Cyclo(Pro-Tyr) elicits conserved cellular damage in fungi by targeting the [H+]ATPase Pma1 in plasma membrane domains.

Bioactive metabolites play a crucial role in shaping interactions among diverse organisms. In this study, we identified cyclo(Pro-Tyr), a metabolite produced by Bacillus velezensis, as a potent inhibitor of Botrytis cinerea and Caenorhabditis elegans, two potential cohabitant eukaryotic organisms. Based on our investigation, cyclo(Pro-Tyr) disrupts plasma membrane polarization, induces oxidative stress and increases membrane fluidity, which compromises fungal membrane integrity. These cytological and physiological changes induced by cyclo(Pro-Tyr) may be triggered by the destabilization of membrane microdomains containing the [H+]ATPase Pma1. In response to cyclo(Pro-Tyr) stress, fungal cells activate a transcriptomic and metabolomic response, which primarily involves lipid metabolism and Reactive Oxygen Species (ROS) detoxification, to mitigate membrane damage. This similar response occurs in the nematode C. elegans, indicating that cyclo(Pro-Tyr) targets eukaryotic cellular membranes.

Mancha3D Code: Multipurpose Advanced Nonideal MHD Code for High-Resolution Simulations in Astrophysics.

The Mancha3D code is a versatile tool for numerical simulations of magnetohydrodynamic (MHD) processes in solar/stellar atmospheres. The code includes nonideal physics derived from plasma partial ionization, a realistic equation of state and radiative transfer, which allows performing high-quality realistic simulations of magnetoconvection, as well as idealized simulations of particular processes, such as wave propagation, instabilities or energetic events. The paper summarizes the equations and methods used in the Mancha3D (Multifluid (-purpose -physics -dimensional) Advanced Non-ideal MHD Code for High resolution simulations in Astrophysics 3D) code. It also describes its numerical stability and parallel performance and efficiency. The code is based on a finite difference discretization and a memory-saving Runge-Kutta (RK) scheme. It handles nonideal effects through super-time-stepping and Hall diffusion schemes, and takes into account thermal conduction by solving an additional hyperbolic equation for the heat flux. The code is easily configurable to perform different kinds of simulations. Several examples of the code usage are given. It is demonstrated that splitting variables into equilibrium and perturbation parts is essential for simulations of wave propagation in a static background. A perfectly matched layer (PML) boundary condition built into the code greatly facilitates a nonreflective open boundary implementation. Spatial filtering is an important numerical remedy to eliminate grid-size perturbations enhancing the code stability. Parallel performance analysis reveals that the code is strongly memory bound, which is a natural consequence of the numerical techniques used, such as split variables and PML boundary conditions. Both strong and weak scalings show adequate performance up to several thousands of processors (CPUs).

Bacillus subtilis biofilm matrix components target seed oil bodies to promote growth and anti-fungal resistance in melon.

Beneficial microorganisms are used to stimulate the germination of seeds; however, their growth-promoting mechanisms remain largely unexplored. Bacillus subtilis is commonly found in association with different plant organs, providing protection against pathogens or stimulating plant growth. We report that application of B. subtilis to melon seeds results in genetic and physiological responses in seeds that alter the metabolic and developmental status in 5-d and 1-month-old plants upon germination. We analysed mutants in different components of the extracellular matrix of B. subtilis biofilms in interaction with seeds and found cooperation in bacterial colonization of seed storage tissues and growth promotion. Combining confocal microscopy with fluorogenic probes, we found that two specific components of the extracellular matrix, amyloid protein TasA and fengycin, differentially increased the concentrations of reactive oxygen species inside seeds. Further, using electron and fluorescence microscopy and metabolomics, we showed that both TasA and fengycin targeted the oil bodies in the seed endosperm, resulting in specific changes in lipid metabolism and accumulation of glutathione-related molecules. In turn, this results in two different plant growth developmental programmes: TasA and fengycin stimulate the development of radicles, and fengycin alone stimulate the growth of adult plants and resistance in the phylloplane to the fungus Botrytis cinerea. Understanding mechanisms of bacterial growth promotion will enable the design of bespoke growth promotion strains.

Intraoral anastomosis in maxillary microvascular reconstruction after oncological excision.

Microvascular anastomosis using an intraoral approach can avoid unnecessary external incisions thus improving patient satisfaction. Furthermore, in case of short pedicle flaps, the lack of proximity of the recipient vessels can be a problem in microvascular reconstruction of the midface. We present our experience in six patients treated for tumours affecting the midface and reconstructed with microvascular flaps through anastomosis to the intraoral aspect of the facial vessels, with the aim of reviewing the use of this technique. Our results showed that intraoral anastomosis is a feasible technique that can be used in the reconstruction after tumours resection, avoiding additional external incisions in patients with no previous cervicotomy incisions. In two cases, a vein graft was interposed to perform the intraoral arterial anastomosis in a tension-free situation without increasing morbidity. The technical features and advantages of intraoral anastomosis were reviewed.

Detection of White Root Rot in Avocado Trees by Remote Sensing.

White root rot, caused by the soilborne fungus Rosellinia necatrix, is an important constraint to production for a wide range of woody crop plants such as avocado trees. The current methods of detection of white root rot are based on microbial and molecular techniques, and their application at orchard scale is limited. In this study, physiological parameters provided by imaging techniques were analyzed by machine learning methods. Normalized difference vegetation index (NDVI) and normalized canopy temperature (canopy temperature - air temperature) were tested as predictors of disease by several algorithms. Among them, logistic regression analysis (LRA) trained on NDVI data showed the highest sensitivity and lowest rate of false negatives. This algorithm based on NDVI could be a quick and feasible method to detect trees potentially affected by white root rot in avocado orchards.

Analysis of Genetic Diversity of Fusarium tupiense, the Main Causal Agent of Mango Malformation Disease in Southern Spain.

Mango malformation disease (MMD) has become an important global disease affecting this crop. The aim of this study was to identify the main causal agents of MMD in the Axarquía region of southern Spain and determine their genetic diversity. Fusarium mangiferae was previously described in the Axarquía region but it represented only one-third of the fusaria recovered from malformed trees. In the present work, fusaria associated with MMD were analyzed by arbitrary primed polymerase chain reaction (ap-PCR), random amplified polymorphic DNA (RAPD), vegetative compatibility grouping (VCG), a PCR screen for mating type idiomorph, and phylogenetic analyses of multilocus DNA sequence data to identify and characterize the genetic diversity of the MMD pathogens. These analyses confirmed that 92 of the isolates were F. tupiense, which was previously only known from Brazil and Senegal. In addition, two isolates of a putatively novel MMD pathogen were discovered, nested within the African clade of the Fusarium fujikuroi species complex. The F. tupiense isolates all belonged to VCG I, which was first described in Brazil, and the 11 isolates tested showed pathogenicity on mango seedlings. Including the prior discovery of F. mangiferae, three exotic MMD pathogenic species have been found in southern Spain, which suggests multiple independent introductions of MMD pathogens in the Axarquía region.

Comparative Genomics Within the Bacillus Genus Reveal the Singularities of Two Robust Bacillus amyloliquefaciens Biocontrol Strains.

Bacillus amyloliquefaciens CECT 8237 and CECT 8238, formerly known as Bacillus subtilis UMAF6639 and UMAF6614, respectively, contribute to plant health by facing microbial pathogens or inducing the plant's defense mechanisms. We sequenced their genomes and developed a set of ad hoc scripts that allowed us to search for the features implicated in their beneficial interaction with plants. We define a core set of genes that should ideally be found in any beneficial Bacillus strain, including the production of secondary metabolites, volatile compounds, metabolic plasticity, cell-to-cell communication systems, and biofilm formation. We experimentally prove that some of these genetic elements are active, such as i) the production of known secondary metabolites or ii) acetoin and 2-3-butanediol, compounds that stimulate plant growth and host defense responses. A comparison with other Bacillus genomes permits us to find differences in the cell-to-cell communication system and biofilm formation and to hypothesize variations in their persistence and resistance ability in diverse environmental conditions. In addition, the major protection provided by CECT 8237 and CECT 8238, which is different from other Bacillus strains against bacterial and fungal melon diseases, permits us to propose a correlation with their singular genetic background and determine the need to search for additional blind biocontrol-related features.

First Report of Mango Malformation Disease Caused by Fusarium mangiferae in Spain.

Mango (Mangifera indica L.) malformation disease (MMD) is one of the most important diseases affecting this crop worldwide, which causes severe economic losses because of the reduction of productivity. Symptoms of MMD in Spain were observed for the first time in April of 2006 in three mango orchards in the Axarquia Region (southern Spain). Symptoms included an abnormal development of vegetative shoots with shortened internodes and dwarfed leaves and hypertrophied short and thickened panicles. In the years of 2006, 2009, and 2010, isolates of Fusarium were obtained from vegetative shoots and floral tissue of symptomatic mango trees from 21 different orchards of cvs. Keitt, Kent, Osteen, Tommy Atkins, and a variety of minor commercial cultivars, all showing typical symptoms of MMD. Different Fusarium-like strains were isolated from infected tissues. Colonies from single-spored isolates possessed dark purple-to-salmon-colored mycelium when grown on potato dextrose agar medium. On fresh carnation leaf agar medium, mycelium contained aerial conidiophores possessing three- to five-celled macroconidia and abundant microconidia in false heads from mono- and polyphialides; while cream-orange-colored sporodochia were produced on the surface of the medium, typical for Fusarium mangiferae. The identification of 37 isolates was confirmed as F. mangiferae by species-specific PCR analysis with the primer pair 1-3 F/R that amplified a 608-bp DNA fragment from all Spanish isolates as well as a representative Israeli control strain, Fus 34, also designated as MRC7560 (2). Pathogenicity using four representative isolates, UMAF F02, UMAF F10, UMAF F17, and UMAF F38 of F. mangiferae from Spain as well as isolate MRC7560, was tested on 2-year-old healthy mango seedlings cv. Keitt by inoculating 15 buds from three different trees with a 20-µl conidial suspension (5 × 107 conidia per ml) per isolate (1). This experiment was conducted twice with two independent sets of plants and at different times (March and November 2010). Typical mango malformation symptoms were detected after bud break in March 2011, 5 and 12 months after inoculation. Symptoms were observed for 60% of the inoculated buds with the four F. mangiferae Spanish isolates and 75% with the MRC7560 control strain, but not with water-inoculated control plants. Recovered isolates from the infected floral and vegetative malformed buds were identical morphologically to those inoculated, and the specific 608-bp fragment described for F. mangiferae was amplified with specific-PCR, thus fulfilling Koch's postulates. To our knowledge, this is the first report of mango malformation disease caused by F. mangiferae in Spain and Europe. References: (1) S. Freeman et al. Phytopathology 89:456, 1999. (2) Q. I. Zheng and R. C. Ploetz. Plant Pathol. 51:208, 2002.

Biocontrol bacteria selected by a direct plant protection strategy against avocado white root rot show antagonism as a prevalent trait.

AIM: This study was undertaken to study bacterial strains obtained directly for their efficient direct control of the avocado white root rot, thus avoiding prescreening by any other possible mechanism of biocontrol which could bias the selection. METHODS AND RESULTS: A collection of 330 bacterial isolates was obtained from the roots and soil of healthy avocado trees. One hundred and forty-three representative bacterial isolates were tested in an avocado/Rosellinia test system, resulting in 22 presumptive protective strains, all of them identified mainly as Pseudomonas and Bacillus species. These 22 candidate strains were screened in a more accurate biocontrol trial, confirming protection of some strains (4 out of the 22). Analyses of the potential bacterial traits involved in the biocontrol activity suggest that different traits could act jointly in the final biocontrol response, but any of these traits were neither sufficient nor generalized for all the active bacteria. All the protective strains selected were antagonistic against some fungal root pathogens. CONCLUSIONS: Diverse bacteria with biocontrol activity could be obtained by a direct plant protection strategy of selection. All the biocontrol strains finally selected in this work were antagonistic, showing that antagonism is a prevalent trait in the biocontrol bacteria selected by a direct plant protection strategy. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the isolation of biocontrol bacterial strains using direct plant protection strategy in the system avocado/Rosellinia. Characterization of selected biocontrol bacterial strains obtained by a direct plant protection strategy showed that antagonism is a prevalent trait in the selected strains in this experimental system. This suggests that antagonism could be used as useful strategy to select biocontrol strains.

First Occurrence of Cucurbit Powdery Mildew Caused by Race 3-5 of Podosphaera fusca in Spain.

A new race of cucurbit powdery mildew was observed for the first time on melon (Cucumis melo) in three research greenhouses in the Axarquia area of southern Spain during the spring of 2008. Fungal growth appeared as white powdery colonies initially restricted to the upper leaf surfaces. Morphological characteristics of colonies, conidiophores, conidia, germ tubes, and appressoria indicated that the powdery mildew fungus was Podosphaera fusca (also known as P. xanthii) (3), a fungal pathogen extensively reported in the area (1). However, the fungus developed on plants of melon cv. PMR 6, which is resistant to races 1 and 2 of P. fusca, suggesting that the fungus could belong to race 3, a race of P. fusca not yet reported in Spain. Race determination was carried out by inoculating the third true leaf of a set of differential melon genotypes that were maintained in a greenhouse. Symptoms and colonization observed on cvs. Rochet, PMR 45, PMR 6, and Edisto 47 indicated that the isolates belonged to race 3-5 of P. fusca. Fungal strains of races 1, 2, and 5 of P. fusca (all present in Spain) were used as controls. Pathotype designation was determined by inoculating different cucurbit genera and species (2). In addition to melon, the isolates were pathogenic on zucchini (Cucurbita pepo) cv. Diamant F1, but failed to infect cucumber (C. sativus) cv. Marketer and watermelon (Citrullus lanatus) cv. Sugar Baby; therefore, the isolates were pathotype BC (2). Races 1, 2, 4, and 5 of P. fusca have been previously reported in the area (1). The occurrence of race 3-5 represents another challenge in the management of cucurbit powdery mildew in Spain. References: (1) D. del Pino et al. Phytoparasitica 30:459, 2002. (2) E. Krístková et al. Sci. Hortic. 99:257, 2004. (3) A. Pérez-García et al. Mol. Plant Pathol. 10:153, 2009.