Biosynthetic Gene Clusters in Sequenced Genomes of Four Contrasting Rhizobacteria in Phytopathogen Inhibition and Interaction with Capsicum annuum Roots.

Through screening of rhizobacteria, species that effectively suppress phytopathogens and/or promote plant growth are found. Genome sequencing is a crucial step in obtaining a complete characterization of microorganisms for biotechnological applications. This study aimed to sequence the genomes of four rhizobacteria that differ in their inhibition of four root pathogens and in their interaction with chili pepper roots to identify the species and analyze differences in the biosynthetic gene clusters (BGCs) for antibiotic metabolites and to determine possible phenotype-genotype correlations. Results from sequencing and genome alignment identified two bacteria as Paenibacillus polymyxa, one as Kocuria polaris, and one that was previously sequenced as Bacillus velezensis. Analysis with antiSMASH and PRISM tools showed that B. velezensis 2A-2B, the strain with the best performance of referred characteristics, had 13 BGCs, including those related to surfactin, fengycin, and macrolactin, not shared with the other bacteria, whereas P. polymyxa 2A-2A and 3A-25AI, with up to 31 BGCs, showed lower pathogen inhibition and plant hostility; K. polaris showed the least antifungal capacity. P. polymyxa and B. velezensis had the highest number of BGCs for nonribosomal peptides and polyketides. In conclusion, the 13 BGCs in the genome of B. velezensis 2A-2B that were not present in the other bacteria could explain its effective antifungal capacity and could also contribute to its friendly interaction with chili pepper roots. The high number of other BGCs for nonribosomal peptides and polyketide shared by the four bacteria contributed much less to phenotypic differences. IMPORTANCE To advance the characterization of a microorganism as a biocontrol agent against phytopathogens, it is highly recommended to analyze the potential of the profile of secondary metabolites as antibiotics that it produces to counteract pathogens. Some specific metabolites have positive impacts in plants. By analyzing sequenced genomes with bioinformatic tools, such as antiSMASH and PRISM, outstanding bacterial strains with high potential to inhibit phytopathogens and/or promote plant growth can be quickly selected to confirm and expand our knowledge of BGCs of great value in phytopathology.

Draft Genome Sequence of Paenibacillus polymyxa 3A-25AI, a Strain Antagonist to Root Rot Causal Phytopathogens.

Here, we report the draft genome sequence of the Paenibacillus polymyxa 3A-25AI strain, isolated from the rhizosphere of wild grass. This strain inhibits Phytophthora capsici and Rhizoctonia solani phytopathogens. The genome size is 5.6 Mb, with a G+C content of 45.59%, and contains 5,079 genes, 4,968 coding DNA sequences (CDSs), 35 tRNAs, 3 rRNAs, and 72 unexpected miscellaneous RNA (miscRNA) features.

Complete Genome Sequence of XaF13, a Novel Bacteriophage of Xanthomonas vesicatoria from Mexico.

The phytopathogenic bacterium Xanthomonas vesicatoria is the causative agent of bacterial spot disease in various Solanaceae family members. Here, we describe the complete genome sequence of XaF13, a novel filamentous phage that infects the phytopathogenic bacterium X. vesicatoria The 7,045-bp genome is predicted to encode 14 open reading frames, 7 of which are related to those of other filamentous Xanthomonas phages.

Genome Sequence of Bacillus halotolerans Strain MS50-18A with Antifungal Activity against Phytopathogens, Isolated from Saline Soil in San Luís Potosí, Mexico.

Bacillus halotolerans strain MS50-18A, isolated from saline soil, possesses antifungal activity toward root rot causal phytopathogens and has friendly interactions with the chili pepper plant. The draft genome sequence is 4.06 Mb in length and contains 4,215 genes. Genes related to glycine/betaine uptake and bacilysin biosynthesis are present, supporting its saline stress tolerance and antifungal activity.

Draft Genome Sequence of Bacillus subtilis 2C-9B, a Strain with Biocontrol Potential against Chili Pepper Root Pathogens and Tolerance to Pb and Zn.

Bacillus subtilis 2C-9B, obtained from the rhizosphere of wild grass, exhibits inhibition against root rot causal pathogens in Capsicum annuum, Pb and Zn tolerance, and plant growth promotion in medium supplemented with Pb. The genome of B. subtilis 2C-9B was sequenced and the draft genome assembled, with a length of 4,215,855 bp and 4,723 coding genes.

Draft genome sequence of Bacillus velezensis 2A-2B strain: a rhizospheric inhabitant of Sporobolus airoides (Torr.) Torr., with antifungal activity against root rot causing phytopathogens.

A Bacillus velezensis strain from the rhizosphere of Sporobolus airoides (Torr.) Torr., a grass in central-north México, was isolated during a biocontrol of phytopathogens scrutiny study. The 2A-2B strain exhibited at least 60% of growth inhibition of virulent isolates of phytopathogens causing root rot. These phytopathogens include Phytophthora capsici, Fusarium solani, Fusarium oxysporum and Rhizoctonia solani. Furthermore, the 2A-2B strain is an indolacetic acid producer, and a plant inducer of PR1, which is an induced systemic resistance related gene in chili pepper plantlets. Whole genome sequencing was performed to generate a draft genome assembly of 3.953 MB with 46.36% of GC content, and a N50 of 294,737. The genome contains 3713 protein coding genes and 89 RNA genes. Moreover, comparative genome analysis revealed that the 2A-2B strain had the greatest identity (98.4%) with Bacillus velezensis.

Draft Genome Sequence of Bacillus velezensis 3A-25B, a Strain with Biocontrol Activity against Fungal and Oomycete Root Plant Phytopathogens, Isolated from Grassland Soil.

Here, we present the draft genome of Bacillus velezensis 3A-25B, which totaled 4.01 Mb with 36 contigs, 3,948 genes, and a GC content of 46.34%. This strain, which demonstrates biocontrol activity against root rot causal phytopathogens in horticultural crops and friendly interactions in roots of pepper plantlets, was obtained from grassland soil in Zacatecas Province, Mexico.

Conserved versatile master regulators in signalling pathways in response to stress in plants.

From the first land plants to the complex gymnosperms and angiosperms of today, environmental conditions have forced plants to develop molecular strategies to surpass natural obstacles to growth and proliferation, and these genetic gains have been transmitted to the following generations. In this long natural process, novel and elaborate mechanisms have evolved to enable plants to cope with environmental limitations. Elements in many signalling cascades enable plants to sense different, multiple and simultaneous ambient cues. A group of versatile master regulators of gene expression control plant responses to stressing conditions. For crop breeding purposes, the task is to determine how to activate these key regulators to enable accurate and optimal reactions to common stresses. In this review, we discuss how plants sense biotic and abiotic stresses, how and which master regulators are implied in the responses to these stresses, their evolution in the life kingdoms, and the domains in these proteins that interact with other factors to lead to a proper and efficient plant response.

Ensamble subcelular de la ribonucleoproteína Ro de 60 kDa a los hYRNAs / Subcellular assemble of the ribonucleoproteínas Ro 60 kDa a the hYRNAs

Ro es un complejo molecular de tres ribonucleoproteínas de 60, 54 y 52 kDa de las que la isoforma de 60 kDa está asociada a uno o varios hYRNAs; se sabe que su ensamble ocurre en el núcleo y en forma de complejo Ro/hYRNA es rápidamente exportado al citoplasma. Este trabajo fue diseñado para determinar si la unión de hYRNA es indispensable para la permanencia nuclear de la proteína Ro de 60 kDa. La interacción entre Ro y hYRNA fue estudiada por inmunofluorescencia y Western blot usando células HEp-2 y anticuerpos anti-Ro. La ribonucleoproteína Ro se localizó en los compartimientos núcleo-citoplásmicos con un patrón granular fino. Para definir si la presencia de hYRNA era esencial en la localización nuclear de Ro se realizaron experimentos adicionales de fluorescencia en células digeridas con RNAasa o tripsina con los siguientes hallazgos. La proteína Ro puede detectarse en el núcleo en ausencia de los hYRNAs, en tanto que su presencia citoplásmica necesariamente está ligada a los hYRNA, ya que la digestión con RNAasa abolió su expresión en citoplasma. El patrón de fluorescencia citoplásmico fue restaurado al reconstituír las células con extractos celulares ricos en hYRNAs. La digestión con tripsina eliminó por completo los gránulos núcleo-citoplásmicos de Ro. Se puede concluir que existen dos pooles nucleares de ribonucleoproteína Ro de 60 kDa, libre y en complejo, en tanto que en el citoplasma solamente existe formando complejos con los hYRNAs