β1A Integrin Is a Master Regulator of Invadosome Organization and Function

Use of patterned surfaces, reverse genetics, and time-controlled photoinactivation showed that β1 but not β3 integrins are required for invadosome formation, self-assembly, and stabilization into a ring structure. The activation state of β1 as well as its phosphorylation by protein kinase C on Ser785 control these process and link to the degradative function

R-Loci arrangement versus downy and powdery mildew resistance level: a Vitis hybrid survey

For the viticulture of the future, it will be an essential prerequisite to manage grapevine diseases with fewer chemical inputs. The development and the deployment of novel mildew resistant varieties are considered one of the most promising strategies towards a sustainable viticulture. In this regard, a collection of 102 accessions derived from crossing Vitis hybrids with V. vinifera varieties was studied. In addition to the true-to-type analysis, an exhaustive genetic characterization was carried out at the 11 reliable mildew resistance (R) loci available in the literature to date. Our findings highlight the pyramiding of R-loci against downy mildew in 15.7% and against powdery mildew in 39.2% of the total accessions. The genetic analysis was coupled with a three-year evaluation of disease symptoms in an untreated field in order to assess the impact of the R-loci arrangement on the disease resistance degree at leaf and bunch level. Overall, our results strongly suggest that R-loci pyramiding does not necessarily mean to increase the overall disease resistance, but it guarantees the presence of further barriers in case of pathogens overcoming the first. Moreover, our survey allows the discovery of new mildew resistance sources useful for novel QTL identifications towards marker-assisted breedin

Applying a defined set of molecular markers to improve selection of resistant grapevine accessions

Smart breeding programs aiming at the improvement of resistance to the main grapevine diseases are based on the application of molecular markers related to resistance genes. Although many markers are available in literature, a general overview of markers associated with disease resistances and suitable for marker assisted selection (MAS) is lacking. Hence, we propose a set of highly valuable markers for MAS, creating a homogeneous way for the grapevine community to proceed in smart breeding. This set is used in the project ‘RebSelect’ at Laimburg Research Centre where a disease resistant collection is being created in collaboration with private farmers and platforms. The collection consists of interesting hybrids released by breeding programs around the world, containing resistances to the principal diseases including downy and powdery mildew but also to other less prevalent pathogens. In order to select parents with multiple resistance genes that could be used for new crosses, the collection will be screened. Here we present preliminary results of the application of a marker set related to resistances in the different accessions of the collectio

A Vitis hybrid “library”: comparing diverse R-loci combinations and mildew resistance levels in field

Nowadays, it is almost universally recognized that the viticulture of the future will require the management of grapevine pests and diseases with fewer chemical inputs. The development and the deployment of novel varieties - which are now extremely resistant to mildews as well as hold the potential to display a durable resistance during the coming years - are considered one of the most promising strategy towards an eco-friendly viticulture. In the frame of the Euregio project VITISANA, a collection of approximately 100 grapevine accessions - including (mid-)resistant genotypes derived from cross pollination between Vitis hybrid and vinifera varieties or backcrosses - was studied. Their leaf and cluster level of downy (DM) and powdery (PM) mildew resistance was evaluated in an untreated field (Marlengo, I) at veraison and harvesting time in both 2016 and 2017. In addition to attempting a true-to-type analysis, an exhaustive genetic characterization was carried out at the 12 exploitable loci associated to mildew resistance (R-loci) available in the literature to date. Besides genotypes carrying a single R-locus associated to DM or PM resistance, our findings highlighted the pyramiding of R-loci against DM in 15% and against PM in 35% of the total accessions. In particular, 56 genotypes resulted pyramided for R-loci to both mildews. Finally, combining the R-loci-based characterization of the studied traditionally bred resistant varieties with their pathogen response in untreated field, we will understand the impact of diverse R-loci assets on overcoming disease attacks under the same environmental conditions

Deciphering the genetic control of fruit texture in apple by multiple family-based analysis and genome-wide association

Fruit texture is a complex feature composed of mechanical and acoustic properties relying on the modifications occurring in the cell wall throughout fruit development and ripening. Apple is characterized by a large variation in fruit texture behavior that directly impacts both the consumer’s appreciation and post-harvest performance. To decipher the genetic control of fruit texture comprehensively, two complementing quantitative trait locus (QTL) mapping approaches were employed. The first was represented by a pedigree-based analysis (PBA) carried out on six full-sib pedigreed families, while the second was a genome-wide association study (GWAS) performed on a collection of 233 apple accessions. Both plant materials were genotyped with a 20K single nucleotide polymorphism (SNP) array and phenotyped with a sophisticated high-resolution texture analyzer. The overall QTL results indicated the fundamental role of chromosome 10 in controlling the mechanical properties, while chromosomes 2 and 14 were more associated with the acoustic response. The latter QTL, moreover, showed a consistent relationship between the QTL-estimated genotypes and the acoustic performance assessed among seedlings. The in silico annotation of these intervals revealed interesting candidate genes potentially involved in fruit texture regulation, as suggested by the gene expression profile. The joint integration of these approaches sheds light on the specific control of fruit texture, enabling important genetic information to assist in the selection of valuable fruit quality apple varietie

Genome wide association studies and whole transcriptomic survey decipher the fruit texture regulation in apple towards the selection of novel superior accessions

Fruit quality is represented by a series of genetically controlled features that change throughout the entire ontogenic life. Among the several quality traits, texture plays a crucial role, impacting both consumers’ appreciation and postharvest performance. In order to decipher its regulation a multidisciplinary approach was employed. Initially, the texture performance was measured with a high resolution phenotyping device, represented by a texture analyzer equipped with an acoustic device. In the first attempt to dissect the fruit texture genetic control, two QTL mapping strategies were used. The first approach employed six bi-parental families linked by a common pedigree scheme, known as pedigree based analysis. The joint analysis of the phenotypic and genotypic data set through a Bayesian statistics identified a series of genomic regions related to both mechanical and acoustic signatures. These regions were further validated with a genome wide association study approach, which considered a much larger phenotypic and genotypic variation. To complement the genetic information, a whole transcriptome analysis was also carried out. To this end, two microarray platforms were designed and used to unravel the functional machinery ongoing during the fruit development and ripening phases, especially with regards to the plant hormone ethylene. In this study, the role of this hormone was dissected applying 1-MCP, a molecule competing with ethylene at receptor level. The combination of these resources provides a valuable source of information, essential to step forward in the comprehension of the genetic and physiological regulation of the fruit texture in apple. This knowledge would enable, in a close future, a more accurate and precise selection of the most favourable and valuable new apple accessions distinguished by a superior fruit quality.</p