Efficacy of Bacillus thuringiensis Cry14 toxin against root knot nematode, Meloidogyne javanica

Ravari, Sareh Baghaee; Moghaddam, E Mahdikhani

doi:10.17221/93/2013-pps

Cited by 26 publications

(4 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although many Cry toxins are known to target various insects, only a few nematicidal crystal protein genes, particularly those targeting plant-parasitic nematodes (PPNs), have been found and utilized, of which only cry5Ba and cry6Aa have been applied into transgenic tomatoes (14)(15)(16). These nematicidal Cry toxins cluster together in phylogenetic subfamilies (17); the Cry5, Cry13A, Cry14A, and Cry21 proteins share the same evolutionary ancestry and are thus clustered into the Cry5 subfamily, which includes the nontoxic proteins Cry5A and Cry21G (6).…”

mentioning

confidence: 99%

Dissimilar Crystal Proteins Cry5Ca1 and Cry5Da1 Synergistically Act against Meloidogyne incognita and Delay Cry5Ba-Based Nematode Resistance

Geng

Liu

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

Cry proteins of Bacillus thuringiensis (Bt) have been successfully used as biopesticides and in transgenic crops throughout the world. However, resources against the most serious agricultural pathogens, plant root-knot nematodes, are limited. The genomes of several highly nematicidal virulent Bt strains from our laboratory have been sequenced, facilitating the identification of novel Cry proteins and other virulence factors. We identified two novel Cry proteins, Cry5Ca1 and Cry5Da1, that exhibit high toxicity against Meloidogyne incognita. Using the Caenorhabditis elegans model, the two Cry5 toxins were shown to negatively affect nematode life span, fertility, and survival. The 50% lethal concentrations (LC 50 s) of Cry5Ca1 and Cry5Da1 were 57.22 g/ml and 36.69 g/ml, respectively. Moreover, a synergistic effect (synergism factor, 1.61 to 2.04) was observed for nematicidal toxicity of Cry5Ca1 and Cry5Da1, which is accordant with the phylogenetic results suggesting that domain II of the two novel Cry5 toxins evolved into two independent clades. Through comparison of the depressed degree of toxicity in the ␤-methylgalactoside detoxification test, we found that the novel toxin Cry5D possesses a different galactosebinding epitope; meanwhile, the finding that Cry5D does not share a motif (GXXXE) in the corresponding loop of domain II with Cry5B could explain the different galactose binding performance. Additionally, low-level cross-resistance of C. elegans bre mutant strains was evident between Cry5B and Cry5D. These results suggest that Cry5D can be used as an alternative to delay the potential resistance of nematodes to Cry5B. IMPORTANCE Although proper gene resources for Bt crops against the most serious agricultural pathogens, plant root-knot nematodes, are limited, we have identified two novel nematicidal toxins, Cry5Ca1 and Cry5Da1, against M. incognita, which have supplied more gene candidates for Bt crops designed against nematodes. Moreover, the association of the dissimilarity between Cry5Da1 and Cry5Ba1 and their low crossresistance can be attributed not only to a low sequence similarity of domain II but also to the structural difference of the key motif and receptor-binding epitope in the loops. This association facilitates the selection of a proper candidate for the prospective design of pyramided Bt crops that can delay potential resistance.KEYWORDS Bacillus thuringiensis, Caenorhabditis elegans, Cry proteins, bre resistance, nematicidal T he agricultural economic damage caused by more than 4,100 species of plantparasitic nematodes (PPNs) has been estimated to cost US$80 billion per year (1, 2), and a large proportion of this cost is due to the serious damage caused by the plant-parasitic nematode Meloidogyne incognita (3). Although many nematophagous

show abstract

mentioning

confidence: 99%

Dissimilar Crystal Proteins Cry5Ca1 and Cry5Da1 Synergistically Act against Meloidogyne incognita and Delay Cry5Ba-Based Nematode Resistance

Geng

Liu

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…2 ). Other toxins, belonging to the Cry5 subfamily, such as Cry5Ca1, Cry5Da1, and Cry14 were recently found to act on PPNs, such as M. incognita and M. javanica [ 42 , 43 ]. The nematicidal cry5 subfamily genes, however, appeared to occur in low frequency in natural environments [ 44 ].…”

Section: Discussionmentioning

confidence: 99%

Suppressing a plant-parasitic nematode with fungivorous behavior by fungal transformation of a Bt cry gene

Cheng

Qin

et al. 2018

Microb Cell Fact

View full text Add to dashboard Cite

BackgroundPine wilt disease, caused by the pinewood nematode Bursaphelenchus xylophilus (PWN), is an important destructive disease of pine forests worldwide. In addition to behaving as a plant-parasitic nematode that feeds on epithelial cells of pines, this pest relies on fungal associates for completing its life cycle inside pine trees. Manipulating microbial symbionts to block pest transmission has exhibited an exciting prospect in recent years; however, transforming the fungal mutualists to toxin delivery agents for suppressing PWN growth has received little attention.ResultsIn the present study, a nematicidal gene cry5Ba3, originally from a soil Bacillus thuringiensis (Bt) strain, was codon-preferred as cry5Ba3Φ and integrated into the genome of a fungus eaten by PWN, Botrytis cinerea, using Agrobacterium tumefaciens-mediated transformation. Supplementing wild-type B. cinerea extract with that from the cry5Ba3Φ transformant significantly suppressed PWN growth; moreover, the nematodes lost fitness significantly when feeding on the mycelia of the cry5Ba3Φ transformant. N-terminal deletion of Cry5Ba3Φ protein weakened the nematicidal activity more dramatically than did the C-terminal deletion, indicating that domain I (endotoxin-N) plays a more important role in its nematicidal function than domain III (endotoxin-C), which is similar to certain insecticidal Cry proteins.ConclusionsTransformation of Bt nematicidal cry genes in fungi can alter the fungivorous performance of B. xylophilus and reduce nematode fitness. This finding provides a new prospect of developing strategies for breaking the life cycle of this pest in pines and controlling pine wilt disease.Electronic supplementary materialThe online version of this article (10.1186/s12934-018-0960-5) contains supplementary material, which is available to authorized users.

show abstract

“…That is, B. thuringiensis strains developed for mosquito larvae do not affect caterpillars. Sareh et al (2015) [18] demonstrated that Bt is active against on controlling other invertebrate of the phylum Nematoda. With the aims of searching of alternatives management strategies for sustainable protection of tomato cultivation, attempts were made to evaluate: (i) the efficacy of different concentrations of EM bio-pesticide on T. absoluta, B. tabaci and M. eurphorbiae populations on tomato; (ii) the effect of EM biological pesticide on the growth rate of tomato plant was also evaluated.…”

Section: Insecticides Properties and Mode Of Action Of Bacillus Thuri...mentioning

confidence: 99%

Management of tomato pests using effective macrooganism (EM) bio-pesticide as alternative pests control method in Bambili, Cameroon

Heumou¹,

Gangue²,

Seino³

et al. 2022

Acta Entomol. Zool.

View full text Add to dashboard Cite

Tuta absoluta, Bemisia tabaci and Macrosiphum eurphorbiae are important pests of tomato in Cameroon. The effect of EM a biopesticide containing Bacillus thuringiensis as active ingredient was evaluated on the suppression of these pests. A completely randomized design with 4 treatments [control (T0); EM 10 ml/l (T1); EM 20 ml/l (T2); EM 30 ml/l (T3)] and 3 replications were used. The biopesticide was sprayed weekly for seven weeks. The variation of insects' populations, T. absoluta impact and plants growth in different plots were compare using ANOVA test. Different concentrations of B. thuringiensis were effective in reducing pests populations and significant difference observed within treatments (DF =3, F=258.69, P=0.0000; DF=3, F=368.50, P=0.0000 and DF=3, F=44.21, P=0.0000) respectively. On the untreated control plots T0, the populations of the three pests showed an exponential expansion within 7 weeks. No significant effect of B. thuringiensis was observed on the plant growth. This biological pesticide can save as alternative pests control for sustainable tomato production.

show abstract

Efficacy of Bacillus thuringiensis Cry14 toxin against root knot nematode, Meloidogyne javanica

Cited by 26 publications

References 20 publications

Dissimilar Crystal Proteins Cry5Ca1 and Cry5Da1 Synergistically Act against Meloidogyne incognita and Delay Cry5Ba-Based Nematode Resistance

Dissimilar Crystal Proteins Cry5Ca1 and Cry5Da1 Synergistically Act against Meloidogyne incognita and Delay Cry5Ba-Based Nematode Resistance

Suppressing a plant-parasitic nematode with fungivorous behavior by fungal transformation of a Bt cry gene

Management of tomato pests using effective macrooganism (EM) bio-pesticide as alternative pests control method in Bambili, Cameroon

Contact Info

Product

Resources

About