RESUMEN
Bacillus thuringiensis Berliner is recognized as a predominant bioinsecticide but its antifungal potential has been relatively underexplored. A novel B. thuringiensis strain NBAIR BtAr was isolated and morphologically characterized using light and scanning electron microscopy, revealing presence of bipyramidal, cuboidal, and spherical parasporal crystals. The crude form of lipopeptides was extracted from NBAIR BtAr and assessed for its antagonistic activity in vitro, and demonstrated 100% inhibition of Sclerotium rolfsii Sacc. at a minimum inhibitory concentration of 50 µL of the crude lipopeptide extract per mL of potato dextrose agar. To identify the antagonistic genes responsible, we performed whole genome sequencing of NBAIR BtAr, revealing the presence of circular chromosome of 5,379,913 bp and 175,362 bp plasmid with 36.06% guanine-cytosine content and 5814 protein-coding sequences. Average nucleotide identity and whole genome phylogenetic analysis delineated the NBAIR BtAr strain as konkukian serovar. Gene ontology analysis revealed associations of 1474, 1323, and 1833 genes with biological processes, molecular function, and cellular components, respectively. Antibiotics & secondary metabolite analysis shell analysis of the whole genome yielded secondary metabolites biosynthetic gene clusters with 100%, 85%, 40%, and 35% similarity for petrobactin, bacillibactin, fengycin, and paenilamicin, respectively. Also, novel biosynthetic gene clusters, along with antimicrobial genes, including zwittermicin A, chitinase, and phenazines, were identified. Moreover, the presence of eight bacteriophage sequences, 18 genomic islands, insertion sequences, and one CRISPR region indicated prior occurrences of genetic exchange and thus improved competitive fitness of the strain. Overall, the whole genome sequence of NBAIR BtAr is presented, with its taxonomic classification and critical genetic attributes that contribute to its strong antagonistic activity against S. rolfsii.
RESUMEN
Stalk rot disease is a major constraint in maize production and till date reported to be caused by two to three species of phytopathogenic fungi but, in our present study, we disclose the first report of stalk rot is caused by complex species of phytopathogens, which belongs to five different genera. Therefore, to substantiate these findings, a total of 105 diseased samples of maize were collected from 21 different locations in six different geographical locations of India from which 48 isolates were used for the research study. Morphological features such as pigmentation, colony color, type of mycelium and pattern of mycelium was examined using macro and microscopic methods. A total of 11 different spp. of pathogens belonging to the five different genera: Fusarium verticillioides (56.25%), F. equiseti (14.5%), F. andiyazi (6.25%), F. solani (2.08%), F. proliferatum (2.08%), F. incarnatum (2.08%), Lasidioplodia theobrame (6.25%), Exserohilum rostrtum (4.16%), Nigrospora spp. (4.16%). and Schizophyllum commune (2.08%) were identified by different housekeeping genes (ITS, TEF-1α, RPB2 and Actin). Fusarium verticillioides, F. equiseti and F. andiyazi were major pathogens involved in stalk rot. This is the first report on F. proliferatum, F. solani, F. incarnatum, Lasidioplodia theobrame, Exserohilum rostrtum, Nigrospora spp. and Schizophyllum commune causing stalk rot of maize and their distribution in the different states of India. Studies on population dynamics of PFSR will enhance the understanding of pathogen behavior, virulence, or its association with different pathogens across India, which will facilitate the development of resistant maize genotypes against the PFSR.
Asunto(s)
Fusarium , Filogenia , Enfermedades de las Plantas , Zea mays , Zea mays/microbiología , Enfermedades de las Plantas/microbiología , India , Fusarium/genética , Fusarium/clasificación , Fusarium/aislamiento & purificación , Fusarium/patogenicidad , ADN de Hongos/genética , Hongos/genética , Hongos/clasificación , Hongos/aislamiento & purificación , Hongos/patogenicidad , Variación GenéticaRESUMEN
Effectors play an important role in host-pathogen interactions. Though an economically significant disease in rice, knowledge regarding the infection strategy of Rhizoctonia solani is obscure. In this study, we performed a genome-wide identification of the effectors in R. solani based on the characteristics of previously reported effector proteins. A total of seven novel effectors (designated as RS107_1 to RS107_7) in the disease mechanism of R. solani were identified and were predicted to be non-classically secreted proteins with functionally conserved domains. The function, reactivity, and stability of these proteins were evaluated through physiochemical characterization. The target proteins involved in the regulation of rice defense mechanisms were identified. Furthermore, the effector genes were cloned and RS107_6 (metacaspase) was heterologously expressed in Escherichia coli to obtain a purified protein of ~36.5 kDa. The MALD-TOF characterization confirmed that the protein belonged to a metacaspase of the Peptidase_C14 protein family, 906 bp in size, and encoded a polypeptide of 301 amino acids. These findings suggest that the identified effectors can potentially serve as a virulence factor and can be targeted for the management of sheath blight in rice.
RESUMEN
Magnaporthe oryzae, the rice blast fungus, is one of the most dangerous rice pathogens, causing considerable crop losses around the world. In order to explore the rice blast-resistant sources, initially performed a large-scale screening of 277 rice accessions. In parallel with field evaluations, fifty-two rice accessions were genotyped for 25 major blast resistance genes utilizing functional/gene-based markers based on their reactivity against rice blast disease. According to the phenotypic examination, 29 (58%) and 22 (42%) entries were found to be highly resistant, 18 (36%) and 29 (57%) showed moderate resistance, and 05 (6%) and 01 (1%), respectively, were highly susceptible to leaf and neck blast. The genetic frequency of 25 major blast resistance genes ranged from 32 to 60%, with two genotypes having a maximum of 16 R-genes each. The 52 rice accessions were divided into two groups based on cluster and population structure analysis. The highly resistant and moderately resistant accessions are divided into different groups using the principal coordinate analysis. According to the analysis of molecular variance, the maximum diversity was found within the population, while the minimum diversity was found between the populations. Two markers (RM5647 and K39512), which correspond to the blast-resistant genes Pi36 and Pik, respectively, showed a significant association to the neck blast disease, whereas three markers (Pi2-i, Pita3, and k2167), which correspond to the blast-resistant genes Pi2, Pita/Pita2, and Pikm, respectively, showed a significant association to the leaf blast disease. The associated R-genes might be utilized in rice breeding programmes through marker-assisted breeding, and the identified resistant rice accessions could be used as prospective donors for the production of new resistant varieties in India and around the world.
Asunto(s)
Magnaporthe , Oryza , Oryza/genética , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Fitomejoramiento , Marcadores Genéticos , GenotipoRESUMEN
For the first time, updated molecular techniques were used to validate and elucidate the effect of the Panchagavya. Metagenomics was used to decipher the bacterial microbiome structure, which showed promising results for their existence and abundance in the Panchagavya.