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Lung cancer is the leading cause of cancer death and non-small cell lung carcinoma (NSCLC) accounting for majority of lung cancers. Thus, it is important to find potential biomarkers, such as glycans and glycoproteins, which can be used as diagnostic tools against NSCLC. Here, the N-glycome, proteome, and N-glycosylation distribution maps of tumor and peritumoral tissues of Filipino lung cancer patients (n = 5) were characterized. We present several case studies with varying stages of cancer development (I−III), mutation status (EGFR, ALK), and biomarker expression based on a three-gene panel (CD133, KRT19, and MUC1). Although the profiles of each patient were unique, specific trends arose that correlated with the role of aberrant glycosylation in cancer progression. Specifically, we observed a general increase in the relative abundance of high-mannose and sialofucosylated N-glycans in tumor samples. Analysis of the glycan distribution per glycosite revealed that these sialofucosylated N-glycans were specifically attached to glycoproteins involved in key cellular processes, including metabolism, cell adhesion, and regulatory pathways. Protein expression profiles showed significant enrichment of dysregulated proteins involved in metabolism, adhesion, cell−ECM interactions, and N-linked glycosylation, supporting the protein glycosylation results. The present case series study provides the first demonstration of a multi-platform mass-spectrometric analysis specifically for Filipino lung cancer patients.

In this work, we developed a targeted glycoproteomic method to monitor the site-specific glycoprofiles and quantities of the most abundant HDL-associated proteins using Orbitrap LC-MS for (glyco)peptide target discovery and QqQ LC-MS for quantitative analysis. We conducted a pilot study using the workflow to determine whether HDL protein glycoprofiles are altered in healthy human participants in response to dietary glycan supplementation.

Biosynthesis of macromolecules requires precursors such as sugars or amino acids, originating from exogenous/dietary sources, reutilization/salvage of degraded molecules, or de novo synthesis. Since these sources are assumed to contribute to one homogenous pool, their individual contributions are often overlooked. Protein glycosylation uses monosaccharides from all the above sources to produce nucleotide sugars required to assemble hundreds of distinct glycans. Here, we demonstrate that cells identify the origin/heritage of the monosaccharide, fucose, for glycosylation. We measured the contribution of GDP-fucose from each of these sources for glycan synthesis and found that different fucosyltransferases, individual glycoproteins, and linkage-specific fucose residues identify and select different GDP-fucose pools dependent on their heritage. This supports the hypothesis that GDP-fucose exists in multiple, distinct pools, not as a single homogenous pool. The selection is tightly regulated since the overall pool size remains constant. We present novel perspectives on monosaccharide metabolism, which may have a general applicability.

Biosynthesis of macromolecules requires precursors such as sugars or amino acids, originating from exogenous/dietary sources, reutilization/salvage of degraded molecules or de novo synthesis. Since these sources are assumed to contribute to one homogenous pool, their individual contributions are often overlooked. Protein glycosylation uses monosaccharides from all the above sources to produce nucleotide sugars required to assemble hundreds of distinct glycans. Here we demonstrate that cells identify the origin/heritage of the monosaccharide, fucose, for glycosylation. We measured the contribution of GDP-fucose from each of these sources for glycan synthesis and found that different fucosyltransferases, individual glycoproteins, and linkage-specific fucose residues identify and select different GDP-fucose pools dependent on their heritage. This supports the hypothesis that GDP-fucose exists in multiple, distinct pools, not as a single homogenous pool. The selection is tightly regulated since the overall pool size remains constant. We present novel perspectives on monosaccharide metabolism, which may have general applicability.

BackgroundImmune checkpoint blockade is an integral component of first-line therapy for most patients with ad-vanced non-small cell lung cancer (NSCLC), however individual patient outcomes are highly variable and improved biomarkers are needed. Protein glycosylation is an emerging mechanism of immune evasion in cancer. We examined blood-based glycopeptide signatures in a cohort of advanced NSCLC patients treated with first-line immune checkpoint blockade.MethodsPretreatment blood samples were obtained from 46 advanced NSCLC patients treated with first line pembrolizumab or pembrolizumab + carboplatin + pemetrexed. All patients provided written in-formed consent to the institutional review board–approved protocols (#02–180 and 13–367) at the Da-na-Farber/Harvard Cancer Center (Boston, MA), and the study was conducted in accordance with the Declaration of Helsinki. Samples were analyzed using an advanced glycoproteomics platform (Inter-Venn Biosciences) that combines ultra-high-performance liquid chromatography coupled to triple quadrupole mass spectrometry with a proprietary neural-network-based data processing engine. 409 individual glycopeptide (GP) signatures derived from 67 abundant serum proteins were analyzed and correlated with overall survival (OS) and other clinical outcomes.ResultsWe identified 30 GPs with abundance differences using a False Discovery Rate (FDR) threshold of 0.05. Using the 5 most predictive GP markers, we created a multivariable model for OS by generating leave-one-out cross-validation (LOOCV) scores and determining an optimized cutoff value of -0.83 (range: -2.2 - 3.4) for these scores using Harrell’s concordance index. The median overall survival was 2.8 years for patients (n=14) whose GP classifier value was above the cutoff and 0.8 years for patients (n=32) whose GP classifier value was below the cutoff (HR 7.4, 95% CI 1.7–32.1, p=0.007) The model’s perfor-mance was not affected by sex, age, or treatment regimen.ConclusionsBlood-based glycopeptide signatures may represent novel, non-invasive biomarkers of clinical out-come to first-line immune checkpoint blockade in advanced NSCLC. Additional research is needed to validate these findings in larger cohorts and to explore potential applications relevant to clinical decision-making.Ethics ApprovalThe study obtained ethics approval from the institutional review board (approved protocol #02–180 and 13–367) at the Dana-Farber/Harvard Cancer Center (Boston, MA), and the study was conducted in accordance with the Declaration of Helsinki.ConsentAll patients provided written informed consent to the institutional review board–approved protocols (#02–180 and 13–367) at the Dana-Farber/Harvard Cancer Center (Boston, MA), and the study was conducted in accordance with the Declaration of Helsinki.

The proteins in the cell membrane of the brain are modified by glycans in highly interactive regions. The glycans and glycoproteins are involved in cell-cell interactions that are of fundamental importance to the brain. In this study, the comprehensive N-glycome and N-glycoproteome of the brain were determined in 11 functional brain regions, some of them known to be affected with the progression of Alzheimer's disease. N-glycans throughout the regions were generally highly branched and highly sialofucosylated. Regional variations were also found with regard to the glycan types including high mannose and complex-type structures. Glycoproteomic analysis identified the proteins that differed in glycosylation in the various regions. To obtain the broader representation of glycan compositions, four subjects with two in their 70s and two in their 90s representing two Alzheimer's disease subjects, one hippocampal sclerosis subject, and one subject with no cognitive impairment were analyzed. The four subjects were all glycomically mapped across 11 brain regions. Marked differences in the glycomic and glycoproteomic profiles were observed between the samples.

High-density lipoprotein (HDL) particles have multiple beneficial and cardioprotective roles, yet our understanding of their full structural and functional repertoire is limited due to challenges in separating HDL particles from contaminating plasma proteins and other lipid-carrying particles that overlap HDL in size and/or density. Here we describe a method for isolating HDL particles using a combination of sequential flotation density ultracentrifugation and fast protein liquid chromatography with a size exclusion column. Purity was visualized by polyacrylamide gel electrophoresis and verified by proteomics, while size and structural integrity were confirmed by transmission electron microscopy. This HDL isolation method can be used to isolate a high yield of purified HDL from a low starting plasma volume for functional analyses. This method also enables investigators to select their specific HDL fraction of interest: from the least inclusive but highest purity HDL fraction eluting in the middle of the HDL peak, to pooling all of the fractions to capture the breadth of HDL particles in the original plasma sample. We show that certain proteins such as lecithin cholesterol acyltransferase (LCAT), phospholipid transfer protein (PLTP), and clusterin (CLUS) are enriched in large HDL particles whereas proteins such as alpha-2HS-glycoprotein (A2HSG), alpha-1 antitrypsin (A1AT), and vitamin D binding protein (VDBP) are enriched or found exclusively in small HDL particles.

OBJECTIVES: The purpose of this secondary outcome analysis is to investigate whether small-quantity lipid-based nutrient supplements (SQ-LNS) alters lipid, protein or glycan composition, or the cholesterol efflux capacity (CEC), of high-density lipoprotein (HDL) particles in children in the International Lipid-Based Nutrient Supplements (iLiNS) DYAD trial in Ghana. METHODS: Plasma samples were obtained from a subcohort of 80 children at 18 months of age from the iLiNS-DYAD-Ghana trial. Mothers were randomized to either iron and folic acid (IFA) in pregnancy and 200 mg/d calcium for 6 months postpartum or SQ-LNS (pregnancy and 6 months postpartum). Children in the SQ-LNS group received SQ-LNS from 6 to 18 months while children in the IFA group did not receive supplements. HDL was isolated from plasma by sequential ultracentrifugation followed by size-exclusion chromatography. Assay of cholesterol efflux was performed in vitro, and glycoproteomic and lipidomic composition were analyzed by mass spectrometry. The primary analysis was a comparison of the effects of intervention groups on HDL lipidome, proteome, and CEC. In the exploratory analysis, we compared the enrichment of glycopeptides in measured HDL-associated proteins between groups. RESULTS: Mean (±SD) HDL CEC was higher among children in the SQ-LNS vs. IFA group (20.9 ± 4.1% vs. 19.4 ± 3.3%; one-tailed p = 0.038). We found no differences in HDL lipidomic or proteomic composition between groups. CONCLUSIONS: Prenatal and postnatal SQ-LNS may improve the CEC of child HDL particles. These improvements may have a potential impact on child health outcomes. FUNDING SOURCES: Supported by Bill & Melinda Gates Foundation grant to the University of California, Davis.

11546 Background: Glycosylation is one of the most ubiquitous and functionally important forms of post-translational modification. The role of differential glycosylation in serum proteins has so far been limited by the technical complexity inherent in generating and interpreting this information. InterVenn has built a novel platform that combines liquid chromatography/mass spectrometry with a proprietary artificial-intelligence-based data processing engine, allowing for highly scalable and reproducible interrogation of glycoproteins with site- and glycan-specificity. Methods: Using this platform, we interrogated 519 glycopeptide (GP) biomarkers derived from 70 serum proteins in pre-treatment samples from a cohort of 103 individuals (56 females, 47 males, age ranging from 18 to 84 years) presenting with one of 20 solid cancer types. All patients were treated with durvalumab and tremelimumab immune checkpoint inhibitor (ICI) therapy. Median follow-up for overall survival (OS) was 11.4 months, with 70 events total observed. OS associations were assessed for individual GPs via Cox regression models and leave-one-out-cross-validation (LOOCV) was employed to generate penalized multivariable prediction scores. Notably, 43 patients had a primary diagnosis of bone and soft tissue sarcoma, and stratified analyses were carried out in this population. Results: We identified 154 biomarkers significantly associated with OS in the full dataset after adjusting for multiple comparisons (FDR < 0.05). Of these, 7 were statistically significant at p < 0.01 in the sarcoma-only subset. LOOCV models built in all cancer types resulted in held-out scores that discriminated those likely to exhibit long-term survival post-ICI therapy from those unlikely to benefit (HR = 4.0, p = 4.91E-08, with 4 GPs included in the final model). Furthermore, LOOCV models including only sarcoma patients demonstrated even stronger predictive attributes (HR = 8.22, p = 2.10E-05, employing 2 glycopeptides). All 9 sarcoma patients with extreme glycosylation signatures for prediction of poor survival displayed quick clinical progression with little benefit from ICI therapy. Relative signal strength and comparative analyses demonstrated strong histotype-specificity inherent in the biomarkers employed for sarcoma vs all cancers. Conclusions: Our results indicate that glycoproteomic liquid biopsy holds potential as a predictive biomarker for identifying sarcoma patients who will derive the greatest benefit from ICI therapy.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Saccharides in our diet are major sources of carbon for the formation of biomass such as proteins, lipids, nucleic acids and glycans. Among the dietary monosaccharides, glucose occupies a central role in metabolism, but human blood contains regulated levels of other monosaccharides as well. Their influence on metabolism and how they are utilized have not been explored thoroughly. Applying metabolic flux analysis on glycan synthesis can reveal the pathways that supply glycosylation precursors and provide a snapshot of the metabolic state of the cell. In this study, we traced the incorporation of six 13C uniformly labeled monosaccharides in the N-glycans, O-glycans and glycosphingolipids of both pluripotent and neural NTERA-2 cells. We gathered detailed isotopologue data for hundreds of glycoconjugates using mass spectrometry methods. The contributions of de novo synthesis and direct incorporation pathways for glucose, mannose, fructose, galactose, N-acetylglucosamine and fucose were determined based on their isotope incorporation. Co-feeding studies revealed that fructose incorporation is drastically decreased by the presence of glucose, while mannose and galactose were much less affected. Furthermore, increased sialylation slowed down the turnover of glycans, but fucosylation attenuated this effect. Our results demonstrated that exogenous monosaccharide utilization can vary markedly depending on the cell differentiation state and monosaccharide availability, and that the incorporation of carbons can also differ among different glycan structures. We contend that the analysis of metabolic isotope labeling of glycans can yield new insights about cell metabolism.

The review focuses on recent aspects (last three years) of glycosylation analyses that provide relevant information about cancer. It includes recent development in glycan and protein enrichment methods for discovery of cancer markers. It will however focus on the recent technological developments in mass spectrometry (MS), bioinformatics and separation methods as they apply toward identifying cancer markers. More specifically, it will cover advances in matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), capillary electrophoresis (CE), and liquid chromatography (LC) coupled to mass spectrometry. The discussions will include glycans, recently identified as potential markers for cancer that have been discovered using the highlighted technologies. We will also discuss emerging glycoproteomic techniques and site-specific methods, and how these methods are being utilized for cancer biomarker discovery. The large amount of data and the complexity of glycoproteomic analysis have been the impetus for developing bioinformatic methods for assigning glycosylation sites and characterizing the potentially very large site- or microheterogeneity. This review will cover the most recent advancements in biomarker discovery of N- and O-glycosylation of proteins as well as the glycolipids. This group collectively constitutes glycosylation on the cell membrane or the glycocalyx. The review will also highlight methods that are highly reproducible, with low coefficient of variation (CV), and scalable for large sample sets. The reader is also referred to other notable earlier reviews on glycomic biomarkers for cancer. Mereiter et al. describe the recent glycomic effort in gastrointestinal cancer.1 A review focused on N-glycomic analysis of colorectal cancer has been published by Sethi and Fanayan.2 N-Glycan, O-glycan, and glycolipid characteristics of colorectal cancer were reviewed by Holst et al.3 Muchena et al. have provided a more general review of glycan biomarkers covering up to the current review period.4 The field of glycoscience also covers a broad area of structures and may include highly anionic (glycosaminoglycans) and monosaccharide (e.g. O-GlcNAc) modifications that require their specific and unique sets of analytical tools. The latter topics are not covered in this review. 1.1. Background of Glycosylation and Cancer There is nearly 50 years of research illustrating that changes in glycosylation accompany cancer.5 Glycosylation is a dynamic process intimately involved in key processes in cells, including cell-cell and cell-extracellular communication as well as cell-cell adhesion, and cellular metabolism. Glycans expressed in several types of glycoconjugates are known to change during cancer genesis and progression.6 These changes increase the structural heterogeneity and alter the functions of cells.7 Glycosylation has been found to enable tumor-induced immunomodulation and metastasis.8–10 The cell-surface structures allow the immune cells to differentiate self/normal cells from non-self/abnormal cells.11 For example, terminal residues on N-glycans, such as sialic acids, are involved in immunity and cell-cell communication.12 Changes in glycosylation of adhesion proteins can largely influence their binding properties, leading to altered cell-cell or cell-matrix contacts.13 Other types of glycans are also involved in cancer. Gangliosides and sphingolipids are involved in transmembrane communication vital in tumor cell growth and invasion.14 Glycosaminoglycans are involved in tumor cell migration15 and motility.16–18 The search for effective markers is aided by the understanding of how glycans are synthesized. The glycan biosynthetic process is a non-template process involving multiple enzymes, some performing competing activities. It is estimated that more than 300 metabolic enzymes, composed of glycosyltransferases and glycosidases, are involved in the biosynthesis and processing of glycans.19–20 The best-known series of pathways belongs to the production of N-glycans (Figure 1). They illustrate the large degree of structural heterogeneity in glycosylation. N-Glycans are produced in a step-wise process beginning with the production of high mannose structures on a lipid, which are transferred to the nascent polypeptide chain to guide protein folding. Once folded, the glycans are then trimmed back and extended to form complex and hybrid structures. The folded protein can be secreted with glycans that range from early in the process to yield high mannose structures to later in the process corresponding to complex or hybrid structures. The number of structures for one glycosylation site can vary by a large degree, from a handful for transferrin21 to over 70 structures for IgG, the most abundant serum glycoprotein.22–23 Open in a separate window Figure 1. Representation of the glycosylation pathway of proteins. The pathway illustrates the complexity and heterogeneity of structures. The proteins may exit the pathway with various levels of glycosylation.

Since high-density lipoprotein (HDL) glycoprofiles are associated with HDL functional capacity, we set out to determine whether diet can alter the glycoprofiles of key HDL-associated proteins, including ApoE, a potent driver of chronic disease risk. Ten healthy subjects consumed a fast food (FF) and a Mediterranean (Med) diet for 4 days in randomized order, with a 4-day wash-out between treatments. A multiple reaction monitoring method was used to characterize the site-specific glycoprofiles of HDL proteins, and HDL functional capacity was analyzed. We describe for the first time that ApoE has 7 mucin-type O-glycosylation sites, which were not affected by short-term diet. The glycoprofiles of other HDL-associated proteins were also unaffected, except thata disialylated ApoC-III glycanwas enriched after Med diet, and a nonsialylated ApoC-III glycan was enriched after FF diet. Twenty-five individual glycopeptides were significantly correlated with cholesterol efflux capacity and 21 glycopeptides were correlated with immunomodulatory capacity. Results from this study indicate that the glycoprofiles of HDL-associated proteins including ApoE are correlated with HDL functional capacity but generally unaffected by diet in the short term, except ApoC-III sialylation. These results suggest that HDL protein glycoprofiles are affected by both acute and long-term factors and may be useful for biomarker discovery.

Streptococcus gordonii and Streptococcus sanguinis are primary colonizers of the tooth surface. Although generally non-pathogenic in the oral environment, they are a frequent cause of infective endocarditis. Both streptococcal species express a serine-rich repeat surface adhesin that mediates attachment to sialylated glycans on mucin-like glycoproteins, but the specific sialoglycan structures recognized can vary from strain to strain. Previous studies have shown that sialoglycan binding is clearly important for aortic valve infections caused by some S. gordonii, but this process did not contribute to the virulence of a strain of S. sanguinis. However, these streptococci can bind to different subsets of sialoglycan structures. Here we generated isogenic strains of S. gordonii that differ only in the type and range of sialoglycan structures to which they adhere and examined whether this rendered them more or less virulent in a rat model of endocarditis. The findings indicate that the recognition of specific sialoglycans can either enhance or diminish pathogenicity. Binding to sialyllactosamine reduces the initial colonization of mechanically-damaged aortic valves, whereas binding to the closely-related trisaccharide sialyl T-antigen promotes higher bacterial densities in valve tissue 72 hours later. A surprising finding was that the initial attachment of streptococci to aortic valves was inversely proportional to the affinity of each strain for platelets, suggesting that binding to platelets circulating in the blood may divert bacteria away from the endocardial surface. Importantly, we found that human and rat platelet GPIbα (the major receptor for S. gordonii and S. sanguinis on platelets) display similar O-glycan structures, comprised mainly of a di-sialylated core 2 hexasaccharide, although the rat GPIbα has a more heterogenous composition of modified sialic acids. The combined results suggest that streptococcal interaction with a minor O-glycan on GPIbα may be more important than the over-all affinity for GPIbα for pathogenic effects., Author summary Infective endocarditis (IE) is a life-threatening infection of heart valves, and streptococci that normally reside in the mouth are a leading cause of this disease. Some oral streptococcal species express a protein on their surface that enables attachment to glycan (sugar) modifications on saliva proteins, an interaction that may be important for colonization of the tooth and other oral surfaces. These "Siglec-like adhesins" are hypervariable in the type and number of glycan structures they bind, ranging from just one to more than six of the structures displayed on the saliva proteins. If streptococci enter into the bloodstream, the Siglec-like adhesin can mediate attachment to similar glycans that decorate platelet or plasma proteins, which can impact the overall virulence of the organism. This study highlights how recognition of a specific type of glycan structure can cause a generally beneficial or neutral microbe to create damage to specific tissues—in this case the heart valves, illustrating one means by which commensal bacteria can become opportunistic or accidental pathogens. The findings further indicate that certain glycan-binding streptococci among the oral microbiota may be predisposed to produce infective endocarditis.

Sialic acid distribution was quantified by LC-MS/MS. The number of sialylated glycoforms increases at sites nearest to the transmembrane domain., Given that unnatural sugar expression is metabolically achieved, the kinetics and disposition of incorporation can lend insight into the temporal and localization preferences of sialylation across the cell surface. However, common detection schemes lack the ability to detail the molecular diversity and distribution of target moieties. Here we employed a mass spectrometric approach to trace the placement of azido sialic acids on membrane glycoconjugates, which revealed substantial variations in incorporation efficiencies between N-/O-glycans, glycosites, and glycosphingolipids. To further explore the propensity for sialylation, we subsequently mapped the native glycome of model epithelial cell surfaces and illustrate that while glycosylation sites span broadly across the extracellular region, a higher number of heterogeneous glycoforms occur on sialylated sites closest to the transmembrane domain. Beyond imaging techniques, this integrative approach provides unprecedented details about the frequency and structure-specific distribution of cell surface sialylation, a critical feature that regulates cellular interactions and homeostatic pathways.

Glycosphingolipids (GSLs) are found in cellular membranes of most organisms and play important roles in cell-cell recognition, signaling, growth, and adhesion, among others. A method based on nanoflow high performance liquid chromatography-chip-quadrupole-time-of-flight mass spectrometry (nanoHPLC Chip-Q-TOF MS) was applied towards identifying and quantifying intact GSLs from a variety of samples, including cultured cell lines and animal tissue. The method provides the composition and sequence of the glycan, as well as variations in the ceramide portion of the GSL. It was used to profile the changes in the glycolipidome of Caco-2 cells as they undergo differentiation. A total of 226 unique GSLs were found among Caco-2 samples from five differentiation time-points. The method provided a comprehensive glycolipidomic profile of a cell during differentiation to yield the dynamic variation of intact GSL structures.

Epithelial cells in the lining of the intestines play critical roles in maintaining homeostasis while challenged by dynamic and sudden changes in luminal contents. Given the high density of glycosylation that encompasses their extracellular surface, environmental changes may lead to extensive reorganization of membrane-associated glycans. However, neither the molecular details nor the consequences of conditional glycan changes are well understood. Here we assessed the sensitivity of Caco-2 and HT-29 membrane N-glycosylation to variations in (i) dietary elements, (ii) microbial fermentation products and (iii) cell culture parameters relevant to intestinal epithelial cell growth and survival. Based on global LC–MS glycomic and statistical analyses, the resulting glycan expression changes were systematic, dependent upon the conditions of each controlled environment. Exposure to short chain fatty acids produced significant increases in fucosylation while further acidification promoted hypersialylation. Notably, among all conditions, increases of high mannose type glycans were identified as a major response when extracellular fructose, galactose and glutamine were independently elevated. To examine the functional consequences of this discrete shift in the displayed glycome, we applied a chemical inhibitor of the glycan processing mannosidase, globally intensifying high mannose expression. The data reveal that upregulation of high mannose glycosylation has detrimental effects on basic intestinal epithelium functions by altering permeability, host–microbe associations and membrane protein activities.

The cell membrane plays an important role in protecting the cell from its extracellular environment. As such, extensive work has been devoted to studying its structure and function. Crucial intercellular processes, such as signal transduction and immune protection, are mediated by cell surface glycosylation, which is comprised of large biomolecules, including glycoproteins and glycosphingolipids. Because perturbations in glycosylation could result in dysfunction of cells and are related to diseases, the analysis of surface glycosylation is critical for understanding pathogenic mechanisms and can further lead to biomarker discovery. Different mass spectrometry-based techniques have been developed for glycan analysis, ranging from highly specific, targeted approaches to more comprehensive profiling studies. In this review, we summarized the work conducted for extensive analysis of cell membrane glycosylation, particularly those employing liquid chromatography with mass spectrometry (LC-MS) in combination with various sample preparation techniques.

The results of long term virus surveys in intensively cultivated vanilla plots in the Society Islands (French Polynesia), between 1999 and 2007 are reported here. The data confirmed a potential for high incidence of aphid borne viruses in particular Cucumber mosaic virus (CMV) and Watermelon mosaic virus (WMV) as well as the non vectored Cymbidium mosaic virus (CymMV). CMV had a particularly high prevalence (over 30% of the plots) and could severely damage up to 50% of the vines before blossom. Severe outbreaks of CMV were correlated to the presence of the weed Commelina diffusa as a reservoir of virus and aphid vectors. The application in 2003 of simple prophylactic measures resulted in a sharp reduction of virus incidence in new plantations, compared to levels of virus diseases recorded in the previous decade. Indeed, at the beginning of fruiting, the incidence of aphid borne viruses did not exceeded 1.6% of vines for the 29 shade houses which adopted the virus prophylaxis. The three remaining shade houses were severely (20–50%) infected by WMV or CymMV because of the planting of virus-infected cuttings. These results demonstrate the benefit of implementing prophylaxis at the scale of an archipelago, and widen the possibilities of developing intensive cultivation of vanilla in other areas confronted with similar virus constraints.

Absent in the wild, Tahitian vanilla (V. tahitensis) is a gourmet spice restricted in distribution to cultivated and feral stands in French Polynesia and Papua New Guinea. Its origins have been elusive. Our objective was to test the purported hybrid derivation and parentage of V. tahitensis from aromatic, neotropical progenitors. Nucleotide sequences from V. tahitensis and neotropical Vanilla were assayed for phylogenetic relatedness in two independently inherited genomic regions, the nuclear ITS region, and the trnH-psbA noncoding region of chloroplast DNA. As predicted to occur for early generation hybrids, placement of V. tahitensis was nonconcordant. All V. tahitensis clustered with V. planifolia from analysis of cpDNA sequences, suggesting V. planifolia as the maternal genome contributor. Phylogenetic reconstruction of ITS sequences showed that most V. tahitensis nested incongruently with V. odorata, but others remained sister to V. planifolia. Recovery of ITS clones in V. tahitensis related to both V. planifolia and V. odorata also supports its biphyletic origin from these two taxa. We interpret the high percentage (95%) of additive polymorphic sites in V. tahitensis relative to its parents as indication of a recent, and probably human-mediated, evolutionary origin.

This study aims to understand the genetic diversity of traditional Oceanian starchy bananas in order to propose an efficient conservation strategy for these endangered varieties. SSR and DArT molecular markers are used to characterize a large sample of Pacific accessions, from New Guinea to Tahiti and Hawaii. All Pacific starchy bananas are shown of New Guinea origin, by interspecific hybridization between Musa acuminata (AA genome), more precisely its local subspecies M. acuminata ssp. banksii, and M. balbisiana (BB genome) generating triploid AAB Pacific starchy bananas. These AAB genotypes do not form a subgroup sensu stricto and genetic markers differentiate two subgroups across the three morphotypes usually identified: Iholena versus Popoulu and Maoli. The Popoulu/Maoli accessions, even if morphologically diverse throughout the Pacific, cluster in the same genetic subgroup. However, the subgroup is not strictly monophyletic and several close, but different genotypes are linked to the dominant genotype. One of the related genotypes is specific to New Caledonia (NC), with morphotypes close to Maoli, but with some primitive characters. It is concluded that the diffusion of Pacific starchy AAB bananas results from a series of introductions of triploids originating in New Guinea area from several sexual recombination events implying different genotypes of M. acuminata ssp. banksii. This scheme of multiple waves from the New Guinea zone is consistent with the archaeological data for peopling of the Pacific. The present geographic distribution suggests that a greater diversity must have existed in the past. Its erosion finds parallels with the erosion of cultural traditions, inexorably declining in most of the Polynesian or Melanesian Islands. Symmetrically, diversity hot spots appear linked to the local persistence of traditions: Maoli in New Caledonian Kanak traditions or Iholena in a few Polynesian islands. These results will contribute to optimizing the conservation strategy for the ex-situ Pacific Banana Collection supported collectively by the Pacific countries.

International audience; Volatile compounds from raw and oven-cooked pulp of the fe'i banana (Musa troglodytarum) were isolated by two different organic solvents (acetone and dichloromethane), and studied by gas chromatography/flame ionization detector (GC/FID) and GC/mass spectrometry (GC/MS). One hundred compounds were identified for the first time, according to their retention time on an apolar capillary column and their mass spectra. They are divided as follows: one sulfur compound (0.1% of the raw dichloromethane extract), four phenols (5.6-41.4%), six lactones (0.1-5.5%), ten hydrocarbons (0.2-3.1%), eleven esters (0.3-2.0%), sixteen miscellaneous compounds (6.1-76.4%), seventeen acids (1.1-43.7%), seventeen carbonyl compounds (0.2-44.3%) and eighteen alcohols (0.9-9.4%). Three compounds were found at a level greater than 1 mg/kg: p-vinyl guaiacol (1.9mg/kg) in the raw fe'i banana acetone extract;; 5-(hydroxymethyl)furfural (7.4mg/kg) in the oven-cooked fe'i banana acetone extract;; (E)-2-hexenal (2.4mg/kg) and p-vinyl guaiacol (2.1mg/kg) in the raw fe'i banana dichloromethane extract and 5-(hydroxymethyl)furfural (4.7mg/kg) in the oven-cooked fe'i banana dichloromethane extract.

In 2014, severe symptoms of leaf curling and yellowing resembling those of tomato yellow leaf curl disease were observed for the first time on tomato ( Solanum lycopersicum ) plants with a 100% incidence in affected greenhouses in Tahiti …

The use of chemical hybridizing agents (CHA) allows production of hybrid wheat seeds. We evaluated the effectiveness of a new CHA (SC2053) to induce male sterility on winter wheat in controlled growth conditions. CHA effectiveness was measured with the application of 4 doses (0–400–700–1000 g.ha−1) at 7 stages. These stages were defined by the length of the main stem spike (1–4–7–11–15–20–40 mm). At heading, individual ears were isolated with a greaseproof paper bag. The seeds formed were counted on treated and control ears. The spikes' sterility was calculated three weeks after flowering. The sterility of the main stem's spike reached 95% to 100% for application of 700 g.ha−1 and 1000 g.ha−1 for main stem spike length of 7 mm to 20 mm. The effects of ear tillering (5 tillers per plant) on CHA effectiveness were also investigated. We observed a significant delay of ear development between the main stem and tillers so that complete sterilities were not reached for each dose. Since tillering in field conditions rarely exceeds 3 ears per plant, CHA effectiveness was studied on plants bearing 3 ears. The mean sterility of the first 3 ears was close to 100% for applications with 700 g.ha−1 and 1000 g.ha−1 at stages from 11 mm to 20 mm of main stem spike length.

International audience; The first vanilla genetic linkage map was constructed by analyzing the progeny of an interspecific cross between Vanilla ×tahitensis J. W. Moore (pro sp.) and Vanilla pompona Schiede. The two-way pseudotestcross mapping strategy was used and a total of 225 amplified fragment length polymorphism (AFLP) markers were mapped on 18 linkage groups covering 1035.85 cM. Thirteen tahitian vanilla morphotypes, one Vanilla planifolia Andrews and recent hybrids were compared by measuring seven morphological traits and by genotyping, with 539 AFLP fragments. The morphotypes studied showed relatively homogenous stem traits but differed in their bean and leaf traits as in their AFLP pattern. Genetic variability and AFLP genotyping comparison suggest a diversification in French Polynesia based on sexual reproduction and are consistent with the hypothesis of a single introduction event. These results are the first step for vanilla breeding program and will be also useful for tahitian vanilla resource preservation.