Botrytone, a new naphthalenone pentaketide produced by Botrytis fabae, the causal agent of chocolate spot disease on Vicia faba

A strain of Botrytis fabae isolated from faba bean (Vicia faba L.) plants displaying clear chocolate spot disease symptoms produced phytotoxic metabolites in vitro. The phytotoxins isolated from the culture filtrate organic extract were characterized by spectroscopic and optical methods. A new naphthalenone pentaketide, named botrytone, was isolated and characterized as (4R)-3,4-dihydro-4,5,8-trihydroxy-1(2H)-naphthalenone together with other well-known closely related naphthalenones such as regiolone and cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones. When tested on leaves of the host plant, with the cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones assayed in mixture, regiolone demonstrated the highest level of phytotoxicity together with cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones. Botrytone showed moderate phytotoxic activity at 1 mg/mL and was still phytotoxic at 0.5 mg/mL.     

Herbicidal potential of stagonolide, a new phytotoxic nonenolide from Stagonospora cirsii

Stagonospora cirsii is a pathogen of Cirsium arvense, causing necrotic lesions on leaves of this noxious weed. The fungus produced toxic metabolites when grown in liquid culture. A new phytotoxin, named stagonolide, was isolated and characterized as (8R,9R)-8-hydroxy-7-oxo-9-propyl-5-nonen-9-olide by spectroscopic methods. Stagonolide was shown to be a nonhost-specific but selective phytotoxin. Leaves of C. arvense were most sensitive and leaves of tomato and pepper (both Solanaceae) were less sensitive to stagonolide, which was assayed at 5 x 10(-3) M, than other plants. Stagonolide assayed at 5 x 10(-6) M was demonstrated to be a strong inhibitor of root growth in seedlings of C. arvense and some other Asteraceae species. Seedlings growth in wheat and radish was much less affected by the toxin, and seedlings of cucumber were insensitive to it.     

Effect of the herbicide MCPA on VA mycorrhizal infection and growth of Pisum sativum

The effect of the hormonal herbicide MCPA on VA mycorrhizal infection and on pea plant growth was examined. Plant growth was decreased by MCPA applied at the rate of 120 ppm. The VA infections of pea roots inoculated with G. mosseae was decreased by the MCPA when applied at high dosis (120 ppm), but those of indigenous endophytes were decreased at the rate of 12 and 120 ppm. MCPA applied to VA inoculated pots eight weeks before pea planting also decreased the VA infection of these plants. These results suggest that VA mycorrhizas was affected not only through the plant but also directly by the application of the herbicide. Glomus mosseae may help plants recover from the deleterious effect of MCPA when applied at intermediary (12 ppm) but not at high dosis (120 ppm).     

Viridenepoxydiol, a new pentasubstituted oxiranyldecene produced by Trichoderma viride

A new pentasubstituted oxiranyldecene, named viridenepoxydiol, has been isolated (0.9 mg/L) from the culture filtrate of a strain of Trichoderma viride showing in vitro and in vivo antagonistic activity against Sclerotium rolfsii, which is the causal agent of crown and stem rot of artichoke. Viridenepoxydiol was characterized as 3,5,9-trimethyl-2-oxiranyl-dec-8-ene-2,5-diol (3) using spectroscopic methods. It showed inhibitor effect on mycelial growth of S. rolfsii and its minimum inhibitory concentration (over 90% inhibition) was found to be 396 mug/mL. This is the first time that viridenepoxydiol was reported.     

Influence of maturation on the alteration of allergenicity of green pea (Pisum sativum L.)

The IgE-binding capacity of different maturation levels of green pea seeds (Pisum sativum L.) of the variety Maxigolt is examined to determine the influence of maturation on the alteration of allergenicity. Different protein extraction methods to get total protein extracts and the protein fractions glutelin, globulin, and albumin from different maturation levels of green pea seeds are applied to SDS-PAGE/silver staining as well as SDS-PAGE/immunoblotting and EAST inhibition experiments using sera of 15 green pea allergic individuals. The SDS-PAGE/silver-staining experiments show the continuous change of protein pattern during maturation. SDS-PAGE/immunoblot and EAST inhibition demonstrate that all levels of green pea seeds show relevant IgE-binding capacity, as do immature seeds. Total IgE-binding capacity rises with the progress of maturation. Although the main allergenic activity is dependent upon the albumin fraction, the glutelin and globulin fractions are also important. The implication of these results is an obvious allergenic potency of all maturation levels, even immature seeds, whereas an increase of allergenicity during maturation could be notched up. The highest allergenic potency is caused by the albumin fraction, but globulin and glutelin fractions also contribute to the allergenicity of green pea.     

Effect of germination on the carbohydrate composition of the dietary fiber of peas (Pisum sativum L.)

The effect of different conditions of pea germination on dietary fiber (DF) composition was studied. Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) were subjected to acid hydrolysis, and the resultant neutral sugars, uronic acids, and Klason lignin were quantified. Germinated peas exhibited significantly higher contents of total dietary fiber (TDF) than the raw sample, due to the increases of both DF fractions. Under darkness conditions, germination exhibited the highest contents of IDF and SDF. Decreasing IDF/SDF ratios showed that the carbohydrate changes did not take place to the same extent during germination, the SDF fraction being the most affected. The detailed chemical composition of fiber fractions reveals increases of cellulose in the IDF of germinated samples, whereas SDF exhibits a decrease of pectic polysaccharides and also increases of polysaccharides rich in glucose and mannose. The DF results were corroborated by a comparative examination of the cell wall carbohydrate composition.     

Digestive stability, micellarization, and uptake by Caco-2 human intestinal cell of chlorophyll derivatives from different preparations of pea (Pisum sativum L.)

The digestive stability, efficiency of micellarization, and cellular accumulation of the chlorophyll pigments of different preparations of pea were investigated, using an in vitro digestion procedure coupled with human intestinal Caco-2 cells. Fresh pea (FP), cooked fresh pea (CFP), frozen pea (FZP), cooked frozen pea (CFZP), and canned pea (CP) were subjected to simulated digestion. Although after digestion the pigment profile was modified for all samples, except CP, allomerization reactions and greater destruction of chlorophylls were observed in only FP, which should be due to enzymes in FP that were denaturalized in the rest of the test foods. A pigment extract of CFZP was also subjected to in vitro digestion, showing a positive effect of the food matrix on the pigment digestive stability. The transfer of the chlorophyll pigments from the digesta to the micellar fraction was significantly more efficient in CFZP (57%, p < 0.0001), not significantly ( p > 0.05) different between CFP, FZP, and CP (28-35%), and lowest in FP (20%). Pheophorbide a stood out as the most-micellarized chlorophyll derivative in all of the samples, reaching levels of up to 98%. Incubation of Caco-2 cells with micellar fractions at the same concentration prepared from each test food showed that pigment absorption was considerably lower ( p < 0.006) in cells incubated with FP, whereas there were no differences among the rest of the preparations. Therefore, factors associated with the food matrix could inhibit or mediate the chlorophyll pigment absorption. These results demonstrated that the industrial preservation processes of peafreezing and canningas well as the cooking have a positive effect on the bioaccessibility and bioavailability of the chlorophyll pigments with respect to the FP sample, emphasizing CFZP with greater bioaccesibilty degree.     

Viridepyronone, a new antifungal 6-substituted 2H-pyran-2-one produced by Trichoderma viride

A new antifungal 6-substituted 2H-pyran-2-one, named viridepyronone, has been isolated from a cultural filtrate of a strain of Trichoderma viride showing antagonistic activity in vitro toward Sclerotium rolfsii, which is the causal agent of crown and stem rot of artichoke. Viridepyronone was characterized as 6-(4-oxopentyl)-2H-pyran-2-one 2 with spectroscopic methods. Bioassays showed that viridepyronone had a good antifungal activity against S. rolfsii, and its minimum inhibitory concentration (over 90% inhibition) was found to be 196 microg/mL. This is the first report of viridepyronone produced by any species of fungi.     

Deleterious properties of certain rhizosphere bacteria on field pea (Pisum sativum) under gnotobiotic and non-sterile conditions

Three strains of Pseudomonas putida, one non-fluorescent and two fluorescent, were investigated in a series of complementary experiments to characterise their inhibitory effects on peas under different environmental conditions. Firstly, a gnotobiotic growth pouch system was developed to observe the deleterious effects of the strains on pea root development. A negative impact of the strains was observed on the development of the root morphology using these pouches which was accompanied with a subsequent reduction in root biomass. By using this method it was concluded that the deleterious effect of one of the strains was dependent on the inoculum density. Secondly, two complementary studies in non-sterile growth systems where pea seeds/seedlings were inoculated with the bacteria, showed deleterious effects on plant biomass by two of the strains. Thirdly, by using a sterile plant growth system allowing microscopic observations on root hair development, all strains were found to be able to induce root hair deformations on pea seedlings. The results showed that the mode of action for the deleterious effect differ between the strains. Based on our findings, we would like to emphasise the necessity to include a palette of different sterile and non-sterile growth systems to be able to identify characteristics of importance for deleterious rhizosphere bacteria.     

Effects of biocontrol bacteria and earthworms on Aphanomyces euteiches root-rot and growth of peas (Pisum sativum) studied in a pot experiment

ABSTRACT

The role of below-ground interactions between microbial biocontrol agents and soil fauna for combatting soil-borne plant diseases have not been studied sufficiently. This study tested the hypothesis that the beneficial bacterium Bacillus velezensis UCMB5113 and the anecic earthworm Lumbricus terrestris positively influence health and growth of peas (Pisum sativum L.) infested with the pathogen Aphanomyces euteiches causing root-rot disease. A greenhouse fully factorial experiment studied the effects of A. euteches, B. velezensis and L. terrestris on the emergence, growth and health of pea plants. The factors B. velezensis and L. terrestris resulted in taller plants (p = .003 and p = .030). B. velezensis treatment resulted in a higher biomass of shoots and roots (p ≤ .001 and p = .005). The effects increased with the presence of both factors (p = .036). Earthworms reduced the disease symptoms significantly (p = .032). The decreased disease symptoms caused by the earthworms might be due to the consumption of A. euteiches (direct effect) as well as soil disturbance (indirect effect). Interactions between the microorganisms added and the earthworms were shown. B. velezensis and L. terrestris can be useful for enhancement of plant growth and for biological control of root-rot in peas.     

Influence of soil humic substances and herbicides on the growth of pea (Pisum sativum L.) in nutrient solution 1

No morphological and length modifications of the root and shoot systems are apparent in pea (Pisum sativum L.) plants of three varieties grown in the presence of 100 mg/L humic acid or fulvic acid or 20 mg/L linuron [3‐(3,4‐dichlorophenyl)‐l‐methoxy‐l‐methylurea] or ametryne [2‐ethylamino‐4‐iso‐propylamino‐6‐methylthio‐1,3,5‐triazine]. A combination of humic substance and herbicide at these concentrations produces in all pea varieties a differentiated and marked reduction in root length and large morphological alterations of roots. Statistical analysis of data show that differentiated and highly significant or significant effects are produced on the shoot and root dry weight by either the humic substance or herbicide alone, and by any combination of two or three factors considered (variety, humic substance, herbicide).     

Integrating archaeobotany,paleogenetics and historical linguistics may cast more light onto crop domestication: the case of pea (Pisum sativum)

This short communication intends to discuss various models and ideas about the very beginnings of plant domestication in the Old World with a specific emphasis on pea (Pisum sativum L.) as one of the most significant crops in the human civilization. It presents a selection of some recent achievements and challenges in studying the earliest days of this important grain legume species by balanced contributions from archaeobotany, paleogenetics and historical linguistics. It will hopefully stimulate a fruitful interdisciplinary discussion and provide a basis for new experimental approaches.     

Inhibiting effects of resveratrol and its glucoside piceid against Venturia inaequalis, the causal agent of apple scab

Resveratrol is a phytoalexin produced in different unrelated plant species such as grapevine and peanut. The effect of resveratrol and its glucoside trans-resveratrol-3-O-beta-D-glycopyranosid (piceid) against Venturia inaequalis, the causal agent of apple scab, was evaluated using a newly established test based on enzymatically isolated cuticular membranes (CMs) from apple (Malus domestica Borkh.) leaves. The test substances resveratrol and piceid were either sorbed to CMs before inoculation with spores or were applied simultaneously with the Venturia inaequalis spores to the CMs, and their effect on germination, appressoria formation, and penetration was examined. Resveratrol had no influence on spore germination but a significant inhibiting effect on penetration when applied simultaneously as well as before. A percentage inhibition of 89.7 +/- 11.5 and 61.8 +/- 35.1 was observed for simultaneous and preapplication, respectively. The resveratrol glucoside piceid had a significant inhibitory effect on germination and completely inhibited penetration of the fungus at concentrations between 200 and 400 microg mL(-1) when applied simultaneously with the spores to the CMs. On piceid-enriched CM (preapplication), spores germinated but penetration was inhibited nearly completely (96.1 +/- 5.1%). Thus, in vitro experiments showed that resveratrol and its glucoside in fact could contribute to improving the pathogen resistance of apple leaves.     

Influence of Dual Inoculation of AM Fungi and Rhizobium on Growth Indices,Production Economics,and Nutrient Use Efficiencies in Garden Pea (Pisum sativum L.)

Field experimentation was conducted at Palampur, India during 2011–2012 in an acid Alfisol to quantify the influence of integrated use of arbuscular mycorrhizal fungi (AMF), Rhizobium and inorganic nitrogen (N) and phosphorus (P) on growth, productivity, profitability, and nutrient use efficiencies in garden pea (Pisum sativum L.). The experiment was laid out in randomized block design (RBD) replicated thrice comprising 13 treatments involving AMF (Glomus mosseae), Rhizobium (R. leguminosarum), and inorganic N and P fertilizers. The results revealed that dual inoculation of pea seed with AMF and Rhizobium enhanced the plant height, leaf area index, and dry matter accumulation significantly by 19.4 and 13.1, 10.7 and 10.7, and 16.6 and 16.7%, respectively at 60 and 120 days after sowing (DAS). Similarly, dual inoculation exhibited significant respective increases of 9.5 and 14.6% in absolute and crop growth rates over generalized recommended NP potassium (K) dose (GRD) during 60–120 DAS. The dual inoculation led to significant respective increases of 1.0 and 2.2, 1.06 and 1.74, 0.21 and 1.5, and 1.05 and 1.60 folds in partial factor productivity, crop recovery efficiency, physiological efficiency, and % recovery of applied N and P, respectively over GRD. The magnitude of increase in pea productivity, net returns, and boron to carbon (B:C) ratio following dual inoculation was to the tune of 20, 54.4, and 104.1%, respectively over GRD. Dual inoculation also exhibited significant increases of 19.4 and 53.1% in production and monetary efficiencies of pea over GRD. Overall, dual inoculation of AMF and Rhizobium with 75% soil-test-based N and P dose in pea has great potential in enhancing pea productivity, profitability, and nutrient use efficiency besides saving about 25% fertilizer N and P without impairing pea productivity in Himalayan acid Alfisol.     

Influence of genotype and processing on the in vitro rate of starch hydrolysis and resistant starch formation in peas (Pisum sativum L.).

The formation of resistant starch (RS) and the rate of starch hydrolysis were evaluated in vitro in a wild type of green-seeded pea genotype RRRbRb BC3 (33-Am) with 32.7% amylose content and in two mutants RRrbrb BC3 (23-Am) and rrRbRb BC3 (65-Am) with amylose contents of 23.3 and 65.1%, respectively. Pea samples were intact or homogenized and subjected either to autoclaving or to boiling at atmospheric pressure. The amount of RS (total starch basis) varied from 6.2 to 12.9% in the 23-Am products and from 31.2 to 33.4% in the 65-Am products. The RS level of the 33-Am product with a regular amylose content was 11.0%. Both the 23-Am and the 65-Am products were abundant sources of dietary fiber (39 and 34%, dry matter basis, respectively) versus 23% in the regular pea product. The amylose/amylopectin ratio was an important determinant of the rate of starch hydrolysis. The hydrolysis indices (HI) and predicted glycemic indices were lowest in the 65-Am peas (HI range = 42-59) as compared to the 23-Am peas (HI range = 53-84). It is concluded that the pea genotypes covered a wide range in starch availability, which is likely to affect nutritional parameters such as glycemic responses and colonic delivery of starch.     

固体生物肥防治黄瓜枯萎病、青椒疫病的田间应用效果评价

利用田间小区试验进行固体生物肥料防治黄瓜枯萎病和青椒疫病的效果研究，对田间应用效果进行评价。结果表明，固体生物肥料对黄瓜枯萎病的防治效果为45．12％、对青椒疫病防治效果达51．79％，达到了差异显著的效果，而且分别增产11．06％和37．19％，其防病与增产效果显著。     

Effect of AM fungi and phosphorus fertilization on P-use efficiency,nutrient acquisition and root morphology in pea (Pisum sativum L.) in an acid Alfisol

Phosphorus (P) availability to plants is a major constraint in acid soils. A study was conducted to determine the effect of arbuscular mycorrhizal fungi (AMF) under varying inorganic P and irrigation regimes on P availability and P-use efficiency in garden pea (Pisum sativum L.) in a Himalayan acid Alfisol. The experiment comprised of 14 treatments replicated thrice in a randomized block design. The results revealed that integrated use of AM fungi and inorganic P at either of the two irrigation regimes (IW/CPE_0.6 or IW/CPE_1.0) enhanced the green pea pod weight, green pod productivity and agronomic efficiency of applied P to the extent of 8.4%, 7.2% and 30.7%, respectively, over non-AMF counterparts as well as “generalized recommended NPK dose and irrigations (GRD).” AMF inoculation also led to enhanced nitrogen (N), P and potassium (K) acquisition (uptake) by 16.3%, 18.2% and 6% over non-AMF counterpart treatments. Further, AMF inoculation at varying P and irrigation regimes sharply enhanced the rooting depth (21.4%), root volume (23.5%), root dry weight (14.9%), root weight density (13.7%) as well as N concentration in root nodules (3.4%) over non-AMF counterparts and GRD practice. AMF also enhanced the mycorrhizal root colonization by 3.2 folds at flowering stage in AMF inoculated pea plants. AMF-imbedded treatments did not alter the available soil nutrient status (macronutrients and micronutrients) significantly in comparison to non-AMF counterparts in pea, available P status, however, increased to the extent of 6.5% over initial status. Further, AMF imbedded plots showed a slight build-up in soil organic carbon with nominal decrease in soil bulk density. AMF inoculation in pea also led to fertilizer P economy by about 25% soil-test-based P dose. Overall, AMF holds great potential in enhancing nutrient acquisition especially P besides influencing root morphology in order to harness better crop yields vis-à-vis fertilizer P economy by about 25% soil-test-based P dose in Himalayan acid Alfisol.     

Characterization of new bisphenol a metabolites produced by CD1 mice liver microsomes and S9 fractions

Bisphenol A [2,2-bis(4-hydroxyphenyl)propane] (BPA) is a widely used industrial chemical resulting in occupational and consumer exposure. BPA possesses weak estrogenomimetic activity and can be cytotoxic, though the underlying mechanisms of its toxicity toward cells are not completely understood. The metabolism of BPA by CD1 mice liver microsomal and S9 fractions was investigated. Nine metabolites were isolated and characterized using HPLC and mass spectrometry. Many of these metabolites were characterized for the first time in mammals, namely isopropyl-hydroxyphenol (produced by the cleavage of BPA), a bisphenol A glutathione conjugate, glutathionyl-phenol, glutathionyl 4-isopropylphenol, and BPA dimers. Most of these metabolites apparently share a common metabolic pathway, for which considerable evidence supports the hypothesis of the production of a reactive intermediate, and also helps explain BPA cytotoxicity.