Ferranicluibacter rubi gen. nov., sp. nov., a new member of family Rhizobiaceae isolated from stems of elmleaf blackberry (Rubus ulmifolius Schott) in Northwest Spain.

Strain CRRU44T was isolated from the stems of Rubus ulmifolius plants growing in Salamanca (Spain). The phylogenetic analysis of the 16S rRNA gene sequence places this strain within the family Rhizobiaceae showing that it is equidistant to the type species of several genera from this family with similarity values ranging from 91.0 to 96.3 %. Strain CRRU44T formed a divergent lineage which clustered with Endobacterium cereale RZME27T, Neorhizobium galegae HAMBI540T and Pseudorhizobium pelagicum R1-200B4T. The phylogenomic analysis showed that strain CRRU44T was equal to or more distant from the remaining genera of the family Rhizobiaceae than other genera among them. The calculated average nucleotide identity based on blast and average amino acid identity values with respect to the type species of all genera from the family Rhizobiaceae were lower than 78.5 and 76.5 %, respectively, which are the currently cut-off values proposed to differentiate genera within this family. All these results together with those from phenotypic and chemotaxonomic analyses support that strain CRRU44T represents a novel species of a novel genus within the family Rhizobiaceae, for which the name Ferranicluibacter rubi gen. nov., sp. nov. is proposed (type strain CRRU44T=CECT 30117T=LMG 31822T).

Increase in phenolic compounds of Coriandrum sativum L. after the application of a Bacillus halotolerans biofertilizer.

BACKGROUND: There is an urgent need for a new sustainable way of satisfying the increasing demand for food worldwide. One of the main challenges is replacing chemical fertilizers with biofertilizers, which include plant root-associated beneficial microorganisms. The present study reports, for the first time, the effects of SCCPVE07 bacterial strain with respect to improving not only plant development, but also the nutritional content and bioactive compounds content of Coriandrum sativum L., one of the most economically important crops, even for plant growth under salinity stress. RESULTS: Innoculated coriander plants (C. sativum L.) showed an increase in potassium, carbon, calcium and iron content. A significant improvement in phenolic compounds contents was also observed. The contents of 5-O-caffeoylquinic acid, cinnamic acid, 4-methoxy-cinnamic acid hexoside, K-3-O rutinoside, Q-3-O-rutinoside, Q-3-O-glucoside and Q-3-O-glucuronide were significantly enhanced. Moreover, an efficient bacterial root colonization and a noted growth promotion were demonstrated. Bacterial genome was sequenced and analysed. Gene coding related to Plant growth promotion (PGP) mechanisms and proteins involved in plant defence from salinity or in the metabolism of phenolic compounds, such as quercetin 2,3-dioxygenase and phenolic acid decarboxylase, were identified. CONCLUSION: The results obtained in the present study show, for the first time, the beneficial effects of the inoculation of a bacterial Bacillus halotolerans biofertilizer on coriander crops with respect to increasing the content in bioactive compounds and plant development. © 2020 Society of Chemical Industry.

Heterologous Expression of Rhizobial CelC2 Cellulase Impairs Symbiotic Signaling and Nodulation in Medicago truncatula.

The infection of legume plants by rhizobia is tightly regulated to ensure accurate bacterial penetration, infection, and development of functionally efficient nitrogen-fixing root nodules. Rhizobial Nod factors (NF) have key roles in the elicitation of nodulation signaling. Infection of white clover roots also involves the tightly regulated specific breakdown of the noncrystalline apex of cell walls in growing root hairs, which is mediated by Rhizobium leguminosarum bv. trifolii cellulase CelC2. Here, we have analyzed the impact of this endoglucanase on symbiotic signaling in the model legume Medicago truncatula. Ensifer meliloti constitutively expressing celC gene exhibited delayed nodulation and elicited aberrant ineffective nodules, hampering plant growth in the absence of nitrogen. Cotreatment of roots with NF and CelC2 altered Ca2+ spiking in root hairs and induction of the early nodulin gene ENOD11. Our data suggest that CelC2 alters early signaling between partners in the rhizobia-legume interaction.

Rhizobium zeae sp. nov., isolated from maize (Zea mays L.) roots.

A bacterial strain designated CRZM18RT was isolated from a root of Zea mays in Spain. The analysis of the 16S rRNA gene sequence showed that this strain belongs to the genus Rhizobium, with Rhizobium cellulosilyticum ALA10B2T and Rhizobium yantingense H66T being the most closely related species with 98.3 and 97.9 % sequence similarity, respectively. The analysis of the concatenated recA and atpD genes showed that strain CRZM18RT forms a cluster with these species and also with Rhizobiumsmilacinae PTYR-5T, but the recA and atpD genes of strain CRZM18RT were phylogenetically distant, with identities lower than 90 and 96 %, respectively. DNA-DNA hybridization analysis showed mean relatedness of 43, 22 and 38 % with respect to R. cellulosilyticum ALA10B2T, R. yantingense LMG 28229T and R. smilacinae LMG 27604T. Phenotypic characteristics also differed from those of the most closely related species of the genus Rhizobium. The major fatty acids were those from summed feature 8 (C18 : 1ω6c/C18 : 1ω7c) and C16 : 0. Based on the genotypic, chemotaxonomic and phenotypic data obtained in this study, we propose to classify strain CRZM18RT in a novel species named Rhizobium zeae sp. nov. (type strain CRZM18RT=LMG 29735T=CECT 9169T).

Mesorhizobium helmanticense sp. nov., isolated from Lotus corniculatus nodules.

In this study, three strains belonging to the genus Mesorhizobium, CSLC115NT, CSLC19N and CSLC37N, isolated from Lotus corniculatus nodules in Spain, were characterized. Their 16S rRNA gene sequences were closely related to those of Mesorhizobium metallidurans STM 2683T, Mesorhizobium tianshanense A-1BST, Mesorhizobium tarimense CCBAU 83306T, Mesorhizobium gobiense CCBAU 83330T and Mesorhizobium caraganae CCBAU 11299T with similarity values higher than 99.7 %. The analysis of concatenated recA and glnII genes showed that the most closely related type strains were M. metallidurans STM 2683T, M. tianshanense A-1BST and M. tarimense CCBAU 83306T with 96, 95 and 94 % similarity values in the recA gene and 95, 94 and 94 % in the glnII gene, respectively. M. metallidurans LMG 24485T, M. tianshanense USDA 3592T and M. tarimense LMG 24338T showed means of 44, 41 and 42 % DNA-DNA relatedness, respectively, with respect to strain CSLC115NT. The major fatty acids were those from summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C16 : 0 and C18 : 1ω7c 11-methyl. The results of phenotypic characterization support that the L. corniculatus nodulating strains analysed in this work belong to a novel species of the genus Mesorhizobium for which the name Mesorhizobium helmanticense sp. nov. is proposed, and the type strain is CSLC115NT (= LMG 29734T=CECT 9168T).

Bacillus terrae sp. nov. isolated from Cistus ladanifer rhizosphere soil.

A bacterial strain designated RA9T was isolated from a root of Cistus ladanifer in Spain. Phylogenetic analyses based on 16S rRNA gene sequences placed the isolate into the genus Bacillus with its closest relatives being Bacillus fortis R-6514T and Bacillus fordii R-7190T with 98.2 % similarity in both cases. DNA-DNA hybridization studies showed mean relatedness values of 29 and 30 %, respectively, between strain RA9T and the type strains of B. fortis and B. fordii. Cells of the isolate were Gram-stain-positive, motile, sporulating rods. Catalase and oxidase were positive. Gelatin, starch and casein were not hydrolysed. Menaquinone MK-7 was the only menaquinone detected and iso-C15 : 0 and anteiso-C15 : 0 were the major fatty acids. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified phospholipid, one unidentifed glycolipid and one unidentified lipid. meso-Diaminopimelic acid was detected in the peptidoglycan. The DNA G+C content was 43.1 mol%. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain RA9T should be considered as representing a novel species of the genus Bacillus, for which the name Bacillus terrae sp. nov. is proposed. The type strain is RA9T (=LMG 29736T=CECT 9170T).

Revision of the taxonomic status of type strains of Mesorhizobium loti and reclassification of strain USDA 3471T as the type strain of Mesorhizobiumerdmanii sp. nov. and ATCC 33669T as the type strain of Mesorhizobiumjarvisii sp. nov.

The species Mesorhizobim loti was isolated from nodules of Lotus corniculatus and its type strain deposited in several collections. Some of these type strains, such as those deposited in the USDA and ATCC collections before 1990, are not coincident with the original strain, NZP 2213T, deposited in the NZP culture collection. The analysis of the 16S rRNA gene showed that strains USDA 3471T and ATCC 33669T formed independent branches from that occupied by Mesorhizobium loti NZP 2213T and related to those occupied by Mesorhizobium opportunistum WSM2075T and Mesorhizobium huakuii IFO 15243T, respectively, with 99.9 % similarity in both cases. However, the analysis of concatenated recA, atpD and glnII genes with similarities lower than 96, 98 and 94 %, respectively, between strains USDA 3471T and M. opportunistum WSM2075T and between strains ATCC 33669T and M. huakuii IFO 15243T, indicated that the strains USDA 3471T and ATCC 33669T represent different species of the genus Mesorhizobium. These results were confirmed by DNA-DNA hybridization experiments and phenotypic characterization. Therefore, the two strains were reclassified as representatives of the two species Mesorhizobium erdmanii sp. nov. (type strain USDA 3471T = CECT 8631T = LMG 17826t2T) and Mesorhizobium jarvisii sp. nov. (type strain ATCC 33669T = CECT 8632T = LMG 28313T).

Revision of the taxonomic status of the species Rhizobium lupini and reclassification as Bradyrhizobium lupini comb. nov.

The species Rhizobium lupini was isolated from Lupinus nodules and included in the Approved Lists of Bacterial Names in 1980. Nevertheless, on the basis of the analysis of the type strain of this species available in DSMZ, DSM 30140(T), whose 16S rRNA gene was identical to that of the type strain of Bradyrhizobium japonicum , R. lupini was considered a later synonym of this species. In this study we confirmed that the strain DSM 30140(T) belongs to the species B. japonicum , but also that it cannot be the original strain of R. lupini because this species effectively nodulated Lupinus whereas strain DSM 30140(T) was able to nodulate soybean but not Lupinus. Since the original type strain of R. lupini was deposited into the USDA collection by L. W. Erdman under the accession number USDA 3051(T) we analysed the taxonomic status of this strain showing that although it belongs to the genus Bradyrhizobium instead of genus Rhizobium , it is phylogenetically distant from B. japonicum and closely related to Bradyrhizobium canariense . The type strains R. lupini USDA 3051(T) and B. canariense BTA-1(T) share 16S rRNA, recA and glnII gene sequences with similarities of 99.8%, 96.5% and 97.1%, respectively. They presented a DNA-DNA hybridization value of 36% and also differed in phenotypic characteristics and slightly in the proportions of some fatty acids. Therefore we propose the reclassification of the species Rhizobium lupini as Bradyrhizobium lupini comb. nov. The type strain is USDA 3051(T) ( = CECT 8630(T) = LMG 28514(T)).

Pseudomonas helmanticensis sp. nov., isolated from forest soil.

A bacterial strain, OHA11(T), was isolated during the course of a study of phosphate-solubilizing bacteria occurring in a forest soil from Salamanca, Spain. The 16S rRNA gene sequence of strain OHA11(T) shared 99.1% similarity with respect to Pseudomonas baetica a390(T), and 98.9% similarity with the type strains of Pseudomonas jessenii, Pseudomonas moorei, Pseudomonas umsongensis, Pseudomonas mohnii and Pseudomonas koreensis. The analysis of housekeeping genes rpoB, rpoD and gyrB confirmed its phylogenetic affiliation to the genus Pseudomonas and showed similarities lower than 95% in almost all cases with respect to the above species. Cells possessed two polar flagella. The respiratory quinone was Q9. The major fatty acids were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c/iso-C15 : 0 2-OH). The strain was oxidase-, catalase- and urease-positive, positive for arginine dihydrolase but negative for nitrate reduction, ß-galactosidase production and aesculin hydrolysis. It was able to grow at 31 °C and at pH 11. The DNA G+C content was 58.1 mol%. DNA-DNA hybridization results showed values lower than 49% relatedness with respect to the type strains of the seven closest related species. Therefore, the combined genotypic, phenotypic and chemotaxonomic data support the classification of strain OHA11(T) to a novel species of the genus Pseudomonas, for which the name Pseudomonas helmanticensis sp. nov. is proposed. The type strain is OHA11(T) ( = LMG 28168(T) = CECT 8548(T)).

Fontibacillus phaseoli sp. nov. isolated from Phaseolus vulgaris nodules.

A bacterial strain, designated BAPVE7BT, was isolated from root nodules of Phaseolus vulgaris in Spain. Phylogenetic analysis based on its 16S rRNA gene sequence placed the isolate into the genus Fontibacillus with Fontibacillus panacisegetis KCTC 13564T its closest relative with 97.1 % identity. The isolate was observed to be a Gram-positive, motile and sporulating rod. The catalase test was negative and oxidase was weak. The strain was found to reduce nitrate to nitrite and to produce ß-galactosidase but the production of gelatinase, caseinase, urease, arginine dehydrolase, ornithine or lysine decarboxylase was negative. Acetoin production and aesculin hydrolysis were found to be positive. Growth was observed to be supported by many carbohydrates and organic acids as carbon source. MK-7 was identified as the predominant menaquinone and the major fatty acid (43.7 %) as anteiso-C15:0, as occurs in the other species of the genus Fontibacillus. Strain BAPVE7BT displayed a complex lipid profile consisting of diphosphatidylglycerol, phosphatidylglycerol, four glycolipids, four phospholipids, two lipids, two aminolipids and an aminophospholipid. Mesodiaminopimelic acid was detected in the peptidoglycan. The G+C content was determined to be 45.6 mol% (Tm). Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain BAPVE7BT should be considered a new species of genus Fontibacillus, for which the name Fontibacillus phaseoli sp. nov. is proposed (type strain, LMG 27589T, CECT 8333T).

Metataxonomic analysis of endophytic bacteria of blackberry (Rubus ulmifolius Schott) across tissues and environmental conditions.

(1) Background: Endophytic bacteria represent an important component of plant wellness. They have been widely studied for their involvement in plant development and enhancement of stress tolerance. In this work, the endophytic communities of roots, stems, and leaves of blackberry (Rubus ulmifolius Schott) were studied in three different niches: natural, riverside, and human-impacted niches. (2) Results: The microbiome composition revealed that Sphingomonadaceae was the most abundant family in all samples, accounting for 9.4-45.8%. In contrast, other families seem to be linked to a specific tissue or niche. Families Microbacteriaceae and Hymenobacteraceae increased their presence in stem and leaf samples, while Burkholderiaceae abundance was important in riverside samples. Alpha and beta diversity analyses showed that root samples were the most diverse, and they gathered together in the same cluster, apart from the rest of the samples. (3) Conclusions: The analysis of the microbiome of R. ulmifolius plants revealed that the composition was essentially the same in different niches; the differences were primarily influenced by plant tissue factors with a core genome dominated by Sphingomonadaceae. Additionally, it was observed that R. ulmifolius can select its own microbiome, and this remains constant in all tissues evaluated regardless the niche of sampling.

Phyllobacterium endophyticum sp. nov., isolated from nodules of Phaseolus vulgaris.

A strain, PEPV15(T), was isolated from a nodule on Phaseolus vulgaris grown in soil in northern Spain. Phylogenetic analyses of 16S rRNA and atpD genes showed that this strain belongs to the genus Phyllobacterium. The most closely related species were, in both cases, Phyllobacterium brassicacearum, Phyllobacterium bourgognense and Phyllobacterium trifolii, the type strains of which gave sequence similarities of 98.9, 98.6 and 98.4 %, respectively, in the 16S rRNA gene and 88.1, 87.5 and 88.7 %, respectively, in the atpD gene. PEPV15(T) contained Q-10 as the major quinone (88 %) and low amounts of Q-9 (12 %). It differed from its closest relatives in its growth in diverse culture conditions and in the assimilation of several carbon sources. The strain was not able to produce nodules in Phaseolus vulgaris. The results of DNA-DNA hybridization, phenotypic tests and fatty acid analyses confirmed that this strain represents a novel species of the genus Phyllobacterium for which the name Phyllobacterium endophyticum sp. nov. is proposed; the type strain is PEPV15(T) ( = LMG 26470(T) = CECT 7949(T)). An emended description of the genus Phyllobacterium is also provided.

Microbiome specificity and fluxes between two distant plant taxa in Iberian forests.

BACKGROUND: Plant-associated microbial communities play important roles in host nutrition, development and defence. In particular, the microbes living within internal plant tissues can affect plant metabolism in a more intimate way. Understanding the factors that shape plant microbial composition and discovering enriched microbes within endophytic compartments would thus be valuable to gain knowledge on potential plant-microbial coevolutions. However, these interactions are usually studied through reductionist approaches (in vitro models or crop controlled systems). Here, we investigate these ecological factors in wild forest niches using proximally located plants from two distant taxa (blueberry and blackberry) as a model. RESULTS: Although the microbial communities were quite similar in both plants, we found that sampling site had a high influence on them; specifically, its impact on the rhizosphere communities was higher than that on the roots. Plant species and sample type (root vs. rhizosphere) affected the bacterial communities more than the fungal communities. For instance, Xanthobacteraceae and Helotiales taxa were more enriched in roots, while the abundance of Gemmatimonadetes was higher in rhizospheres. Acidobacteria abundance within the endosphere of blueberry was similar to that in soil. Several taxa were significantly associated with either blackberry or blueberry samples regardless of the sampling site. For instance, we found a significant endospheric enrichment of Nevskia in blueberry and of Sphingobium, Novosphingobium and Steroidobacter in blackberry. CONCLUSIONS: There are selective enrichment and exclusion processes in the roots of plants that shapes a differential composition between plant species and sample types (root endosphere-rhizosphere). The special enrichment of some microbial taxa in each plant species might suggest the presence of ancient selection and/or speciation processes and might imply specific symbiosis. The selection of fungi by the host is more pronounced when considering the fungal trait rather than the taxonomy. This work helps to understand plant-microbial interactions in natural ecosystems and the microbiome features of plants.

New insight into the bark beetle ips typographus bacteriome reveals unexplored diversity potentially beneficial to the host.

BACKGROUND: Ips typographus (European spruce bark beetle) is the most destructive pest of spruce forests in Europe. As for other animals, it has been proposed that the microbiome plays important roles in the biology of bark beetles. About the bacteriome, there still are many uncertainties regarding the taxonomical composition, insect-bacteriome interactions, and their potential roles in the beetle ecology. Here, we aim to deep into the ecological functions and taxonomical composition of I. typographus associated bacteria. RESULTS: We assessed the metabolic potential of a collection of isolates obtained from different life stages of I. typographus beetles. All strains showed the capacity to hydrolyse one or more complex polysaccharides into simpler molecules, which may provide an additional carbon source to its host. Also, 83.9% of the strains isolated showed antagonistic effect against one or more entomopathogenic fungi, which could assist the beetle in its fight against this pathogenic threat. Using culture-dependent and -independent techniques, we present a taxonomical analysis of the bacteriome associated with the I. typographus beetle during its different life stages. We have observed an evolution of its bacteriome, which is diverse at the larval phase, substantially diminished in pupae, greater in the teneral adult phase, and similar to that of the larval stage in mature adults. Our results suggest that taxa belonging to the Erwiniaceae family, and the Pseudoxanthomonas and Pseudomonas genera, as well as an undescribed genus within the Enterobactereaceae family, are part of the core microbiome and may perform vital roles in maintaining beetle fitness. CONCLUSION: Our results indicate that isolates within the bacteriome of I. typographus beetle have the metabolic potential to increase beetle fitness by proving additional and assimilable carbon sources for the beetle, and by antagonizing fungi entomopathogens. Furthermore, we observed that isolates from adult beetles are more likely to have these capacities but those obtained from larvae showed strongest antifungal activity. Our taxonomical analysis showed that Erwinia typographi, Pseudomonas bohemica, and Pseudomonas typographi species along with Pseudoxanthomonas genus, and putative new taxa belonging to the Erwiniaceae and Enterobacterales group are repeatedly present within the bacteriome of I. typographus beetles, indicating that these species might be part of the core microbiome. In addition to Pseudomonas and Erwinia group, Staphylococcus, Acinetobacter, Curtobacterium, Streptomyces, and Bacillus genera seem to also have interesting metabolic capacities but are present in a lower frequency. Future studies involving bacterial-insect interactions or analysing other potential roles would provide more insights into the bacteriome capacity to be beneficial to the beetle.

Herbaspirillum canariense sp. nov., Herbaspirillum aurantiacum sp. nov. and Herbaspirillum soli sp. nov., isolated from volcanic mountain soil, and emended description of the genus Herbaspirillum.

Three Gram-negative, motile and slightly curved rod-shaped bacteria, strains SUEMI03(T), SUEMI08(T) and SUEMI10(T), were isolated from an old volcanic mountain soil on Tenerife (Canary Islands). The three strains were related phylogenetically to Herbaspirillum seropedicae. 16S rRNA gene sequence similarity was 99.2-99.6 % among strains SUEMI03(T), SUEMI08(T) and SUEMI10(T), which presented 97.5, 97.8 and 97.7 % identity, respectively, with respect to H. seropedicae DSM 6445(T). The three strains grew optimally in TSB at 28 °C and contained summed features 3 (C(16:1)ω6c and/or C(16:1)ω7c) and 8 (C(18:1)ω6c and/or C(18:1)ω7c) and C(16:0) as major cellular fatty acids. The DNA G+C contents of strains SUEMI03(T), SUEMI08(T) and SUEMI10(T) were 61.6, 60.4 and 61.9 mol%, respectively. Strains SUEMI03(T), SUEMI08(T) and SUEMI10(T) presented less than 60 % interstrain DNA relatedness and less than 30 % relatedness with respect to H. seropedicae DSM 6445(T). In spite of their common geographical origin, the three strains isolated in this study presented several phenotypic differences, presenting phenotypic profiles highly divergent from that of H. seropedicae. Therefore, we propose that the strains isolated in this study represent three novel species of the genus Herbaspirillum, named Herbaspirillum canariense sp. nov. (type strain SUEMI03(T) = LMG 26151(T) = CECT 7838(T)), Herbaspirillum aurantiacum sp. nov. (type strain SUEMI08(T) = LMG 26150(T) = CECT 7839(T)) and Herbaspirillum soli sp. nov. (type strain SUEMI10(T) = LMG 26149(T) = CECT 7840(T)).

Comparative Genomics of the Genus Pseudomonas Reveals Host- and Environment-Specific Evolution.

Each Earth ecosystem has unique microbial communities. Pseudomonas bacteria have evolved to occupy a plethora of different ecological niches, including living hosts, such as animals and plants. Many genes necessary for the Pseudomonas-niche interaction and their encoded functions remain unknown. Here, we describe a comparative genomic study of 3,274 genomes with 19,056,667 protein-coding sequences from Pseudomonas strains isolated from diverse environments. We detected functional divergence of Pseudomonas that depends on the niche. Each group of strains from a certain environment harbored a distinctive set of metabolic pathways or functions. The horizontal transfer of genes, which mainly proceeded between closely related taxa, was dependent on the isolation source. Finally, we detected thousands of undescribed proteins and functions associated with each Pseudomonas lifestyle. This research represents an effort to reveal the mechanisms underlying the ecology, pathogenicity, and evolution of Pseudomonas, and it will enable clinical, ecological, and biotechnological advances. IMPORTANCE Microbes play important roles in the health of living beings and in the environment. The knowledge of these functions may be useful for the development of new clinical and biotechnological applications and the restoration and preservation of natural ecosystems. However, most mechanisms implicated in the interaction of microbes with the environment remain poorly understood; thus, this field of research is very important. Here, we try to understand the mechanisms that facilitate the differential adaptation of Pseudomonas-a large and ubiquitous bacterial genus-to the environment. We analyzed more than 3,000 Pseudomonas genomes and searched for genetic patterns that can be related with their coevolution with different hosts (animals, plants, or fungi) and environments. Our results revealed that thousands of genes and genetic features are associated with each niche. Our data may be useful to develop new technical and theoretical advances in the fields of ecology, health, and industry.

Unveiling the genomic potential of Pseudomonas type strains for discovering new natural products.

Microbes host a huge variety of biosynthetic gene clusters that produce an immeasurable array of secondary metabolites with many different biological activities such as antimicrobial, anticarcinogenic and antiviral. Despite the complex task of isolating and characterizing novel natural products, microbial genomic strategies can be useful for carrying out these types of studies. However, although genomic-based research on secondary metabolism is on the increase, there is still a lack of reports focusing specifically on the genus Pseudomonas. In this work, we aimed (i) to unveil the main biosynthetic systems related to secondary metabolism in Pseudomonas type strains, (ii) to study the evolutionary processes that drive the diversification of their coding regions and (iii) to select Pseudomonas strains showing promising results in the search for useful natural products. We performed a comparative genomic study on 194 Pseudomonas species, paying special attention to the evolution and distribution of different classes of biosynthetic gene clusters and the coding features of antimicrobial peptides. Using EvoMining, a bioinformatic approach for studying evolutionary processes related to secondary metabolism, we sought to decipher the protein expansion of enzymes related to the lipid metabolism, which may have evolved toward the biosynthesis of novel secondary metabolites in Pseudomonas. The types of metabolites encoded in Pseudomonas type strains were predominantly non-ribosomal peptide synthetases, bacteriocins, N-acetylglutaminylglutamine amides and ß-lactones. Also, the evolution of genes related to secondary metabolites was found to coincide with Pseudomonas species diversification. Interestingly, only a few Pseudomonas species encode polyketide synthases, which are related to the lipid metabolism broadly distributed among bacteria. Thus, our EvoMining-based search may help to discover new types of secondary metabolite gene clusters in which lipid-related enzymes are involved. This work provides information about uncharacterized metabolites produced by Pseudomonas type strains, whose gene clusters have evolved in a species-specific way. Our results provide novel insight into the secondary metabolism of Pseudomonas and will serve as a basis for the prioritization of the isolated strains. This article contains data hosted by Microreact.

Estimation of actual evapotranspiration in barley crop through a generalized linear model.

Evapotranspiration is a key variable of the water cycle. Its calculation requires several ground data that frequently are not available. This study contains a detailed method and measurements of meteorological and energy balance variables that can be used to estimate the daily actual evapotranspiration (ETa). A linear generalized model is obtained to calculate the ETa from common variables measured in meteorological stations. The method showed a good performance over a barley crop of easthern Argentine Pampas and can be applied and tested in other great plains. Measurements of soil-plant-atmosphere are included The routines to reproduce the method are included The generalized method allows the calculation of daily ETa over crops and was tested over barley crops.

Measuring land surface temperature, near-infrared and short-wave infrared reflectance for estimation of water availability in vegetation.

The vegetation water status is a crucial variable for modelling of drought impact, vegetation productivity and water fluxes. Methods for spatial estimation of this variable still need to be improved. The integration of remotely sensed data of land surface temperature (LST) and water vegetation indices based on near-infrared (NIR) and short-wave infrared (SWIR) reflectance for estimation of vegetation water content and water available for evapotranspiration require more analysis. This study contains a detailed method and measurements of LST, NIR and SWIR reflectance of soybean, corn and barley taken in field campaigns in central Argentine Pampas and laboratory with a ST PRO Raytek (8-14 µm) and a spectrometer SVC HR-1024i (0.35 and 2.5 µm). Also, relative water content of leaves was measured in laboratory during the dehydration process. This method and dataset could be also used for researching other wavelengths between 0.35 and 2.5 µm as indicator of water vegetation status (e.g. solar-induced chlorophyll fluorescence, photosynthesis).•Procedures useful to measure field spectra of vegetation are presented.•Not only the traditional method to measure leaves spectra in laboratory, but also in field were applied.•The method allows the integration of spectra and thermal data as a proxy of vegetation water status.

Mechanisms of Action of Microbial Biocontrol Agents against Botrytis cinerea.

Botrytis cinerea is a phytopathogenic fungus responsible for economic losses from USD 10 to 100 billion worldwide. It affects more than 1400 plant species, thus becoming one of the main threats to the agriculture systems. The application of fungicides has for years been an efficient way to control this disease. However, fungicides have negative environmental consequences that have changed popular opinion and clarified the need for more sustainable solutions. Biopesticides are products formulated based on microorganisms (bacteria or fungi) with antifungal activity through various mechanisms. This review gathers the most important mechanisms of antifungal activities and the microorganisms that possess them. Among the different modes of action, there are included the production of diffusible molecules, both antimicrobial molecules and siderophores; production of volatile organic compounds; production of hydrolytic enzymes; and other mechanisms, such as the competition and induction of systemic resistance, triggering an interaction at different levels and inhibition based on complex systems for the production of molecules and regulation of crop biology. Such a variety of mechanisms results in a powerful weapon against B. cinerea; some of them have been tested and are already used in the agricultural production with satisfactory results.