Transcriptome driven characterization of curly-and smooth-leafed endives reveals molecular differences in the sesquiterpenoid pathway

Endives(Cichorium endivia L.)are popular vegetables,diversified into curly/frisée-and smooth/broad-leafed(escaroles)cultivar types(cultigroups),and consumed as fresh and bagged salads.They are rich in sesquiterpene lactones(STL)that exert proven function on bitter taste and human health.The assembly of a reference transcriptome of 77,022 unigenes and RNA-sequencing experiments were carried out to characterize the differences between endives and escaroles at the gene structural and expression levels.A set of 3177 SNPs distinguished smooth from curly cultivars,and an SNP-supported phylogenetic tree separated the cultigroups into two distinct clades,consistently with the botanical varieties of origin(crispum and latifolium,respectively).A pool of 699 genes maintained differential expression pattern(core-DEGs)in pairwise comparisons between curly vs smooth cultivars grown in the same environment.Accurate annotation allowed the identification of 26 genes in the sesquiterpenoid biosynthesis pathway,which included several germacrene A synthase,germacrene A oxidase and costunolide synthase members(GAS/GAO/COS module),required for the synthesis of costunolide,a key precursor of lactucopicrin-and lactucin-like sesquiterpene lactones.The core-DEGs contained a GAS gene(contig83192)that was positively correlated with STL levels and recurrently more expressed in curly than smooth endives,suggesting a cultigroup-specific behavior.The significant positive correlation of GAS/GAO/COS transcription and STL abundance(2.4-fold higher in frisée endives)suggested that sesquiterpenoid pathway control occurs at the transcriptional level.Based on correlation analyses,five transcription factors(MYB,MYB-related and WRKY)were inferred to act on contig83192/GAS and specific STL,suggesting the occurrence of two distinct routes in STL biosynthesis.

Hydroperoxides and cytokines as biomarkers in detecting atherosclerosis predisposition in cigarette smokers

Objectives: Smoking increases oxidative modification of LDL, associated with lower HDL plasma levels, systemic inflammatory response and endothelial dysfunction. We tested the hypothesis that the risk status for coronary atherosclerosis disease (CAD) of cigarettes smokers might be identified by means of serum oxidative levels and vascular inflammation determination. Design and Methods: Oxidative stress levels, cytokines, and the metabolic status were investigated on 499 subjects admitted to our institute. The association between biomarkers and smoking habits in the presence/absence of disease and with the number of vessel affected, was studied. Results: Oxidative stress and inflammatory levels (p < 0.001) were strongly induced by smoking habits. Serum values of the subjects categorised as CAD, non CAD and healthy subjects differed significantly (p < 0.001) only for the degree of oxidative stress. Glycaemia was able to affect C-reactive protein serum levels with a positive association (p < 0.05). The analysis of the study population indicated that serum oxidative stress levels significantly increased with increasing number of vessels affected (p < 0.01). When statistical analysis was performed separately in both smoking groups, smokers did not show any particular difference for both oxidative stress and inflammation markers between the two groups of cardiovascular patients (CAD and non CAD) and the control group, while for non smokers, the differences were evident. Conclusion: These findings indicate that the considered biomarkers, especially oxidative stress, can be useful to predict the biological damage caused by cigarette smoking, as well as to identify subjects characterised by a higher risk of cardiovascular event, but cannot evaluate the presence of disease in subjects with smoking habit.

The COP9 SIGNALOSOME Is Required for Postembryonic Meristem Maintenance in Arabidopsis thaliana

Cullin-RING E3 ligases （CRLs） regulate different aspects of plant development and are activated by modification of their cullin subunit with the ubiquitin-like protein NEDD8 （NEural precursor cell expressed Developmentally Down-regulated 8） （neddylation） and deactivated by NEDD8 removal （deneddylation）. The CONSTITUTIVELY PHOTOMORPHOGENIC9 （COP9） signalosome （CSN） acts as a molecular switch of CRLs activity by reverting their neddylation status, but its contribution to embryonic and early seedling development remains poorly characterized. Here, we analyzed the phenotypic defects of csn mutants and monitored the cullin deneddylation/neddylation ratio during embryonic and early seedling development. We show that while csn mutants can complete embryogenesis （albeit at a slower pace than wildtype） and are able to germinate （albeit at a reduced rate）, they progressively lose meristem activity upon germination until they become unable to sustain growth. We also show that the majority of cullin proteins are progressively neddylated during the late stages of seed maturation and become deneddylated upon seed germination. This developmentally regulated shift in the cullin neddylation status is absent in csn mutants. We conclude that the CSN and its cullin deneddylation activity are required to sustain postembryonic meristem function in Arabidopsis.

FISSION1A, an Arabidopsis Tail-Anchored Protein, Is Localized to Three Subcellular Compartments

Dear Editor, The multiple targeting proteins that have been described in yeast, mammals, and plants have generated intriguing areas of inquiry, including the evolutionary relevance of common proteins shared by different organelles, the mechanisms that determine targeting to each organelle, and, finally, the extent of this phenomenon. Several dual-targeted proteins have been identified in eukaryotic cells.