Pan Proteome of Xanthomonas campestris pv. campestris Isolates Contrasting in Virulence.

Fully sequenced genomes of Xanthomonas campestris pv. campestris (Xcc) strains are reported. However, intra-pathovar differences are still intriguing and far from clear. In this work, the contrasting virulence between two isolates of Xcc - Xcc51 (more virulent) and XccY21 (less virulent) is evaluated by determining their pan proteome profiles. The bacteria are grown in NYG and XVM1 (optimal for induction of hrp regulon) broths and collected at the max-exponential growth phase. Shotgun proteomics reveals a total of 329 proteins when Xcc isolates are grown in XVM1. A comparison of both profiles reveals 47 proteins with significant abundance fluctuations, out of which, 39 show an increased abundance in Xcc51 and are mainly involved in virulence/adaptation mechanisms, genetic information processing, and membrane receptor/iron transport systems, such as BfeA, BtuB, Cap, Clp, Dcp, FyuA, GroEs, HpaG, Tig, and OmpP6. Several differential proteins are further analyzed by qRT-PCR, which reveals a similar expression pattern to the protein abundance. The data shed light on the complex Xcc pathogenicity mechanisms and point out a set of proteins related to the higher virulence of Xcc51. This information is essential for the development of more efficient strategies aiming at the control of black rot disease.

Quantitative expression of microRNAs in Brassica oleracea infected with Xanthomonas campestris pv. campestris.

Brassica oleracea var. capitata (cabbage) is an economically important crop affected by black rot disease caused by Xanthomonas campestris pv. campestris (Xcc). MicroRNAs (miRNAs) play an important role in plant defense modulation and therefore the analysis of these molecules can help better understand plant-pathogen interactions. In this study, we report the differential expression of four miRNAs that seem to participate in the plant response to Xcc infection. Northern Blot and RT-qPCR techniques were used to measure miRNA expression in resistant (União) and susceptible (Kenzan) cultivars. From 6 miRNAs analyzed, 4 were detected and differentially expressed, showing a down- and upregulated expression profile in susceptible and resistant cultivars, respectively. These results suggest that miR156, miR167, miR169, and miR390 could play a role in B. oleracea resistance enhancement against Xcc and could be explored as potential resistance markers in B. oleracea-Xcc interaction.

Chloroplast Proteome of Nicotiana benthamiana Infected by Tomato Blistering Mosaic Virus.

Tymovirus is a genus of plant pathogenic viruses that infects several dicotyledonous plants worldwide, causing serious diseases in economically important crops. The known cytopathic effect on the host cell organelles involves chloroplast membrane deformation and the induction of vesicles in its periphery. These vesicles are known to be the location where tymoviral genomic RNA replication occurs. Tomato blistering mosaic virus (ToBMV) is a tymovirus recently identified in tomato plants in Brazil, which is able to infect several other plants, including tobacco. In this work, we investigated the chloroplast proteomic profile of ToBMV-infected N. benthamiana using bidimensional electrophoresis (2-DE) and mass spectrometry, aiming to study the virus-host interaction related to the virus replication and infection. A total of approximately 200 spots were resolved, out of which 36 were differentially abundant. Differential spots were identified by mass spectrometry including photosynthesis-related and defense proteins. We identified proteins that may be targets of a direct interaction with viral proteins, such as ATP synthase ß subunit, RNA polymerase beta-subunit, 50S ribosomal protein L6 and Trigger factor-like protein. The identification of these candidate proteins gives support for future protein-protein interaction studies to confirm their roles in virus replication and disease development.

Draft Genome Sequence of Pantoea ananatis Strain 1.38, a Bacterium Isolated from the Rhizosphere of Oryza sativa var. Puntal That Shows Biotechnological Potential as an Inoculant.

Pantoea ananatis 1.38 is a strain isolated from the rhizosphere of irrigated rice in southern Spain. Its genome was estimated at 4,869,281 bp, with 4,644 coding sequences (CDSs). The genome encompasses several CDSs related to plant growth promotion, such as that for siderophore metabolism, and virulence genes characteristic of pathogenic Pantoea spp. are absent.

Genome Sequence of Pantoea ananatis Strain AMG 501, a Plant Growth-Promoting Bacterium Isolated from Rice Leaves Grown in Paddies of Southern Spain.

Pantoea ananatis AMG 501 is a plant growth-promoting bacterium isolated from rice leaves. Its genome was estimated at 5,102,640 bp with 4,994 coding sequences, encompassing genes related to the metabolism of carbohydrates, to the synthesis of auxins, siderophores, and homoserine lactones, and to the type I, II, III, IV, and VI secretion systems.

Genome Sequence of Pantoea sp. Strain 1.19, Isolated from Rice Rhizosphere, with the Capacity To Promote Growth of Legumes and Nonlegumes.

Pantoea sp. 1.19, a plant growth-promoting bacterium (PGPB), was isolated from the rhizosphere of rice plants in Spain. Its genome, estimated at 3,771,065 bp, encodes 3,535 coding sequences (CDSs), carrying genes for synthesis of auxins, homoserine lactones, enzymes, siderophores, and quorum sensing. Several CDSs emphasize its biotechnological potential as an agriculture inoculant.

Draft Genome Sequence of Pantoea ananatis Strain AMG521, a Rice Plant Growth-Promoting Bacterial Endophyte Isolated from the Guadalquivir Marshes in Southern Spain.

The rice endophyte Pantoea ananatis AMG521 shows several plant growth-promoting properties and promotes rice yield increases. Its draft genome was estimated at 4,891,568 bp with 4,704 coding sequences (CDS). The genome encodes genes for N-acylhomoserine lactone (AHL) synthases, AHL hydrolases, hyperadherence (yidQ, yidP, and yidR), fusaric acid resistance, and oxidation of lignin, highlighting its biotechnological potential.