Genetic diversity and functional characterization of endophytic Bacillus thuringiensis isolates from the North Western Indian Himalayas

Mishra, Pankaj Kumar; Bisht, Shekhar Chandra; Ruwari, Pooja; Subbanna, A. R. N. S.; Bisht, Jaideep Kumar; Bhatt, J. C.; Gupta, H. S.

doi:10.1007/s13213-016-1244-0

Cited by 17 publications

(11 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, endophytic Bt was recently reported in cotton (Monnerat et al ., ), coffee (Miguel et al ., ) and wheat (Tao et al ., ). Furthermore, several studies on the colonization and translocation of Bt have been performed in beans (Maduell et al ., ; García‐Suárez et al ., ), cabbage (Monnerat et al ., ; Praça et al ., ), many different legumes (Tanuja et al ., ; Mishra et al ., ) and bryophytes (Lin et al ., ). These studies open new perspectives for the use of this bacterium as a biocontrol agent for sap‐sucking insects (Jurat‐Fuentes & Jacksony, ).…”

Section: Introductionmentioning

confidence: 99%

Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs

et al. 2019

View full text Add to dashboard Cite

Bacillus thuringiensis (Bt) toxins are effective in controlling insect pests either through the spraying of products or when expressed in transgenic crops. The discovery of endophytic Bt strains opened new perspectives for studies aimed at the control of sapsucking insects, such as the Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae), a vector of "Candidatus Liberibacter spp.," associated with citrus huanglongbing (HLB). In this study, translocation of endophytic Bt strains in citrus seedlings inoculated with Bt suspension delivered by soil-drench, and their systemic pathogenicity to D. citri nymphs were investigated. The pathogenicity of three wild-type Bt strains against D. citri third-instar nymphs was demonstrated. Among the 10 recombinant strains tested (each of them harboring a single cry or cyt gene), 3 can be highlighted, causing 42%-77% and 66%-90% nymphal mortality at 2 and 5 d after inoculation, respectively. The isolation of Bt cells from young citrus shoots and dead nymphs, and PCR performed with specific primers, confirmed the involvement of the Bt strains in the psyllid mortality. This is the first report showing the translocation of Bt strains from citrus seedling roots to shoots and their potential to control D. citri nymphs that fed on these soil-drench inoculated seedlings. The Bt strains that caused the highest mortality rates have the potential to be used as bioinsecticides to control D. citri and the identified genes can be used for the production of transgenic Bt citrus.

show abstract

Section: Introductionmentioning

confidence: 99%

Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Despite the extensive research about B. thuringiensis, most of the work has focused on the relevance of B. thuringiensis for pest control in agriculture. Its ecology related with other lifestyles (free or plant-associated) and the interaction with other microorganisms or plant hosts have been poorly addressed, since this species has mainly considered an entomopathogenic or saprophytic bacterium (10,31,32,54,72,73). In turn, the mechanisms that B. thuringiensis uses to spread in soil or other habitats are still unknown.…”

Section: Discussionmentioning

confidence: 99%

The quorum sensing system NprR-NprRB contributes to spreading and fitness in colony biofilms ofBacillus thuringiensis

Verdugo-Fuentes

Rocha

2021

Preprint

View full text Add to dashboard Cite

Quorum sensing (QS) are intercellular communication mechanisms to coordinate bacterial gene expression in response to signaling molecules. In Bacillus thuringiensis the QS system NprR-NprRB (receptor protein-signaling peptide) regulates the expression of genes related to nutrient scavenging during necrotrophism and also modulates sporulation onset. However, the relevance of QS in free-living stages of B. thuringiensis is less known. In this work, we depict the contribution of this QS system to spreading in colony biofilms. Through a spreading assay in spotted colonies of B. thuringiensis Bt8741 Wt and derived mutants, we find that the spreading phenotype depends on the NprR regulator and on the extracellular signaling NprRB peptide. We also show that this phenotype is associated to an increased fitness of the bacterium in these experimental conditions. Exogenous addition of a lipopeptide surfactant was sufficient to recover spreading in the ΔnprR-nprRB mutant, indicating that the phenotype could be mediated by the lipopeptide kurstakin. Finally, we suggest that the spreading is relevant in nature, since it occurs in the sole presence of soil nutrients, and it is conserved in several species of Bacillus commonly found in soil. This novel function of NprR-NprRB highlights the relevance of this QS system on the evolution and on the free-lifestyle ecology of B. thuringiensis.

show abstract

“…Bacillus thuringiensis is a genetically diverse species, so its large number of strains can form several different profiles according to their genetic profile 48 . The high genetic variability of Bt may be related to both the influence of geographic and ecological factors 19,37,35 because this bacterium is isolated from several substrates and has a wide range of target hosts.…”

Section: Discussionmentioning

confidence: 99%

“…One factor that may or may not explain the correlation with the Bt collection sites is that the diversity may also be associated with the region's climate, soil conditions where the samples were collected, and the influence of other microbial communities present in the region 37 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Genetic diversity of Brazilian Bacillus thuringiensis isolates with toxicity against Aedes aegypti (Diptera: Culicidae)

Fernandes

Costa

Oliveira

et al. 2021

Preprint

View full text Add to dashboard Cite

Bacillus thuringiensis (Bt) isolates native to Maranhão (BtMA) that are highly toxic to Aedes aegypti larvae and seven standard subspecies of Bt were analyzed for genetic diversity using the rep-PRC technique with BOX, ERIC, REP, MB1, and GTG 5 markers. The rep-PCR technique is considered an extremely reliable, reproducible, fast and highly discriminatory technique that may be used even among populations of the same species. These five markers revealed a total of 38 polymorphic DNA fragments for 30 BtMA isolates. Eight groups were obtained with the dendrogram generated through Pearson's correlation analysis, with four groups formed only with BtMA isolates and four comprised of isolates of BtMA and the standard subspecies toxic to dipterans and lepidopterans. Despite the high genetic diversity of BtMA, a low correlation between the collection site, gene content and mortality against A. aegypti larvae was evidenced. The clustering of the standard subspecies of Bt that were toxic against dipterans with BtMA isolates confirm the mosquitocidal action of the native isolates from Maranhão, and they can be used as an alternative for A. aegypti control and other insects of medical importance and for the control of agricultural pests.

show abstract

Genetic diversity and functional characterization of endophytic Bacillus thuringiensis isolates from the North Western Indian Himalayas

Cited by 17 publications

References 39 publications

Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs

Selection of Bacillus thuringiensis strains in citrus and their pathogenicity to Diaphorina citri (Hemiptera: Liviidae) nymphs

The quorum sensing system NprR-NprRB contributes to spreading and fitness in colony biofilms ofBacillus thuringiensis

Genetic diversity of Brazilian Bacillus thuringiensis isolates with toxicity against Aedes aegypti (Diptera: Culicidae)

Contact Info

Product

Resources

About