Coexpression gene network analysis of cold-tolerant Solanum commersonii reveals new insights in response to low temperatures

AbstractAmong 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

DNA-based technologies for grapevine biodiversity exploitation: state of the art and future perspectives

The cultivated grapevine, Vitis vinifera subsp. vinifera L., is represented by an enormous population of varieties and clones. They arise from the accumulation of gametic and somatic mutations during centuries of sexual and asexual propagation. These varieties represent a vast reservoir of traits/alleles that could be useful in improving the berry quality as well as against environmental stresses. However, most of them are still unexploited. For this reason, an efficient characterization system is essential to define the varietal identity, avoid cases of synonymy (identical genotypes but different names) and homonymy (same names but different genotypes) and deepen our understanding of the existing diversity within the grape germplasm. The plethora of DNA-based high-throughput technologies currently available provides promising tools for the analysis of diversity, overcoming many of the limitations of phenotypic-based diversity analyses. However, the analysis of intra-varietal diversity remains challenging. In this scenario, after summarizing the causes and consequences of grapevine genetic inter- and intra-varietal diversity, we review the DNA-based technologies used for varietal genotyping, emphasizing those able to distinguish clones within a variety. This review provides an update on the technologies used to explore grapevine diversity, the knowledge of which is necessary for an efficient exploitation and conservation of the grapevine germplasm

Genotype-specific changes associated to early synthesis of autotetraploids in wild potato species

Polyploidy is an important factor in plant evolution that may trigger drastic genome reorganization and phenotypic differentiation. In the last decade, extensive studies have been carried to understand the consequences of allopolyploidization, where the effects of ploidy change may be confounded by interspecific hybridization. By contrast, less is known on autopolyploidization, which only involves doubling of homologous chromosomes. This study was undertaken to assess leaf anatomical modifications and gene expression changes occurring after doubling the somatic chromosome complement of diploid (2n = 2x = 24) potato species Solanum commersonii Dunal and S. bulbocastanum Dunal. Polyploidization did not induce qualitative changes in leaf structure and, for several leaf traits, anatomic modifications were stochastic. In addition, in both species a diploid superiority was generally observed, suggesting the occurrence of a high-ploidy syndrome. Expression change study was carried out on eight important cell cycle-regulatory genes in plant. It revealed a strong alteration of the expression patterns in the 4x genotypes with respect to the 2x parents. Changes often exceed the twofold, with no consistent trend towards up- or down regulation when comparing 2x vis-à-vis 4x. We discuss the possible relevance of epigenetic changes in controlling the expression of duplicated genes

High AN1 variability and interaction with basic helix-loop-helix co-factors related to anthocyanin biosynthesis in potato leaves

AN1 is a regulatory gene that promotes anthocyanin biosynthesis in potato tubers and encodes a R2R3 MYB transcription factor. However, no clear evidence implicates AN1 in anthocyanin production in leaves, where these pigments might enhance environmental stress tolerance. In our study we found that AN1 displays intraspecific sequence variability in both coding/non-coding regions and in the promoter, and that its expression is associated with high anthocyanin content in leaves of commercial potatoes. Expression analysis provided evidence that leaf pigmentation is associated to AN1 expression and that StJAF13 acts as putative AN1 co-regulator for anthocyanin gene expression in leaves of the red leaf variety "Magenta Love", while a concomitant expression of StbHLH1 may contribute to anthocyanin accumulation in leaves of "Double Fun". Yeast two-hybrid experiments confirmed that AN1 interacts with StbHLH1 and StJAF13 and the latter interaction was verified and localized in the cell nucleus by bimolecular fluorescence complementation assays. In addition, transgenic tobacco (Nicotiana tabacum) overexpressing a combination of either AN1 with StJAF13 or AN1 with StbHLH1 showed deeper purple pigmentation with respect to AN1 alone. This further confirmed AN1/StJAF13 and AN1/StbHLH1 interactions. Our findings demonstrate that the classical loci identified for potato leaf anthocyanin accumulation correspond to AN1 and may represent an important step to expand our knowledge on the molecular mechanisms underlying anthocyanin biosynthesis in different plant tissues. This article is protected by copyright. All rights reserved

Anticancer activities of anthocyanin extract from genotyped Solanum tuberosum L. "Vitelotte"

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Crossotomy <i>vs</i> crossectomy for saphenous vein sparing surgery in patients with varicose veins due to ostial incontinence: protocol for double blind, multicenter, randomized trial

Double‑blind/multicenter/randomized trial protocol. Eligibility criteria: age 18-70 yrs; C2-C5 leg varices secondary to the Great Saphenous Vein (GSV) incontinence; GSV size 6-10mm, at 10cm from the Saphenous-Femoral Junction (SFJ); ostial reflux lasting >0.5 sec at duplex ultrasound; negative reflux elimination test; acceptance of the GSV sparing treatment plus partial/total varicose veins removal. Exclusion criteria: non-isolated GSV reflux; district already treated; pregnancy/lactation; impaired walking ability; deep vein thrombosis/insufficiency; severe comorbidities. Participants recruited from 7 Italian tertiary referral centres. Interventions: crossotomy (no SFJ’s tributaries ligation) vs crossectomy. The study aimed to verify if GSV drainage through the SFJ’s tributaries reduces groin/peripheral recurrences. Primary endpoint: 1-year GSV reflux recurrence, positive to the Valsalva maneuver, originating from the SF. Participants equally randomized. Participants, care givers, and those assessing the outcomes blinded to group assignment

Studi del La.Car.Topon.St. Laboratorio di Cartografia e Toponomastica Storica. N. 3-4 (2007-2008)

269 p. : ill. in gran parte color