Metabolite profiling characterises chemotypes of Musa diploids and triploids at juvenile and preflowering growth stages

Open Access Journal; Published online: 15 March 2019Bananas (Musa spp.) are consumed worldwide as dessert and cooking types. Edible banana varieties are for the most part seedless and sterile and therefore vegetatively propagated. This confers difficulties for breeding approaches against pressing biotic and abiotic threats and for the nutritional enhancement of banana pulp. A panel of banana accessions, representative of the diversity of wild and cultivated bananas, was analysed to assess the range of chemotypes available globally. The focus of this assessment was banana leaves at two growth stages (juvenile and pre-flowering), to see when during the plant growth metabolic differences can be established. The metabolic data corresponded to genomic trends reported in previous studies and demonstrated a link between metabolites/pathways and the genomes of M. acuminata and M. balbisiana. Furthermore, the vigour and resistance traits of M. balbisiana was connected to the phenolic composition and showed differences with the number of B genes in the hybrid accessions. Differences in the juvenile and pre-flowering data led to low correlation between the growth stages for prediction purposes

Assessment of metabolic variability and diversity present in leaf, peel and pulp tissue of diploid and triploid Musa spp.

Banana (Musa spp.) plants produce many health promoting compounds in leaf, peel and pulp. For a robust metabolic analysis of these tissues, leaf at five developmental stages were compared to assess suitable sampling practices. Results confirmed that the common sampling practise of leaf 3 is applicable for metabolic comparisons. The developed work flow was applied to analyse the metabolite diversity present in 18 different Musa varieties, providing baseline levels of metabolites in leaf, peel and pulp tissue. Correlation analysis was then used to ascertain whether similar trends can be detected in the three plant tissues of the diversity panel. The genome group displayed a dominant role in the composition of the metabolome in all three tissues. This led to the conclusion that a correlation between tissues was only possible within a genome group as the different parental backgrounds caused too great a variation in the metabolomes. It also suggests the metabolome could be used to monitor the interaction/hybridisation of genomes during breeding programmes

Metabolite data of cassava leaf, stem and root

Raw data of LC-MS analysis of leaf, stem and root tissue of 20 cassava landraces. (LCMS_3Tissues_metabolic profiling.xlsx) Raw data of LC-MS analysis of cassava leaf tissue. (LCMS_Leaf_metabolic profiling.xlsx) AMDIS output of GC-MS analysis of leaf, stem and root tissue of 20 cassava landraces. (GCMS_3Tissues_AMDIS output.xlsx

Lipid analysis of sweet potato sucrose gradient (amyloplast subcellular fractionation)

"5SwPot": Sweet potato roots (freeze-dried powder) were extracted from five different phenotypes (W-white, Y-yellow, O-orange, LP-yellow/purple, P-purple) and subjected to analysis by LC-MS/MS with a HILIC and C8 column. This allowed the separation of phospho- & galactosyl lipids and TAGs, respectively. Data was processed with Agilent Profinder. "Fractions": Sweet potato amyloplasts were extracted from two different phenotypes (O-orange, P-purple) and subcellular components separated with a sucrose gradient. The fractions were extracted with chloroform and analysed by LC-MS/MS with a HILIC and C8 column. This allowed the separation of phospho- & galactosyl lipids and TAGs, respectively. Data was processed with Agilent Profinder

Proteome analysis of fbn mutants

MSMS analysis of trypsin idgested peptides of plastoglobule fractions of:AC - Ailsa CraigAzy - Azygous40 - Quadruple fibrillin mutantTriple - triple fibrillin mutan

Agroinfection of N.benthamiana

Metabolite profiling by LC-QTof (negative mode) of four N. benthamiana accessions under agroinfiltration. (XLSX file) AMDIS output of GC-MS of polar and non-polar extracts of the same plant material as above. (TXT files

Stochastic Model Explains the Role of Excitation and Inhibition in Binaural Sound Localization in Mammals

Interaural time differences (ITDs), the differences of arrival time of the sound at the two ears, provide a major cue for low-frequency sound localization in the horizontal plane. The first nucleus involved in the computation of ITDs is the medial superior olive (MSO). We have modeled the neural circuit of the MSO using a stochastic description of spike timing. The inputs to the circuit are stochastic spike trains with a spike timing distribution described by a given probability density function (beta density). The outputs of the circuit reproduce the empirical firing rates found in experiment in response to the varying ITD. The outputs of the computational model are calculated numerically and these numerical simulations are also supported by analytical calculations. We formulate a simple hypothesis concerning how sound localization works in mammals. According to this hypothesis, there is no array of delay lines as in the Jeffress' model, but the inhibitory input is shifted in time as a whole. This is consistent with experimental observations in mammals