Tissue specific expression of PvPGIP2 to improve wheat resistance against Fusarium graminearum

Fusarium Head Blight (FHB) is one of the most important wheat diseases caused by Fusarium spp.. The pathogen infects the spike at flowering time and causes severe yield losses and deterioration of grain quality due to the secretion of mycotoxins during infection. The understanding of the precise mode of pathogen entering and the subsequent floral tissue colonize is a crucial point to control FHB. Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the pectin-depolymerizing activity of polygalacturonases (PGs) secreted by pathogens. The constitutive expression of the bean PvPGIP2 limits FHB symptoms and reduces mycotoxin accumulation in wheat. To better understand which spike tissues plays a role in limiting Fusarium infection, we have produced transgenic wheat plants expressing PvPGIP2 in the endosperm or simultaneously in lemma, palea, anthers and rachis. This latter approach reduced FHB symptoms, whereas the expression of PvPGIP2 only in the endosperm did not affect FHB development, indicating that when the pathogen has reached the endosperm, inhibition of pathogen PGs ineffective to prevent fungal spread

Tissue-specific expression of PvPGIP2 to improve wheat resistance against Fusarium graminearum

Fusarium Head Blight (FHB) is one of the most important wheat diseases caused by some fungi of the genus Fusarium. The pathogen infects the spike at flowering time and causes severe yield losses and deterioration of grain quality due to the secretion of mycotoxins during infection. The understanding of the precise mode of pathogen entering and the subsequent floral tissue colonize is a crucial point to control FHB. Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the pectin-depolymerizing activity of polygalacturonases (PGs) secreted by microbial pathogens and insects. The constitutive expression of the bean PvPGIP2 limits FHB symptoms and reduces mycotoxin accumulation in wheat. To better understand the spike tissues that play a role in limiting Fusarium infection, we have produced transgenic wheat plants expressing PvPGIP2 or in the endosperm or simultaneously in lemma, palea, anthers and rachis. We showed that this latter approach reduced FHB symptoms caused by F. graminearum compared to control non transgenic plants. The extent of disease symptom reduction was similar to what obtained when PvPGIP2 was expressed constitutively. We showed also that different level of PvPGIP2 accumulation produced similar level of protection. Conversely, the expression of PvPGIP2 only in the endosperm did not affect FHB symptom development, indicating that when the pathogen has reached the endosperm, inhibition of the polygalacturonase (PG) activity of the pathogen is ineffective to prevent fungal spread. Probably the rich source of the endosperm tissue makes the PG activity dispensable for pathogen colonization. Alternatively, the massive growth of the fungus at this stage produces a large amount of PG that is not inhibited by the available PGIP

EXPRESSION OF BEAN PGIP2 UNDER CONTROL OF THE BARLEY LEM1 PROMOTER LIMITS FUSARIUM GRAMINEARUM INFECTION IN WHEAT

Fusarium Head Blight (FHB) caused by Fusarium graminearum is one of the most destructive fungal diseases of wheat worldwide. The pathogen infects the spike at flowering time and causes severe yield losses, deterioration of grain quality, and accumulation of mycotoxins. Better understanding of the means of pathogen entry and colonization of floral tissue is crucial to providing effective protection against FHB. Polygalacturonase inhibiting proteins (PGIPs) are cell wall proteins that inhibit the activity of polygalacturonases (PGs), a class of pectin-depolymerizing enzymes secreted by microbial pathogens, including Fusaria. The constitutive expression of a bean PGIP (PvPGIP2) under control of the maize Ubi1 promoter limits FHB symptoms and reduces mycotoxin accumulation in wheat grain [Janni et al. 2008 Molec. Plant Microb. Interact. 21:171]. To better understand which spike tissues play major roles in limiting F. graminearum infection, we explored the use of PvPGIP2 to defend specific spike tissues by expressing it under control of the barley Lem1 promoter [Somleva and Blechl 2005 Cer. Res. Comm. 33:665]. We show here that the expression of PvPGIP2 in lemma, palea, rachis and anthers reduced FHB symptoms caused by F. graminearum compared to symptoms in infected nontransgenic plants. However, the expression of PvPGIP2 only in the endosperm under control of a HMW-glutenin gene promoter did not affect FHB symptom development, indicating that once the pathogen has reached the endosperm, inhibition of the pathogen\u2019s PG activity is not effective in preventing its further spread

Comparison between First- and Second-Generation Cryoballoon for Paroxysmal Atrial Fibrillation Ablation

Introduction. Cryoballoon (CB) ablation has emerged as a novel treatment for pulmonary vein isolation (PVI) for patients with paroxysmal atrial fibrillation (PAF). The second-generation Arctic Front Advance (ADV) was redesigned with technical modifications aiming at procedural and outcome improvements. We aimed to compare the efficacy of the two different technologies over a long-term follow-up. Methods. A total of 120 patients with PAF were enrolled. Sixty patients underwent PVI using the first-generation CB and 60 patients with the ADV catheter. All patients were evaluated over a follow-up period of 2 years. Results. There were no significant differences between the two groups of patients. Procedures performed with the first-generation CB showed longer fluoroscopy time (36.3±16.8 versus 14.2±13.5 min, resp.; p=0.00016) and longer procedure times as well (153.1±32 versus 102±24.8 min, resp.; p=0.019). The overall long-term success was significantly different between the two groups (68.3 versus 86.7%, resp.; p=0.017). No differences were found in the lesion areas of left and right PV between the two groups (resp., p=0.61 and 0.57). There were no significant differences in procedural-related complications. Conclusion. The ADV catheter compared to the first-generation balloon allows obtaining a significantly higher success rate after a single PVI procedure during the long-term follow-up. Fluoroscopy and procedural times were significantly shortened using the ADV catheter

Comparison between First-and Second-Generation Cryoballoon for Paroxysmal Atrial Fibrillation Ablation

Introduction. Cryoballoon (CB) ablation has emerged as a novel treatment for pulmonary vein isolation (PVI) for patients with paroxysmal atrial fibrillation (PAF). The second-generation Arctic Front Advance (ADV) was redesigned with technical modifications aiming at procedural and outcome improvements. We aimed to compare the efficacy of the two different technologies over a long-term follow-up. Methods. A total of 120 patients with PAF were enrolled. Sixty patients underwent PVI using the firstgeneration CB and 60 patients with the ADV catheter. All patients were evaluated over a follow-up period of 2 years. Results. There were no significant differences between the two groups of patients. Procedures performed with the first-generation CB showed longer fluoroscopy time (36.3 ± 16.8 versus 14.2 ± 13.5 min, resp.; = 0.00016) and longer procedure times as well (153.1 ± 32 versus 102±24.8 min, resp.; = 0.019). The overall long-term success was significantly different between the two groups (68.3 versus 86.7%, resp.; = 0.017). No differences were found in the lesion areas of left and right PV between the two groups (resp., = 0.61 and 0.57). There were no significant differences in procedural-related complications. Conclusion. The ADV catheter compared to the first-generation balloon allows obtaining a significantly higher success rate after a single PVI procedure during the long-term follow-up. Fluoroscopy and procedural times were significantly shortened using the ADV catheter

Pyramiding PvPGIP2 and TAXI-III But Not PvPGIP2 and PMEI enhances resistance against fusarium graminearum

Plant protein inhibitors counteract the activity of cell wall-degrading enzymes (CWDEs) secreted by pathogens to breach the plant cell-wall barrier. Transgenic plants expressing a single protein inhibitor restrict pathogen infections. However, since pathogens secrete a number of CWDEs at the onset of infection, we combined more inhibitors in a single wheat genotype to reinforce further the cell-wall barrier. We combined polygalacturonase (PG) inhibiting protein (PGIP) and pectin methyl esterase inhibitor (PMEI), both controlling the activity of PG, one of the first CWDEs secreted during infection. We also pyramided PGIP and TAXI-III, a xylanase inhibitor that controls the activity of xylanases, key factors for the degradation of xylan, a main component of cereal cell wall. We demonstrated that the pyramiding of PGIP and PMEI did not contribute to any further improvement of disease resistance. However, the presence of both pectinase inhibitors ensured a broader spectrum of disease resistance. Conversely, the PGIP and TAXI-III combination contributed to further improvement of Fusarium head blight (FHB) resistance, probably because these inhibitors target the activity of different types of CWDEs, i.e., PGs and xylanases. Worth mentioning, the reduction of FHB symptoms is accompanied by a reduction of deoxynivalenol accumulation with a foreseen great benefit to human and animal health

Reproductive biology of Ophelia barquii (Annelida, Opheliidae) along the Salento Peninsula (Mediterranean Sea, South Italy)

This study investigates two populations of a polychaete identified as Ophelia barquii Fauvel, 1927, collected in two beaches from the Adriatic (Alimini beach) and Ionian (Gallipoli beach) coasts from the Salento Peninsula. Each population was analyzed monthly from April 2017 to March 2018. In both beaches, populational density decreased from April to August with a complete absence of worms from August to the following January. We hypothesize that this trend results from horizontal migration of individuals for reproductive purposes. Sexual maturation was asynchronous between the two populations, with individuals becoming ripe earlier in Alimini than in Gallipoli. Significant differences in body size were recorded between the two populations, with specimens larger in Gallipoli than in Alimini, suggesting that they could belong to different species. However, lifecycle studies performed under laboratory conditions showed that both populations follow a similar developmental path and can cross-fertilize. The larval development featured a very short period of pelagic life, the shortest known so far for any species of Ophelia

PvPGIP2 accumulation in specific floral tissues but not in the endosperm limits fusarium graminearum infection in wheat

Fusarium head blight (FHB) caused by Fusarium graminearum is one of the most destructive fungal diseases of wheat worldwide. The pathogen infects the spike at flowering time and causes severe yield losses, deterioration of grain quality, and accumulation of mycotoxins. The understanding of the precise means of pathogen entry and colonization of floral tissue is crucial to providing effective protection against FHB. Polygalacturonase (PG) inhibiting proteins (PGIPs) are cell-wall proteins that inhibit the activity of PGs, a class of pectin-depolymerizing enzymes secreted by microbial pathogens, including Fusarium spp. The constitutive expression of a bean PGIP (PvPGIP2) limits FHB symptoms and reduces mycotoxin accumulation in wheat grain. To better understand which spike tissues play major roles in limiting F. graminearum infection, we explored the use of PvPGIP2 to defend specific spike tissues. We show here that the simultaneous expression of PvPGIP2 in lemma, palea, rachis, and anthers reduced FHB symptoms caused by F. graminearum compared with symptoms in infected nontransgenic plants. However, the expression of PvPGIP2 only in the endosperm did not affect FHB symptom development, indicating that once the pathogen has reached the endosperm, inhibition of the pathogen's PG activity is not effective in preventing its further spread.s

Determinants of plant community composition of remnant biancane badlands: a hierarchical approach to quantify species-environment relationships

Question: Which environmental variables best explain patterns in the vegetation of biancane badlands? What is the role of spatial scales in structuring the vegetation of biancane badlands within the agricultural matrix? Location: Five biancane badlands in Central Italy (Tuscany). Methods: An object-oriented approach on high-resolution multispectral images was used to classify physiognomic vegetation types in five biancane badlands.Within each badland, data on vascular plant species abundance were collected using a stratified random design. Variation partitioning based on partial redundancy analysis was used to evaluate the contribution of three sets of environmental predictors, recorded at the spatial scales of plot, patch and biancane badland in explaining patterns in plant community composition. Results: Environmental variables included in the final model – electrical conductivity and carbon/nitrogen ratio (plot scale), shape index (patch scale) and area (biancane badland scale) – accounted for 15.5% of the total variation in plant community composition. Soil characteristics measured at the plot level explained the majority of variation. In the smallest badlands, Bromus erectus perennial grasslands were absent, while annual grasslands, linked with harsh soil conditions (i.e. high soil salinity), were not affected by either the surface area of biancane badlands or by the soil nitrogen availability. Conclusions: The identification of the major predictors of patterns in remnant vegetation requires conducting investigations at multiple spatial scale. Management strategies should operate at different spatial scale, preventing any further reduction in the size of existing badlands and relying on habitat- instead of area-focused conservation practices