Carbendazim Treatment Research Articles

Post-harvest treatment of carbendazim in Chinese chives using TiO2 nanofiber photocatalysis with different anatase/rutile ratios

Carbendazim residues in Chinese chives were treated by photocatalysis using the following three electrospun TiO2 nanofibers: TTiP/PVP, TTiP/PVAc, and TBOT/PVP. The as-spun fibers were calcined at 500–650 °C to achieve anatase/rutile (A/R) ratios of 100:0, 80:20, 70:30, 50:50, and 30:70. The obtained anatase crystallite sizes were in the range of 13.9–28.1 nm, while the rutile crystallite sizes were 21.1–30.6 nm. The experiments were conducted in glass reactors. These were filled with water and each type of the fiber and irradiated from above by black light lamps for 5 min. Then, 50 g of the samples of Chinese chives was immersed for 5, 15, 30, and 60 min. Carbendazim in the chives was extracted using the matrix solid-phase dispersion (MSPD) method and analyzed using UHPLC. The ˙OH formation from each fiber type was investigated using the coumarin fluorescent probe method. An A/R ratio of 70:30 yielded the highest ˙OH formation, as well as the greatest carbendazim degradation. Rutile plays a crucial role in inhibition of electron-hole recombination and ˙O2− stabilization. The degradation efficiencies for carbendazim from TTiP/PVP, TTiP/PVAc, and TBOT/PVP fibers after a 60-min treatment were 98.6–99.5%, 91.2–97.1%, and 99.5–99.9%, respectively. The TTiP/PVP and TBOT/PVP fibers produced levels of retained carbendazim in the chives that were within EU maximum residue limits of 0.1 mg/kg. The thermal stability of the TTiP/PVAc fiber limited ˙OH formation and carbendazim degradation.

Integrated management of castor wilt disease

Field trials were conducted for management of the wilt disease in castor during 2016-17 and 2017-18. Soilsolarisation during summer followed by seed treatment and soil application of carbendazim as well as soil solarisation along with seed treatment and soil application of Trichoderma harzianum were effective in reduction of wilt disease. Pathogen population had also decreased in soil samples collected at the time of harvest in plots with solarization, neem cake, and Trichoderma applied treatments.

Carbendazim-resistance associated β2 -tubulin substitutions increase deoxynivalenol biosynthesis by reducing the interaction between β2 -tubulin and IDH3 in Fusarium graminearum.

Microtubule is a well-known structural protein participating in cell division, motility and vesicle traffic. In this study, we found that β2 -tubulin, one of the microtubule components, plays an important role in regulating secondary metabolite deoxynivalenol (DON) biosynthesis in Fusarium graminearum by interacting with isocitrate dehydrogenase subunit 3 (IDH3). We found IDH3 negatively regulate DON biosynthesis by reducing acetyl-CoA accumulation in F. graminearum and DON biosynthesis was stimulated by exogenous acetyl-CoA. In addition, the expression of IDH3 significantly decreased in the carbendazim-resistant mutant nt167 (Fgβ2 F167Y ). Furthermore, we found that carbendazim-resistance associated β2 -tubulin substitutions reducing the interaction intensity between β2 -tubulin and IDH3. Interestingly, we demonstrated that β2 -tubulin inhibitor carbendazim can disrupt the interaction between β2 -tubulin and IDH3. The decreased interaction intensity between β2 -tubulin and IDH3 resulted in the decreased expression of IDH3, which can cause the accumulation of acetyl-CoA, precursor of DON biosynthesis in F. graminearum. Thus, we revealed that carbendazim-resistance associated β2 -tubulin substitutions or carbendazim treatment increases DON biosynthesis by reducing the interaction between β2 -tubulin and IDH3 in F. graminearum. Taken together, the novel findings give the new perspectives of β2 -tubulin in regulating secondary metabolism in phytopathogenic fungi.

Evaluation of components of IPM for basmati rice against rice root-knot nematode, Meloidogyne graminicola

The IPM module for basmati rice, synthesised and validated by ICAR-NCIPM on a large-scale in farmers’ participatory mode during 2010-2014 at Bambawad (Gautam Budh Nagar, UP) area, mainly involved green manuring, seed treatment with carbendazim or Trichoderma harzianum, seedling root dip in Pseudomonas fluorescens, pest monitoring and need-based application of bio-agents/chemical pesticides. During the recent survey, Meloidogyne graminicola was identified as a serious pest, however, it was not recorded above threshold levels in villages where IPM was implemented. With this view, repeated In vitro and In vivo trials were conducted to evaluate the role of individual IPM component against M. graminicola infesting rice cultivar PB 1121 during 2016-2018 at NCIPM-Rajpur Khurd campus. Highest mortality of M. graminicola juveniles was observed in carbendazim treatment (93%) followed by T. harzianum + P. fluorescens (75%). However, revival was recorded lowest in the latter. Results of In vivo studies indicated carbofuran as the most effective treatment in reducing the multiplication of M. graminicola as compared to other treatments. Among the bio-pesticides, T. harzianum significantly reduced number of galls per plant as well as soil population. Sesbania (chopped plant) extract significantly (P<0.05) enhanced biomass of rice plant up to 68% followed by T. harzianum (56%). Sesbania extract also enabled plant to tolerate higher number of M. graminicola galls with a reduction of 37.5% in nematode population as compared to control. Study suggests that incorporation of IPM components over the years not only improve the soil health and fertility but also helps to manage the root-knot nematode, M. graminicola.

Molecular characterization of carbendazim resistance of Fusarium species complex that causes sugarcane pokkah boeng disease

BackgroundPokkah boeng is one of the most serious and devastating diseases of sugarcane and causes significant loss in cane yield and sugar content. Although carbendazim is widely used to prevent fungal diseases, the molecular basis of Fusarium species complex (FSC) resistance to carbendazim remains unknown.ResultsThe EC50 (fungicide concentration that inhibits 50% of mycelial growth) values of carbendazim for 35 FSC isolates collected in cane growing regions of China were ranged from 0.5097 to 0.6941 μg mL− 1 of active ingredient (a.i.), in an average of 0.5957 μg a.i. mL− 1. Among carbendazim-induced mutant strains, SJ51M (F. verticillioides) had a CTG rather than CAG codon (Q134L) at position 134 of the FVER_09254 gene, whereas in the mutant strain HC30M (F. proliferatum) codon ACA at position 351 of the FPRO_07779 gene was replaced by ATA (T351I). Gene expression profiling analysis was performed for SJ51M and its corresponding wild type strain SJ51, with and without carbendazim treatment. The gene expression patterns in SJ51 and SJ51M changed greatly as evidenced by the detection of 850 differentially expressed genes (DEGs). Functional categorization indicated that genes associated with oxidation-reduction process, ATP binding, integral component of membrane, transmembrane transport and response to stress showed the largest expression changes between SJ51M and SJ51. The expression levels of many genes involved in fungicide resistance, such as detoxification enzymes, drug efflux transporters and response to stress, were up-regulated in SJ51M compared to SJ51 with and without carbendazim treatment.ConclusionFSC was sensitive to carbendazim and had the potential for rapid development of carbendazim resistance. The transcriptome data provided insight into the molecular pathways involved in FSC carbendazim resistance.

Effects of carbendazim and astaxanthin co-treatment on the proliferation of MCF-7 breast cancer cells.

There has been a controversy in the oncology field about the use of antioxidants along with chemotherapeutics in cancer treatment. This study aimed to investigate the effects of a potent antioxidant (astaxanthin) co-treatment with a promising anti-cancer drug (carbendazim), which is in phase I clinical trials, on MCF-7 breast cancer cell proliferation. MCF-7 cells were treated with carbendazim, astaxanthin, or their combinations and incubated for 24h. After the incubation, each treatment group was evaluated for proliferation, cell cycle progression, and production of reactive oxygen species (ROS) using WST-1, flow cytometry, and CM-H2DCFDA, respectively. All tested carbendazim and astaxanthin combinations increased the anti-proliferative effect of Carb treatment alone and increased the G2/M phase cell cycle arrest compared to the DMSO-treated control. Astaxanthin, at all concentrations tested, reduced the elevated intracellular ROS levels induced by the carbendazim treatment. Our data suggest that astaxanthin and carbendazim co-treatment enhances the anti-proliferative effect of carbendazim as a single agent, while alleviating the carbendazim treatment-associated ROS production in MCF-7 cells. These findings may contribute to the current debate on the use of antioxidants along with anti-cancer drugs in cancer chemotherapy.

Alternaria and Cercospora Leaf Spot Diseases of Niger (Guizotia abyssinica Cass.) – A Traditional Tribal Crop of South Gujarat, India, with Cost Benefit Ratio in Relation to Different Fungicides

Abstract Niger (Guizotia abyssinica Cass.) is an important minor oil seed crop grown in dry areas grown mostly by tribal and interior places as life line of tribal segment. Tribal people mainly use its oil for cooking purpose, above than that there were also other uses. Hence, the niger crop should be protected from the infection. The crop is affected by number of fungal diseases. Therefore, a field experiment was formulated for three years with the four replications at the Niger Research Station (NRS) at Navsari Agricultural University (NAU), Vanarasi, Navsari (Gujarat) on the foliar diseases of GN-1 variety of niger crop. In this experiment, six different fungicides along with one control have been evaluated to control the Alternaria and Cercospora leaf spot diseases, out of which all the fungicidal treatments were significantly superior over the control. Here, foliar spray on the incidence of diseases was compared with the control (without any treatment). All the fungicidal treatments were significantly superior over the control to reduce Alternaria and Cercospora leaf spot diseases of Niger crop. Treatment of Carbendazim + Mancozeb (0.2 %) with two sprays first from the initiation of the disease and second after the interval of 15 days recorded the lowest incidence of Alternaria (14.56) and Cercospora (14.94) leaf spot diseases of niger and recorded the highest seed yield 337 seed yield kg/ha along with the net return with cost benefit ratio graph.

Seed infusion with liquid microbial consortia for improving germination and vigour in blackgram [Vigna mungo (L.) Hepper

Blackgram seeds soaked in the liquid cultures viz., Rhizobium @ 1: 50 dilution for 3 h or phosphobacteria @ 1:50 dilution for 4 h or PPFM @ 1:100 dilution for 3 h have showed the increased germination and vigour. Among the cultures, PPFM performed better with the population of 3 x 104 cfu g-1 of seed during three months storage. Also, increased seed vigour was found in the seed infusion treatment with microbial consortia viz., Rhizobium @1:50 dilution + PPFM @1:100 dilution (1:1) for 3 h with the populations of 3 x 104 and 2 x 104 cfu g-1 of seed respectively. In addition, the seed infusion with PPFM liquid culture @ 1:100 dilution for 3 h followed by polymer coating @ 5 ml kg-1 or carbendazim treatment @ 2 g kg-1 or polymer coating @ 5 ml kg-1 + carbendazim treatment @ 2 g kg-1 of seed have recorded the increased germination and vigour. However, the reduction in bioinoculants population was noticed when the seeds treated with carbendazim fungicide. Nevertheless, the minimum population of 1 x 104 cfu g-1 of seed was recorded in the fungicide treated seeds.

Cyto-genotoxic consequences of carbendazim treatment monitored by cytogenetical analysis using Allium root tip bioassay.

Environmental pollution is one of the major problems of these days. One of the reasons of environmental pollution is the indiscriminate use of agrochemicals in agriculture. Fungicides are being extensively used in agriculture for enhancing crop yield and growth by controlling fungal growth. Fungicide carbendazim is widely applied to soil and seeds of vegetable/cereal crops in India and is effective against a very broad spectrum of fungi. The present study was designed to monitor the cyto-genotoxic effects of carbendazim directly in treated soils by cytogenetical analysis using Allium cepa root tip bioassay. In a pot experiment, fungicide carbendazim was added to soil at the rates of 2.5, 5, 7.5, and 10mgkg-1 soil and uniform size onion bulb was planted in each pot, and three replicates were maintained for each dose at 1, 7, 15, 30, and 45days after application and roots from onion bulbs were fixed for cytogenetical analysis. Findings indicate that carbendazim treatment leads to a significant dose and duration-dependent decrease in percent mitotic index with related increase in mitotic inhibition. Statistical analysis showed a significant effect of carbendazim doses and duration of treatment on the percentage relative abnormality rate of A. cepa. Phase indices of our study showed high numbers of cells in prophase as compared to other phases at some doses of treatment. The different types of chromosomal abnormalities observed in our study serve as indicators of genotoxicity of carbendazim and we report for the first time the effect of its application directly in soil using a plant test system.

Conventional and reduced-risk fungicides to control postharvest Diplodia and Phomopsis stem-end rot on lemons

Abstract Stem-end-rot (SER), caused by Lasiodiplodia theobromae or Diaporthe citri, is an important postharvest disease in humid and warm citrus growing areas, such as the Northwestern region of Argentina. The commercial control of SER has been accomplished by applications of the systemic fungicide carbendazim (CARB). However, alternative chemicals for this fungicide are needed due to increasing restrictive regulations in overseas markets. The aim of this work was to evaluate the effectiveness of conventional and reduced-risk postharvest fungicides to control SER. In vitro tests show that L. theobromae was more resistant to fungicides than D. citri. In trials using artificially inoculated lemons, SER caused by D. citri (Phomopsis SER) was controlled by the fungicides evaluated. The conventional fungicides imazalil and thiabendazole (TBZ) were the most effective chemicals to control SER caused by L. theobromae (Diplodia SER), while other fungicides, as fludioxanil, azoxystrobin, pyrimetanil and propiconazole, were not effective. The best control of Diplodia SER was obtained by immersion for 60 s in 2000 mg/L of TBZ at pH 5 and 20 °C. In this condition, TBZ-residue loading on lemons was 3.0 mg-L−1, which did not exceed the allowed maximum residue levels. TBZ applied in lemon commercial treatments is the best option to reduce SER caused by both pathogens. At this time, this is the unique suitable alternative to replace CARB treatment in Argentinean packinghouses.

CURBING ACTINOMYCETES AND THIDIAZURON ENHANCED MICROPROPAGATION IN THE RARE ALPINIA GALANGA - A MEDICINAL ZINGIBER

Objective: Elimination of endophytic actinomycetes before micropropagation using antibiotic pre-treatment in rhizome bud explants of Alpinia galanga. Then, the formulation of an operative protocol for Micropropagation of the same void of endophytic actinomycetes. Methods: A treatment of mercury chloride and carbendazim, alone and in combination was used as surface sterilants. A pre-treatment of rifampicin and fusidic acid was used against actinomycete endophyte disinfection of rhizome bud explants. Then, Murashige and Skoog (MS) medium supplemented with various concentrations of cytokinins were used for micropropagation of disinfected explants. Results: A treatment of 0.1% (w/v) mercury chloride and 0.1% (w/v) carbendazim, one after the other for 5 minutes gave the best sterility of 83.3%. A pre-treatment of Rifampicin 100 mg/l and fusidic acid 100 mg/l for 2 hrs gave the best disinfection of 70% against actinomycete endophytes. A combination of thidiazuron (TDZ) 0.45 μM and 6-benzyladenine 13.32 μM in MS medium resulted in 9.4 shoots per explant. MS medium fortified with 10.74 μMof 1-naphthaleneacetic acid gave the best rooting of 20 roots/shoot. inter simple sequence repeat marker genetic similarity of regenerants with the mother plant was confirmed. Conclusion: This study shows the potency of Rifampicin and Fusidic acid to disinfect explants from actinomycete endophytes and is significant as the first report on curbing actinomycetes endophytes in plant tissue culture of A. galanga. This is also the first report conferring the dissimilar regeneration capabilities of TDZ in comparison to other cytokinins in Zingiberaceae.

Effect of organic and inorganic salts against sour rot (Geotrichum candidum) of Tomato

Carbendazim and nine selected organic and inorganic salt compounds, considered as common food additives, were evaluated for their activity against Geotrichum candidum, causal agent of tomato sour rot. The maximum inhibition of mycelial growth were recorded in carbendazim (82.9%) followed by sodium carbonate (43.9%), while minimum inhibition was recorded in magnesium sulphate (6.0%) as compared to control. Carbendazim was found most effective and five salts in vitro were tested in vivo. All tested salt compounds significantly reduced the disease severity. The lowest disease severity was recorded in treatment of carbendazim (63.6%) followed by sodium carbonate (73.8%) and highest disease severity was recorded in sodium thiosulphate (83.5%) as compared to control (100%). Physiological loss in weight was minimum in carbendazim (2.3%) and calcium carbonate (3.0%), as compared to control (8.0%). Highest lycopene content of tomato was obtained in sodium carbonate (5.04 mg/100g) followed by boric acid (4.49 mg/100g), as compared to control (5.05 mg/100g).

Evaluation of botanicals and bioagents against chickpea wilt complex pathogens

Botanicals and bioagents were evaluated by following poison food technique and dual culture technique against three pathogens. Data indicate significant difference on mean colony diameter at all the internal over uninoculated control. Fungicides carbendazim treatment recorded 100 per cent growth inhibition against Fusarium oxysporum f.sp. ciceri, Rhizoctonia bataticola, Sclerotium rolfsii. Among botanicals Azadirachta indica at 20 per cent conc. Inhibits 84.44 per cent growth of Fusarium oxysporum f. sp. ciceri, 85.22 per cent growth of Rhizoctonia bataticola and 85.55 per cent growth of Sclerotium rolfsii. Trichoderma viride found most effective for restricting mycelial growth of Fusarium oxysporum f. sp ciceri. Pseudomonas fluorescens found most effective for inhibiting mycelial growth of Rhizoctonia bataticola. In case of Sclerotium rolfsii, Trichoderma harzianum was found most effective. How to view point the article : More, P.S. and Parate, R.L. (2016). Evaluation of botanicals and bioagents against chickpea wilt complex pathogens. Internat. J. Plant Protec., 9(2) : 469- 473, DOI : 10.15740/HAS/IJPP/9.2/469-473.

Changes in soil microbial community structure and function associated with degradation and resistance of carbendazim and chlortetracycline during repeated treatments

The degradation characteristics of carbendazim (CBD) and chlortetracycline (CTC) in individual and combined treatments, and dynamics of soil microbial structural and functional diversity as well as their potential relations were studied during three repeated treatments using different concentrations. The results showed that the degradation half-life of CBD at concentrations of 3mg/kg and 6mg/kg obviously increased, but that of CTC at levels of 1mg/kg and 10mg/kg decreased with increasing treatment frequency. Soil microbial activity and functional diversity displayed the suppression trend in CBD treatment and the suppression-recovery-stimulation trend in CTC and CBD+CTC treatments, which were consistent with the findings of decreased degradation rate of CBD and increased degradation rate of CTC. 16S amplicon sequencing analysis revealed five potentially dominant CTC-resistant microbial genera including Bacillus, Actinobacillus, Pseudomonas, Mycobacterium, and Corynebacterium, which may mainly carry major facilitator superfamily transporter protein, ribosomal protection protein, and other proteins encoded by tetA, tetB, tetC, tetH, tetL, tetM, tetO, tetV, tetW, tetX, tetZ, tet33, and tet39. These five dominant genera may jointly contribute to the elevated bacterial community resistance to CTC. Our findings provided a better understanding of microbial community structure and function changes in repeatedly treated soils with CBD and CTC.

Oral Exposure of Mice to Carbendazim Induces Hepatic Lipid Metabolism Disorder and Gut Microbiota Dysbiosis.

Carbendazim (CBZ) has been considered as an endocrine disruptor that caused mammalian toxicity in different endpoints. Here, we revealed that oral administrations with CBZ at 100 and 500 mg/kg body weight for 28 days induced hepatic lipid metabolism disorder which was characterized by significant increases of hepatic lipid accumulation and triglyceride (TG) levels in mice. The serum cholesterol (TC), high-density lipoprotein, and low-density lipoprotein levels also increased after CBZ exposure. Correspondingly, the relative mRNA levels of some key genes related to lipogenesis and TG synthesis increased significantly both in the liver and fat. Moreover, the increase in serum IL-1β and IL-6 levels by the treatment of CBZ indicated the occurring of inflammation. Furthermore, the levels of bioaccumulation of CBZ in the liver and gut were very low as compared in the feces, indicating that most of CBZ stayed in gastrointestinal tract and interacted with gut microbiota until excreted. At phylum level, the amounts of the Bacteroidetes decreased significantly in the feces after 5 days CBZ exposure. High throughput sequencing of the 16S rRNA gene V3-V4 region revealed a significant reduction in richness and diversity of gut microbiota in the cecum of CBZ-treated mice. UniFrac principal coordinates analysis observed a marked shift of the gut microbiota structure in CBZ-treated mice away from that of the controls. More deeply, operational taxonomic units' analysis identified that a total of 361 gut microbes were significant changed. In CBZ-treated groups, the relative abundance of Firmicutes, Proteobacteria, and Actinobacteria increased and that of Bacteroidetes decreased. Our findings suggested that CBZ could lead hepatic lipid metabolism disorder and gut microbiota dysbiosis in mice.

Involvement of FgMad2 and FgBub1 in regulating fungal development and carbendazim resistance in Fusarium graminearum

Resistance to carbendazim of Fusarium graminearum is conferred by point mutation in the β2‐tubulin gene that plays an important role in spindle assembly. The spindle assembly checkpoint is a cellular surveillance system that is critical for maintaining genomic stability. Predicted protein Mad2‐ and Bub1‐encoding genes in F. graminearum (FgMad2 and FgBub1) were isolated and characterized. There was no difference in FgMad2 and FgBub1 expression levels between carbendazim‐sensitive and ‐resistant strains; however, after carbendazim treatment FgMad2 expression increased while FgBub1 expression stayed the same. Both the FgMad2 and FgBub1 deletion mutants became more sensitive to carbendazim. The FgMad2 deletion mutants grew more slowly, produced fewer conidia and both hyphae and conidia were malformed. Conversely, deletion of FgBub1 had no effect on fungal development other than a reduction in conidia production. FgMad2 deletion mutants exhibited a severe decrease in perithecia production and pathogenicity along with a down‐regulation of trichothecene production, whereas FgBub1 deletion mutants exhibited only a slight reduction in perithecia production and was accompanied by a twofold increase in trichothecene production. Overall, the results indicate that both FgMad2 and FgBub1 are involved in carbendazim resistance and trichothecene biosynthesis, and FgMad2 plays an important role in fungal development in F. graminearum.

Evaluation of Bacillus subtilis (JN032305) biofungicide to control chilli anthracnose in pot controlled conditions

Colletotrichum gloeosporioides (Penz.) causing anthracnose is a potent pathogen of chilli resulting in significant yield loss. The in vitro root colonisation study showed an increase in root bacterial count by 10 × 105 colony forming units/cm root for Bacillus subtilis after 15 days of germination. Population level of the antagonist was stable in talc till the 180th day (30°C – 1.6 × 108; 4°C – 1.9 × 108) and in lignite till the 150th day (30°C – 1.5 × 108; 4°C – 1.3 × 108). Combined application of B. subtilis and carbendazim enhanced all biometric parameters with reduction in disease incidence. Soil, seed, root dip and foliar spray treatment significantly enhanced the growth parameters of chilli in B. subtilis inoculated treatments in comparison to the untreated control. Seed application resulted in highest plant fresh weight (76.84 g) and dry weight (34.17 g) compared to the untreated control (50 g and 21 g fresh and dry weight, respectively). Highest plant height ranging from 70 cm (soil application) to 77 cm (dip treatment) with Bacillus inoculation was comparable with carbendazim treatment (61 cm with soil application) and 78 cm (dip treatment) and significantly higher than the untreated control (58.2 cm with soil and 61 cm with application, respectively). Dip treatment resulted in significant increase in root length with B. subtilis (33 cm) and carbendazim (32.5 cm) in comparison to untreated control (15 cm). Co-inoculation of pathogen with B. subtilis (singly and with carbendazim) not only reduced the disease incidence but also improved all the biometric parameters in comparison to challenge inoculation. Root dip application was effective in promoting growth while seed application was effective in disease control.

Antagonistic potential of native strain Streptomyces aurantiogriseus VSMGT1014 against sheath blight of rice disease.

A total of 132 actinomycetes was isolated from different rice rhizosphere soils of Tamil Nadu, India, among which 57 showed antagonistic activity towards Rhizoctonia solani, which is sheath blight (ShB) pathogen of rice and other fungal pathogens such as Macrophomina phaseolina, Fusarium oxysporum, Fusarium udum and Alternaria alternata with a variable zone of inhibition. Potential actinomycete strain VSMGT1014 was identified as Streptomyces aurantiogriseus VSMGT1014 based on the morphological, physiological, biochemical and 16S rRNA sequence analysis. The strain VSMGT1014 produced lytic enzymes, secondary metabolites, siderophore, volatile substance and indole acetic acid. Crude metabolites of VSMGT1014 showed activity against R. solani at 5 µg ml(-1); however, the prominent inhibition zone was observed from 40 to 100 µg ml(-1). Reduced lesion heights observed in culture, cells-free filtrate, crude metabolites and carbendazim on challenge with pathogen in the detached leaf assay. The high content screening test clearly indicated denucleation of R. solani at 5 µg ml(-1) treatment of crude metabolite and carbendazim respectively. The results conclude that strain VSMGT1014 was found to be a potential candidate for the control of ShB of rice as a bio fungicide.

Induced systemic resistance and growth promotion in tomato by an indole‐3‐acetic acid‐producing strain of Paenibacillus polymyxa

AbstractPaenibacillus polymyxa strain CF05, a plant‐growth‐promoting rhizobacterium (PGPR) showed inhibitory effect on Fusarium oxysporum f. sp. lycoersici in vitro, causal agent of Fusarium‐wilt of tomato. In the greenhouse experiments, tomatoes inoculated with strain CF05 promoted the significant growth. Meanwhile, strain CF05 suppressed the Fusarium‐wilt with 78.24% in control efficiency, which was similar to the carbendazim treatment. The bacterial culture supernatant was found to have the presence of indole‐3‐acetic acid (IAA), which could be accumulated throughout the growth. Furthermore, strain CF05 could greatly stimulate the activities of phenylalanine ammonia‐lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD) and superoxide dismutase (SOD) in either the absence or the presence of fungal pathogen, and the stimulation stayed throughout the entire experimental assessment. Activities of POD and SOD reached the maximum amount at the second day post‐inoculation (dpi) after inoculation while activities of PAL and PPO reached the maximum amount at the third dpi and the fourth dpi, respectively. Moreover, strain CF05 could stimulate the H2O2 and phenol contents in the initial phase after pathogen inoculation. These results suggest that the sustained and timely induction of defence enzymes and accumulation of H2O2 and phenolics treated with P. polymyxa might have contributed to restriction of invasion of fungal pathogen in tomato roots. In summary, P. polymyxa strain CF05, which elicited both plant growth promotion and induction of defence response, could be potential agent to improve the yield of tomato and manage Fusarium‐wilt disease.

Synthesis and Antitumor Activity of Heterocycles Related to Carbendazim

Three types of compounds were synthesized from carbendazim (1), a benzimidazole derivative (Scheme ). They included a group of esters at N1 prepared by treating carbendazim with isocyanates bearing ester groups (2a, 2b, 2c), carboxyalkyl‐1,2,3,4‐tetrahydro‐s‐triazino[1,2‐a]benzimidazole‐2,4‐dione esters (3a and 3b, 3d and 3c derived from 3a. The antitumor potencies of the N1 esters were in the range of 7 to 40 μM, which compares favorably with carbendazim, but their water solubilities were low. The s‐triazine derivatives showed activity against pancreatic tumor cells, and one of them (3b) was active in mice, but they were not effective against other tumor types. Treatment of carbendazim with 3‐bromopropionyl chloride produced 1‐methoxycarbonyl‐4‐oxo‐1,2,3,4‐tetrahydropyrimido[1,2‐a]benzimidazole (4), which gave 1‐(3‐aminopropionyl)benzimidazole 2‐methylcarbamates, substituted on the amino nitrogen (5a, 5b, and 5d), when treated with amines. These products showed some antitumor activity in cell cultures, and an ethoxy derivative (5c), obtained by treating 1‐methoxycarbonyl‐4‐oxo‐1,2,3,4‐tetrahydropyrimido[1,2‐a]benzimidazole with sodium ethoxide, was active in the 67–150 μM range. Some of the new compounds had good water solubility. Carbendazim kills tumor cells by inhibiting tubulin; however, s‐triazine 3b, which differs from it in size and functional groups, does not act by this mechanism.