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WRKY protein family is one of the largest transcription factor (TF) family in plants and is involved in growth and development, signal transduction and stress response. In spite of their important role in plant adaptation and survival, to date no studies have addressed into exploring WRKY gene family components and their different characteristics in wild potato species, known to be a powerful and informative reservoir of several useful genes and alleles . In this study, 79 and 84 genes encoding putative WRKY TFs have been identified in two potato wild species, Solanum commersonii and S. chacoense. Phylogenetic analysis of WRKY proteins divided ScWRKYs and SchWRKYs into three groups and seven subgroups. Their classification and characterization with respect to protein structure and comparative phylogenetic analyses suggested an interspecific variability in the WRKY family. Furthermore, we analyzed their expression profiles in different tissues and under various stresses and we were able to select ScWRKY045 as a good candidate in wounding-response, ScWRKY055 as a bacterial infection triggered WRKY and ScWRKY023 as a multiple stress-responsive WRKY gene. Those WRKYs were further studied through interactome analysis allowing the identification of potential co-expression relationships between ScWRKYs/SchWRKYs and genes of various pathways. Our study allowed a genome-wide survey and characterization of the WRKY gene family in wild potatoes and the selection of WRKY genes that could be considered as potential candidates for both breeding efforts and functional studies.

Cultivated grapevine, Vitis vinifera subsp. vinifera L., is one of the most widely grown fruit crops in the world. Sexual hybridization has been a major driving force for its evolution and has generated thousands of varieties, whereas somatic mutations are the major source of intra-varietal grapevine diversity. Nowadays, more than 450 varieties are registered in Italy, and thousands of clones are recognized. All these grapes are proudly used to make some of the world’s finest wines, thanks not only to history, traditions, and excellent pedo-climatic conditions but also to a particularly heterogeneous collection of varieties, some of which have been growing here since the first half of the 19th century. However, in the past few decades the grapevine biodiversity has been eroded, due to the worldwide predominance of few successful cultivars and to cultivation restrictions for varieties not included in official grapevine lists. Therefore, there is a significant decrease of raw material for future selection and to address new breeding objectives. An efficient characterization system is important to define population structures, to avoid cases of synonymy (identical genotypes but different names) and homonymy (same names but different genotypes), and protect breeders’ rights. The oldest grape discrimination techniques are based on phenological traits analysis carried out during all vegetative cycle. These techniques are elaborate and time-consuming. Characterization of grapevine has today been complemented by the use of DNA-based techniques, which enables more accurate identification and overcomes many of the limitations of phenotypic-based diversity analysis. Through the exploitation of molecular markers, many cases of synonymies/homonymies have been identified in the Italian collections. However, when molecular markers have been used to study clonal variation, consistent results have not always been obtained. The plethora of high-throughput technologies currently available provides promising tools for the analysis of diversity within the varieties. Moreover, the anticipated improvements in NGS capacity will lead to further decrease the persample cost and increase the quality of the resulting genotype data. In this scenario, the objective of this paper is to review on varietal authentication methods with particular emphasis on those capable to distinguish clones within variety populations. After reporting the causes and consequences of genetic inter- and intra-varietal diversity, we will review the methodologies currently applied to unraveling them. We then provide information on the potential of post-genomic techniques as powerful tools to identify synonymous and homonymous cases and to distinguish clonal populations.

Aglianico grapes are known for their high content of proanthocyanidins (PAs), which are responsible for the astringency of wines derived from this cultivar. However, the accumulation of PAs and their genetic control during berry development remain largely unexplored. This work aimed to monitor astringency causing PAs in Aglianico berries and correlate them with the expression of 14 key genes. Berries were collected during ripening and dissected in skins and seeds. PAs were fractionated and the content of total phenolics, flavans, anthocyanins, tannins reactive towards salivary proteins and tannin structural composition were evaluated. The results provided evidence that PAs were more abundant in seeds than in skins as expected, with differences in the structural composition between tissues, which did not varied during ripening. Expression analysis showed that Aglianico is able to accumulate polyphenols due to its ability to modulate key genes in a tissue-specific manner.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Furthermore, three new combinations are proposed. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Grapevine (Vitis vinifera L.) seeds are rich in polyphenols including proanthocyanidins, molecules with a variety of biological effects including anticancer action. We have previously reported that the grape seed semi-polar extract of Aglianico cultivar (AGS) was able to induce apoptosis and decrease cancer properties in different mesothelioma cell lines. Concomitantly, this extract resulted in enriched oligomeric proanthocyanidins which might be involved in determining the anticancer activity. Through transcriptomic and metabolomic analyses, we investigated in detail the anticancer pathway induced by AGS. Transcriptomics analysis and functional annotation allowed the identification of the relevant causative genes involved in the apoptotic induction following AGS treatment. Subsequent biological validation strengthened the hypothesis that MDM2 could be the molecular target of AGS and that it could act in both a p53-dependent and independent manner. Finally, AGS significantly inhibited tumor progression in a xenograft mouse model of mesothelioma, confirming also in vivo that MDM2 could act as molecular player responsible for the AGS antitumor effect. Our findings indicated that AGS, exerting a pro-apoptotic effect by hindering MDM2 pathway, could represent a novel source of anticancer molecules.

El nostre propòsit, aquí, és el d’articular una idea de po- ètica de l’amistat en l’obra de Winfried Georg Sebald. L’es- criptor alemany, tal vegada el més significatiu entre el final del segle xx i el començament del nou mil·lenni, ha captat l’atenció internacional per una llarga sèrie de temes que re- corren la seva obra: l’interès per la memòria històrica, amb una referència específica al tema de la Xoà i a la recons- trucció del diàleg entre el poble jueu i el poble alemany, sense oblidar temes més específicament «poetològics» com la relació entre el llenguatge i la imatge o la utilització d’es- tratègies intertextuals. Seguint l’estela de les reflexions de Walter Benjamin, Sebald també és tingut per un dels grans «melancòlics» de la modernitat, i és ben sabuda l’escassa freqüència amb què en la seva obra apareix el pronom tu i quan rarament l’escriptura de l’autor s’obre a la forma tra- dicionalment romàntica d’un diàleg entre els personatges.

Interspecific somatic hybridization is a noteworthy breeding strategy that allows the production of novel genetic variability when crossing barriers exist between two parental species. Although the genetic consequences of somatic hybridization have been well documented, little is known on its impact at the epigenetic level. The objective of our research was to investigate the epigenetic changes, in particular DNA methylation, occurring in a population of potato somatic hybrids. The analysis of 96 Solanum × michoacanum (+) S. tuberosum somatic hybrids from five fusion combinations and their parents was carried out by methylation-sensitive amplified polymorphism (MSAP) and high-performance liquid chromatography (HPLC) methods. Six MSAP primer combinations generated 622 unique bands, of which 295 were fully methylated. HPLC analysis showed from 15.5% to 16.9% total cytosine methylation within the parental forms. Overall, the MSAP and HPLC methods indicated an increase in DNA methylation in the somatic hybrids in comparison to their parents. Among the latter, a lower degree of DNA methylation in the wild S. × michoacanum species than S. tuberosum was found. Our findings indicated that somatic hybridization changed the level of cytosine methylation in the studied potato somatic hybrids.

Among abiotic stressors, cold is one of the most harmful for the cultivated potato (Solanum tuberosum L.), a frost-sensitive crop. RNA sequencing (RNA-seq) profiling of two different clones of wild potato (S. commersonii Dun.) contrasting in their capacity to withstand low temperatures revealed a higher number of differentially expressed genes (DEGs) under nonacclimated conditions (NAC) in tolerant clone cmm1T vs. the susceptible cmm6-6 (1,002 and 8,055 DEGs, respectively). By contrast, the number of DEGs was much more comparable when both genotypes were under acclimated conditions (AC). Indeed, a total of 5,650 and 8,936 DEGs were detected in the tolerant genotype vs. the susceptible. Gene ontology (GO) classification under NAC showed a significant role for transcription regulation, lignin catabolic genes, and regulation of plant type secondary cell wall in the cold-tolerant genotypes, suggesting an important role in conferring tolerance response. By contrast, response to stress and response to stimuli were enriched GO categories in both clones under AC. Unsigned weighted correlation networks analysis (WGCNA) allowed identification of coexpressed hub genes with possible main regulatory functions and major impacts on the phenotype. Among those identified, we clarified the role of CBF4. This gene showed contrasting expression profiles in the two clones under NAC, being induced in cold-tolerant cmm1T but suppressed in susceptible cmm6-6. By contrast, under AC, CBF4 was upregulated in both clones. Our study provides a global understanding of mechanisms involved following exposure to NAC and AC in S. commersonii. The mechanisms described here will inform future investigations for detailed validation in studies regarding cold tolerance in plants.

Wild potatoes, as dynamic resource adapted to various environmental conditions, represent a powerful and informative reservoir of genes useful for breeding efforts. WRKY transcription factors (TFs) are encoded by one of the largest families in plants and are involved in several biological processes such as growth and development, signal transduction, and plant defence against stress. In this study, 79 and 84 genes encoding putative WRKY TFs have been identified in two wild potato relatives, Solanum commersonii and S. chacoense. Phylogenetic analysis of WRKY proteins divided ScWRKYs and SchWRKYs into three Groups and seven subGroups. Structural and phylogenetic comparative analyses suggested an interspecific variability of WRKYs. Analysis of gene expression profiles in different tissues and under various stresses allowed to select ScWRKY045 as a good candidate in wounding-response, ScWRKY055 as a bacterial infection triggered WRKY and ScWRKY023 as a multiple stress-responsive WRKY gene. Those WRKYs were further studied through interactome analysis allowing the identification of potential co-expression relationships between ScWRKYs/SchWRKYs and genes of various pathways. Overall, this study enabled the discrimination of WRKY genes that could be considered as potential candidates in both breeding programs and functional studies.

Steroidal glycoalkaloids (SGAs) are a class of nitrogen-containing glycosides occurring in several plant families and biosynthesized through a specific pathway. HMG-CoA reductase is the first enzyme of this pathway, and its transcription can be regulated by biotic and abiotic stressors and even in a tissue-specific manner. This study aimed to characterize the HMG genes family in a tuber-bearing potato species, Solanum commersonii, using transcriptional and functional approaches. Our results provided evidence that four ScHMGs with different tissue-specificities represent the HMG gene family in S. commersonii and that they originated from ScHMG1 through segmental duplications. Phylogenetic analysis suggests that ScHMG1 is the direct ortholog of AtHMG1, which is associated with SGAs accumulation in plants. Its overexpression in S. commersonii revealed that this gene plays a key role in the accumulation of glycoalkaloids regulating the production of dehydrocommersonine.

We provide advances in DCL and RDR gene diversity in Solanaceae. We also shed light on DCL and RDR gene expression in response to cold stress. DICER-like (DCL) and RNA-dependent RNA polymerase (RDR) genes form the core components to trigger small non-coding RNA (ncRNA) production. In spite of this, little is known about the two gene families in non-model plant species. As their genome sequences are now available, the cultivated potato (Solanum tuberosum) and its cold-tolerant wild relative Solanum commersonii offer a valuable opportunity to advance our understanding of the above genes. To determine the extent of diversification and evolution of DCLs and RDRs in these species, we performed a comparative analysis. Seven DCLs were identified in the two species, whereas seven and six RDR genes were found in S. tuberosum and S. commersonii, respectively. Based on phylogenetic analysis with DCLs and RDRs from several species, we provide evidence for an increase in their number in both potato species. We also disclosed that tandem duplications played a major role in the evolution of these gene families in Solanaceae. DCL and RDR expression was investigated in different tissues and under cold and virus stresses, with divergent profiles of the tandem duplicated genes being found in different tissues. DCL paralogs showed a contrasting expression in S. tuberosum and S. commersonii following cold stress and virus infection. By contrast, no change in RDR transcript activity was detected following both stresses. Overall, this study provides the first comparative genomic analysis of the core components of the RNAi machinery in Solanaceae and offers a scaffold for future functional analysis of these gene families.

World potato production continuously requires new cultivars to satisfy farmers’ and consumers’ demand. Tuber yield and quality are some of the main potato breeding targets. In this study, 27 advanced potato clones from 7 hybrid families were evaluated for yield, tuber specific gravity and chipping ability. Variability in tuber yield was found between families as well as between clones. Forty-eight percent of clones showed higher productivity compared to the best control (Agria, 1.1 Kg). Families displayed significant differences also in terms of tubers specific gravity, with about 70% of clones with a score higher than 1.080, which was considered the minimum acceptable value for processing. Chipping ability was evaluated at harvesting time and after cold storage with and without reconditioning. The majority of studied clones showed a good chipping ability score (, Advances in Horticultural Science, Vol 31 No 3 (2017)