scholarly journals Bacillus cereusHS24 Suppresses Conidia Germination ofMagnaporthe oryzaeby Inhibiting the Ca2+Signaling Pathway

2018 ◽  
Author(s):  
Wenxiang Huang ◽  
Xingyu Liu ◽  
Xiaosi Zhou ◽  
Yu Chen ◽  
Ye Li ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Rice Blast ◽  
Germ Tube ◽  
Molecular Mechanisms ◽  
Inhibitory Effect ◽  
Control Agent ◽  
Conidial Germination ◽  
Phenotypic Change ◽  
Conidia Germination ◽  
Germ Tube Elongation

AbstractRice yield is greatly reduced due to rice blast, a worldwide multi-cycle fungal disease caused by the ascomyceteMagnaporthe oryzae.Previously,Bacillus cereusHS24 was isolated from rice growing area, which showed a strong bio-control effect onM. oryzae.In order to better exploit it as a bio-control agent, HS24 has been studied for its mechanism of controlling rice blast. Our results showed that conidial germination ofM. oryzaewas significantly inhibited by HS24 suspension,nand the inhibition rate reached to 97.83% at the concentration of 10 CFU/ml. The transcriptional level ofCAMKII, PMC1andCCH1,which are key genes involved in Ca2+signaling pathway, were significantly decreased in HS24-treated conidia. The treatment ofM. oryzaewith Ca2+signaling pathway inhibitors KN-93, Verapamil, and cyclopiazonic acid (CPA) significantly reduced conidial germination rate and inhibited germ tube elongation. This inhibition effect was found to be concentration-dependent, similar to the HS24 treatment. By quantifying free Ca2+inM. oryzaeconidia, a significant reduction of intracellular free Ca2+concentration in HS24-treated conidia in comparison to sterile water-treated conidia was found. The addition of exogenous Ca2+did not abolish the inhibitory effect of HS24 on the reduction of intracellular free Ca2+concentration and conidial germination. In conclusion,B. cereusHS24 can inhibit conidial germination by suppressing Ca2+signaling inM. oryzae,and thus offers a great potential as a bio-control agent in rice blast management.ImportanceIn the bio-control of rice blast, most of researches focused on the inhibitory effect of bio-control agents on development ofM. oryzae, including inhibition of conidia germination, germ tube deformity, mycelium growth inhibition, etc, while little work has elucidated the molecular mechanisms underlying the various phenotypic change inM. oryzae.In order to better exploit HS24 as a potential bio-control agent, we studied the molecular mechanisms underlying the suppression ofB. cereusHS24 onM. oryzaeGuy11, and draw the conclusion that HS24 may inhibit conidia germination and germ tube elongation through inhibiting the Ca2+signaling pathway. In this study, we characterized the morphological and physiological changes ofM. oryzaewhen interacting withB. cereusHS24, and further investgated the responses ofM. oryzaeCa2+signallig pathway to HS24 treatment. Thus we have provided one more piece for theB. cereus/M. oryzaesupression puzzle at the molecular level.

scholarly journals Saprophytic microorganisms with potential for biological control of Botrytis cinerea on Geraldton waxflower flowers

2001 ◽  
Vol 41 (5) ◽  
pp. 697 ◽  
Author(s):  
D. R. Beasley ◽  
D. C. Joyce ◽  
L. M. Coates ◽  
A. H. Wearing
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Conidial Germination ◽  
Pseudomonas Sp ◽  
Trichoderma Spp ◽  
Fusarium Sp ◽  
Flower Abscission ◽  
Germ Tube Elongation

Saprophytic bacteria, yeasts and filamentous fungi were isolated from Geraldton waxflower flowers and screened to identify potential antagonism towards Botrytis cinerea. Isolates from other sources (e.g. avocado) were also tested. Isolates were initially screened in vitro for inhibition of B. cinerea conidial germination, germ tube elongation and mycelial growth. The most antagonistic bacteria, yeasts and fungi were selected for further testing on detached waxflower flowers. Conidia of the pathogen were mixed with conidia or cells of the selected antagonists, co-inoculated onto waxflower flowers, and the flowers were sealed in glass jars and incubated at 20˚C. The number of days required for the pathogen to cause flower abscission was determined. The most antagonistic bacterial isolate, Pseudomonas sp. 677, significantly reduced conidial germination and retarded germ tube elongation of B. cinerea. None of the yeast or fungal isolates tested was found to significantly reduce conidial germination or retard germ tube elongation, but several significantly inhibited growth of B. cinerea. Fusarium sp., Epicoccum sp. and Trichoderma spp. were the most antagonistic of these isolates. Of the isolates tested on waxflower, Pseudomonas sp. 677 was highly antagonistic towards B. cinerea and delayed waxflower abscission by about 3 days. Trichoderma harzianum also significantly delayed flower abscission. However, as with most of the fungal antagonists used, inoculation of waxflower flowers with this isolate resulted in unsightly mycelial growth.

Quercetin suppresses the chymotrypsin-like activity of proteasome via inhibition of MEK1/ERK1/2 signaling pathway in hepatocellular carcinoma HepG2 cells

2018 ◽  
Vol 96 (5) ◽  
pp. 521-526 ◽  
Author(s):  
Youming Ding ◽  
Xiaoyan Chen ◽  
Bin Wang ◽  
Bin Yu ◽  
Jianhui Ge ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
P38 Mapk ◽  
Protease Activity ◽  
Molecular Mechanisms ◽  
Inhibitory Effect ◽  
Proteasome Activity ◽  
Flavonoid Compound ◽  
Jnk Signaling ◽  
Promising Target ◽  
Jnk Signaling Pathway

The proteasomal system is a promising target for cancer treatment. Quercetin (Que), a flavonoid compound with antitumor ability, displays the inhibitory effect on proteasome activity. However, the underlying molecular mechanisms are ill defined. The present study found that Que treatment significantly reduced the chymotrypsin-like protease activity of proteasome whereas the trypsin- and caspase-like protease activities remained unchanged in HepG2 cancer cells, along with activation of p38 MAPK and JNK and reduction of ERK1/2 phosphorylation. Que-reduced proteasome activity could not be reverted by inhibition of p38 MAPK and JNK signaling pathway. In addition, MEK1 overexpression or knockdown upregulated or downregulated the chymotrypsin-like protease activity of proteasome, respectively. Both Que and MEK1/ERK1/2 inhibitor attenuated the expression levels of proteasome β subunits. These results indicate that Que-induced suppression of MEK1/ERK1/2 signaling and subsequent reduction of proteasome β subunits is responsible for its inhibitory impacts on proteasome activity.

scholarly journals Inhibitory effect of Pseudomonas spp. on the development of Botrytis cinerea and Penicillium expansum

2010 ◽  
Vol 40 (No. 4) ◽  
pp. 128-134 ◽  
Author(s):  
H. Bryk ◽  
B. Dyki ◽  
P. Sobiczewski
Keyword(s):  
Botrytis Cinerea ◽  
Spore Germination ◽  
Germ Tube ◽  
Inhibitory Effect ◽  
Penicillium Expansum ◽  
Bacterial Strains ◽  
Liquid Cultures ◽  
Pseudomonas Spp ◽  
Apple Leaves ◽  
Germ Tube Elongation

The influence of antagonistic Pseudomonas spp. on the development of Botrytis cinerea and Penicillium expansum was studied in liquid cultures. Two strains of Pseudomonas spp. (B194 and B224), originally isolated from apple leaves and fruits, respectively, inhibited spore germination and germ tube elongation of B. cinerea or P. expansum. The inhibitory effect depended on the concentration of bacteria in the cultures. After a prolonged time of incubation (48–76 h) lysis and fragmentation of hyphae of both fungi was observed. In some cases the hyphae of B. cinerea developed abnormally if the bacterial strains were present – the hyphal tips were swollen and ball-shaped spore-like structures aggregated in chains were formed.

Ginsenoside Rh1 Improves Type 2 Diabetic Nephropathy through AMPK/PI3K/Akt-Mediated Inflammation and Apoptosis Signaling Pathway

2021 ◽  
pp. 1-19
Author(s):  
Wen-Ya Su ◽  
Ying Li ◽  
Xuan Chen ◽  
Xin Li ◽  
Heng Wei ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Fasting Blood Glucose ◽  
Insulin Level ◽  
Inhibitory Effect ◽  
Inflammatory Factors ◽  
Treatment And Prevention ◽  
Ameliorative Effect

Although ginseng (Panax ginseng C.A. Meyer) has received extensive attention in the treatment and prevention of type 2 diabetes mellitus (T2DM) in the past few decades, there are few studies on the complications of T2DM. At present, obesity-linked diabetic nephropathy (DN) has become the most prevailing element of the end-stage renal failure in the world. The aim of this work is to evaluate the ameliorative effects of ginsenoside Rh1 (G-Rh1) on DN induced by high fat diet plus streptozotocin (HFD/STZ) through some potential and combined mechanisms of action. The results showed that G-Rh1 treatment at 5 and 10 mg/kg for 8 weeks exerted excellent effects in controlling fasting blood glucose (FBG), improving glucose tolerance, and increasing insulin level. In addition, G-Rh1 effectively prevents the excessive production of advanced glycation end products (AGEs), a diabetic nephropathy marker, in HFD/STZ induced DN mice. Meanwhile, oxidation indicators including SOD, GSH, and MDA were improved by G-Rh1 treatment to varying degrees. It is worth noting that G-Rh1 not only inhibits the secretion of Nox1 and Nox4 in kidney tissues, but also has an inhibitory effect on inflammatory factors and NF-[Formula: see text]B signaling pathway. Importantly, further in-depth research on molecular mechanisms provides vital evidence that the ameliorative effect of G-Rh1 on DN is related to the inhibition of apoptosis and the AMPK/PI3K/Akt signaling pathway. In summary, G-Rh1 may be of great value in improving the treatment of DN although more experimental data is needed.

scholarly journals Calcium Signaling Is Suppressed in Magnaporthe oryzae Conidia by Bacillus cereus HS24

2020 ◽  
Vol 110 (2) ◽  
pp. 309-316 ◽  
Author(s):  
Wenxiang Huang ◽  
Xingyu Liu ◽  
Xiaosi Zhou ◽  
Xiaoli Wang ◽  
Xinyu Liu ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Signaling Pathway ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Cyclopiazonic Acid ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
High Concentration ◽  
Dependent Protein ◽  
Conidium Germination

Rice yield is greatly reduced owing to rice blast, a polycyclic fungal disease caused by the ascomycete Magnaporthe oryzae. Previously, Bacillus cereus HS24, isolated from a rice farm, showed a strong antimicrobial effect toward M. oryzae. To better exploit it as a biocontrol agent, HS24 was studied for the mechanism that it uses to suppress rice blast. Conidium germination in M. oryzae was significantly inhibited by HS24, whereby inhibition reached 97.8% at the concentration of 107 CFU/ml. The transcription levels of Ca2+/calmodulin-dependent protein kinase II, PMC1, and CCH1, key genes involved in the M. oryzae Ca2+ signaling pathway, were significantly decreased in HS24-treated conidia at high concentration. The treatment of M. oryzae with the corresponding Ca2+ signaling pathway inhibitors KN-93, verapamil, and cyclopiazonic acid significantly reduced conidium germination. This inhibitory effect was found to be concentration dependent, similar to the HS24 treatment. We also found that HS24 was able to decrease the intracellular free Ca2+ concentration in M. oryzae conidia significantly. The addition of exogenous Ca2+ did not diminish the inhibitory effect of HS24 on the reduction of intracellular free Ca2+ concentration and the level of conidium germination. In conclusion, B. cereus HS24 at high concentration prevents extracellular Ca2+ from entering the conidia in M. oryzae, causes a significant reduction of intracellular free Ca2+ concentration, and results in the inhibition of conidium germination.

scholarly journals In vitro evaluation of fungicides and biocontrol agents for efficacy against Neofusicoccum spp that cause dieback of blueberries

2014 ◽  
Vol 67 ◽  
pp. 323-323
Author(s):  
K.M.S. Tennakoon ◽  
H.J. Ridgway ◽  
E.E. Jones ◽  
M.V. Jaspers
Keyword(s):  
Mycelial Growth ◽  
Germ Tube ◽  
Stem Canker ◽  
Conidial Germination ◽  
Biocontrol Agents ◽  
Dual Plate ◽  
Twig Blight ◽  
Different Parts ◽  
Germ Tube Elongation

Several botryosphaeriaceous species have been reported to cause stem canker twig blight and dieback of blueberries with different Botryosphaeria species reported in different parts of the world This research evaluated nine fungicides for their ability to reduce mycelial growth conidial germination and germ tube elongation of four common and pathogenic botryosphaeriaceous species recovered from New Zealand blueberries Furthermore two biocontrol agents were tested against the same species using dual plate assays Fludioxonil carbendazim flusilazole and tebuconazole were the most effective for inhibition of mycelial growth of three isolates each of Neofusicoccum australe N luteum N parvum and N ribis EC50 values for these fungicides were less than 01 mg ai/litre Carbendazim and iprodione (both EC50 004 mg/litre) were the most effective for reduction of conidial germination of all four species In addition these two fungicides were effective for inhibition of germ tube elongation with mean EC50 values of 004 and 01 mg/litre respectively The biocontrol agents Trichoderma atroviride and Bacillus subtilis reduced mycelial growth of all species tested with a range of macroscopic interactions This study has indicated the most promising fungicides and biocontrol agents for further investigations to protect pruning wounds in blueberries

scholarly journals In Vitro Effects of Five Different Classes of Fungicides on Growth and Development of Botrytis cinerea Isolated from Tree Peony in China

HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 1984-1988 ◽  
Author(s):  
Yuee Tian ◽  
Zhiping Che ◽  
Di Sun ◽  
Jiaxuan He ◽  
Shengming Liu ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Germ Tube ◽  
Early Stage ◽  
Petri Dish ◽  
Inhibitory Effect ◽  
Limiting Factor ◽  
Tree Peony ◽  
Disease Occurrence ◽  
Germ Tube Elongation

Gray mold caused by Botrytis cinerea has become an important limiting factor for tree peony production. Currently, chemical control is still the main means of managing the disease in China. The objective of this study was to test fungicides with different mechanisms of action in controlling B. cinerea on tree peony. The inhibitory efficacy of five fungicides on four asexual stages was measured in the petri dish containing culture medium amended with a tested fungicide at various concentrations. The results showed that carbendazim had the strongest inhibition effect against all four stages of B. cinerea, with the EC50 values of 0.1037, 0.0563, 0.5578, and 0.0797 mg·L–1, respectively. The inhibitory effect of diethofencarb was only slightly less than that of carbendazim on conidia production, germination, and germ tube elongation. The inhibitory effect of procymidone was second only to that of carbendazim on colony expansion. The results indicated that carbendazim and diethofencarb could be used as protective fungicides to spray in the early stage of disease occurrence to inhibit conidia germination and germ tube elongation, so as to reduce the infection rate of B. cinerea and prevent disease occurrence. Carbendazim, procymidone, and diethofencarb mainly inhibit the reinfection of B. cinerea by inhibiting the growth of mycelium and the production of conidia, so they could be used as control fungicides during the occurrence phase of the disease.

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