Purification and characterization of Bowman-Birk and Kunitz isoinhibitors from the seeds of Rhynchosia sublobata (Schumach.) Meikle, a wild relative of pigeonpea.

Rhynchosia sublobata, a wild relative of pigeonpea, possesses defensive proteinase/protease inhibitors (PIs). Characterization of trypsin specific PIs (RsPI) separated from seeds by column chromatography using 2-D gel electrophoresis and Edman degradation method identified R. sublobata possessed both Bowman-Birk isoinhibitors (RsBBI) and Kunitz isoinhibitors (RsKI). A quick method was developed to separate RsBBI and RsKI from RsPI based on their differential solubility in TCA and acetate buffer. N-terminus sequencing of RsBBI and RsKI by MALDI-ISD ascertained the presence of Bowman Birk and Kunitz type isoinhibitors in R. sublobata. RsBBI (9216 Da) and RsKI (19,412 Da) exhibited self-association pattern as revealed by western blotting with anti-BBI antibody and MALDI-TOF peptide mass fingerprint analysis, respectively. RsBBI and RsKI varied significantly in their biochemical, biophysical and insecticidal properties. RsBBI inhibited the activity of trypsin (Ki = 128.5 ±â€¯4.5 nM) and chymotrypsin (Ki = 807.8 ±â€¯23.7 nM) while RsKI (Ki = 172.0 ±â€¯9.2 nM) inhibited the activity of trypsin alone, by non-competitive mode. The trypsin inhibitor (TI) and chymotrypsin inhibitor (CI) activities of RsBBI were stable up to 100 °C. But, RsBBI completely lost its TI and CI activities on reduction with 3 mM DTT. Conversely, RsKI lost its TI activity on heating at 100 °C and retained >60% of its TI activity in presence of 3 mM DTT. CD spectroscopic studies on RsBBI and RsKI showed their secondary structural elements in the following order: random coils > ß-sheets/ß-turns > α-helix. However, RsKI showed reversible denaturation midpoint (Tm) of 75 °C. Further, the significant inhibitory activity of RsBBI (IC50 = 24 ng) and RsKI (IC50 = 59 ng) against trypsin-like gut proteases of Achaea janata (AjGPs) and Helicoverpa armigera (HaGPs) suggest them as potential biomolecules in the management of A. janata and H. armigera, respectively.

Isolation and identification of Ammodendron bifolium endophytic bacteria and the action mechanism of selected isolates-induced seed germination and their effects on host osmotic-stress tolerance.

This study aimed to identify Ammodendron bifolium endophytic bacteria, and to evaluate promoting mechanism of selected isolates on seed germination and their effects on host osmotic-stress tolerance. Forty-five strains were isolated from A. bifolium and were classified into 13 different genera by 16S rDNA gene sequence analysis. AY3, AY9 and AG18, which were identified as Staphylococcus, Kocuria, Bacillus sp., promoted host seed ethylene release during germination. Ethrel and 1-aminocyclopropane-1-carboxylic acid (ACC) imitated the effect of AY3, AY9 and AG18 on seed germination. The data suggest that ethylene mediates AY3-, AY9-, AG18-induced A. bifolium seed germination. In addition, osmotic stress prevented seed germination and radicle elongation. However, the inhibitory effect of osmotic stress on seed germination and radicle elongation were rescued by AY3, AY9 and AG18. The results show that AY3, AY9 and AG18 increased osmotic-stress tolerance in A. bifolium. AY3, AY9, AG18 induced A. bifolium seed germination through promoting ethylene production during endophytic bacteria-plant interaction, and increase osmotic-stress tolerance in A. bifolium. AY3, AY9 and AG18 are potential candidates for the protection of A. bifolium.

Antifungal and Antimicrobial Properties of a Purified Protease Inhibitor from Macrotyloma Uniflorum Seeds.

BACKGROUND: Plant protease Inhibitors (PIs) play key roles in regulation of many biological activities and being less toxic, more potent and specific in comparision to chemical inhibitors. METHODS: A new proteinaceous trypsin inhibitor was isolated and purified from Macrotyloma uniflorum seeds with a molecular mass of 25 KDa was purified to homogeneity via three sequential purification steps i.e., ammonium sulphate precipitation to CNBr activativated Sepharose 4B coupled trypsin affinity chromatography. Purified protease inhibitor (PI) showed optical specific activities of 665 µmols of tyrosine released/ml/min. RESULTS: Overall, there was a remarkable increase in the fold of purification. MUTI is stable to denaturation by heat (upto 80°C), pH (4-10).The inhibitory activity increased to two fold in the presence of mercuric chloride and got reduced by half in the presence of ferric chloride. SDS, Dithiothreitol, ß-mercaptoethanol, Hydrogen peroxide, Triton X 100 enhanced its inhibitory activity whereas activity was reduced in the presence of DMSO. Chemical modification of the inhibitor by DEPC decreased its activity but the activity was increased considerably when modified with NE and PMSF. Presence of protease inhibitor activity was confirmed by reverse zymography and Dot- blot. Also MUPI has antifungal and antimicrobial properties. MUPI inhibited Phytophthora capsici by 16.6% and Rhizoctonia solani by 27.7%. CONCLUSION: Antibacterial activity was shown against Staphylococcus aureus and Pseudomonas aeruginosa. MUPI retained 90% inhibition upon storage at 4°C for over a period of six months. Thus PI can be effectively exploited to increase the shelf life of seafood.

Anti-hyperglycemic Properties of a Purified Proteinaceous Protease Inhibitor from Macrotyloma Uniflorum Seeds.

INTRODUCTION: Fabaceae are a rich source of protease inhibitors. METHODS: A proteinaceous protease inhibitor of 25 KDa designated as Macrotyloma uniflorum protease inhibitor (MUPI) was isolated from seeds of Macrotyloma uniflorum and purified to homogeneity by ammonium sulphate precipitation, DEAE Sepharose column and CNBr activated Sepharose 4B Trypsin affinity chromatography. The purity was checked by reverse phase HPLC. Long-term type 2 diabetes can lead to various biological complications, such as hypertension and heart-related diseases. The glucose uptake studies were carried out with the purified MUPI and it reveals its potential to be explored as a potent anti-hyperglycemic agent. MUPI was rendered safer on HepG2 cells after MTT cytotoxicity assay. RESULTS: The results of glucose uptake studies suggest MUPI to be equally efficient to that of the positive control drug Metformin against diabetes mellitus. CONCLUSION: The significance of plant-based inhibitors for modulating carbohydrate breakdown and control of glycemic index is explored to reduce the risk factors and side effects of the available drugs.

Sword bean variants and different pretreatments influence protein extraction and protein properties.

Two variants of the sword bean (Canavalia gladiata), namely the white sword bean (WSB) and the red sword bean (RSB), are known. The MgCl2 concentration-dependent canavalin solubility showed different behavior among the extracts from distinct beans prepared by distinct pretreatments. Pretreatment and bean selection are important factors for use in food chemical and biochemical experiments.

α-TIP aquaporin distribution and size tonoplast variation in storage cells of Vicia faba cotyledons at seed maturation and germination stages.

Vacuoles have been shown to undergo deep modifications in relation to plant developmental stages and in the maintaining the cellular homeostasis. In this context, we studied the variations of the vacuolar membrane size and α-TIP aquaporin distribution at early and advanced seed stages of maturation, germination and embryo growth in Vicia faba cotyledon storage cells.

Correlation between mtDNA complexity and mtDNA replication mode in developing cotyledon mitochondria during mung bean seed germination.

The currently accepted model of recombination-dependent replication (RDR) in plant mitochondrial DNA (mtDNA) does not clearly explain how RDR progresses and how highly complex mtDNA develops. This study aimed to investigate the correlation between RDR and mtDNA complexity during mitochondrial development in mung bean (Vigna radiata) seed, and the initiation and processing of RDR in plant mitochondria. Flow cytometry, pulsed-field gel electrophoresis, electron microscopy, real-time PCR and biochemical studies were used in this study. The highly dynamic changes in mtDNA complexity correspond to mtDNA RDR activity throughout mitochondrial development. With in vitro freeze-thaw treatment or prolonged in vivo cold incubation, the mtDNA rosette core disappeared and the rosette structure converted to a much longer linear DNA structure. D-loops, Holliday junctions and putative RDR forks often appeared near the rosette cores. We hypothesize that the rosette core may consist of condensed mtDNA and a replication starting sequence, and play an initial and central role in RDR. The satellite cores in the rosette structure may represent the re-initiation sites of mtDNA RDR in the same parental molecule, thereby forming highly complex and giant mitochondrial molecules, representing the RDR intermediates, in vivo.

Tripartite mutualism: facilitation or trade-offs between rhizobial and mycorrhizal symbionts of legume hosts.

UNLABELLED: • PREMISE OF THE STUDY: Multiple mutualist effects (MMEs) are common in nature, yet we lack a predictive understanding of how two mutualists on the same host will influence each other and whether these effects will be positive or negative. Leguminous plants maintain root symbioses with two nutritional mutualists: rhizobia that fix atmospheric nitrogen and arbuscular mycorrhizal fungi (AMF) that increase phosphorus uptake. Both symbionts receive plant carbon, and host genetic networks that regulate colonization are partially shared by both symbioses; whether these factors generate trade-offs or facilitation between rhizobial and AMF symbionts of legumes is not well known.• METHODS: We evaluated host allocation to each symbiont in three settings. First, in situ in a remnant prairie, then in a greenhouse experiment with multiple plant populations, and finally under manipulated rhizobium densities in the greenhouse.• KEY RESULTS: In the remnant prairie, rhizobium nodule number and colonization of AMF were positively correlated, and plants with increased nodule number had higher fitness in the field, generating indirect selection on the colonization of AMF. In the greenhouse experiment, allocation to each symbiont was genetically variable among populations, with some suggestion that rhizobium and AMF colonization are positively genetically correlated. Finally, increasing the number of rhizobia in the soil decreased AMF colonization.• CONCLUSIONS: Our results suggest that trade-offs between plant colonization by rhizobia and AMF are context dependent and might not be common under field conditions, but that physiological and/or genetic drivers couple these two symbioses in nature.

Identification of candidate genes and molecular markers for heat-induced brown discoloration of seed coats in cowpea [Vigna unguiculata (L.) Walp].

BACKGROUND: Heat-induced browning (Hbs) of seed coats is caused by high temperatures which discolors the seed coats of many legumes, affecting the visual appearance and quality of seeds. The genetic determinants underlying Hbs in cowpea are unknown. RESULTS: We identified three QTL associated with the heat-induced browning of seed coats trait, Hbs-1, Hbs-2 and Hbs-3, using cowpea RIL populations IT93K-503-1 (Hbs positive) x CB46 (hbs negative) and IT84S-2246 (Hbs positive) x TVu14676 (hbs negative). Hbs-1 was identified in both populations, accounting for 28.3% -77.3% of the phenotypic variation. SNP markers 1_0032 and 1_1128 co-segregated with the trait. Within the syntenic regions of Hbs-1 in soybean, Medicago and common bean, several ethylene forming enzymes, ethylene responsive element binding factors and an ACC oxidase 2 were observed. Hbs-1 was identified in a BAC clone in contig 217 of the cowpea physical map, where ethylene forming enzymes were present. Hbs-2 was identified in the IT93K-503-1 x CB46 population and accounted for of 9.5 to 12.3% of the phenotypic variance. Hbs-3 was identified in the IT84S-2246 x TVu14676 population and accounted for 6.2 to 6.8% of the phenotypic variance. SNP marker 1_0640 co-segregated with the heat-induced browning phenotype. Hbs-3 was positioned on BAC clones in contig512 of the cowpea physical map, where several ACC synthase 1 genes were present. CONCLUSION: The identification of loci determining heat-induced browning of seed coats and co-segregating molecular markers will enable transfer of hbs alleles into cowpea varieties, contributing to higher quality seeds.

The co-occurrence of two pyridine alkaloids, mimosine and trigonelline, in Leucaena leucocephala.

Leucaena leucocephala is a nitrogen-fixing tropical leguminous tree that produces two pyridine alkaloids, i. e. mimosine [beta-(3-hydroxy-4-pyridon-1-yl)-L-alanine] and trigonelline (1-methylpyridinium-3-carboxylate). Mimosine has been detected in leaves, flowers, pods, seeds, and roots, and it is one of the principal non-protein amino acids that occurs in all organs. Asparagine was the most abundant amino acid in flowers. The mimosine content varied from 3.3 micromol/g fresh weight (FW) in developing flowers to 171 micromol/g FW in mature seeds. Trigonelline was also detected in leaves, flowers, pods, and seeds, but not roots. The trigonelline content was lower than that of mimosine in all organs. It varied from 0.12 micromol/g FW in developing seeds to 2.6 micromol/g FW in mature seeds. [2-14C]Nicotinic acid supplied to the developing seeds was incorporated into trigonelline but not mimosine. This indicates that the pyridine and dihydroxypyridine structures of these two alkaloids are derived from distinct precursors. The physiological functions of mimosine and trigonelline are discussed briefly.

Chemical and phytochemical compositions of Voandzeia subterranea seeds.

The seeds of Voandzeia subterranean (L.) Thouars (Fabaceae), from Congo-Brazzaville were studied for proximate, qualitative and quantitative compositions. Phytochemical screening of various solvent extracts showed the presence of alkaloids, flavonoids, glycosides, saponins, steroids, triterpenoids, phenols, anthocyanins and carotenoids. Tannins and anthraquinones were not found. Quantitative analysis showed a high amount of alkaloids (34.40 ±0.2%), flavonoids (4.93 ± 0.17%), saponins (2.20 ± 0.11%) and anthocyanins (1.00 ± 0.12%) in decreasing order. Phenols (0.60 ± 0.12%) and carotenoids had low yields (0.26 ± 0.07%). Proximate analysis of the seeds showed high moisture, carbohydrate and energy content values (49.14, 20.53% and 956.14 kJ 100 g(-1), respectively). The results showed low ash content (3.84%) and the relatively high fat (7.84%) and protein content (18.65%). The mineral analysis revealed that potassium (3.15%) and phosphorus (1.74%) were the most abundant minerals. Calcium (0.35) and magnesium (0.39%), were found in low amounts. Sodium, iron and aluminum were detected in trace quantities (0.01%). Manganese was not detected in the present study. The seeds were found to be important both for their nutrients and non-nutrients which determined the medicinal and nutritional value of the plant.

Effect of de cortication and roasting on trypsin inhibitors and tannin contents of cowpea (Vigna unguiculata L. Walp) seeds.

This study was carried out to evaluate the nutritive value of cowpea seeds. Also to minimize the presence of some anti nutritional factors such as tannin and trypsin inhibitors. It is aimed to determined the best method by which we can reduce the anti nutritional factors. Samples of raw, decorticated and decorticated roasted cowpea seeds were subjected to proximate analysis. The results show that for dry matter (93.63, 94.33 and 95.9), for crude protein (29.18, 31.80 and 29.73), for ash (4.60, 4.0 and 5.52) for fiber (6.22, 3.75 and 4.32) for ether extract (2.30, 2.50 and 1.60) for nitrogen free extract (51.33, 52.28 and 54.73), respectively for raw, decorticated and decorticated roasted seeds. Tannin content percentages were determined using method. The results were (0.76, 0.02 and 0.005), respectively. Trypsin inhibitors were determined using enzymatic method the results were (1.68, 0.74 and 1.36), respectively for raw, decorticated and decorticated roasted cowpea seeds. It is concluded that chemical composition was varied between the treatments. Decorticated seeds gives high level of protein followed by the others. De cortication significantly reduced tannin content by 85%. Roasting significantly decreased trypsin inhibitors by 65%. Processing of cowpea seeds either mechanically or by heat, significantly improve their nutritional value.

Screening of protease producing fungi for microbial digestion of seed proteins and synthesis of amino acids-metalnutrient chelates.

The problem of metalnutrient deficiency is becoming more serious with the introduction of modern agricultural practices. As a result, metalnutrient deficiency is recognized as one of the critical yield limiting factors. Metalnutrients are generally offered in their sulphate or oxide forms. However, it is reported that organically bound minerals generally have a higher bioavailability than inorganic minerals. Chelation makes otherwise unavailable metalnutrients plant available. Amino acids are well known among various chelating agents. In present investigation the fungus Paecilomyces variotii PR-4 was isolated from soil and was used for production of protease and determination of its activity. Proteins from germinating seeds of chick pea, mung bean, soybean and cowpea were hydrolyzed for the production of amino acids. Amino acids were recovered, estimated and utilized for chelation of metalnutrients viz., Zn, Cu, Fe, Mn, Mg, B and Mo. The resultant chelates were employed to detect with Fourier Transform Infra-Red Spectrophotometer (FTIR) analysis. The peaks of most intensive bands in the IR spectra of ligands recorded were present in the intervals of the wave numbers 3500-3300 and 1720-1700 cm(-1). Chelation of metalnutrients led to the broadening of peak and changes of the peak position of hydroxyl groups, which indicated the binding of the carboxylic groups and primary amine groups of amino acids to the metalnutrients. The resultant amino acids-metalnutrient chelates can be utilized as organic fertilizer.

The bonobo-dialium positive interactions: seed dispersal mutualism.

A positive interaction is any interaction between individuals of the same or different species (mutualism) that provides a benefit to both partners such as increased fitness. Here we focus on seed dispersal mutualism between an animal (bonobo, Pan paniscus) and a plant (velvet tamarind trees, Dialium spp.). In the LuiKotale rainforest southwest of Salonga National Park, Democratic Republic of Congo, seven species of the genus Dialium account for 29.3% of all trees. Dialium is thus the dominant genus in this forest. Dialium fruits make up a large proportion of the diet of a habituated bonobo community in this forest. During the 6 months of the fruiting season, more than half of the bonobos' feeding time is devoted to Dialium fruits. Furthermore, Dialium fruits contribute a considerable proportion of sugar and protein to bonobos' dietary intake, being among the richest fruits for these nutrients. Bonobos in turn ingest fruits with seeds that are disseminated in their feces (endozoochory) at considerable distances (average: 1.25 km after 24 hr of average transit time). Endozoochory through the gut causes loss of the cuticle protection and tegumentary dormancy, as well as an increase in size by water uptake. Thus, after gut passage, seeds are better able to germinate. We consider other primate species as a potential seed disperser and conclude that Dialium germination is dependent on passage through bonobo guts. This plant-animal interaction highlights positive effects between two major organisms of the Congo basin rainforest, and establishes the role of the bonobo as an efficient disperser of Dialium seeds. Periodicals, Inc.

Seed yield of mungbean (Vigna radiata (L.) Wilczek) in relation to growth and developmental aspects.

Growth parameters such as leaf area (LA), total dry mass (TDM) production, crop growth rate (CGR), relative growth rate (RGR), and net assimilation rate (NAR) were compared in six varieties of mungbean under subtropical condition (24°8' N 90°0' E) to identify limiting growth characters for the efficient application of physiology breeding for higher yields. Results revealed that a relatively smaller portion of TDM was produced before flower initiation and the bulk of it after anthesis. The maximum CGR was observed during pod filling stage in all the varieties due to maximum leaf area (LA) development at this stage. Two plant characters such as LA and CGR contributed to the higher TDM production. Results indicated that high yielding mungbean varieties should possess larger LA, higher TDM production ability, superior CGR at all growth stages, and high relative growth rate and net assimilation rate at vegetative stage which would result in superior yield components.

Characterization and systematic implications of the diversity in timing of programmed cell death of the suspensors in Leguminosae.

PREMISE OF THE STUDY: In angiosperm seeds, the developing embryo acquires nutrients via a suspensor that typically undergoes programmed cell death (PCD) at the early cotyledon stage. However, in Leguminosae (the third largest angiosperm family), the suspensors can disappear at the heart-shaped stage (i.e., prior to the cotyledon stage) or still persist at the cotyledon stage. Here, in a comprehensive survey of legume suspensors and embryos, the variation and the evolutionary direction of timing of suspensor PCD in Leguminosae were characterized, and systematic implications were evaluated. METHODS: Suspensor development and morphology for 66 leguminous species from 49 genera, 21 tribes, and 3 subfamilies were comparatively studied using standard paraffin sectioning and light microscopy. KEY RESULTS: Three patterns of suspensor PCD were observed at the early cotyledon stage. (A) The suspensor persisted. (B) The suspensor separated from the wall of the embryo sac and persisted as a vestige at the radicle apex. (C) The suspensor disappeared completely, and the absorption of nutrients by embryo was carried out via a "contact zone" between the embryo and the endosperm. Pattern C of early suspensor PCD was found only in the tribe Fabeae. An ancestral character reconstruction revealed that the long-lived suspensors of pattern A represented a plesiomorphic condition in Leguminosae and that the suspensors of pattern C evolved only once in the common ancestor of Fabeae. CONCLUSIONS: In Leguminosae, short-lived suspensors have thus evolved multiple times from long-lived suspensors. It remains largely unknown, however, how the embryo acquires nutrients after the early suspensor PCD.

Effect of different processing methods on antioxidant activity of underutilized legumes, Entada scandens seed kernel and Canavalia gladiata seeds.

The present study is proposed to determine the antioxidant activity of raw and processed samples of underutilized legumes, Entada scandens seed kernel and Canavalia gladiata seeds. The indigenous processing methods like dry heating, autoclaving and soaking followed by autoclaving in different solutions (plain water, ash, sugar and sodium bicarbonate) were adopted to seed samples. All other processing methods than dry heat showed significant reduction in phenolics (2.9-63%), tannins (26-100%) and flavonoids (14-67%). However, in processed samples of E. scandens, the hydroxyl radical scavenging activity and ß-carotene bleaching inhibition activity were increased, whereas, 2,2-azinobis (3-ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS·(+)), ferric reducing antioxidant power (FRAP), metal chelating and superoxide anion scavenging activity were similar to unprocessed ones. In contrary, except dry heating in C. gladiata, all other processing methods significantly (P<0.05) reduced the 2,2'-diphenyl-1-picryl-hydrazyl (DPPH·) (20-35%), ABTS·(+) (22-75%), FRAP (34-74%), metal chelating (30-41%), superoxide anion radical scavenging (8-80%), hydroxyl radical scavenging (20-40%) and ß-carotene bleaching inhibition activity (15-69%). In addition, the sample extracts of raw and dry heated samples protected DNA damage at 10 µg. All processing methods in E. scandens and dry heating in C. gladiata would be a suitable method for adopting in domestic or industrial processing.

Genotypic differences in pod wall and seed growth relate to invertase activities and assimilate transport pathways in asparagus bean.

BACKGROUND AND AIMS: Coordination of sugar transport and metabolism between developing seeds and their enclosing fruit tissues is little understood. In this study the physiological mechanism is examined using two genotypes of asparagus bean (Vigna unguiculata ssp. sesquipedialis) differing in pod wall and seed growth rates. Pod growth dominates over seed growth in genotype 'Zhijiang 121' but not in 'Zhijiang 282' in which a 'bulging pod' phenotype is apparent from 8 d post-anthesis (dpa) onward. METHODS: Seed and pod wall growth rates and degree of pod-bulging were measured in the two genotypes together with assays of activities of sucrose-degrading enzymes and sugar content in pod wall and seed and evaluation of cellular pathways of phloem unloading in seed coat using a symplasmic fluorescent dye, 5(6)-carboxyfluorescein (CF). KEY RESULTS: Activities of cell wall, cytoplasmic and vacuolar invertases (CWIN, CIN and VIN) were significantly smaller in pod walls of '282' than in '121' at 10 dpa onwards. Low INV activities were associated with weak pod wall growth of '282'. In seed coats, CF was confined within the vasculature in '282' but moved beyond the vasculature in '121', indicating apoplasmic and symplasmic phloem unloading, respectively. Higher CWIN activity in '282' seed coats at 6-8 dpa correlated with high hexose concentration in embryos and enhanced early seed growth. However, CWIN activity in '282' decreased significantly compared with '121' from 10 dpa onwards, coinciding with earlier commencement of nuclei endoreduplication in their embryos. CONCLUSIONS: The study shows genotypic differences between 'bulging pod' and 'non-bulging' phenotypes of asparagus bean in sucrose metabolism in relation to the pathway of phloem unloading in developing seed coats, and to pod and seed growth. Low INV activity in pod wall corresponds to its shortened and weak growth period; by contrast, the apoplasmic path in the seed coat is associated with high CWIN activity and strong early seed growth.

The effect of total extract of Securigera securidaca L. seeds on serum lipid profiles, antioxidant status, and vascular function in hypercholesterolemic rats.

AIM OF THE STUDY: Seeds of Securigera securidaca are used for the treatment of disorders such as hyperlipidemia, diabetes, and epilepsy in Iranian folk medicine. The possible hypolipidemic and antioxidative effects of hydroalcoholic extract of S. securidaca seeds as well as the effect of the extract on vascular reactivity were investigated in hypercholesterolemic rats. MATERIALS AND METHODS: High-fat fed wistar rats received orally different doses of the extract for 20 days. At the end of the experiment vein blood and liver were collected to measure the lipid profile, lipid peroxidation, and antioxidative enzyme activities. The thoracic aorta was excised and used for isolated vessel preparation and histological study. RESULTS: The extract produced significant reductions (p<0.05) in the level of low-density lipoprotein (LDL) and triglyceride with concomitant reduction in lipid deposition in the liver. The extract also suppressed markedly (p<0.001) the hypercholesterolemia-induced elevation of malondialdehyde levels both in serum and liver. In hypercholesterolemic rats the endothelium-dependent vasodilatation was improved significantly (p<0.05) by 100mg/kg/day of the extract. However, in histological study no atherosclerotic lesion was observed. CONCLUSION: These results suggest that S. securidaca seed in addition to decrease lipid levels and peroxidation, is able to improve vascular endothelium-dependent relaxation in hypercholesterolemia.

Abiotic stress enhances androgenesis from isolated microspores of some legume species (Fabaceae).

To induce androgenesis in field pea, grass pea and the model legume species Medicago truncatula, isolated microspores of various genotypes of these three species were submitted to a range of abiotic stresses prior to and during their initial culture, in order to stimulate them to divide and form embryos. Some stress agents had a positive effect on androgenesis from the treated microspores. Submission of flower buds to a cold period prior to anther excision or microspore isolation, modifying the osmotic pressure of the medium during initial culture and electroporation of isolated microspores were the three major individual stress agents to have an impact on the efficiency of androgenetic proliferation and subsequent differentiation from the microspores of pea, grass pea and M. truncatula genotypes. A combination of osmotic and electric shocks significantly improved responses from isolated microspores and yielded microcalluses and then calluses, but only few underwent morphogenesis. Further work is under way to improve responses and extend them to other genotypes. The results reported here are, to the best of our knowledge, the first successful results from isolated microspores of these species.