Search

Premise of research. Root allocation and morphology can be influenced by nutritional symbiosis with arbuscular mycorrhizal (AM) fungi. In the presence of AM fungi, plants could alter root allocatio...

The incorporation of natural essential oils to the pigsʼ diet in intensive production systems is a potential tool to improve gut health and prevent infections without using antibiotics. Nevertheless, different products, even containing the same compounds, coming from the same botanical species, may exert dissimilar biological effects due differences in the technological processes by which they are produced and preserved. For this reason, suitability of a given product based on natural extracts, intended for swine production must be thoroughly evaluated. In the present study, we assessed the effects of three additives containing oregano (Lippia origanoides) essential oil, alone or in combination with clover (Eugenia caryophillata) essential oil, with or without being microencapsulated, on gastrointestinal health and on some performance parameters in a commercial pig production farm. Recently weaned piglets were randomly divided in four groups, and basal diet or essential oil-supplemented diet (OCE; MOCE; MOE) was randomly assigned to each of the groups from weaning to finishing. Blood samples were collected at pre-established days after weaning. Intestinal sampling took place at 42 and 72 days of age. Pigs consuming the supplemented diets showed higher intestinal metabolic activity during the post-weaning period, decreasing the impact of weaning stress on enterocytesʼ metabolism. Intestinal barrier function was not affected in pigs consuming microencapsulated products. All treated groups showed improved intestinal architecture, increased digestive enzymes activity and caecal VFA concentrations. The incorporation of the dietary essential oils products brought beneficial effects on gastrointestinal health that were reflected in improved performance parameters.

Studying the legume nodule microbiome is important for understanding the development and nutrition of the plants inhabited by the various microbes within and upon them. We analyzed the microbiomes of these underground organs from both an important crop plant (Medicago sativa) and a related legume (M. polymorpha) using metagenomic and culture-based techniques to identify the main cultivatable contributors to plant growth enhancement. Using high-throughput sequencing, culturing, and in planta techniques, we identified and analyzed a broad population of the bacterial taxa within Medicago nodules and the surrounding soil. Fifty-one distinct bacterial strains were isolated and characterized from nodules of both Medicago species and their growth-promoting activities were studied. Sequencing of 16S rRNA gene amplicons showed that in addition to Ensifer, the dominant genus, a large number of Gram-positive bacteria belonging to the Firmicutes and Actinobacteria were also present. After performing ecological and plant growth-promoting trait analyses, selecting the most promising strains, and then performing in planta assays, we found that strains of Bacillus and Micromonospora among others could play important roles in supporting the growth, health, and productivity of the host plant. To our knowledge, the comparison of the biodiversity of the microbiota of undomesticated vs. cultivated Medicago roots and nodules is novel and shows the range of potential Plant Growth-Promoting Bacteria that could be used for plants of agricultural interest. These and other nodule-isolated microbes could also serve as inoculants with rhizobia with the goal of replacing synthetic fertilizers and pesticides for sustainable agriculture.

Chickpea shoot exogenously treated with cytokinin showed stunted phenotype of root, shoot and significantly reduced nodule numbers. Genome-wide identification of LRR-RLKs in chickpea and Medicago resulted in 200 and 371 genes respectively. Gene duplication analysis revealed that LRR-RLKs family expanded through segmental duplications in chickpea and tandem duplications in Medicago. Expression profiling of LRR-RLKs revealed their involvement in cytokinin signaling and plant organ development. Overexpression of KLAVIER ortholog of chickpea, Ca_LRR-RLK147, in roots revealed its localization in the membrane but showed no effect on root nodulation despite increased cle peptide levels. Two findings (i) drastic effect on nodule number by exogenous cytokinin treatment to only shoot and restoration to normal nodulation by treatment to both root and shoot tissue and (ii) no effect on nodule number by overexpression of Ca_LRR-RLK147 establishes the fact that despite presence of cle peptides in root, the function of Ca_LRR-RLK147 was shoot mediated during AON.

The analgesic, antidiarrheal, and neuro-pharmacological potentials of Medicago denticulata leaves extract were screened in animal models. Potential analgesic response was noted (*P

Local adaptation is common in plants, yet characterization of its underlying genetic basis is rare in herbaceous perennials. Moreover, while many plant species exhibit intraspecific chemical defence polymorphisms, their importance for local adaptation remains poorly understood. We examined the genetic architecture of local adaptation in a perennial, obligately-outcrossing herbaceous legume, white clover (Trifolium repens). This widespread species displays a well-studied chemical defence polymorphism for cyanogenesis (HCN release following tissue damage) and has evolved climate-associated cyanogenesis clines throughout its range. Two biparental F2 mapping populations, derived from three parents collected in environments spanning the U.S. latitudinal species range (Duluth, MN, St. Louis, MO and Gainesville, FL), were grown in triplicate for two years in reciprocal common garden experiments in the parental environments (6,012 total plants). Vegetative growth and reproductive fitness traits displayed trade-offs across reciprocal environments, indicating local adaptation. Genetic mapping of fitness traits revealed a genetic architecture characterized by allelic trade-offs between environments, with 100% and 80% of fitness QTL in the two mapping populations showing significant QTL×E interactions, consistent with antagonistic pleiotropy. Across the genome there were three hotspots of QTL colocalization. Unexpectedly, we found little evidence that the cyanogenesis polymorphism contributes to local adaptation. Instead, divergent life history strategies in reciprocal environments were major fitness determinants: selection favoured early investment in flowering at the cost of multiyear survival in the southernmost site versus delayed flowering and multiyear persistence in the northern environments. Our findings demonstrate that multilocus genetic trade-offs contribute to contrasting life history characteristics that allow for local adaptation in this outcrossing herbaceous perennial.

Phoma black stem and leaf spot disease of annual Medicago spp., caused by Phoma medicaginis, not only can devastate forage and seed yield but can reduce herbage quality by inducing production of phytoestrogens (particularly coumestrol and 4′-O-methylcoumestrol), which can also reduce the ovulation rates of animals grazing infected forage. We determined the consequent phytoestrogen levels on three different annual Medicago species/cultivars (Medicago truncatula cultivar Cyprus, Medicago polymorpha var. brevispina cultivar Serena, and Medicago murex cultivar Zodiac) after inoculation with 35 isolates of P. medicaginis. Across the isolate × cultivar combinations, leaf disease incidence, petiole/stem disease incidence, leaf disease severity, petiole disease severity, and leaf yellowing severity ranged up to 100, 89.4, 100, 58.1, and 61.2%, respectively. Cultivars Cyprus and Serena were the most susceptible and cultivar Zodiac was the most resistant to P. medicaginis. Isolates WAC3653, WAC3658, and WAC4252 produced the most severe disease. Levels of phytoestrogens in stems ranged from 25 to 1,995 mg/kg for coumestrol and from 0 to 418 mg/kg for 4′-O-methylcoumestrol. There was a significant positive relationship of disease incidence and severity parameters with both coumestrol and 4′-O-methylcoumestrol contents, as noted across individual cultivars and across the three cultivars overall, where r = 0.39 and 0.37 for coumestrol and 4′-O-methylcoumestrol, respectively (P < 0.05). Although cultivar Serena was most susceptible to P. medicaginis and produced the highest levels of phytoestrogens in the presence of P. medicaginis, cultivar Zodiac contained the highest levels of phytoestrogens in comparison with other cultivars in the absence of P. medicaginis. There was a 15-fold increase in coumestrol in cultivar Serena but only a 7-fold increase in cultivar Zodiac from infection of P. medicaginis. The study highlights that the intrinsic ability of a particular cultivar to produce phytoestrogens in the absence of the pathogen, and its comparative ability to produce phytoestrogens in the presence of the P. medicaginis, are both important and highly relevant to developing new annual Medicago spp. cultivars that offer improved disease resistance and better animal reproductive outcomes.

Metabolomic studies on root uptake and transformation of bioactive compounds, like cereal benzoxazinoids (BXs) in non-BX producing plants, are very limited. Therefore, a targeted mass-spectrometry-based metabolomics study was performed to elucidate the root uptake of BXs in white clover (

Species interactions are a unifying theme in ecology and evolution. Both fields are currently moving beyond their historical focus on isolated pairwise relationships to understand how ecological communities affect focal interactions. Additional species can modify both the number of interactions and the fitness consequences of each interaction (i.e., selection). Although only selection affects the evolution of the focal interaction, the two are often conflated, limiting our understanding of the evolution of multispecies interactions. We manipulated aboveground herbivory on the legume Medicago lupulina in the field and quantified its effect on number of symbionts and the per-symbiont impact on plant performance in two belowground symbioses: mutualistic rhizobia bacteria (Ensifer meliloti) and parasitic root-knot nematodes (Meloidogyne hapla). We found that herbivores modified the number of rhizobia nodules, as well as the benefit per nodule. However, each effect was specific to a distinct herbivory regime: natural herbivory affected nodule number, whereas leafhoppers (Cicadellidae) weakened the per nodule benefit. We did not detect any effect of herbivory on nematode gall number or the cost of infection. Our data demonstrate that distinguishing between symbiont number from the fitness consequences of symbiosis is crucial to accurately infer how pairwise interactions will evolve in a community.

Low-cost materials with a highly efficient adsorption capability prepared from corn straw and medicago (abbreviated to CB and MB), which can effectively remove benzo(

Summary The critical role of cytokinin in early nodulation in legumes is well known. In our study, exogenous cytokinin application to roots of the important crop legume, chickpea (Cicer arietinum L.), led to the formation of pseudo‐nodules even in the absence of rhizobia. Hence, a genome‐wide analysis of the cytokinin signalling, two‐component system (TCS) genes, was conducted in chickpea, Medicago and Cajanus cajan. The integrated phylogenetic, evolutionary and expression analysis of the TCS genes was carried out, which revealed that histidine kinases (HKs) were highly conserved, whereas there was diversification leading to neofunctionalization at the level of response regulators (RRs) especially the TypeB RRs. Further, the functional role of the CaHKs in nodulation was established by complementation of the sln1Δ mutant of yeast and cre1 mutants of (Medicago) which led to restoration of the nodule‐deficient phenotype. Additionally, the highest expressing TypeB RR of chickpea, CaRR13, was functionally characterized. Its localization in the nucleus and its Y1H assay‐based interaction with the promoter of the early nodulation gene CaNSP2 indicated its role as a transcription factor regulating early nodulation. Overexpression, RNAi lines and complementation of cre1 mutants with CaRR13 revealed its critical involvement as an important signalling molecule regulating early events of nodule organogenesis in chickpea.

Medicago sativa is an important worldwide forage species containing characteristic secondary metabolites such as saponin which are reported to be biologically active. The objective of this study wa...

The objective of this systems-scale study was to investigate grazing season timeframes on pasture and milk production and on milk processability of dairy systems with compact spring-calving dairy cows grazing white clover (Trifolium repens L.) based grassland. Fifty-four primiparous and multiparous Holstein-Friesian dairy cows were used in a one-factor study with 3 systems (n = 18) and repeated over 2 yr (2008/09 and 2009/10). The 3 systems were: early spring calving with annual fertilizer N input of 100 kg·ha-1 applied in spring (ES100N; 2.1 cows·ha-1; grazing February to November), early spring calving without fertilizer N (ES0N; 1.6 cows·ha-1; grazing February to November) and late spring calving without fertilizer N (LS0N; 1.53 cows·ha-1; grazing April to January). Annual pasture production was affected by an interaction between grazing system and year: Mean annual pasture yields for 2008 and 2009 were ES100N; 10.35 and 9.88, ES0N; 8.88 and 8.63, LS0N; 9.18 and 10.31 t of dry matter (DM)·ha-1 (SEM 0.39). LS0N had higher pasture DM yield in 2009 due to higher clover DM production and biological N fixation compared with the other systems. Clover stolon and root mass in the following February was correlated with stolon and root mass in the previous November with 64% of stolon mass present on LS0N in February (R2 = 0.84). There were no detectable differences in per-lactation milk yield (6,335 kg·cow-1), fat, protein and lactose yields (271, 226, 297 kg·cow-1, respectively), cow liveweight (585 kg) or body condition score (3.02). Although winter grazing favored subsequent clover DM production, biological N fixation and pasture DM production, delaying calving date in spring and extending lactation into the following winter led to inefficient use of this pasture by the grazing herd and lowered the quality of late-lactation milk for processing purposes. Hence, a mean calving date in mid- to late-February is recommended for zero-fertilizer N input clover-based grassland.

Several ATP-binding cassette (ABC) transporters involved in the arbuscular mycorrhizal symbiosis and nodulation have been identified. We describe three previously unreported ABC subfamily B transporters, named AMN1, AMN2, and AMN3 (ABCB for mycorrhization and nodulation), that are expressed early during infection by rhizobia and arbuscular mycorrhizal fungi. These ABCB transporters are strongly expressed in symbiotically infected tissues, including in root-hair cells with rhizobial infection threads and arbusculated cells. During nodulation, the expression of these genes is highly induced by rhizobia and purified Nod factors and is dependent on DMI3 but is not dependent on other known major regulators of infection, such as NIN, NSP1, or NSP2. During mycorrhization their expression is dependent on DMI3 and RAM1 but not on NSP1 and NSP2. Therefore, they may be commonly regulated through a distinct branch of the common symbiotic pathway. Mutants with exonic Tnt1-transposon insertions were isolated for all three genes. None of the single or double mutants showed any differences in colonization by either rhizobia or mycorrhizal fungi, but the triple amn1 amn2 amn3 mutant showed an increase in nodule number. Further studies are needed to identify potential substrates of these transporters and understand their roles in these beneficial symbioses. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

S-adenosylmethionine decarboxylase (SAMDC) mediates the biosynthesis of polyamines (PAs) and plays a positive role in plants’ response to adversity stress tolerance. In this study, we isolated a SAMDC gene from white clover, which is located in mitochondria. It was strongly induced when white clover exposed to drought (15% PEG6000), salinity (200 mM NaCl), 20 μM spermidine, 100 μM abscisic acid, and 10 mM H2O2, especially in leaves. The INVSc1 yeast introduced with TrSAMDC1 had tolerance to drought, salt, and oxidative stress. Overexpression of TrSAMDC1 in Arabidopsis showed higher fresh weight and dry weight under drought and salt treatment and without growth inhibition under normal conditions. Leaf senescence induced by drought and saline was further delayed in transgenic plants, regardless of cultivation in 1/2 MS medium and soil. During drought and salt stress, transgenic plants exhibited a significant increase in relative water content, maximum photosynthesis efficiency (Fv/Fm), performance index on the absorption basis (PIABS), activities of antioxidant protective enzymes such as SOD, POD, CAT, and APX, and a significant decrease in accumulation of MDA and H2O2 as compared to the WT. The concentrations of total PAs, putrescine, spermidine, and spermidine in transgenic lines were higher in transgenic plants than in WT under normal and drought conditions. These results suggested that TrSAMDC1 could effectively mitigate abiotic stresses without the expense of production and be a potential candidate gene for improving the drought and salt resistance of crops.

The purpose of the research was to determine the effect of the foliar use of a growth regulator with the trade name of Tytanit, containing titanium ascorbate, on photosynthetic activity and chlorophyll content in Medicago × varia T. Martyn leaves. There were two kinds of plots: C – control series; Ti – plants treated with Tytanit, containing 8.5 g of titanium in 1 dm3. The following parameters were determined: maximum photosystem II efficiency (Fv/Fm) in a dark-adapted state, actual photosystem II efficiency (ΔF/Fm’) in a light-adapted state, photochemical quenching factor (QP), non-photochemical quenching factor (QN), and chlorophyll a and b content. The Fisher-Snedecor test was used to determine whether the impact of experimental factors was significant, and the HSD 0.05 value was calculated using Tukey’s test. Compared to control, the photosynthetic apparatus performance of alfalfa was positively affected by the regulator compared to control. Tytanit applied to plant leaves increased their photosynthetic activity as a result of an increase in the content of chlorophyll pigments. It was also found that periods of rainfall deficiency did not affect the beneficial effects of the regulator.

Multispectral imaging (MSI) has become a new fast and non-destructive detection method in seed identification. Previous research has usually focused on single models in MSI data analysis, which always employed all features and increased the risk to efficiency and that of system cost. In this study, we developed a stacking ensemble learning (SEL) model for successfully identifying a single seed of sickle alfalfa (

Heat shock transcription factors (HSF) are divided into classes A, B and C. Class A transcription factors are generally recognized as transcriptional activators, while functional characterization of class B and C heat shock transcription factors have not been fully developed in most plant species. We isolated and characterized a novel HSF transcription factor gene

Background Calcineurin B-like proteins (CBLs) are ubiquitous Ca2+ sensors that mediate plant responses to various stress and developmental processes by interacting with CBL-interacting protein kinases (CIPKs). CBLs and CIPKs play essential roles in acclimatization of crop plants. However, evolution of these two gene families in the genus Medicago is poorly understood. Results A total of 68 CBL and 135 CIPK genes have been identified in five genomes from Medicago. Among these genomes, the gene number of CBLs and CIPKs shows no significant difference at the haploid genome level. Phylogenetic and comprehensive characteristic analyses reveal that CBLs and CIPKs are classified into four clades respectively, which is validated by distribution of conserved motifs. The synteny analysis indicates that the whole genome duplication events (WGDs) have contributed to the expansion of both families. Expression analysis demonstrates that two MsCBLs and three MsCIPKs are specifically expressed in roots, mature leaves, developing flowers and nitrogen fixing nodules of Medicago sativa spp. sativa, the widely grown tetraploid species. In particular, the expression of these five genes was highly up-regulated in roots when exposed to salt and drought stress, indicating crucial roles in stress responses. Conclusions Our study leads to a comprehensive understanding of evolution of CBL and CIPK gene families in Medicago, but also provides a rich resource to further address the functions of CBL-CIPK complexes in cultivated species and their closely related wild relatives.

Plants are known to be a great source of phytochemicals for centuries. Medicago, belonging to the Family Fabaceae, is a large and well spread genus comprising about 83 cosmopolitan species, of which one-third are annuals and span diverse ecological niches. Medicago species are rich in saponins mainly classified into three classes, namely, steroid alkaloid glycosides, triterpene glycosides, and steroid glycosides. These saponins are important compounds having diverse pharmacological and biological activities. As a whole, 95 of saponins are reported to date occurring in Medicago species using various latest extraction/isolation techniques. Considering the multiple biological and pharmacological potential of Medicago species due to saponins along with structural diversity, we compiled this review article to sum up the recent reports for the pharmacological potential of the Medicago’s derived saponins in modern as well as traditional medication systems. The current manuscript produces data of chemical structures and molecular masses of all Medicago species saponins simultaneously. The toxicity of certain pure saponins (aglycones) has been reported in vitro; hederagenin appeared highly toxic in comparison to medicagenic acid and bayogenin against X. index, while soyasaponin I, containing soyasapogenol B as a glycone, appeared as the least toxic saponin. The diversity in the structural forms shows a close relationship for its biological and pharmacological actions. Moreover, saponins showed antioxidant properties and the mechanism behind antimicrobial potential also elaborated in this review article is mainly because of the side sugar groups on these compounds. The collected data presented herein include chemical structures and molecular masses of all saponins so far. Their biological activity and therapeutic potential are also discussed. This information can be the starting point for future research on this important genus.

Here, we assess the differential impact of drought on root carbon metabolism in the widely cultivated alfalfa (Medicago sativa, Ms) and the model legume Medicago truncatula (Mt). Understanding how carbon allocation is regulated under drought stress conditions is a central issue to improving alfalfa productivity under future climate change scenarios. Alfalfa and Medicago truncatula were compared under water deficit conditions. Root carbon metabolism of the taproot and fibrous roots was analysed. M. truncatula drought tolerance variability was compared to that of alfalfa using six accessions of the Medicago Hapmap project. The prominent taproot is much less developed in M. truncatula than in alfalfa with the former exhibiting an extensive fibrous root system. In both examined Medicago species the taproot contained the major pools of soluble protein, sucrose and pinitol, whereas the major pools of hexoses and carbon metabolism enzymes appeared to be in the fibrous roots. Under water-deficit conditions, the response of M. sativa strongly differed from that of M. truncatula at the root level. Water deficit conditions differentially modulate the root carbon metabolism of M. sativa and M. truncatula. Mt maintained a more active carbon metabolism in the fibRs, as sucrose, myo-inositol and pinitol accumulated to cope with the water deficit (WD). Conversely, the root system of Ms did not accumulate cyclitols and carbon metabolism was more severely affected under water deficit conditions. This differentially exerted control may determine the drought response of these two close relatives.

Plants establish symbioses with mutualistic fungi, such as arbuscular mycorrhizal (AM) fungi, and bacteria, such as rhizobia, to exchange key nutrients and thrive. Plants and symbionts have coevolved and represent vital components of terrestrial ecosystems. Plants employ an ancestral AM signaling pathway to establish intracellular symbioses, including the legume–rhizobia symbiosis, in their roots. Nevertheless, the relationship between the AM and rhizobial symbioses in native soil is poorly understood. Here, we examined how these distinct symbioses affect root-associated bacterial communities in Medicago truncatula by performing quantitative microbiota profiling (QMP) of 16S rRNA genes. We found that M. truncatula mutants that cannot establish AM or rhizobia symbiosis have an altered microbial load (quantitative abundance) in the rhizosphere and roots, and in particular that AM symbiosis is required to assemble a normal quantitative root-associated microbiota in native soil. Moreover, quantitative microbial co-abundance network analyses revealed that AM symbiosis affects Rhizobiales hubs among plant microbiota and benefits the plant holobiont. Through QMP of rhizobial rpoB and AM fungal SSU rRNA genes, we revealed a new layer of interaction whereby AM symbiosis promotes rhizobia accumulation in the rhizosphere of M. truncatula. We further showed that AM symbiosis-conditioned microbial communities within the M. truncatula rhizosphere could promote nodulation in different legume plants in native soil. Given that the AM and rhizobial symbioses are critical for crop growth, our findings might inform strategies to improve agricultural management. Moreover, our work sheds light on the co-evolution of these intracellular symbioses during plant adaptation to native soil conditions.

Medicago archiducis-nicolai Sirjaev and M. ruthenica (L.) Ledebour are two phylogenetically closely related species in the section Platycarpae within Medicago. M. archiducis-nicolai is endemic to the Qinghai–Tibetan Plateau (QTP), shows more tolerance to abiotic stress than M. ruthenica, which inhabits relatively temperate areas, and has the potential to be domesticated and used as a legume forage germplasm in alpine meadows. Here, we analyzed the population genetic structure and genetic diversity of these species using 20 putatively neutral EST-SSR markers. Twenty-four wild populations, including 21 M. archiducis-nicolai and 3 M. ruthenica, were divided into two clusters that were consistent with current taxonomy. The 21 M. archiducis-nicolai populations were clustered into two geographically related groups. Positive relationships between population genetic distance and geographical factors, including geographical distance and altitudinal difference, revealed that the genetic differentiation of M. archiducis-nicolai populations was driven by both geographical distance and the complex topography of the QTP. Medicago archiducis-nocilai, a narrow-range endemic on the QTP, had lower genetic diversity than the more widespread M. ruthenica. Medicago archiducis-nicolai populations from the central platform of the QTP had relatively high genetic diversity, whereas those occupying the east platform and edge of the QTP showed variable levels of genetic diversity, implying the presence of refugia on the central platform. These results have implications for the genetic resource management and exploitation of M. archiducis-nicolai and provide novel insights into the mechanisms underlying the adaptation of this species to the harsh environment of the QTP.

Hospital wastewaters are produced in large volumes in Pakistan (∼362–745 L/bed.day) and are discharged without proper treatment. They are widely used by farmers for crop irrigation and induce a phytotoxic effect on plant growth. The study was conducted to evaluate the effect of untreated and treated hospital wastewater on seed germination of a fodder crop Trifolium alexandrinum (Berseem clover) and a food crop Solanum lycopersicum (tomato). A bacterial consortium was formed with three bacterial strains, i.e., Alcaligenes faecalis and Bacillus paramycoides spp., which were individually proven efficient in previous studies. The concentrations of untreated and treated hospital wastewater (25, 50, 75 and 100%) were used to irrigate these crop seeds. To assess the efficiency of treatment, the germination percentage, delay index, germination index, stress tolerance indices, seedling vigour index and phytotoxicity index were calculated and were statistically proven significant. The seeds grown in treated wastewater concentrations showed negative values of phytotoxicity indices (tomato: −0.36, −0.47, −0.78 and −1.11; Berseem clover: −0.23) which indicate a stimulatory or non-toxic effect on seedling growth. Our work proposes that this bacterial consortium is efficient for hospital wastewater treatment before crop irrigation. HIGHLIGHTS Bacterial consortia proficiently used for hospital wastewater treatment.; Novel combination of Alcaligenes faecalis and Bacillus paramycoides spp. promotes the efficiency of hospital wastewater treatment.; Consortium proved to be capable of phytotoxicity reduction in two crop plants, Trifolium alexandrinum (Berseem clover) and Solanum lycopersicum (tomato), irrigated with treated hospital wastewater concentrations.

Auxin induced in root culture (AIR12) is a single gene in Arabidopsis and codes for a mono-heme cytochrome b, but it is unknown whether plant AIR12 is involved in abiotic stress responses. MfAIR12 was identified from Medicago falcata that is legume germplasm with great cold tolerance. Transcript levels of MfAIR12 and its homolog MtAIR12 from Medicago truncatula was induced under low temperature. Overexpression of MfAIR12 led to the accumulation of H2 O2 in apoplast and enhanced cold tolerance, which was blocked by H2 O2 scavengers, indicating that the increased cold tolerance was dependent upon the accumulated H2 O2 . In addition, declined cold tolerance was observed in Arabidopsis mutant air12, which could be restored by expressing MfAIR12. Compared to the wild type, higher levels of ascorbic acid and ascorbate redox state, as well as transcripts of the C repeat/dehydration responsive element-binding factor (CBF) transcription factors and their downstream cold-responsive genes, were observed in MfAIR12 transgenic lines, but lower levels of those in air12 mutant. It is suggested AIR12 confers cold tolerance as a result of the altered H2 O2 in the apoplast that is signaling in the regulation of CBF cold response pathway and ascorbate homeostasis.

Messina (Melilotus siculus) is a new annual pasture legume with better combined waterlogging and salt tolerance than other annual legumes. Messina cv. Neptune and a new salt-tolerant rhizobial symbiont (Sinorhizobium medicae SRDI-554) were made available to Australian growers in 2017. Messina is related to the annual medics (Medicago spp.) that are nodulated by the same genus of rhizobia and regarded as sensitive to soil acidity. Because some saltland soils are acidic, it is important to understand the sensitivity of messina to soil acidity in order to avoid failures during early adoption. Acidity tolerance of the messina–Sinorhizobium symbiosis was investigated in a hydroponic experiment (inoculation with SRDI-554, or the salt-intolerant strain WSM-1115 recommended for medics), and in three acidic soils (pHCa 4.3–5.5) (inoculation with SRDI-554 ± lime pelleting of seed), in the greenhouse. In the hydroponic experiment, the percentage of messina plants (with SRDI-554) that formed nodules declined at pH levels between 5.7 (43%) and 5.5 (4%). Strain SRDI-554 was slightly more sensitive to acidity than strain WSM-1115. In the acidic soils, more plants formed nodules than in the hydroponic experiment at similar pH levels; however, without lime pelleting, nodule number was inadequate at soil pHCa

Symbiotic nitrogen fixation is benefit to sustainable agriculture and global nitrogen cycle. Many small peptides were identified as regulators involving in the interaction between rhizobia and legume. Here we reported Nodule Rich Protein 2 (MtNRP2) encoding a small peptide in Medicago truncatula, belonged to a group of nodule rich protein restricted in legume species. MtNRP2 expressed highly in root nodule and its promoter was active during the initiation and development of root nodule and lateral root. To investigate the function of MtNRP2 in nodulation, we generated MtNRP2-overexpression and MtNRP2-knockdown transgenic Medicago. MtNRP2-overexpression transgenic lines performed normal nodulation phenotype compared with vector control. However, in the MtNRP2-RNAi transgenic plants, the decrease of MtNRP2 expression lead to the increase of infection threads number (7 day post inoculation) and nodules number (3 week post inoculation); meanwhile, the expression of MtRGF3 and MtPUB1 was inhibited. These results suggested that MtNRP2 negatively regulated nodulation in Medicago truncatula.

Medicago lupulina L. — Habit: Herb. Habitat: LMDF; 1 700–2 900 m. Distribution: I. Voucher: Naro Moru Track, Alt. 2 365 m, 10 Jun. 2010, Kirika et al. KMK77 (EA). References: Fries & Fries (1927b), Bussmann (1993, 1994)., Published as part of Zhou, Ya-Dong, Mwachala, Geoffrey, Hu, Guang-Wan & Wang, Qing-Feng, 2022, Annotated checklist of the vascular plants of Mount Kenya, East Africa, pp. 1-108 in Phytotaxa 546 (1) on page 47, DOI: 10.11646/phytotaxa.546.1.1, http://zenodo.org/record/6550464, {"references":["Fries, R. E. & Fries, T. C. E. (1927 b) Beitrage zur Kenntnis der Flora des Kenia, Mt. Aberdare und Mt. Elgon. X. Notizblatt des Koniglichen Botanischen Gartens und Museums zu Berlin 10 (91): 69 - 101. https: // doi. org / 10.2307 / 3994819","Bussmann, R. W. (1993) The forest of Mt. Kenya (Kenya): A phytosociological approach with special reference to ecological problems. Ph. D. Thesis, Eberhard Karls Universitat Tubingen, Tubingen, 119 pp.","Bussmann, R. W. (1994) The forest of Mt. Kenya (Kenya): Vegetation, ecology, destruction and management of a tropical mountain forest ecosystem. Ph. D. dissertation, Universitat Bayreuth Startseite, Bayreuth, 252 pp."]}

Pod shattering is a seed dispersal strategy and an important agronomical trait in domesticated crops. The relationship between pod shattering and pod morphology in the genus Medicago is well known; however, the detailed mechanism underlying pod dehiscence in Medicago ruthenica, a perennial legume used for forage production, is unknown. Here, the pod ventral sutures of shatter-resistant and shatter-susceptible M. ruthenica genotypes were examined at 8, 12, 16, and 20 d after flowering. The mechanism of pod shattering was analyzed through microscopic observations, polygalacturonase (PG) and cellulase (CE) activity analyses, and RNA-sequencing (RNA-Seq), and the results were verified via reverse transcriptase-quantitative polymerase chain reaction. Pod shattering at the ventral suture in M. ruthenica occurs via a combination of two mechanisms: degradation of the middle lamella at the abscission layers (ALs) and detachment of lignified cells on either side of the ALs triggered by physical forces. Increased PG and CE activities in the pod ventral suture are essential for AL cell-autolysis in the shatter-susceptible genotype. RNA-Seq revealed that 11 genes encoding PG and CE were highly expressed in the ventral sutures of the shatter-susceptible genotype. The expression levels of auxin biosynthesis-related genes decreased in the AL cells and they were negatively associated with pod dehiscence. These results enhance our understanding of the pod shattering mechanism not only in M. ruthenica but also in other leguminous plants.

Medicago ruthenica is an important perennial forage with multiple characteristics of resistance. In this study, we sequenced and characterized the complete chloroplast genome of M. ruthenica 'Taihang', which is 124, 254 bp in length. A total of 108 genes were identified, including 74 protein-coding, 30 tRNA, and four rRNA genes. Phylogenetic analysis based on 27 chloroplast genomes showed that M. ruthenica 'Taihang' has a close relationship with M. ruthenica from Qinghai Province, China. The data are useful in better understanding the genetic diversity and stress resistance of Medicago and contribute to the phylogenetic study of Trifolieae.

International audience; Organogenesis of legume root nodules begins with the nodulation factor-dependent stimulation of compatible root cells to initiate divisions, signifying an early nodule primordium formation event. This is followed by cellular differentiation, including cell expansion and vascular bundle formation, and we previously showed that Lotus japonicus NF-YA1 is essential for this process, presumably by regulating three members of the SHORT INTERNODES/STYLISH (STY) transcription factor gene family.In this study, we used combined genetics, genomics and cell biology approaches to characterize the role of STY genes during root nodule formation and to test a hypothesis that they mediate nodule development by stimulating auxin signalling.We show here that L. japonicus STYs are required for nodule emergence. This is attributed to the NF-YA1-dependent regulatory cascade, comprising STY genes and their downstream targets, YUCCA1 and YUCCA11, involved in a local auxin biosynthesis at the post-initial cell division stage. An analogous NF-YA1/STY regulatory module seems to operate in Medicago truncatula in association with the indeterminate nodule patterning.Our data define L. japonicus and M. truncatula NF-YA1 genes as important nodule emergence stage-specific regulators of auxin signalling while indicating that the inductive stage and subsequent formation of early nodule primordia are mediated through an independent mechanism(s).

The issue of the use of mineral forms of nitrogen for legumes is still a source of debate among scientists. Under the environmental conditions of the foothill zone of RNO-Alania, the field experiments were laid to study the activity of the symbiotic system and the productivity of the alfalfa depending on the type of nitrogen nutrition and the presence of a virulent active strain of rhizobia. The research was carried out in 2017– 2019. Soil – chernozems leached. Objects: crops of Medicago varia Mart.; industrial strain of rhizotorphin 425a; inoculum of high-mountain strains of nodule bacteria; starting doses of nitrogen fertilizers. The dimensions of the symbiotic apparatus were studied according to the G.S. Posypanov method. The specific activity of symbiosis was 4.2 to 9.0 mg/kg. The maximum amount of air nitrogen (456.1 kg/ha) for three years of experiments was fixed by the symbiotic system of alfalfa in the variant with pre-sowing seed inoculation with high-mountain strains of nodule bacteria. This indicates their higher activity and competitiveness compared to the industrial strain of rhizotorphin 425a and indigenous strains of rhizobia from the pre-mountain zone of RNO-Alania. Mineral forms of nitrogen significantly inhibited the activity of the symbiotic system. As a result, the amount of fixed nitrogen decreased by 3.5–9.0 %. In the pre-mountain zone, under natural conditions, the growth and development of plants were provided with atmospheric nitrogen by 66 %, the rest of the need for the element (34 %) they satisfied with soil nitrogen. The maximum involvement of molecular nitrogen of the atmosphere in the biological cycle was distinguished by the variant with pre-sowing inoculation of seeds by virulent active strains of rhizobia, in which the share of air nitrogen participation in plant nutrition averaged 71–73 % over the three years of research.

AimWe investigated how substrate hydraulic properties respond to the presence of arbuscular mycorrhizal fungi (AMF) in root-containing and root-free substrate zones in aMedicago truncatula-Rhizophagus irregularismodel system.MethodsBefore planting, two compartments constructed from standard soil sampling cores (250 cm3) were implanted into non-mycorrhizal and mycorrhizal pots containing a sand-zeolite-soil mix. One compartment allowed root penetration (1 mm mesh cover) and the other only hyphal ingrowth (42 μm mesh cover). After eight weeks of growth under maintenance of moist conditions, the cores were subjected to water retention measurements. Additionally, we measured water retention of bare substrates before and after drying events to check for successful maintenance of moist conditions in pots.ResultsDrying of bare substrates decreased water retention, but planting at least sustained it. The parameters of water retention models responded linearly to root morphological traits across mycorrhizal and non-mycorrhizal substrates. Hyphae-only colonization comparatively affected the course of water retention in ways that suggest increased pore space heterogeneity while maintaining water storage capacity of substrates.ConclusionsHence, water contents corresponded to different substrate matric potentials in non-mycorrhizal and mycorrhizal pots. We conclude that changes to water retention in AMF colonized substrates can contribute to a widely observed phenomenon, i.e. that mycorrhizal plants differ in their moisture stress response from non-mycorrhizal plants.

Topiciality. Flora of Azerbaijan has a diverse vegetation cover and is rich in choice. However, today these sources of raw materials are not fully used to meet the needs of medicine and national economy. We conducted a resource reconnaissance survey of species of the genus Medicago in Azerbaijan and identified regions of mass growth. New natural habitats are located in different environmental conditions and it is possible to change the diagnostic features of the morphological and anatomical structure of plant materials, as well as the chemical composition. The combination of additional morphological and anatomical features allows a more accurate determination of the authenticity of the raw material. Aim. To study the diagnostic signs of morphological and anatomical structure of Medicago falcata L. raw materials from the flora of Azerbaijan. Materials and methods. Plant samples were fixed in a solution made in 0.1 M phosphate buffer (pH = 7.4), containing 2.5 % glutar-aldehyde, 2 % paraformal-aldehyde, 4 % sucrose, and 0.1 % picric acid. The fixed materials have been submitted to the Electron Microscopy Laboratory of the Azerbaijan Medical University for study by electron microscopy. Samples have been postfixed in 1 %-osmium tetraoxide solution prepared in phosphate buffer (pH 7.4) within two hours after being left in the same fixer for one day. Araldite-Epon blocks made from materials using general methods adopted in electron microscopy. The semi-thin (1-2 µm) sections from the blocks taken on a EM UC7 (Leica, Germany) ultramicrotome, stained with methylene blue, azure II, and basic fuchsin were observed under microscope Primo Star (Zeiss, Germany) and images of required parts were shot with EOS D650 (Canon, Chine) digital camera. Results and discussion. Multicellular trichome covered on both leaf sides. Adaxial epidermis a sheet plate have sinuous cells, and abaxial epidermis have differed slightly sinuous cells with clear-shaped walls. In leaflet anatomy of plant vascular bundles are of the collateral type. Stomatas are located from both sides of a leaf. Stomata belong to anisocytic structure. The epidermis of the stem consists of elongated thick-walled cells with anisocytic stomata. The calyx is densely covered by trichomes. The outer epidermis of cross-section of the keel petals cells is the wing horns cells form. And inner epidermis consists of oval cells. Mesophyll cells inside the leaf consist of loose spongy cells on the underside with several conducting bundles (dorsoventral). Conclusions . Morphological and anatomical studying of raw material Medicago falcata L. has shown, that there are prominent features of a structure:four large conductive bundles are located on the cross section of the stem at the corners of the ribs on two sides. Between angular conductive bundles, there are three conductive bundles, and the other two sides are located along one conductive bundle. Therefore, M. Falcata L. differs from M. Sativa L. The epidermis of the stem consists of elongated thickened-walls cells with anisocytic stomata. The indicated diagnostic morphological and anatomical characters could be used in the compilation of a monograph and in identifying plant materials on the raw material of Medicago falcata L.

Heat stress decreases crop growth and yield worldwide. Spermidine (Spd) is a small aliphatic amine and acts as a ubiquitous regulator for plant growth, development and stress tolerance. Objectives of this study were to determine effects of exogenous Spd on changes in endogenous polyamine (PA) and γ-aminobutyric acid (GABA) metabolism, oxidative damage, senescence and heat shock protein (HSP) expression in white clover subjected to heat stress. Physiological and molecular methods, including colorimetric assay, high performance liquid chromatography and qRT-PCR, were applied. Results showed that exogenous Spd significantly alleviated heat-induced stress damage. Application of Spd not only increased endogenous putrescine, Spd, spermine and total PA accumulation, but also accelerated PA oxidation and improved glutamic acid decarboxylase activity, leading to GABA accumulation in leaves under heat stress. The Spd-pretreated white clover maintained a significantly higher chlorophyll (Chl) content than untreated plants under heat stress, which could be related to the roles of Spd in up-regulating genes encoding Chl synthesis (PBGD and Mg-CHT) and maintaining reduced Chl degradation (PaO and CHLASE) during heat stress. In addition, Spd up-regulated HSP70, HSP70B and HSP70-5 expression, which might function in stabilizing denatured proteins and helping proteins to folding correctly in white clover under high temperature stress. In summary, exogenous Spd treatment improves the heat tolerance of white clover by altering endogenous PA and GABA content and metabolism, enhancing the antioxidant system and HSP expression and slowing leaf senescence related to an increase in Chl biosynthesis and a decrease in Chl degradation during heat stress.

Legumes are a key player in sustainable agriculture. They are a potential tool as forage for reclamation of saline soils. However, still there is a need to balance between tolerance of the forage during different developmental stages and its productivity. The present work aimed to study salinity tolerance of four wild Medicago species, as an initial step to select new species that can be grown in salt-affected soils or used as wild relatives to improve alfalfa. Seeds of M. polymorpha, M. intertexta, M. truncatula and M. lupulina, collected from different natural habitats, as well as alfalfa were germinated under different salinity levels to evaluate germination percentage and germination speed. Generally, seeds of M. truncatula collected from desert habitat showed the highest mean germination percentage followed by alfaalfa, while seeds of M. intertexta collected from salt-affected habitat exhibited the highest mean germination speed, followed by M. lupulina. Under severe salt stress, M. intertexta exhibited the highest aerial biomass index, followed by M. truncatula and M. lupulina, while M. polymorpha and alfalfa came as inferiors. Mineral contents and ion leakage of the studied species were determined and discussed. M. intertexta, M. truncatula and M. lupulina, collected from stressful habitats, tended to maintain osmotic and ionic homeostasis by relying on accumulation of the less energetic cost ions (Na+) in roots and sugars and K+ in shoots scoring the highest aerial biomass and tolerance index, orderly. Therefore, the results recommend cultivating these species in salt-affected lands or using them as wild relatives to improve alfalfa.

Genetic mutagenesis is a very efficient tool in studying genes function. Because of the great benefits of legumes as human food and animal feed worldwide, we used a model plant Medicago truncatula for identification gene function related to nitrogen fixation process. Our mutant is a Medicago mutant line contains a tobacco Tnt 1 retro-transposon mobile element with the two Long Terminal Repeats (LTR) inserted within the genome. Our mutant is predicted to contain a mutation in gene/s belonging to symbiotic interaction between legume and rhizobia. A novel technique was used based on using fluorescent oligonucleotide primers against oligonucleotide primers for Tnt 1-LTRs of our mutant. This novel protocol was very successful in detecting the polymorphism between our mutant line and the wild variant R108 using Biosystems 310 Genetic Analyzer. Electropherograms of the mutant line and wild type gave a total of 561 well- resolved AFLP peaks, 357of which were polymorphic peaks and 204 were monomorphic peaks. This novel technique enables the calculation percentage of polymorphism between the mutant line and the wild type. Additionally, primers combinations amplified more bands from others to detect polymorphism between the plants

Tricin (3',5'-dimethoxylated flavone) is a predominant flavonoid amongst monocots but occurs only in isolated and unrelated dicot lineages. Although tricin biosynthesis has been intensively studied in monocots, it has remained largely elusive in tricin-accumulating dicots. We investigated a subgroup of cytochrome P450 (CYP) 75B subfamily flavonoid B-ring hydroxylases (FBHs) from two tricin-accumulating legumes, Medicago truncatula and alfalfa (Medicago sativa), by phylogenetic, molecular, biochemical and mutant analyses. Five Medicago cytochrome P450 CYP75B FBHs are phylogenetically distant from other legume CYP75B members. Among them, MtFBH-4, MsFBH-4 and MsFBH-10 were expressed in tricin-accumulating vegetative tissues. In vitro and in planta analyses demonstrated that these proteins catalyze 3'- and 5'-hydroxylations critical to tricin biosynthesis. A key amino acid polymorphism, T492G, at their substrate recognition site 6 domain is required for the novel 5'-hydroxylation activities. Medicago truncatula mtfbh-4 mutants were tricin-deficient, indicating that MtFBH-4 is indispensable for tricin biosynthesis. Our results revealed that these Medicago legumes had acquired the tricin pathway through molecular evolution of CYP75B FBHs subsequent to speciation from other nontricin-accumulating legumes. Moreover, their evolution is independent of that of grass-specific CYP75B apigenin 3'-hydroxylases/chrysoeriol 5'-hydroxylases dedicated to tricin production and Asteraceae CYP75B flavonoid 3',5'-hydroxylases catalyzing the production of delphinidin-based pigments.

International audience; Root system architecture (RSA) influences the effectiveness of resources acquisition from soils but the genetic networks that control RSA remain largely unclear.We used rhizoboxes, X-ray computed tomography, grafting, auxin transport measurements and hormone quantification to demonstrate that Arabidopsis and Medicago CEP (C-TERMINALLY ENCODED PEPTIDE)-CEP RECEPTOR signalling controls RSA, the gravitropic set-point angle (GSA) of lateral roots (LRs), auxin levels and auxin transport.We showed that soil-grown Arabidopsis and Medicago CEP receptor mutants have a narrower RSA, which results from a steeper LR GSA. Grafting showed that CEPR1 in the shoot controls GSA. CEP receptor mutants exhibited an increase in rootward auxin transport and elevated shoot auxin levels. Consistently, the application of auxin to wild-type shoots induced a steeper GSA and auxin transport inhibitors counteracted the CEP receptor mutant's steep GSA phenotype. Concordantly, CEP peptides increased GSA and inhibited rootward auxin transport in wild-type but not in CEP receptor mutants.The results indicated that CEP-CEP receptor-dependent signalling outputs in Arabidopsis and Medicago control overall RSA, LR GSA, shoot auxin levels and rootward auxin transport. We propose that manipulating CEP signalling strength or CEP receptor downstream targets may provide means to alter RSA.

Under natural conditions, Medicago denticulata produces heteromorphic seeds differing in seed coat colour—cream and brownish black. The present study was conducted in order to determine morphological and physiological differences among heteromorphic seeds of M. denticulata in relation to dormancy and germination behaviour. Brownish black seeds with high moisture content were non-dormant and germinated to a high percentage. However, cream seeds with low moisture content were dormant and exhibited lesser germination without dormancy breaking treatments. Scanning electron microscope studies revealed papillose surface pattern in both seeds. However, brownish black seeds differed from cream seeds by having small cracks scattered all over the surface. Various dormancy breaking treatments viz., sandpaper scarification, soaking in sulphuric acid and hot water significantly increased the germination of cream seeds indicating seed coat imposed dormancy in these seeds. Accelerated ageing of brownish black seeds for 20 or more days resulted in complete inhibition of germination. Whereas, some cream seeds (~ 13%) aged for 20 days were still able to germinate. With accelerated ageing, both seeds recorded decrease in starch and total soluble proteins with concomitant increase in membrane leakage, total soluble sugars and free amino acids. Persistence studies under field conditions revealed that cream seeds present on soil surface or at a burial depth of 2 and 10 cm were able to germinate up to 12 months; but no germination was observed in brownish black seeds buried for 12 or more months. Results of accelerated ageing studies and field persistence suggest longer persistence for cream seeds as compared to brownish black seeds.

Rhizobial nitrogen fixation in legumes provides spillover benefits to neighbouring plants such as pasture grasses. Generally, it is understood to be unidirectional between plant functional groups, providing a benefit from legumes to grasses. We question whether bidirectional complementarity also exists in terms of exploiting the wider soil nutrient pool. We test this hypothesis using soil cores with their component vegetation assemblages sampled from a hill country pasture in South Island, New Zealand. The soil was deficient in key essential elements: P, S, B, Mo and Ni. Facilitation from grasses to clovers was evident; legume-grass mixtures procured more nutrients from the soil than when either species was growing alone. When grasses and clover grow together in unfertilized grassland, more nitrogen is procured by the plant community, and other limiting plant nutrients in the soil are better exploited. Coexistence with grasses is favourable to clovers in terms of soil biogeochemistry.

Background Drought is one of the main causes of losses in forage crop yield and animal production. Medicago ruthenica (L.) cv. Zhilixing is a high-yielding alfalfa cultivar also known for its high tolerance to drought. We analyzed the transcriptome profile of this cultivar throughout drought stress and recovery and we were able to describe its phased response through the expression profiles of overlapping gene networks and drought-specific genes. Results The ABA and auxin signal transduction pathways are overlapping pathways in response to drought and drought recovery in forage crops. Medicago ruthenica (L.) cv. Zhilixing adopts different strategies at different degrees of drought stress. On the 9th day of drought, transcriptional regulations related to osmoregulation are enhanced mainly through increased activities of carbohydrate and amino acid metabolism, while photosynthetic activities were reduced to slow down growth. With drought prolonging, on the 12th day of drought, the synthesis of proline and other stored organic substances was suppressed in general. After recovery, Medicago ruthenica synthesizes flavonoids through the flavonoid biosynthesis pathway to remove accumulated ROS and repair the oxidative damage from water stress. In addition, the regulation of circadian rhythm seems to accelerate the drought recovery process. Conclusions Medicago ruthenica adapts to drought by regulating the osmoregulatory system and photosynthesis, which appears to involve the ABA and auxin signaling pathways as key regulators. Furthermore, the synthesis of flavonoids and the regulation of the circadian rhythm can accelerate the recovery process. These results enriched our knowledge of molecular responses to drought and drought recovery in Medicago ruthenica and provide useful information for the development of new legume forage grass varieties with improved adaptability to drought stress.