Search Results (583)

Correct floral morphology determines the accuracy of fruit formation, which is crucial for reproductive success in higher plants. Despite this, an abnormal, multi-pistil phenotype has been observed in the flowers of many plants. In this review, we gather information on the multi-pistil phenomenon in various species and highlight potential causes, as well as possible consequences, of the trait. Our assessment of the reported multi-pistil phenotype in rice (Oryza sativa L.), wheat (Triticum aestivum L.), tomato (Solanum lycopersicum L.), Medicago, sweet cherry (Prunus avium L.), rye (Secale cereale L.), and rapeseed (Brassica napus L. and B. campestris L.) leads us to conclude that hybridization and mutation are the main factors that give rise to this phenotype. We also delve into the inheritance patterns of the multi-pistil phenotype and factors that influence this trait, such as nuclear–cytoplasmic interactions, temperature conditions, and shading. Finally, we discuss the effects of multi-pistil flowers on the yield of these plants. This analysis increases our understanding of floral development and lays the foundation for the potential utilization of the multi-pistil trait to increase seed production in crops. Full article

Alfalfa (Medicago sativa), recognized as the most valuable legume feed crop, faces significant challenges in enhancing both qualitative and quantitative production amidst the pressures of climate change. This review highlights these challenges, including the underutilization of genomic and genetic resources, while proposing potential solutions through genome editing. Our focus is on leveraging CRISPR/Cas technology in conjunction with decades of advancements in conventional breeding to expedite the improvement of alfalfa. By adopting this approach, we aim to overcome the limitations of traditional alfalfa improvement approaches and accelerate the development of improved cultivars capable of thriving in changing climates. Key candidate traits for CRISPR/Cas genome editing, as reviewed in the latest literature, include nutrient use efficiency, freezing tolerance, and resistance to pests and diseases. We dissect literature on potential gene pathways associated with these traits, providing molecular breeders with valuable insights for utilizing CRISPR/Cas genome editing. Furthermore, we propose editing modalities to expedite the development of stress-resilient, genome-edited alfalfa that can effectively cope with climate change. Full article

This research investigated the impact of various mixed sowing combinations on soil nutrients and grass yield within the rhizosphere across different seasons. Three varieties of leguminous forages—Medicago sativa ‘Gannong No. 3’ (GN3), M. sativa ‘Gannong No. 9’ (GN9), and M. sativa ‘Juneng No. 7’ (JN7)—as well as three varieties of grasses—Leymus chinensis ‘Longmu No. 1’ (LC), Agropyron mongolicum ‘Mengnong No. 1’ (AC), and Bromus inermis ‘Yuanye’ (BI)—were used as experimental materials for mixed sowing combinations; the monocultures of each material served as controls. We explored the seasonal effects of different legumes and grasses intercropping combinations on rhizosphere soil nutrients and grass yield in the Hexi Corridor region of China. The results indicated that the levels of soil enzyme activity, microbial biomass, and soil nutrients in the rhizosphere across the various treatments followed the following sequence: summer > spring > autumn. The soil enzyme activities and microbial biomass of various mixed sowing combinations were significantly higher than those of the monocultures within the same growing season (p < 0.05). Specifically, the activities of alkaline phosphatase (APA), catalase (CAT), soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), soil microbial biomass phosphorus (SMBP), soil organic matter (SOM), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) within the GN9+BI group were the highest among all treatments. The hay yields of GN3, GN9, and JN7 were markedly greater than those of their respective mixed sowing combinations (p < 0.05). Correlation analysis revealed a positive relationship between enzyme activities, microbial biomass, and soil nutrient levels. This comprehensive evaluation indicated that the mixed sowing combinations of GN9 + BI and GN9 + LC are particularly well suited for widespread adoption in the Hexi Oasis irrigation area. Full article

Microbial inoculants are vital for promoting plant growth and facilitating the ecological restoration of degraded forested regions near abandoned mine sites. However, the direct application of liquid microbial inoculants is often challenging due to low microbial activities and poor transport efficiencies, which limit their effectiveness in complex soil environments. To tackle these challenges, this study utilized immobilized microbial technology to evaluate the effectiveness of solid microbial inoculants sourced from peat (P), biochar (BC), and spent mushroom substrates (SMSs) in enhancing the soil’s multifunctionality and promoting plant growth. Specifically, this research sought to assess the effectiveness of solid microbial inoculants derived from peat (P), biochar (B), and spent mushroom substrates (SMSs) in enhancing soil multifunctionality and promoting plant growth in nutrient-deficient soils that were affected by abandoned mine sites. We aimed to evaluate the performance of different solid microbial inoculants in improving the soil’s nutrient content and enzyme activities. A 24-week pot experiment was conducted using Medicago sativa L. in nutrient-poor soil. The results demonstrated that, in contrast to peat and biochar, SMSs effectively interacted with microbial inoculants and significantly improved the nutrient content and enzyme activities of nutrient-deficient soil. It was noted that β-1,4-glucosidase (BG), invertase, β-1,4-N-acetylglucosaminidase (NAG), urease, and soil available phosphorus increased by 204%, 405%, 118%, 198%, and 297%, respectively. The soil’s multifunctionality improved by 320% compared with the CK, and the plant biomass also increased significantly. Further, our random forest analysis indicated that the soil available phosphorus, ammonium nitrogen, total nitrogen, total carbon content, arylsulfatase, pH, total phosphorus, NAG, and BG were key environmental factors that induced changes in plant biomass. These findings highlighted the potential of SMSs as an effective carrier for immobilized microbial inoculants, which provides a sustainable approach for the restoration of forest soils surrounding abandoned mine sites, as well as a promising avenue for the valorization of agricultural waste. Full article

Aluminum (Al) toxicity is a serious environmental constraint facing crop production in acidic soils, primarily due to the oxidative damage it causes to plant tissues. Alfalfa (Medicago sativa), a globally important forage crop, is highly susceptible to Al-induced stress, necessitating the development of Al-tolerant cultivars for sustainable forage production. In this study, we investigated the regulatory role of miR156 in Al stress response in alfalfa. Transcript analysis revealed significant downregulation of miR156 in alfalfa roots after 8 h of Al exposure, suggesting a negative role for miR156 in response to Al. To further investigate the role of miR156 in regulating agronomic traits and alfalfa’s Al tolerance, we utilized the short tandem target mimic (STTM) method to silence miR156 in alfalfa (MsSTTM156), which led to an upregulation of SQUAMOSA PROMOTER BINDING-LIKE (SPL) target genes, albeit with variable miR156 dose-dependent effects across different transgenic genotypes. Morphological characterization of MsSTTM156 plants revealed significant negative changes in root architecture, root and shoot biomass, as well as flowering time. Under Al stress, overexpression of miR156 in alfalfa (MsmiR156OE) resulted in stunted growth and reduced biomass, whereas moderate MsmiR156 silencing enhanced root dry weight and increased stem basal diameter. In contrast, MsmiR156OE reduced plant height, stem basal diameter, shoot branching, and overall biomass under Al stress conditions. At the molecular level, silencing miR156 modulated the transcription of cell wall-related genes linked to Al tolerance, such as polygalacturonase 1(MsPG1) and polygalacturonase 4 (MsPG4). Furthermore, miR156 influenced the expression of indole-3-acetic acid (IAA) transport-related genes auxin transporter-like protein (MsAUX1) and auxin efflux carrier components 2 (MsPIN2), with MsSTTM156 and MsmiR156OE plants showing lower and higher transcript levels, respectively, upon Al exposure. These findings reveal the multi-layered role of miR156 in mediating Al tolerance, providing valuable insights into the genetic strategies that regulate response to Al stress in alfalfa. Full article

Amino acid metabolism constitutes a major metabolic pathway in plants, playing an important role in the modulation of plant responses to stress. In this study, we investigated the amino acid metabolism responses of M. sativa (Medicago sativa L.) and M. truncatula (Medicago truncatula L.) plants under salt stress using transcriptomic and proteomic approaches to elucidate their salt stress tolerance mechanisms in relation to the regulation of amino acid homeostasis. Transcriptome and proteome sequencing followed by Kyoto Gene and Genome Encyclopedia enrichment analysis revealed 34 differentially expressed genes and 45 differentially expressed proteins involved in valine, leucine, and isoleucine degradation, tyrosine metabolism, and glutathione metabolism. Significant differences were observed in the expression of glutathione S-transferase (GST) within the glutathione metabolic pathway between M. sativa and M. truncatula. The induction of valine, leucine, and isoleucine metabolism, aldehyde dehydrogenases (ALDHs), and alanine-glyoxylate aminotransferases (AGXTs), involved in intracellular reactive oxygen species scavenging, also significantly differed under salt stress. Significant differences were identified in the expression of tyrosine decarboxylases (TDCs) involved in tyrosine metabolism, which are responsible for tyramine biosynthesis and can enhance plant tolerance to salt stress. This study delved into the effects of amino acid metabolism on the salt tolerance mechanisms of M. sativa and M. truncatula, which is crucial in guiding the future breeding of salt-tolerant alfalfa varieties. Full article

This study addresses the agricultural impact of the grasshopper Sphenarium purpurascens and evaluates the efficacy of entomopathogenic fungi (EPF), Beauveria bassiana, and Metarhizium robertsii, formulated in vegetable oil emulsions as sustainable pest control agents. The losses caused by S. purpurascens at different developmental stages (N4, N5, and adult) were assessed in five economically significant crops (Medicago sativa, Zea mays, Helianthus sp., Cynodon dactylon, and Cucurbita pepo), revealing a marked preference for Helianthus sp. and C. pepo, with consumption rates reaching 0.92 g/48 h during N4 and N5 stages, while adults showed preference for M. sativa (1.18 g/48 h) and Z. mays (1.15 g/48 h). The viability of EPF in oil emulsions (20% and 40% concentrations) was evaluated, demonstrating that formulations with Azadirachta indica and Moringa oleifera maintained over 99% fungal viability compared to the control absolute with distilled water (DW). The effectiveness of EPF against S. purpurascens adults was tested, with EPF on M. robertsii combined with Persea americana achieving 100% mortality within 72 h. Finally, the pathogenicity and dispersion of EPF in oil emulsions were evaluated, demonstrating that, at 240 h, the B. bassiana + A. indica strain (with three inoculated insects) achieved 100% mortality. It was observed that the number of inoculated adults directly influenced the mortality of S. purpurascens. These findings highlight the potential of EPF as a sustainable pest management strategy, emphasizing the need for further field trials to optimize its application and mitigate agricultural losses caused by S. purpurascens. Full article

Alum mining leads to significant heavy metal and acid pollution within soils. Phytoremediation is a common strategy used to treat alum mine soils, but its efficiency is frequently compromised by the alum-mining-induced impairment of plant growth. To improve the strength of plants against mine pollution, this study constructed the artificial yeast strain ScHB (heavy metal-binding protein-containing Saccharomyces cerevisiae) expressing the de novo designed protein HBGFP (heavy metal-binding green fluorescence protein) and investigated its effect on the phytoremediation of alum mine soils with soil physiochemical assays and heavy metal quantification. This protein was composed of an N-terminal signal peptide, an HB (heavy metal-binding) domain, and a GFP (green fluorescence protein) domain, as well as a C-terminal glycolphosphatidylinositol-anchoring fragment. The exposure of the HBGFP on the ScHB surface increased the growth rate of the yeast cells and enhanced cadmium capture from the cadmium-containing medium. After culturing Medicago sativa in the alum mine soils for 30 days, ScHB remarkably increased the plants’ average height from 17.5 cm to 27.9 cm and their biomass from 3.03 g/plant to 4.35 g/plant, as well as increasing the accumulation of antioxidant agents in the plants. Moreover, the ScHB cells strongly improved the soil quality, with an increase in the soil pH values from 5.47 to 6.21 to 6.9, and increased the levels of soil organic matter, total nitrogen, available phosphorus, and living bacteria. Furthermore, ScHB efficiently improved the plants’ abilities to remove soil heavy metals, decreasing the levels of cadmium, lead, chromium, and copper by 90%, 86%, 97%, and 88%, respectively. This study developed a genetic engineering method to improve the efficiency of phytoremediation against pollution from alum mining. Full article

Nanoparticles (NPs) have generated significant interest in various fields due to the unique properties that materials exhibit at the nanoscale. This study presents a comparative analysis of copper nanoparticles (Cu-NPs) and cobalt nanoparticles (Co-NPs) synthesized via conventional solvothermal and green hydrothermal synthesis using ethylene glycol and Medicago sativa extract, respectively. The conventional solvothermal synthesis showed higher efficiency for both Cu-NPs and Co-NPs with yields of 32.5% and 26.7%, respectively. Characterization through UV–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) revealed that while solvothermal synthesis produced larger particles (76.5 nm for Cu-NPs, 86.8 nm for Co-NPs), the green hydrothermal method yielded smaller particles (53.8 nm for Cu-NPs, 67.7 nm for Co-NPs) with better control over particle size distribution and spherical morphology, showing minimal agglomeration. UV–vis confirmed metal oxide formation, while FTIR showed complex patterns in NPs (green hydrothermal), indicating plant extract compounds. Antifungal evaluation against Pseudocercospora fijiensis showed complete inhibition at 2000 ppm for both NP types, with no mycelial growth after 30 days. When integrated into chitosan, solvothermal NPs produced rougher surfaces, and scanning electron microscope (SEM) confirmed the presence of copper and cobalt in the nanocomposites. This study provides insights into the synthesis of nanoparticles using an environmentally friendly process and their microbiological applications for future use in organic agriculture. Full article

This study posits that strategically optimizing irrigation and fertilization regimes can enhance the productivity and water use efficiency (WUE) of alfalfa (Medicago sativa L.), thereby mitigating the constraints imposed by soil impoverishment and water scarcity in forage production systems of arid and semi-arid regions. Conducted over two years, the outdoor pot experiment investigated the effects of water regulation during the branching and bud stages (each at 60–100% θ_0.85, where θ_0.85 = 0.85θfc) and different levels of nitrogen and phosphorus fertilization (0–280 kg/ha each) on alfalfa yield and WUE. Using Response Surface Methodology (RSM) with a Central Composite Design (CCD), we modeled the relationships between input variables and key response parameters: total yield, evapotranspiration (ET), and WUE. The response surface models exhibited high reliability, with coefficients of determination R², adjusted R², predicted R², and adequate precision exceeding 0.94, 0.90, 0.86, and 13.6, respectively. Sensitivity analysis indicated that water regulation during critical growth stages, particularly the branching stage, had the most significant impact on yield and ET, while nitrogen and phosphorus fertilization positively influenced WUE. Within the appropriate range of water management, judicious fertilization significantly enhanced alfalfa production performance, although excessive inputs resulted in diminishing returns. This study identified the optimal conditions for sustainable production: branching stage water regulation (82.26–83.12% θ_0.85) and bud stage water regulation (78.11–88.47% θ_0.85), along with nitrogen application (110.59–128.88 kg/ha) and phosphorus application (203.86–210 kg/ha). These findings provide practical guidelines for improving the sustainability and efficiency of alfalfa production in resource-limited environments. Full article

Selenium (Se) is an essential micronutrient, yet its deficiency remains a global concern. This study investigates the biofortification of alfalfa (Medicago sativa cv. ProINTA Super Monarca GR9) via foliar Se application to enhance Se accumulation and transformation into bioavailable organic forms. A controlled environment experiment in a plant growth chamber and a one-season open-field trial (January 2023, Argentina) were conducted. Treatments included sodium selenate (Se(VI)), sodium selenite (Se(IV)), and a 1:1 mixture, applied at 45 and 90 g Se ha⁻¹, with and without the biostimulant BIOFORGE^®. Treated plants exhibited increased Se content, correlating with the applied doses. X-ray absorption spectroscopy (XAS) confirmed that most inorganic Se was transformed into organic Se forms, with Se(IV) treatments yielding the highest concentrations of organic Se species such as selenocysteine (SeCys) and selenomethionine (SeMet). Open-field trials showed a complete conversion of Se, though total Se accumulation was lower than in controlled conditions. Se treatments did not affect forage quality or biomass production. The biostimulant slightly reduced Se uptake but did not compromise biofortification. These results highlight Se(IV) as the optimal treatment for alfalfa biofortification, presenting a sustainable strategy to enhance dietary Se intake through functional foods. Full article

Megalurothrips usitatus (Bagnall) is one of the most important pests harming alfalfa (Medicago sativa L.) in Ningxia. In the field, Orius strigicollis (Poppius) is abundant. It has a high search efficiency and consumption rate of prey on a wide range of thrips and is often used as a biological control agent for these insects. To understand the predatory function and biological control potential of O. strigicollis on M. usitatus, the predatory ability of adults of O. strigicollis on second-instar larvae and adults of M. usitatus was measured under indoor conditions, and the Holling II and Hassell–Varley models were fitted to calculate the predatory function response, search efficiency, intraspecific interference, and predation preference of O. strigicollis on second-instar larvae and adults of M. usitatus. Our results showed that the predatory ability of O. strigicollis on second-instar larvae of M. usitatus was 78.62, and the theoretical maximum daily predation was 76.92. The predatory ability of O. strigicollis on adults of M. usitatus was 52.79, and the theoretical maximum daily predation was 52.62. The daily predation of O. strigicollis was positively correlated with prey density and negatively correlated with search efficiency. The rate of predatory action on prey decreased with an increasing O. strigicollis density, while the intensity of apportioned competition increased with an increasing O. strigicollis density. The results of the prey preference experiment showed that the preference of O. strigicollis for second-instar larvae of M. usitatus was significantly higher than for adults of M. usitatus. In conclusion, the indoor experiment data can provide an effective reference for the use of O. strigicollis to control M. usitatus infestation, providing an important biological control agent for controlling M. sativa thrips. Full article

Alfalfa (Medicago sativa), an important leguminous forage crop, is valued for its high nutritional content, substantial yield, palatability, and broad adaptability. Drought is among the most significant environmental constraints on alfalfa growth, particularly in the karst regions of southwestern China. In this study, we conducted pot experiments to investigate the growth and physiological responses of seven alfalfa varieties introduced into the karst region of Guizhou under drought conditions. The results revealed that drought stress markedly reduced both plant height and aboveground biomass accumulation. Moreover, under drought stress, these alfalfa varieties exhibited increased root length, root surface area, and root tip number; elevated protective enzyme activities; and decreased levels of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), thereby maintaining relatively higher water content. Each of the seven varieties displayed distinct growth and physiological adaptation mechanisms under drought stress. Integrating principal component analysis and membership function analysis, we ranked the drought resistance of these alfalfa varieties from highest to lowest as follows: Crown > WL525 > Colosseo > Victoria > PANGO > Giant 801 > Dimitra. These findings provide valuable insights for introducing drought-resistant alfalfa varieties into karst regions of southwestern China and offer guidance for breeding and cultivation strategies across various environmental conditions. Full article

Background: Alfalfa (Medicago sativa) is one of the most valuable forages in the world. As an outcrossing species, it needs bright flowers to attract pollinators to deal with self-incompatibility. Although various flower colors have been observed and described in alfalfa a long time ago, the biochemical and molecular mechanism of its color formation is still unclear. Methods: By analyzing alfalfa lines with five contrasting flower colors including white (cream-colored), yellow, lavender (purple), dark purple and dark blue, various kinds and levels of anthocyanins, carotenoids and other flavonoids were detected in different colored petals, and their roles in color formation were revealed. Results: Notably, the content of delphinidin-3,5-O-diglucoside in lines 3, 4 and 5 was 58.88, 100.80 and 94.07 times that of line 1, respectively. Delphinidin-3,5-O-diglucoside was the key factor for purple and blue color formation. Lutein and β-carotene were the main factors for the yellow color formation. By analyzing differentially expressed genes responsible for specific biochemical pathways and compounds, 27 genes were found to be associated with purple and blue color formation, and 14 genes were found to play an important role in yellow color formation. Conclusions: The difference in petal color between white, purple and blue petals was mainly caused by the accumulation of delphinidin-3,5-O-diglucoside. The difference in petal color between white and yellow petals was mainly affected by the production of lutein and β-carotene. These findings provide a basis for understanding the biochemical and molecular mechanism of alfalfa flower color formation. Full article

Nitrogen (N) and phosphorus (P) are key limiting factors for carbon (C) fluxes in artificial grasslands. The impact of their management on ecosystem C fluxes, including net ecosystem productivity (NEP), ecosystem respiration (ER), and gross ecosystem productivity (GEP) in the Loess Plateau is unclear. An experiment was conducted to study changes in these C fluxes with varying N (0, 5, 10, 15, and 20 g N m⁻²) and P (0 and 10 g P m⁻²) additions from 2022 to 2023 in a lucerne plantation. Results showed that N addition positively influenced NEP and GEP in the first year after planting with N addition at the rate of 10 g N m⁻² was optimal for C assimilation, but it had negligible effect on ER in both two years in the studied lucerne (Medicago sativa ssp. sativa) plantation. Phosphorus addition significantly increased ER and stimulated GEP, resulting in an increasing effect on NEP only at the early stage after planting. The addition of N and P enhanced soil N and P availability and further improved the leaf chemical stoichiometry characteristics, leading to changes in biomass distribution. The more belowground biomass under N addition and more aboveground production under P addition resulted in different responses of ecosystem C fluxes to N and P addition. The results suggest that the effects of N and P fertilization management on the ecosystem C cycle may be largely dependent on the distribution of above- and belowground plant biomass in the artificial grassland ecosystem. Full article