Legume Tree Research Articles

Complete Dried Ration for Ruminant Based on Pennisetum purpureum cv. Mott Enriched Phyto-Protein of Tree Legumes Leaf

Indonesia is a country with a big human population in the world, still import red meat, since the price of this commodity is higher than those import. The problem is supply of forages is insufficient due to limitation of space for forage production. Especially during the dry season the forages almost disappears and farmers face on shortage supply of forage followed decrease beef production. This research aimed to study the effects of enriched protein of tree legume leaf on complete dry ration based on tropical grass. The treatments were: T-0 = P.purpureum (control); T-1 = PP + GS+Crt; T-2 = PP + LL + Crt; T-3 = PP + IZ + Crt. Treatments were arranged on Completely Randomized Design, with 5 replications. Twenty male goats with average body weight +15 Kg has been used. The results of this research showed that treatment T-3 with I. zolingeriana (IZ) as a source of phyto-protein in complete rations has the best results on all variables measured. It could be concluded that leaves of this tree legumes prospective to support the application of technology complete ration based on local resources to resolve the problem of shortages of feeds supply to ruminant in the tropic region.

Nitrogen and phosphorus influence Acacia saligna invasiveness in the fynbos biome

This study attempts to understand how invasive legumes such as Acacia saligna may compete with indigenous legumes such as Virgilia divaricata. The two species are trees with similar growth forms. We studied the competitive ability of invasive and indigenous seedlings under variations in soil phosphorus availability. South African fynbos vegetation is threatened by invasive Acacia. The indigenous tree legume, Virgilia, grows in similar phosphorus soil conditions as Acacia although there is a gap in the knowledge of their physiology. We investigated the utilization of different inorganic P sources by the invasive A. saligna and the native V. divaricata in the presence and absence of root nodules in each species. Plant performance in terms of photosynthesis and biomass production was also analysed. Plants were cultivated in silica sand supplied with Long Ashton nutrient solution, modified to contain either 50 μM P or 500 μM P applied as NaH2PO4·2H2O. Rate of growth was estimated as the increase in mass in plants harvested after 4 and 8 weeks of growth. After 4 weeks of growth, the seedlings of Virgilia grew quicker and produced more biomass than Acacia, under both phosphorus conditions. However, this was reversed after 8 weeks of growth, with Acacia out-competing Virgilia. Increased growth of the invasive legumes was achieved by relying on soil nitrogen under high phosphorus conditions and shifting to atmospheric sources under lower phosphorus levels. The strategies of altering photosynthetic carbon balance and nitrogen acquisition under varying soil phosphorus conditions potentially underpin the invasive potential of Acacia in fynbos soils.

Cocoa agroforest multifunctionality and soil fertility explained by shade tree litter traits

Abstract Manipulating plant functional diversity to improve agroecosystem multifunctionality is a central challenge of agricultural systems world‐wide. In cocoa agroforestry systems (cAFS), shade trees are used to supply many services to farmers, yet their impact on soil functioning and cocoa yields is likely to vary substantially among tree species. Here we compared the impact of five shade tree species (Canarium schweinfurthii (Canarium), Dacryodes edulis (Safou), Milicia excelsa (Iroko), Ceiba pentandra (Kapok tree), Albizia adianthifolia (Albizia)) and unshaded conditions on the functioning of poor sandy savanna soils within eight cocoa farms in Central Cameroon. We assessed the effects of plant functional traits, leaf litterfall and fine root biomass on a range of soil functions and on cocoa yield. Shade trees generally improved soil pH, , and Olsen P content, biomass production of bioassays and soil total C and N content, while leaving cocoa yields unchanged. However, these effects varied largely among species. Improvements of soil functions were low under the two fruit trees (Canarium and Dacryodes), medium under the legume tree Albizia and high under the two timber trees (Milicia and Ceiba). Low litter recalcitrance was most strongly associated with increases in soil fertility indicators such as N and P availability, whereas soil C and N content increased with litter Ca restitution. Synthesis and applications. We demonstrate that cocoa agroforest multifunctionality is substantially influenced by the functional traits of shade tree species. Shade tree species with the most dissimilar traits to cocoa (cocoa showing the lowest leaf litter quality) showed the largest improvement of soil functions. Therefore, selection of shade trees based on their functional traits appears as a promising practice to adequately manage soil functioning. In order to fully assess the beneficial role of shade trees in these agroecosystems. Future research will need to extend this approach to other below‐ground traits and other aspects of multifunctionality such as long‐term cocoa health and yield.

Development, rooting and nodulation of mororó (<i>Bauhinia cheilantha</i>) cuttings harvested in different seasons

To increase the establishment options of the tropical forage legume tree, mororó (Bauhinia cheilantha), a native of the Caatinga vegetation in Northeast Brazil, a vegetative propagation study was carried out. In 2 experiments the performance of cuttings taken from 2 different locations on the mother plant (apical and basal branches) was evaluated on 4 different substrates: washed sand (SA); soil (S); soil in a moist chamber (S+MC); and vermiculite (V), in which cuttings were ‘planted’. The variables analyzed were: bud emergence; presence of expanded leaves; length and width of expanded leaves; and development of roots. For the first experiment, cuttings were taken in the dry season (December), for the second experiment in the rainy season (June). Cutting season had the major effect on all variables, particularly emerging buds (37‒90% in the dry vs. 1‒34% in the rainy season) and expanded leaves (23‒60% in the dry vs. 1‒13% in the rainy season). The best results were obtained in substrates S+MC and SA, the latter applying particularly for root development. It seems cuttings can be taken from any part of the mother plant but should be taken in the dry season, when an adequate supply of nutrients exists in the branches. Further studies are warranted to determine how to increase the success of root development on cuttings.

Structural characterization and pod yields of populations of the fodder legumes trees <i>Piliostigma thonningii.</i> and <i>Prosopis africana</i> along the toposequence in western Burkina Faso

Plant communities including fodder trees play an important role in livestock production in semi-arid zones of West Africa. This study was carried out at two sites of the western region of Burkina Faso and aimed to provide information on the current status of the natural savanna-woodland pastures and predict the pod production of Piliostigma thonningii and Prosopis africana, two key fodder species of these ecosystems. All woody species were systematically identified and their dbh and height were measured in plots along a toposequence. Pods were collected from 60 trees of P. thonningii and P. africana and the stem circumference at breast height and the crown diameter were also measured. To predict pod production, regression analysis was used to develop predictive allometric equations by selecting tree size variables for fitting to models. Results showed a total of 24 species belonging to 11 families and 22 genera were inventoried with clear tendency to shrub invasion of the toposequence locations. P. thonningii trees had a good regeneration status while P. Africana individuals were old. The two species had good potential for natural regeneration of the stands from seedlings. The pod production prediction equations for both species were significantly correlated to dendrometric traits (P˂0.0001). They were species-specific, and the equations developed for each species were different. It is not advised to apply the same formula to predict pod production of fodder trees species at different savanna-woodland locations throughout West Africa.Keywords: Browse species, dendrometric traits, class distribution, Fodder equation, Natural savannawoodland pastures, Toposequence, West Africa.

In vitro rumen biohydrogenation of unsaturated fatty acids in tropical grass-legume rations.

Aim:The aim of this study was to evaluate the effects of various combinations of tropical grass-legume species in rations on the biohydrogenation (BH) activity of unsaturated fatty acids (FAs), C18:0 composition, and fermentation profile in an in vitro rumen system.Materials and Methods:Samples of the following five fodder plants were used: One species of grass (Pennisetum purpureum) and four species of tree legumes (Leucaena leucocephala, Gliricidia sepium, Calliandra calothyrsus, and Indigofera zollingeriana). The following eight experimental diets were evaluated: 50% P. purpureum + 50% L. leucocephala (LL I); 50% P. purpureum + 50% G. sepium (GS I); 50% P. purpureum + 50% C. calothyrsus (CC I); 50% P. purpureum + 50% I. zollingeriana (IZ I); 75% P. purpureum + 25% L. leucocephala (LL II); 75% P. purpureum + 25% G. sepium (GS II); 75% P. purpureum + 25% C. calothyrsus (CC II); and 75% P. purpureum + 25% I. zollingeriana (IZ II). Each ration was replicated 3 times. In vitro rumen incubation was performed for 48 h, according to the Tilley and Terry method. Determination of the FA profiles of the forage materials and rumen fluid samples was performed using gas chromatography.Results:The percentage of polyunsaturated FA (PUFA) in the forage materials ranged from 34.18% (P. purpureum) to 74.51% (C. calothyrsus). The percentage of monounsaturated FA (MUFA) ranged from 5.06% (P. purpureum) to 8.71% (L. leucocephala). The percentage of saturated FA (SFA) was the lowest at 19.12% (C. calothyrsus) and highest at 60.76% (P. purpureum). In vitro BH of C18:3 n-3, C18:2 n-6, C18:1 n-9, and C18 PUFA in the experimental diets ranged from 72% to 100%. The BH of C18:1 n-9 in GS I (80%) and IZ I (72%) was significantly different (p<0.05). The percentage of C18:0 was 10-50% and significantly different (p<0.05) among treatments, with the highest (of 50%) in GS II. No significant differences (p>0.05) were observed in the fermentation parameters (pH, total volatile FAs, in vitro dry matter digestibility, and in vitro organic matter digestibility) among the treatments, except in NH3 concentration (p<0.05).Conclusion:The various combinations of tropical legumes do not have significant inhibitory effects on the BH of C18:2 n-6, C18:3 n-3, and C18 PUFA after in vitro incubation for 48h. Furthermore, an increase in the tropical legume ratio in the ration tends to suppress C18:0 formation after the fermentation simulation process. IZ I has the potential to reduce C18:1 n-9 (MUFA) disappearance and yield an ideal rumen fermentation profile.

Adenogasteria leguminivora Davis &amp; Vargas gen. et sp. nov. (Lepidoptera: Gracillariidae): a new seed‐feeding micromoth associated with Fabaceae in Peru and Chile

AbstractThe adult, pupa, larva and biology of Adenogasteria leguminivora Davis &amp; Vargas gen. et sp. nov. (Lepidoptera: Gracillariidae: Ornixolinae) from Peru and Chile are described and illustrated. This micromoth was previously reported in the agronomic literature as a pest of Caesalpinia spinosa (Molina) (Fabaceae) in Peru, but its taxonomic status remained unknown until now. Its larvae feed on the seeds of three legume trees: Acacia macracantha, C. spinosa and Inga feuillei. Adenogasteria leguminivora superficially resembles other sympatric gracillariids but can be separated on key morphological features and host plant preferences. Eggs of A. leguminivora are laid on the fruit surface, from where the larva burrows until it reaches the cotyledons, which are mined by the two early (sap‐feeding) instars and almost completely consumed by the last three (tissue‐feeding) instars. Subsequently, the mature larva leaves the fruit and constructs an elongated silk cocoon ornamented with a few silk bubbles before pupation. A maximum likelihood analysis of DNA barcodes clustered the A. leguminivora sequences as a single independent phylogenetic unit within Ornixolinae, sister to the Chileoptilia + Philodoria clade, regardless of the host plant and geographic origin of the samples. The genetic divergence of A. leguminivora to the nearest neighbour in COI barcodes was &gt;10%.

Dung decomposition of cattle grazing from mixed pastures of Signalgrass (Brachiaria decumbens Stapf.) and tree legumes

The mineralization rate of ruminant manure may influence the fertilization management of pastures. This study aimed to evaluate feces decomposition of heifers grazing signalgrass (Brachiaria decumbens Stapf.) fertilized or not with N, or intercropped with legumes in the dry forest region. Two experiments were conducted; the first one was a CRD that evaluated the evolution of CO2 from a mixture of soil and feces (10:1) during 22 days of incubation in a hermetically sealed bucket with a solution of NaOH 0.5 mol L-1. The second one was a RCBD that evaluated the in situ decomposition of feces in nylon bags in time periods 4, 8, 16, 32, 64, 128 and 256 days after incubation above ground. The single negative exponential mathematical model was adequate (P ≤ 0.0001) to quantify the CO2 evolution of the mixture of soil and feces, indicating that 78% of CO2 was released at the beginning of the incubation, especially for the feces collected in the signalgrass pastures intercropped with Gliricidia sepium (Jacq.) Kunth ex Walp. (gliricídia). After the first 5 days, CO2 evolution was more stable. Remaining biomass in the litterbag along decomposition fitted the single negative exponential model (P &lt; 0.001). Greater relative decomposition rate (k) of bovine fecal biomass occurred for the N-fertilized signalgrass treatment (k = 0.0031 g g-1 day-1) and a lesser rate for the treatment intercropped with Mimosa caesalpiniifolia Benth. (sabiá) (k = 0.0018 g g-1 day-1). Nitrogen fertilization in signalgrass pasture favored the decomposition of bovine feces at the end of 256 days of incubation.

The widely distributed legume tree Vachellia (Acacia) nilotica subsp. indica is nodulated by genetically diverse Ensifer strains in India

Vachellia (syn. Acacia) nilotica subsp. indica is a widespread legume tree in India of ecological and economic importance due to its ability to nodulate and fix nitrogen. The structure of V. nilotica nodules was examined and diversity of its rhizobial symbionts in various locations in India was assessed. More than a hundred strains were purified from indeterminate Vachellia-type root nodules on seedlings grown in alkaline soils from different regions of Thar Desert in Western Rajasthan and in neighbouring states (Gujarat, Haryana, Punjab). Plants grown in acidic soils of Meghalaya and Nagaland failed to nodulate. Twenty-one strains identified as species of Ensifer (Sinorhizobium) based on their 16S rRNA gene sequences and grouped into seven recA-types. Eight strains were characterized using two additional housekeeping (glnII, dnaK) and symbiotic (nodA, nifH) genes. A concatenated core gene phylogeny revealed that V. nilotica-Ensifer strains are novel and genetically diversified from E. saheli, E. arboris, E. terangae and E. americanus. Most are distinct from Ensifer strains previously reported in mimosoid, caesalpinioid and papilionoid legume species of W. Rajasthan. These Ensifer strains harboured typical mimosoid-type symbiotic genes that were diversified from E. arboris, E. kostiensis and E. terangae. They nodulated other mimosoids (Prosopis cineraria, Mimosa hamata, Senegalia senegal and Vachellia spp.), but failed to make symbiotic interactions with a papilionoid crop species, Vigna radiata, suggesting their specificity towards mimosoids. Vachellia nilotica is quite promiscuous, fixing nitrogen in symbiosis with diverse strains of Ensifer, and has successfully invaded various agro-climatic regions, thus indicating that it could be exploited for agroforestry projects.

Notes on the extended distribution of Humboldtia bourdillonii (Fabales: Fabaceae), an Endangered tree legume in the Western Ghats, India

Humboldtia bourdillonii is an Endangered tree legume; considered endemic to its type locality in the Periyar Tiger Reserve in Idukki District of Kerala State. A new population of this highly threatened endemic species is located in the Vagamon Hills of Kottayam District which is about 70km away from its original locality. The newly located population is drastically affected by the severe floods and landslides that occurred in Kerala state during August 2018. Urgent conservation measures are needed to protect the population from further loss.&#x0D;

The Mimosoid tree Leucaena leucocephala can be nodulated by the symbiovar genistearum of Bradyrhizobium canariense

Leucaena leucocephala is a Mimosoid legume tree indigenous to America that has spread to other continents, although it is not still present in some European countries such as Portugal. Nevertheless, we found that this legume can be nodulated in this country by slow-growing rhizobial strains which were identified as Bradyrhizobium canariense trough the analysis of the core genes recA and glnII. The analysis of the symbiotic gene nodC showed that these strains belong to the symbiovar genistearum, which commonly nodulates Genistoid legumes. Although two strains nodulating L. leucocephala in China and Brazil were classified within the genus Bradyrhizobium, they belong to undescribed species and to the symbiovars glycinearum and tropici, respectively. Therefore, we report here for the first time the ability of L. leucocephala to establish symbiosis with strains of B. canariense sv genistearum confirming the high promiscuity of L. leucocephala, that allows it to establish symbiosis with rhizobia native to different continents increasing its invasiveness potential.

Fine root density and vertical distribution of Leucaena leucocephala and grasses in silvopastoral systems under two harvest intervals

Understanding belowground morphological mechanisms of trees and grasses is a complicated task but can help in the design and management of silvopastoral systems. In this study, we evaluated the effect of the harvest intervals (i.e. 30 and 50 days) of aboveground biomass on the fine root density and vertical distribution in two silvopastoral systems (SPS): one comprising Leucaena leucocephala (legume tree) and Cynodon plectostachyus (grass) and the other L. leucocephala and Panicum maximum. We used a completely randomized design with four repetitions. We sampled fine roots by using a metal cylinder (8 cm diameter and 50 cm length) 7 days after each harvest. We washed the samples with pressurized water to separate them from the soil. The roots were digitalized at a resolution of 600 dpi to determine the diameter and specific root length by using IJ Rhizo® software. Samples were subsequently dried to quantify fine root mass. We found that the greater percentages of fine roots were between 0.4 and 0.8 mm for the legume and between 0.2 and 0.4 mm for grasses. The fine root length and mass density of P. maximum was higher (P 0.05). The effect of harvest interval was significant only in some soil layers in both SPS (P > 0.05). Most of the pasture roots were found in the upper soil layer (0–20 cm), while L. leucocephala roots were present to deeper soil layers. We conclude that P. maximum has a greater rooting capacity and a more rapid recovery than C. plectostachyus, which has greater diameters and lower root density. However, L. leucocephala presented deeper and thicker fine roots in both SPS, which is a good indication of its belowground recovery capacity to aboveground disturbances.

Effects of mechanical and acid scarification on germination performance of Schizolobium parahyba (Fabaceae – Caesalpinioideae) seeds

Improving seed germination of native species is fundamental for assisting restoration practices, particular in highly degraded ecosystems such as tropical moist forests. Tropical moist forests of Central and South America continue to decrease as a result of fragmentation and conversion of forested land to agriculture. Schizolobium parahyba is a pioneer legume tree species widely used in restoration practices due to its fast growth rate, nitrogen-fixing capacity, and wood properties. Seeds of this species exhibit low germination as a result of physical dormancy, which highly limits its propagation on a large scale. We evaluated the effects of mechanical and acid scarification treatments with solutions of sulfuric (10%, 20%) and chloridric (25%, 50%, 75%) on Schizolobium parahyba seed germination. Mechanically scarified seeds had higher germination percentage (92.5%) than seeds treated with chloridric acid (50%), sulfuric acid (33.13±.2.11%) or intact seeds (17.5%). Seeds soaked in 10% sulfuric acid for 1 and 5 minutes exhibited higher germination values than seeds soaked in 20% for 10 minutes. Seeds soaked in 75% and 50% chloridric acid solutions for 5 and 10 minutes had an overall higher and faster germination than seeds soaked in 25% for 1 minute. This study indicates that mechanical scarification and acid scarification with solutions of chloridric acid solutions of 50% and 75% can highly improve large-scale propagation of S.parahyba and thus assist habitat restoration and conservation practices in degraded moist tropical forests.

Leucaena feeding systems in Argentina. I. Five decades of research and limitations for adoption

Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.This review describes the history of research in Leucaena leucocephala (leucaena) feeding systems carried out by the National Institute of Agricultural Technology (INTA) over the last 5 decades and discusses the main limitations resulting in poor adoption in Argentina. Leucaena was introduced in the subtropical region of the north of the country in the late 1960s and early 1970s. Since then, INTA has conducted research to evaluate forage and animal productivity, leucaena accessions, rhizobial strains, contribution to soil carbon and total nitrogen and density effects on competition and other ecosystem interactions in silvopastoral systems. In spite of the convincing research results showing the excellent potential of leucaena to increase forage quality and animal production in suitable areas, there has been poor adoption of this forage tree legume on a broad scale.

Economic analysis of cattle fattening systems based on forage tree legume diets in eastern Indonesia

Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.Research and government agencies in eastern Indonesia have identified 2 systems with potential to increase productivity and incomes of small-holder cattle producers: improved cattle feeding practices through forage tree legumes (FTL); and the development of more efficient and specialized cattle-fattening systems. Extensive research has been conducted on production and technical aspects of FTL-fattening systems, but there is a gap in research on economic incentives for households to adopt the systems. This paper provides an economic analysis of a leucaena-fattening system in a village in West Timor. It draws on trial data from associated technical research projects and detailed semi-structured interviews with farmers and other stakeholders to populate a bio-economic model built for the research. Under all measures of profitability, leucaena-fattening systems in representative households are profitable in the wet season. Importantly, ’returns to person days’ are higher than off-farm incomes. The activity generates cash income, increasingly required to meet cash expenses in modern rural Indonesian society. However, returns vary considerably between households, are considerably lower in the dry season and, as would be expected, are sensitive to relative prices of feeder and finished cattle.

Evaluating Soil Organic Carbon Sequestration Potential of Tree Species in Subtropical and Humid forest of Brahmaputra Valley, Assam

Soil organic carbon sequestration potential of different tree was analyzed in every year. Five years after plantation average soil organic carbon was recorded highest under fast growing non legume trees (1.82 %) followed by medium growing (1.72 %) and then slow growing (1.60 %). SOC sequestration potential of legume tree species was significantly lower. It was 1.80 % under fast growing legumes, 1.58 % in medium growing and 1.55 % in slow growing legume trees. On individual comparison of non legume trees, Anthocephalus chinensis found to sequester more (1.98%) carbon as soil organic carbon followed by Trewia nudiflora (1.66%), Alstonia scholaris (1.62%) and Lagerstroemia.speciosa (1.57%). Lowest soil organic carbon sequestration was found under Chukrasia. tabularis (1.26%). No significant difference was observed in SOC sequestration potential between Dipterocarpus retusus, Artocarpus chaplasha, Ficus hispida, Mallotus albus, Litsea nitida, Castanopsis indica, Taphrosia candida, Albizzia procera and A. lebbek.

The relationship between plant density and survival to water stress in seedlings of a legume tree

ABSTRACT Competition for soil water is one of the major processes that drive the assembly of plant communities, particularly in regions subjected to long dry seasons. The relationship between plant density and soil water competition has strong, but poorly understood, practical implications for population dynamics, restoration and conservation. We planted seedlings of the pioneer legume tree Senegalia polyphylla in containers and assessed the effects of plant density on their resistance to water stress. We completely eliminated the above-ground parts (stem and shoots) of randomly selected plants at 60-days post-planting in order to create three different densities of seedlings. We saturated the soil of the remaining seedlings and then deprived them of additional water until all seedlings died. We assessed the time elapsed from water suppression to wilting and death of individual plants. We found a strong negative relationship between plant density and time to wilting or death. Seedlings survived water stress 80% longer when density was reduced by two-thirds. Planting in lower densities or reducing density by thinning should be considered as strategies to enhance resistance to water stress in drought-prone regions.

Rhizobial inoculation in black wattle plantation (Acacia mearnsii De Wild.) in production systems of southern Brazil.

Black wattle (Acacia mearnsii De Wild.) is a tree legume native to southeast Australia, but present in all continents. Today it covers about 142,400ha in Brazil, with plantations concentrated in the southern region of the country. Black wattle may form nodules and establish rhizobial symbiosis capable of fixing N2, but rhizobial inoculation is not done in commercial plantations. About 40kgha-1 of urea is applied during seedling transplantation. In this review, evidences by which rhizobial inoculation affects monoculture, mixed cultivation, and agroforestry black wattle production systems were searched in literature. Previous measurements in cultivated forests have indicated that biological nitrogen fixation in black wattle may provide up to 200kg of N ha-1year-1 to the soil. Therefore, rhizobia inoculation may bring several opportunities to improve black wattle production systems. Black wattle is not a very selective partner in the rhizobial symbiosis, but the genus Bradyrhizobium dominates the rhizobial diversity of black wattle nodules. Investigation on rhizobial diversity in soils where the crop is cultivated may represent an opportunity to find more effective rhizobia strains for inoculants. The successful history of biological nitrogen fixation in grain legumes must inspire the history of tree legumes. Microbiology applied to forestry must overcome challenges on the lack of trained professionals and the development of new application technologies.

Gene isolation and structural characterization of a legume tree defensin with a broad spectrum of antimicrobial activity.

The recombinant EcgDf1 defensin has an antimicrobial effect against both plant and human pathogens. In silico analyses predict that EcgDf1 is prone to form dimers capable of interacting with the membranes of microorganisms. Plant defensins comprise a large family of antimicrobial peptides (AMP) with a wide range of biological functions. They are cysteine-rich molecules, highly sequence diverse but with a conserved and stable structure. In this work, a defensin gene (EcgDf1) was isolated from Erythrina crista-galli, a legume tree native from South America. The predicted peptide presents eight cysteines, with a γ-core motif GXCX3-9C and six cysteines distributed like the typical defensin αβ motif. The mature EcgDf1 coding sequence was heterologously expressed in Escherichia coli strains and purified by affinity chromatography. Possible dimer and oligomers of EcgDf1 were visible in SDS electrophoresis. Moreover, its 3D structure, determined by homology modeling, docking, and molecular dynamics simulations, was found to be compatible with the formation of homodimers between the β3 and β1-loop-α1, leaving the β2-loop-β3 free to interact with lipid membranes. The purified recombinant peptide inhibited the growth of several critical plant and human pathogens, like the opportunistic fungi Candida albicans and Aspergillus niger and the plant pathogens Clavibacter michiganensis ssp. michiganensis, Penicillium expansum, Botrytis cinerea, and Alternaria alternata. EcgDf1 is a promising candidate for the development of antimicrobial products for use in agriculture and medicine.

Identification of oxidosqualene cyclases from the medicinal legume tree Bauhinia forficata: a step toward discovering preponderant α-amyrin-producing activity.

Triterpenoids are widely distributed among plants of the legume family. However, most studies have focused on triterpenoids and their biosynthetic enzymes in model legumes. We evaluated the triterpenoid aglycones profile of the medicinal legume tree Bauhinia forficata by gas chromatography-mass spectrometry. Through transcriptome analyses, homology-based cloning, and heterologous expression, we discovered four oxidosqualene cyclases (OSCs) which are responsible for the diversity of triterpenols in B.forficata. We also investigated the effects of the unique motif TLCYCR on α-amyrin synthase activity. B.forficata highly accumulated α-amyrin. We discovered an OSC with a preponderant α-amyrin-producing activity, which accounted for at least 95% of the total triterpenols. We also discovered three other functional OSCs (BfOSC1, BfOSC2, and BfOSC4) that produce β-amyrin, germanicol, and cycloartenol. Furthermore, by replacing the unique motif TLCYCR from BfOSC3 with the MWCYCR motif, we altered the function of BfOSC3 such that it no longer produced α-amyrin. Our results provide new insights into OSC cyclization, which is responsible for the diversity of triterpenoid metabolites in B.forficata, a non-model legume plant.