant combination is not yet in-depth. Therefore, this study selected Medicago sativa L., Bromus inermis Leyss, and Festuca arundinacea Schreb., which were commonly used for restoring degraded land in China to inoculate with three AMF separately, to explore the effects of different AMF inoculation on the growth performance and nutrient absorption of different plants and to provide a scientific basis for the research and development of the combination of mycorrhiza and plants. We set up four treatments with inoculation Entrophospora etunicata (EE), Funneliformis mosseae (FM), Rhizophagus intraradices (RI), and non-inoculation. The main research findings are as follows: the three AMF formed a good symbiotic relationship with the three grassland plants, with RI and FM having more significant inoculation effects on plant height, biomass, and tiller number. Compared with C, the aboveground biomass of Medicago sativa L., Bromus inermis Leyss, and Festuca arundinacea Schreb. inoculated with AMF increased by 101.30-174.29%, 51.67-74.14%, and 110.67-174.67%. AMF inoculation enhanced the plant uptake of N, P, and K, and plant P and K contents were significantly correlated with plant biomass. PLS-PM analyses of three plants all showed that AMF inoculation increased plant nutrient uptake and then increased aboveground biomass and underground biomass by increasing plant height and root tillering. This study showed that RI was a more suitable AMF for combination with grassland degradation restoration grass species and proposed the potential mechanism of AMF-plant symbiosis to increase yield.

More than a meat- or synthetic nitrogen fertiliser-substitute: a review of legume phytochemicals as drivers of 'One Health' via their influence on the functional diversity of soil- and gut-microbes

Legumes are essential to healthy agroecosystems, with a rich phytochemical content that impacts overall human and animal well-being and environmental sustainability. While these phytochemicals can have both positive and negative effects, legumes have traditionally been bred to produce genotypes with lower levels of certain plant phytochemicals, specifically those commonly termed as 'antifeedants' including phenolic compounds, saponins, alkaloids, tannins, and raffinose family oligosaccharides (RFOs). However, when incorporated into a balanced diet, such legume phytochemicals can offer health benefits for both humans and animals. They can positively influence the human gut microbiome by promoting the growth of beneficial bacteria, contributing to gut health, and demonstrating anti-inflammatory and antioxidant properties. Beyond their nutritional value, legume phytochemicals also play a vital role in soil health. The phytochemical containing residues from their shoots and roots usually remain in-field to positively affect soil nutrient status and microbiome diversity, so enhancing soil functions and benefiting performance and yield of following crops. This review explores the role of legume phytochemicals from a 'one health' perspective, examining their on soil- and gut-microbial ecology, bridging the gap between human nutrition and agroecological science.

Distribution and Pathogenicity of Fusarium Species Associated with Soybean Root Rot in Northeast China

Fusarium root rot is an increasingly severe problem in soybean cultivation. Although several Fusarium species have been reported to infect soybean roots in Heilongjiang province, their frequency and aggressiveness have not been systematically quantified in the region. This study aimed to investigate the diversity and distribution of Fusarium species that cause soybean root rot in Heilongjiang province over two years. A total of 485 isolates belonging to nine Fusarium species were identified, with F. oxysporum and F. solani being the most prevalent. Pot experiments were conducted to examine the relative aggressiveness of different Fusarium species on soybean roots, revealing that F. oxysporum and F. solani were the most aggressive pathogens, causing the most severe root rot symptoms. The study also assessed the susceptibility of different soybean cultivars to Fusarium root rot caused by F. oxysporum and F. solani. The results indicated that the soybean cultivar DN51 exhibited the most resistance to both pathogens, indicating that it may possess genetic traits that make it less susceptible to Fusarium root rot. These findings provide valuable insights into the diversity and distribution of Fusarium species that cause soybean root rot and could facilitate the development of effective management strategies for this disease.

Integrating metagenomics and metabolomics to study the response of microbiota in black soil degradation

As the largest commercial food production base and ecological security barrier, land degradation in black soil areas seriously threatens the global food supply and natural ecosystems. Therefore, determining the response of soil microbiota is crucial to restoring degraded soils. This study combined metagenomics and metabolomics to investigate the effect of different degrees of soil degradation on microbial community composition and metabolic function in black soils. It was found that alpha diversity in degraded soils (Shannon: 22.3) was higher than in nondegraded soil (ND) (Shannon: 21.8), and the degree of degradation significantly altered the structure and composition of soil microbial communities. The results of LEfSe analysis obtained 9 (ND), 7 (lightly degraded, LD), 10 (moderately degraded, MD), and 1 (severely degraded, SD) biomarkers in four samples. Bradyrhizobium, Sphingomonas, and Ramlibacter were significantly affected by soil degradation and can be considered biomarkers of ND, MD, and SD, respectively. Soil nutrient and enzyme activities decreased significantly with increasing black soil degradation, soil organic matter (SOM) content decreased from 11.12 % to 1.97 %, and Sucrase decreased from 23.53 to 6.59 mg/g/d. In addition, C was the critical driver affecting microbial community structure, contributing 61.2 % to differences in microbial community distribution, and microbial altering relative abundance which participle in the carbon cycle to respond to soil degradation. Metabolomic analyses indicated that soil degradation significantly modified the soil metabolite spectrum, and the metabolic functions of most microorganisms responding to soil degradation were adversely affected. The combined multi-omics analysis further indicated that biomarkers dominate in accumulating metabolites. These findings confirmed that due to their role in the composition and functioning of these degraded soils, these biomarkers could be employed in strategies for managing and restoring degraded black soils.