PROCESS FOR ELICITING A PLANT BY MEANS OF EDIBLE MACROSCOPIC FUNGAL EXTRACTS
20190254288 · 2019-08-22
Inventors
- Céline Faugeron (Saint-Just-le-Martel, FR)
- Vincent Gloaguen (Limoges, FR)
- Cédric Astier (Vicq-sur-Breuilh, FR)
- Charlotte Moine (Limoges, FR)
Cpc classification
A01N25/04
HUMAN NECESSITIES
A01N65/00
HUMAN NECESSITIES
A01N65/00
HUMAN NECESSITIES
International classification
Abstract
Process for conferring a protection against a pathogen upon a plant by elicitation by an aqueous composition, the active agents of which are extracted from edible fungi (parasol mushroom, pleurotus, button mushroom). An alkaline extraction is carried out, then an enzymatic hydrolysis, to obtain a fraction less than 100 kDa. The process consists in spraying the aerial parts of the plant with the composition obtained in this way; this thereby acts to combat cryptogamic diseases of plants such as vines, fruit trees, vegetable crops and cereals.
Claims
1-31 (canceled)
32. An aqueous composition comprising active agents obtained by: alkaline extraction of a powder of edible macroscopic fungi, then neutralizing of the obtained extract before proceeding to its filtration; dilution of the filtered extract, then enzymatic hydrolysis with a glycosidase at between 10 to 65 C., wherein the hydrolysis thus performed is stopped by inactivating the enzyme at a temperature above 65 C.; filtration of the obtained hydrolyzate to isolate an active fraction of molecular weight less than 100 kDa.
33. The composition according to claim 32, wherein the alkaline extraction step is carried out at a temperature between 20 and 100 C., while maintaining under stirring a suspension of 5 to 15 parts by weight of mushroom powder in an alkaline aqueous solution having a pH greater than 10; and the neutralization of the solution obtained by the alkaline extraction step is carried out with an organic or inorganic acid and that the precipitate obtained is removed; and the product obtained after neutralization of the alkaline extract is subjected to several filtrations, to separate the acid salt(s) and the simple sugars from the liquid phase.
34. The composition according to claim 32, wherein the enzymatic hydrolysis performed with the glycosidase is maintained until to 24 h with stirring.
35. The composition according to claim 32, wherein the edible fungi subjected to an alkaline extraction are species selected from the group formed by oyster mushrooms, parasol mushrooms and button mushrooms.
36. The composition according to claim 32, wherein the concentration of active agents is of 1.5 to 4.0% by weight.
37. The composition according to claim 32, wherein: the composition comprises a protein content of 5 to 15% by weight relative to the composition's dry matter; the composition comprises a total sugar content of 60 to 80% by weight relative to the composition's dry matter; the composition has a monosaccharide formulation corresponding to a weight proportion of 38 to 50% of glucose, 18 to 28% of galactose, 20 to 30% of mannose, and 0.5 to 4% of glucosamine and/or acetylated glucosamine; the composition comprises 35 to 45% by weight of glucans relative to its dry matter; and the composition comprises 30 to 50% by weight of a dry matter, whose molecular weight is greater than 10 kDa.
38. The composition according to claim 32, wherein the composition contains at least one compatible formulation agent.
39. The composition according to claim 38, wherein the composition comprises at least one anti-phytopathogenic agent chosen from the group consisting of a fungicidal agent, an antibacterial agent, an antiviral agent, a pesticidal agent, and a biocontrol agent.
40. The composition according to claim 32, wherein the composition contains at least one nutrient for plants for simultaneous application.
41. A method suitable for conferring protection against a pathogen by elicitation on an agronomically useful or ornamental plant, wherein the method consists in treating at least some of the aerial parts of the plant with an aqueous composition such as defined in claim 32.
42. The method according to claim 41, wherein the method consists in treating by spraying the aerial parts of the plants to be treated with a composition having a pH of between 4 and 8, wherein the concentration of active agents is 150 to 400 g/mL.
43. The method according to claim 41, wherein the method is associated with a treatment of the aerial parts of the plant to be treated with a conventional phytosanitary agent applied simultaneously or sequentially or alternately.
44. The method according to claim 41, wherein the method is a preventive treatment against fungal diseases in particular those selected from the group formed by diseases of the vine, fruit trees, vegetable crops and cereals, and in particular against downy mildew (Plasmopara viticola), powdery mildew (Erysiphe necator), gray mold (Botrytis cinerea) of the vine, late blight (Phytophthora infestans) of the potato, yellow rust (Puccinia striiformis), Septoria leaf blotch (Septoria sp.), Fusarium head blight (Fusarium graminearum) of wheat, and apple scab (Venturia inaequalis).
45. The method according to claim 41, wherein the method is implemented in the early vegetative stages and/or in the adult and reproductive vegetative stages.
46. The method according to claim 41, wherein the method is implemented at repeated time intervals, as often as necessary, preferably every 8 to 15 days.
47. A method suitable for conferring protection against a pathogen by elicitation on an agronomically useful or ornamental plant, wherein the method consists in treating at least some of the aerial parts of the plant with an aqueous composition such as defined in claim 33.
48. A method suitable for conferring protection against a pathogen by elicitation on an agronomically useful or ornamental plant, wherein the method consists in treating at least some of the aerial parts of the plant with an aqueous composition such as defined in claim 34.
49. A method suitable for conferring protection against a pathogen by elicitation on an agronomically useful or ornamental plant, wherein the method consists in treating at least some of the aerial parts of the plant with an aqueous composition such as defined in claim 35.
50. A method suitable for conferring protection against a pathogen by elicitation on an agronomically useful or ornamental plant, wherein the method consists in treating at least some of the aerial parts of the plant with an aqueous composition such as defined in claim 36.
51. The method according to claim 41, wherein the method is repeated every 8 to 15 days.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The invention will be described in connection with the attached drawing figures, in which:
[0054]
[0055]
[0056]
[0057]
[0058]
[0059]
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
[0067]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLES
Example 1
[0068] 100 g of dried and finely crushed parasol mushrooms (<1 mm) are incorporated in 1 liter of 8% sodium hydroxide with added 0.1% sodium borohydride. The suspension is stirred at room temperature for 24 hours. By adding a solution of glacial acetic acid, the medium is brought to pH 6.5. Glucanase is added at a rate of 0.1% w/V and the mixture is stirred at room temperature for 20 hours. The hydrolyzate is centrifuged and then filtered. The solution is then ultrafiltered in a tangential ultrafiltration system of the Pellicon mini type marketed by MILLIPORE equipped with a 100 kDa porosity membrane. The permeate obtained is then subjected to a membrane ultrafiltration of 1 kDa to desalt the solution. The solution is concentrated and freeze-dried. Thus, 7 g of a beige powder which constitutes the hydrolyzate EX1 is obtained.
Example 2
[0069] The raw material consists of the stems of mushroom Pleurotus Ostreatus. 200 g of oyster mushroom stems dried and finely ground (<1 mm) are dispersed in 2 L of 8% sodium hydroxide in the presence of 0.1% sodium borohydride. The extraction is carried out at room temperature for 24 hours, with mechanical stirring. By centrifugation, the insoluble fraction in NaOH/NaBH.sub.4 is removed. The supernatant obtained is then neutralized with glacial acetic acid. The enzymatic system chosen is a -glucanase of Aspergillus niger, and added to the extract at 0.1% w/V. The whole is kept at room temperature for 3 hours. After denaturation at 100 C. for 10 min, the medium is centrifuged. The extract obtained is clarified by filtration. The resulting filtrate is subjected to microfiltration on a 0.1 m porosity membrane and then on a 100 kDa membrane at a pressure of 1 bar. The system used is a tangential ultrafiltration system of the Pellicon mini type marketed by MILLIPORE. This permeate is subjected to ultrafiltration on a 1 kDa membrane at a pressure of 2 bar to desalt the solution. This gives a retentate, which is then lyophilized. 15 g of a beige color powder constituting the EX2 extract are obtained.
Example 3
[0070] The raw material is button mushrooms. 100 g of dried and finely ground mushrooms (<1 mm) are dispersed in 1.5 L of 8% sodium hydroxide in the presence of 0.1% sodium borohydride. The extraction is carried out at room temperature for 24 hours, with magnetic stirring. The medium is then neutralized with acetic acid. After centrifugation, the supernatant is ultrafiltered at 1 kDa. -glucanase is added to the extract at 0.1 w/V. The mixture is stirred at room temperature for 24 hours. After denaturation at 100 C. for 10 min, the medium is centrifuged. This permeate is subjected to ultrafiltration on a membrane of 1 kDa. This gives a retentate, which is then lyophilized. 1 g of a beige color powder constituting the EX3 extract is obtained.
Example 4
[0071] Study showing stimulation of tomato defenses by extract of oyster mushroom EX2 (see
[0076]
[0077]
[0078]
[0079]
[0080]
[0081]
Example 5
[0082] Study showing the stimulation of defenses in tomato by the extract of parasol mushroom in the presence of Botrytis cinerea (see
[0084] (BBCH 12 102). Each batch of plants consists of 6 plants distributed in 3 pots. [0085] At t=0, each plant is treated with extract of parasol mushroom EX1 in the form of a solution of 0.4 g/L by foliar spraying until runoff. The operation is renewed at t=2 days and t=5 days. Control plants are treated at the same periodicity but with an aqueous solution of surfactant sold under the trademark Tween at 0.5% by weight. [0086] At t=7 days, the plants are inoculated by the pathogenic fungus (Botrytis cinerea, strain UBOCC-A-101100 from the University of Western Brittany). A suspension of conidia (about 10.sup.5 conidia/mL) in aqueous surfactant solution sold under the trademark Tween at 0.5% by weight, is deposited on several leaves in the form of regularly distributed droplets (100 L/plant). [0087] At t=14 days, the plants are harvested by taking leaf discs from each plant, which are frozen at 80 C. RNAs are extracted from the leaf samples. [0088] The levels of expression of defense genes are quantified by Reverse Transcription Polymerase Chain Reaction (RT-PCR) amplification techniques using molecular probes specific to known and selected genes. [0089] These genes correspond to that encoding the PAL and to several proteins of pathogenesis (PR proteins): PR1 (protein marker of the systemic response of plants), PR2 (glucanase type protein), and PR3 (chitinase type protein). [0090] Gene expression levels are quantified by reference to a constitutive gene, that of tubulin. The results are expressed as a ratio between the level of expression of the gene related to defense processes and the level of expression of tubulin.
[0091]
[0092] The control exhibits an activation of the defense genes, particularly PAL and PR1 (PR3 and PR2 are less strongly activated) because of the presence of the pathogen (
Example 6
[0093] Study showing the stimulation of the defenses in the apple tree by the extract of oyster mushroom (see
[0098] they are relative expressions with respect to the WATER control, normalized by the geometric mean of the relative expressions of 3 reference genes (TuA, Actin, GAPDH). These relative expressions are transformed into log2 to give the same weight to inductions and repressions of genes.
TABLE-US-00001 TABLE 1 Names of defense genes and defense pathways with which they are associated Type of defense Name of genes Proteins PR PR4 Pathogenesis-related protein 4 (hevein-like) PR14 Pathogenesis-related protein 14 (lipid transfer protein) PR15 Pathogenesis-related protein 15 (oxalate oxidase) Phenylpropanoid PAL Phenylalanine ammonia-lyase pathway PPO Polyphenol oxidase Cystein pathway CSL alliinase Oxidative stress Apox Ascorbate peroxidase PDX Peroxidase Salicylic acid pathway EDS1 Disease resistant protein 1 WRKY WRKY transcription factor 30 Jasmonic acid pathway JAR Jasmonate resistant 1 Ethylene pathway ACCO 1-aminocyclopropene-1-carboxylate oxidase EIN3 EIN3-binding F box protein 1
[0099]
[0100] Pretreatment with oyster extract stimulates the expression of many genes associated with different defense pathways (pathway of phenylpropanoids, oxidative stress, hormonal signaling . . . ), which confirms the elicitor effect of the extract in increasing defense responses in the presence of pathogens.
Example 7
[0101] Study showing the stimulation of defenses in the vine by the extract of parasol mushroom in the presence of Botrytis cinerea (see
[0104] The controls are not treated. [0105] At t=7 days, all the plants are inoculated by the pathogenic fungus (Botrytis cinerea, UBOCC-A-101100 strain from the University of Western Brittany). A suspension of conidia (approximately 10.sup.5 conidia/mL) in an aqueous solution at 0.5% by weight of the surfactant sold under the trademark Tween is deposited on several leaves in the form of regularly distributed droplets (1 000 L/plant). [0106] At t=14 days, the treated and inoculated leaves are harvested and protein extracted in a suitable buffer to measure the phenylalanine ammonia lyase (PAL) and peroxidase enzymatic activities in the corresponding extracts. [0107] Specific enzyme activities are expressed as a percentage of the value obtained for the treated plants relative to those of the untreated control plants.
[0108]
[0109] Strong stimulation of PAL and peroxidase enzymatic activities are observed following pretreatment of vine plants by the extract of parasol mushroom; these activities are increased by 25% for PAL and multiplied by 5 for peroxidase.
Example 8
[0110] Effectiveness of the extract of parasol mushroom on the reduction of potato late blight symptoms in open-field trials: [0111] A field trial was conducted on the potato (Solanum tuberosum, Ditta variant) in 2014 in Auchy-les-Mines (62, France) in order to determine the effectiveness of the parasol mushroom extract protection against late blight (Phytophthora infestans). The planting was carried out on Apr. 18, 2014. [0112] On the experimental plot, 4 micro-plots per treatment condition were statistically distributed; [0113] Five treatments were carried out with the extract of parasol mushroom: June 11 (stage 40 cm), the 06/18/14 (stage BBCH 60), the 06/25/14 (stage BBCH 70) and the 07/09/14 (stage BBCH 74). [0114] At the beginning of the trial, the pressure of the late blight was significant which required the application of a synthetic fungicide, dithane (between June 1, stage 5 cm, and Jun. 7, 2014, stage 20 cm). [0115] Then, given the less favorable weather conditions for the subsequent development of the disease, two artificial contaminations of the plot were made: the first by a suspension of spores from contaminated leaves from a pile of waste (May 30, 2014), the second on Jun. 2, 2014 by an inoculum from a laboratory (Eurofins, Loos en Gohelle). These two contaminations allowed a homogeneous pressure of late blight to be obtained on the plot.
[0116] The notations presented in
Example 9
[0117] Efficacy of oyster mushroom extract on reducing downy mildew (Plasmopara viticola) symptoms in vines during open-field trials (see
[0118] An open-field trial was conducted on the vine (Vitis vinifera, Grenache black grape) during the year 2015 in Villelongue dels monts (66, France) to determine the effectiveness of the extract of oyster mushroom as a protection against downy mildew (Plasmopara viticola), alone or alternately with the Bordeaux mixture (BB) (750 g Cu/ha). [0119] On the experimental plot, 4 micro-plots per treatment condition were statistically distributed; the test was conducted under controlled conditions with artificial contamination on May 17 limited to the first strain of each elementary plot and the general humidity was maintained by regular sprinkling. [0120] Treatments performed between May 12, 2015 and Jul. 6, 2015 at a dose of 200 L/ha are shown in Table 2. The control receives no treatment; the copper treatment consists in applying between May 12, 2015 and Jul. 6, 2015 the Bordeaux mixture at a dose equivalent to 750 g Cu/ha (seven applications in total). The extract of oyster mushroom EX2 is applied in the form of an aqueous solution at 35 g/ha, either alone or alternately with Bordeaux mixture (oyster mushroom extract/Cu). A modality intended to evaluate the effectiveness of treatments based on Bordeaux mixture at the same dose that the copper treatment but applied 3 times instead of 7, was also evaluated (Cu1/2).
[0121] Table 2 shows the treatment schedule for the various modalities (open field vine/mildew test).
TABLE-US-00002 Treatments Dates May 12, May 18, May 28, Jun. 5, Jun. 16, Jun. 26, Jul. 6, 2015 2015 2015 2015 2015 2015 2015 BBCH stages 55 57 63 73 75 79 79 Control Copper BB BB BB BB BB BB BB Oyster Ple Ple Ple Ple Ple Ple Ple mushroom extract Oyster BB Ple BB Ple BB Ple BB mushroom extract/Cu Cu BB BB BB BB: Bordeaux mixture; Ple: extract of oyster mushroom; : no treatment
[0122] The notations presented in
[0123]
[0124] The extract of oyster mushroom thus allows a reduction of the symptoms of attack by the mildew. The efficiency rate of 57% is not as high as that of the copper treatment (89%) used here as a fungicide. However, the alternate treatment (oyster mushroom extract/copper) has a higher level of effectiveness (82%): it therefore makes it possible to propose an effective crop protection solution allowing a reduction in the use of the fungicide. The oyster mushroom extract applied alternately with the copper shows a level of efficiency much higher (82%) than that of the copper dose, thus confirming the stimulation of the defenses of the plant by the extract of oyster mushroom.
Example 10
[0125] Effectiveness of oyster mushroom extract on the reduction of symptoms associated with powdery mildew (Erysiphe necator) on vines during open-field trials (see
[0126] An open-field trial was conducted on the vine (Vitis vinifera, Chardonnay grape variety) in 2015 in Alenya (66, France) to determine the effectiveness of the extract of oyster mushroom EX2 in protection against powdery mildew (Erysiphe necator), alone or alternately with Thiovit (8 kg/ha). [0127] On the experimental plot, 4 micro-plots per treatment condition were statistically distributed; [0128] Powdery mildew appeared relatively late on bunches after a very discrete phase on leaves. At first count on June 25 (vegetative stage BBCH 77), a correct level of disease was found in untreated control plots with 70.50% frequency and 30.25% intensity attack. At the second count on July 23 (vegetative stage BBCH 85), an attack of 77.50% in frequency and 40.60% in intensity was observed. [0129] The treatments were carried out between Apr. 17, 2015 and Jun. 26, 2015 at a dose of 180 L/ha and are presented in Table 3. The control receives no treatment. The sulfur treatment consists of applying, between Apr. 14, 2015 and Jun. 26, 2015, the product sold under the trade name Thiovit at a dose equivalent to 8 kg/ha (eight applications in total). The extract of oyster mushroom EX2 is applied in the form of a 35 g/ha solution, either alone or alternately with the aforementioned Thiovit (oyster mushroom extract/sulfur). A modality intended to evaluate the treatment effectiveness based on the aforementioned product Thiovit at the same dose as the sulfur treatment, but applied 4 times instead of 7 was also evaluated (S1/2).
[0130] The different modalities are presented in Table 3 below.
TABLE-US-00003 TABLE 3 Treatment schedule for the different modalities (open-field vine/powdery mildew test) T1 T2 T3 T4 T5 T6 T7 T8 Dates May 12, May 18, May 28, Jun. 5, Jun. 16, Jun. 26, Jul. 6, May. 26, 2015 2015 2015 2015 2015 2015 2015 2015 BBCH stages 15 53 55 61 73 75 77 77 TREATMENTS Control Sulfur S S S S S S S S Oyster Ple Ple Ple Ple Ple Ple Ple Ple mushroom extract Oyster S Ple S Ple S Ple S Ple mushroom/ S extract S S S S S
[0131]
[0132] The extract of oyster mushroom reduces the symptoms of powdery mildew attack. The rate of effectiveness of 65% is not as high as that of the sulfur treatment (92%) used here as a fungicide. However, the alternating treatment (oyster mushroom extract/sulfur) has a higher effectiveness level (96%): it therefore makes it possible to propose an effective crop protection solution, which makes it possible to reduce the use of the fungicide. The extract of oyster mushroom applied alternately with the sulfur shows a level of effectiveness much higher (96%) than that of the 1/2 dose of sulfur (87%), thus confirming the stimulation of the defenses of the plant by the extract of oyster mushroom.
[0133] Therefore, in order to control powdery mildew or downy mildew, the fungicide/oyster mushroom extract alternate program has shown a sufficient level of protection for safe management of vine growing in the open field.
Example 11
[0134] Study showing the stimulation of defenses by the oyster mushroom extract and the button mushroom extract for Brachypodium distachyon in the presence of Fusarium graminearum.
[0135] A model temperate cereal plant, Brachypodium distachyon, was grown under glass and used for this test 4 weeks after sowing. A batch of 10 plants per repetition was constituted and two biological repetitions were performed.
[0136] The pretreatments consisted in applying, by spraying, the oyster mushroom extract and the button mushroom extract of Examples 2 and 3 at a concentration of 0.35 g/L, on all the ears at days 0, 2 and 5, until runoff. Inoculation of Fusarium graminearum was performed at day 7 (=mid-anthesis stage, BBCH65) by spraying all ears with a 10.sup.5 spore/mL spore suspension.
[0137] Plant harvests take place at t=0, t=24 h or t=48 h. Several analyses are implemented:
[0138] Fusarium wilt symptoms were observed at 10 days post-inoculation;
[0139] The fungal biomass was quantified and expressed in ng of F. graminearum genomic DNA for 10 ng of total genomic DNA (plant +fungus) determined by quantitative PCR. Specific primers of the F. graminearum TUB2 gene were used to determine the amount of fungal genomic DNA by reference to a standard range.
[0140] The expression of two B. distachyon defense genes was followed: the PAL gene encoding the phenylalanine-ammonialyase (1st enzyme in the phenylpropanoid biosynthesis pathway) and the PR9 gene encoding a pathogenesis-related protein (PR). Two reference genes were used, ACT7 and UBC18. The expression of these two genes was determined in ears treated beforehand with the extract of oyster mushroom or button mushroom against control ears, inoculated with the strain PH-1 of F. graminearum.
[0141]
[0142] The results show a significant reduction in the symptoms of Fusarium wilt on plants treated with mushroom extracts. Thus, extracts of oyster mushroom and button mushroom confer protection against B. distachyon infection by F. graminearum of 77% and 94.7%, respectively.
[0143]
[0144] Quantification of the F. graminearum biomass on the different ears indicates a negligible amount of fungal genomic DNA within the same amount of total genomic DNA (plant +fungus) on the ears pretreated with each of the two extracts by comparison. with the untreated control (
[0145]
[0146] The results indicate that the relative expression of PAL and PR9 genes is more induced 48 hours after inoculation by F. graminearum in the ears treated with extracts of oyster mushroom and button mushroom than in non pre-treated ears (