Search Results (23)

Background/Objectives: Global warming and rising CO₂ concentrations pose significant challenges to plant systems. Amid these pressures, this study contributes to understanding how tropical species respond by simultaneously evaluating reproductive and genetic traits. It specifically investigates the effects of maternal exposure to warming and elevated CO₂ on progeny physiology, genetic diversity, and population structure in Stylosanthes capitata, a resilient forage legume native to Brazil. Methods: Maternal plants were cultivated under controlled treatments, including ambient conditions (control), elevated CO₂ at 600 ppm (eCO₂), elevated temperature at +2 °C (eTE), and their combined exposure (eTEeCO₂), within a Trop-T-FACE field facility (Temperature Free-Air Controlled Enhancement and Free-Air Carbon Dioxide Enrichment). Seed traits (seeds per inflorescence, hundred-seed mass, abortion, non-viable seeds, coat color, germination at 32, 40, 71 weeks) and abnormal seedling rates were quantified. Genetic diversity metrics included the average (A) and effective (Ae) number of alleles, observed (Ho) and expected (He) heterozygosity, and inbreeding coefficient (Fis). Population structure was assessed using Principal Coordinates Analysis (PCoA), Analysis of Molecular Variance (AMOVA), number of migrants per generation (Nm), and genetic differentiation index (Fst). Two- and three-way Analysis of Variance (ANOVA) were used to evaluate factor effects. Results: Compared to control conditions, warming increased seeds per inflorescence (+46%), reduced abortion (−42.9%), non-viable seeds (−57%), and altered coat color. The germination speed index (GSI +23.5%) and germination rate (Gr +11%) improved with warming; combined treatments decreased germination time (GT −9.6%). Storage preserved germination traits, with warming enhancing performance over time and reducing abnormal seedlings (−54.5%). Conversely, elevated CO₂ shortened GSI in late stages, impairing germination efficiency. Warming reduced Ae (−35%), He (−20%), and raised Fis (maternal 0.50, progeny 0.58), consistent with the species’ mixed mating system; A and Ho were unaffected. Allele frequency shifts suggested selective pressure under eTE. Warming induced slight structure in PCoA, and AMOVA detected 1% (maternal) and 9% (progeny) variation. Fst = 0.06 and Nm = 3.8 imply environmental influence without isolation. Conclusions: Warming significantly shapes seed quality, reproductive success, and genetic diversity in S. capitata. Improved reproduction and germination suggest adaptive advantages, but higher inbreeding and reduced diversity may constrain long-term resilience. The findings underscore the need for genetic monitoring and broader genetic bases in cultivars confronting environmental stressors. Full article

The application of green manure (GM), particularly leguminous varieties, demonstrates significant benefits for crop cultivation in acidic soils by enhancing the soil organic nitrogen (No) pool. To maximize these agronomic advantages, it is crucial to implement scientifically grounded application strategies. To this end, an incubation experiment was conducted to investigate the content, movement distance, and accumulation of acidic soil organic N (No) at different distances from the GM application microsite. Stylosanthes GM (10 or 40 ton/ha) was applied with or without phosphate fertilizer (monocalcium phosphate, MCP) at 44 kg/ha P, placed on the surface of soil cylinders. The GM/fertilizer and soil were incubated for 14 and 28 d. The results indicated the total organic nitrogen (TNo) content—including both non-acid-hydrolyzable N (NAHNo) and acid-hydrolyzable N (AHNo) fractions—significantly (p < 0.05) increased at the GM microsite after GM application. The influence of GM generally weakened as the distance from the site increased, and the spatial impact range exhibited significant modulation by three key parameters: incubation period, GM rates, and MCP addition. Subsequent analysis revealed a positive correlation between GM rate/incubation period and the movement distance of No fractions at GM microsite, demonstrating rate-dependent temporal dynamics. They were also increased by the addition of MCP after a longer incubation period but inhibited after a shorter period. This information will improve the efficiency of GM use, with or without MCP addition, and decrease the environmental load due to N pollution caused by GM. Full article

A compendium of the legumes of the subfamily Papilionoideae, tribes Amorpheae, Brongniarteae, and Dalbergieae in northeastern Mexico is presented for the first time, including changes in their botanical nomenclature within tribes and genera. Based on recently published studies, the taxonomic limits of several genera and new ones segregated such as Marina and Ctenodon are clarified and included. Based mainly on fieldwork over the past 40 years, as well as reviewing specimens in national and international herbaria, we show the total diversity of legumes of the subfamily Papilionoideae, tribes Amorpheae, Brongniarteae, and Dalbergieae. The three tribes include 16 genera and 75 species. Tribe Amorpheae comprises five genera (Amorpha, Dalea, Eysenhardtia, Marina, and Psorothamnus) and forty-three species; tribe Brongniartieae comprises two genera Brongniartia and Harpalyce) and eight species; and tribe Dalbergieae comprises nine genera (Aeschynomene, Amicia, Arachis, Ctneodon, Dalbergia, Diphysa, Nissolia, Stylosanthes, and Zornia) and twenty-four species. Dalea is by far the genus with the highest number of species and infraspecific categories, as well as in a number of endemisms because 17 (51%) of them are endemic to Mexico, and six of them are endemic to the northeastern part of the country. Of the 13 species of Eysenhardtia present in Mexico, 31% of them reach the northeast region and three of them are exclusive to this region. There are no species of the Brongniartieae and Dalbergieae tribes endemic to northeastern Mexico, but 10 of their species are endemic to Mexico. Full article

The ensiling potential of Tamani guinea grass (Panicum maximum cv. BRS Tamani) and Stylosanthes cv. Bela in monoculture or intercropped systems, and the effect of two treatments on ensiling (with and without inoculant) on fermentation quality and nutritional composition of the silage after 50 days of ensiling, were evaluated. The experiment was conducted at the Instituto Federal Goiano, Campus Rio Verde, Goiás, Brazil, using a randomized block design with four replications in a 3 × 2 factorial scheme, totaling 24 experimental silos. The forage was harvested during a 28-day regrowth cycle. Results indicated that silages without inoculants showed inadequate fermentative characteristics, compromising nutritional preservation. The addition of microbial inoculants improved the fermentation process, ensuring proper preservation of silage. The intercropping of Tamani guinea grass with Stylosanthes cv. Bela resulted in higher dry matter production and improved the nutritional value of the silage, with increases of 3.46% in crude protein content, 20.96% in ADIP (acid detergent insoluble protein), 6.31% in soluble carbohydrates, and 10.06% in starch compared to the silage of Tamani guinea grass in monoculture. Therefore, the use of silage from intercropped Tamani guinea grass and Stylosanthes cv. Bela with the addition of inoculants can be recommended as a productive and sustainable practice, reducing costs associated with protein and mineral supplementation. Full article

Legumes enhance pasture health and soil productivity by fixing atmospheric nitrogen and boosting soil microbiota. We investigated the effects of tropical pasture legumes, including butterfly pea (Clitoria ternatea), seca stylo (Stylosanthes scabra), desmanthus (Desmanthus virgatus), lablab (Lablab purpureus), and Wynn cassia (Chamaecrista rotundifolia), on the soil microbial community and buffel grass (Cenchrus ciliaris) gene expression. Additionally, we explored the impact of a phytogenic bioactive product (PHY) in the coculture system. A pot trial using soil enriched with cow paunch compost included four treatments: monoculture of buffel grass and five legume species with and without PHY supplementation and coculture of buffel grass with each legume species with and without PHY supplementation. Actinobacteriota and Firmicutes were the dominant bacterial phyla. Regardless of PHY application, the coculture of buffel grass with legumes positively influenced microbial composition and diversity. Transcriptomic analysis revealed significant gene expression changes in buffel grass shoots and roots, with each legume uniquely affecting nitrogen metabolism. Lablab and Wynn cassia exhibited similarities in modulating metabolic processes, butterfly pea contributed to mycotoxin detoxification, and desmanthus balanced cell death and growth. Seca stylo enhanced root cell growth and regeneration. These findings offer insights for optimizing legume–grass coculture systems, enhancing soil activity and promoting sustainable agriculture. Full article

Substantial proteolysis occurs and free amino acids can be degraded to biogenic amines by decarboxylation during stylo (Stylosanthes guianensis) ensiling. High biogenic amine concentrations in silage are harmful to the health of ruminant animals. The purposes of this work were to (1) analyze the biogenic amines and amino acids concentrations, bacterial composition, and fermentation profile of spontaneously fermented stylo silage, (2) explore the effect of formic acid or sugar additive on these silage parameters, and (3) further reveal the correlations between silage amines and fermentation parameters, amino acids, and bacteria. Freshly chopped stylo was treated with distilled water (control), formic acid (4 mL/kg), and sugar (20 g/kg) and fermented for 28 days. The results indicated that putrescine (321 mg/kg dry matter), cadaverine (384 mg/kg dry matter), and tyramine (127 mg/kg dry matter) rapidly increased in concentration and become predominant in the control silage after 28 days of fermentation. Applying formic acid and sugar at ensiling, especially the acidifier, significantly decreased putrescine, cadaverine, tyramine, and total biogenic amine concentrations compared with the control treatment (p < 0.0001). Clostridium pabulibutyricum, Weissella cibaria and W. paramesenteroides were the predominant bacteria in the control silage, and the application of both additives remarkably lowered their relative abundance in comparison with the control treatment (p < 0.001). Correlation analysis showed that putrescine, cadaverine, and tyramine were positively related to pH, butyric acid, non-protein nitrogen, and ammonia nitrogen (p < 0.01). These amines also had significant correlations with C. pabulibutyricum, W. cibaria and W. paramesenteroides (p < 0.001). Putrescine, cadaverine, and tyramine were the main biogenic amines and C. pabulibutyricum was the predominant undesirable bacterium in naturally fermented stylo silage. C. pabulibutyricum, W. cibaria and W. paramesenteroides were positively related to putrescine, cadaverine, and tyramine formation. The application of formic acid or sugar significantly reduced the undesirable bacterial population and improved the fermentation and hygienic quality of the stylo silage. These findings lay the foundation for further elucidating the microbial mechanism underlying the main biogenic amine formation during fermentation of stylo silage. Full article

This study focused on exploring the effects of Neolamarckia cadamba leaf extract (NE) on the fermentation process and bacterial community of stylo (Stylosanthes guianensis) silage. Fresh raw materials of stylo were ensiled with 0%, 1%, and 2% NE, and various fermentation parameters, nitrogen components, and microbial compositions were analyzed at different time points (days 3, 7, 14, and 30) during the ensiling process. The experiment showed that, in comparison to the control group, incorporating NE into the ensiling process resulted in improved fermentation parameters, including increased lactic acid and acetic acid levels, as well as decreased pH, coliform population, and ammonia nitrogen concentration. Moreover, the relative abundances of Lactobacillus and Pediococcus were augmented, while the growth of Enterobacter was inhibited by the NE addition. These results suggest that NE has potential as a novel additive for silage, promoting a reduction in harmful bacteria and enhancements in the nutritional quality and fermentation characteristics of stylo silage. Full article

S. scabra is an important forage and extremophilic plant native to the Brazilian Caatinga semiarid region. It has only recently been subjected to omics-based investigations, and the generated datasets offer insights into biotechnologically significant candidates yet to be thoroughly examined. INSs (inositol and its derivatives) and RFO (raffinose oligosaccharide family) pathways emerge as pivotal candidates, given their critical roles in plant physiology. The mentioned compounds have also been linked to negative impacts on the absorption of nutrients in mammals, affecting overall nutritional intake and metabolism. Therefore, studying these metabolic pathways is important not just for plants but also for animals who depend on them as part of their diet. INS and RFO pathways in S. scabra stood out for their abundance of identified loci and enzymes. The enzymes exhibited genomic redundancy, being encoded by multiple loci and various gene families. The phylogenomic analysis unveiled an expansion of the PIP5K and GolS gene families relative to the immediate S. scabra ancestor. These enzymes are crucial for synthesizing key secondary messengers and the RFO precursor, respectively. Transcriptional control of the studied pathways was associated with DOF-type, C₂H₂, and BCP1 transcription factors. Identification of biological processes related to INS and RFO metabolic routes in S. scabra highlighted their significance in responding to stressful conditions prevalent in the Caatinga environment. Finally, RNA-Seq and qPCR data revealed the relevant influence of genes of the INS and RFO pathways in the S. scabra response to water deprivation. Our study deciphers the genetics and transcriptomics of the INS and RFO in S. scabra, shedding light on their importance for a Caatinga-native plant and paving the way for future biotechnological applications in this species and beyond. Full article

Stylo (Stylosanthes spp.) is an important pasture legume with strong aluminum (Al) resistance. However, the molecular mechanisms underlying its Al tolerance remain fragmentary. Due to the incomplete genome sequence information of stylo, we first conducted full-length transcriptome sequencing for stylo root tips treated with and without Al and identified three Snakin/GASA genes, namely, SgSnakin1, SgSnakin2, and SgSnakin3. Through quantitative RT-PCR, we found that only SgSnakin1 was significantly upregulated by Al treatments in stylo root tips. Histochemical localization assays further verified the Al-enhanced expression of SgSnakin1 in stylo root tips. Subcellular localization in both tobacco and onion epidermis cells showed that SgSnakin1 localized to the cell wall. Overexpression of SgSnakin1 conferred Al tolerance in transgenic Arabidopsis, as reflected by higher relative root growth and cell vitality, as well as lower Al concentration in the roots of transgenic plants. Additionally, overexpression of SgSnakin1 increased the activities of SOD and POD and decreased the levels of O₂^·− and H₂O₂ in transgenic Arabidopsis in response to Al stress. These findings indicate that SgSnakin1 may function in Al resistance by enhancing the scavenging of reactive oxygen species through the regulation of antioxidant enzyme activities. Full article

Anthracnose caused by Colletotrichum gloeosporioides is a destructive disease of Stylosanthes (stylo). Combination treatment of phloretin and pterostilbene (PP) has been previously shown to effectively inhibit the conidial germination and mycelial growth of C. gloeosporioides in vitro. In this study, the effects of PP treatment on the growth of C. gloeosporioides in vivo and the biocontrol mechanisms were investigated. We found that exogenous PP treatment could limit the growth of C. gloeosporioides and alleviate the damage of anthracnose in stylo. Comparative transcriptome analysis revealed that 565 genes were up-regulated and 239 genes were down-regulated upon PP treatment during the infection by C. gloeosporioides. The differentially expressed genes were mainly related to oxidative stress and chloroplast organization. Further physiological analysis revealed that application of PP after C. gloeosporioides inoculation significantly reduced the accumulation of O₂^•− level and increased the accumulation of antioxidants (glutathione, ascorbic acid and flavonoids) as well as the enzyme activity of total antioxidant capacity, superoxide dismutase, catalase, glutathione reductase, peroxidase and ascorbate peroxidase. PP also reduced the decline of chlorophyll a + b and increased the content of carotenoid in response to C. gloeosporioides infection. These results suggest that PP treatment alleviates anthracnose by improving antioxidant capacity and reducing the damage of chloroplasts, providing insights into the biocontrol mechanisms of PP on the stylo against anthracnose. Full article

Stylosanthes scabra is a scientifically orphaned legume found in the Brazilian Caatinga biome (a semi-arid environment). This work utilized omics approaches to investigate some ecophysiological aspects of stress tolerance/resistance in S. scabra, study its genomic landscape, and predict potential metabolic pathways. Considering its high-confidence conceptual proteome, 1694 (~2.6%) proteins were associated with resistance proteins, some of which were found in soybean QTL regions that confer resistance to Asian soybean rust. S. scabra was also found to be a potential source of terpenes, as biosynthetic gene clusters associated with terpene biosynthesis were identified in its genome. The analysis revealed that mobile elements comprised approximately 59% of the sequenced genome. In the remaining 41% of the sections, some of the 22,681 protein-coding gene families were categorized into two informational groups: those that were specific to S. scabra and those that expanded significantly compared to their immediate ancestor. Biological process enrichment analyses indicated that these gene families play fundamental roles in the adaptation of S. scabra to extreme environments. Additionally, phylogenomic analysis indicated a close evolutionary relationship between the genera Stylosanthes and Arachis. Finally, this study found a high number (57) of aquaporin-encoding loci in the S. scabra genome. RNA-Seq and qPCR data suggested that the PIP subfamily may play a key role in the species’ adaptation to water deficit conditions. Overall, these results provide valuable insights into S. scabra biology and a wealth of gene/transcript information for future legume omics studies. Full article

A trial was conducted to investigate the growth and production characteristics of four plant species, marking the initiation of research on roadside revegetation processes in the southern region of Piauí state, Brazil. The trial was conducted in greenhouse conditions to evaluate the response of the species—two native legumes (Arachis pintoi and Stylosanthes macrocephala) and two grasses (Brachiaria humidicula—non-native and Paspalum notatum—native)—under different fertilization and irrigation treatments. Data were collected in two harvest operations, measuring the following variables: total plant height, population density per pot, number of live leaves, plant moisture content, total forage biomass, and root biomass. The results suggested that fertilization and irrigation caused no significant effect on the major species development characteristics that allay with the highway agency interests. Arachis pintoi showed the best results with the lowest height (24.1 cm in Experiment 1 and 19.2 cm in Experiment 2) and the greatest total forage biomass yield (6.4 g plant⁻¹ in Experiment 1 and 4.1 g plant⁻¹ in Experiment 2). Thus, we recommend that the results found in this study should be extended to field experiments and long-term research. Because our study did not explore mixed-species designs, adopting such evaluation could offer advantages in achieving more comprehensive and resilient revegetation outcomes and help decision-making regarding target species to compose the roadside revegetation operations. Full article

Mixed ensiling of Stylosanthes guianensis and Pennisetum sinese is an alternative method to improve the nutrient composition of feeds for healthy and green ruminant production in the tropics. This study examined the fermentation quality, nutritional composition, and microbial population in silage to select the most suitable ratio of mixed silage containing different proportions of S. guianensis and P. sinese. It was completely randomized and consisted of four treatments with five replications based on fresh weight as follows: S0, 100% P. sinese; S15, 85% P. sinese + 15% S. guianensis; S30, 70% P. sinese + 30% S. guianensis; and S45, 55% P. sinese + 45% S. guianensis. The silage samples were opened and detected after ensiling for 30 days. The results showed that the content of dry matter and crude protein in mixed silage increased with the increase in S. guianensis, while the content of acid detergent fiber decreased significantly, and the maximum or minimum value appeared in the S45 group. As the proportion of S. guianensis increased, the pH, ammonia nitrogen, and acetic acid in mixed silage gradually increased, but the lactic acid content decreased. In addition, the content of lactic acid bacteria and yeast showed a significant downward trend. Further study showed that there was a complex correlation between nutrient compositions, fermentation characteristics, and microbial numbers in mixed silage, especially dry matter, crude protein, and lactic acid bacteria. From the sensory evaluation of silage, S30 was excellent and exhibited an aromatic smell, a hazel color, and the loosest texture. However, from the results of the proportion of organic acids in mixed silage fermentation and further principal component analysis, the highest comprehensive score was in the S15 group. Considering the nutritional compositions and fermentation quality, the optimum ratio of mixed fermentation between S. guianensis and P. sinese in this experiment was 30:70. Full article

Rainfed agriculture, though resource-poor, contributes to around 40 percent of total food production in India. Fodder grass-strip-based systems improve soil’s physical and biological properties, control soil erosion, and help in slope stabilization without compromising productivity. Permanent fodder grass strips can effectively check the depletion of soil nutrients and can also act as sediment traps vis-à-vis meeting the green fodder requirement for small ruminants. This study was carried out with the major objective to quantify the impact of grass-strip-based cropping systems on soil quality. Further fodder quality assessment was carried out using the grass quality index for small ruminant feed and the profitability of different treatments was analyzed. Random block design (RBD) with three treatments which included two types of fodder grass (Brachiaria ruziziensis and Stylosanthes hamata) on both sides of the cropped field was used for the study. The results showed that the soil quality increased from 0.39 to 0.52 and the runoff reduced significantly with soil loss reduction by 65-70 percent. The fodder quality assessment showed that the palatability of Stylosanthes hamata and Brachiaria ruziziensis was about 65 percent and 40 percent, respectively. The fodder grass strip increased the net returns by 30 percent. This easily adaptable natural resource management technology reduces soil nutrient loss and will help resource-poor rainfed farmers to maintain soil health and productivity under variable rainfall conditions with fair support to small ruminants. Full article

The present study aims to estimate the dynamic effects of moisture levels and inoculants on the fermentation quality and in vitro degradability of Stylosanthes silage. In this experiment, Stylosanthes was ensiled with (1) no additive (control), (2) Lactobacillus plantarum (LP), (3) Lactobacillus plantarum carrying heterologous genes encoding multifunctional glycoside hydrolases (xg), or (4) LP + xg and was wilted until different moisture levels (60% and 72%) were attained. The ensiled bags were unpacked after different storage periods to determine the chemical composition and fermentation quality of the Stylosanthes silage. Moreover, the in vitro degradability was also determined 45 days after the ensiling process. The results show that the silage prepared with freshly mowed Stylosanthes also had a lower pH and NH₃- N content. Adding transgenic engineered lactic acid bacteria xg not only decreased the NDF and ADF content of the silage, but also improved the in vitro digestibility significantly. We concluded that the addition of xg to Stylosanthes silage can improve its quality and increase in vitro digestibility and gas production. The results provide technical support and a theoretical basis for the utilization of warm-season forage silage. Full article