HS-SPME-GC-MS Analyses of Volatiles in Plant Populations—Quantitating Compound × Individual Matrix Effects

Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrometry (GC-MS) is widely employed for volatile analyses of plants, including mapping populations used in plant breeding research. Studies often employ a single internal surrogate standard, even when multiple analytes are measured, with the assumption that any relative changes in matrix effects among individuals would be similar for all compounds, i.e., matrix effects do not show Compound × Individual interactions. We tested this assumption using individuals from two plant populations: an interspecific grape (Vitis spp.) mapping population (n = 140) and a tomato (Solanum spp.) recombinant inbred line (RIL) population (n = 148). Individual plants from the two populations were spiked with a cocktail of internal standards (n = 6, 9, respectively) prior to HS-SPME-GC-MS. Variation in the relative responses of internal standards indicated that Compound × Individual interactions exist but were different between the two populations. For the grape population, relative responses among pairs of internal standards varied considerably among individuals, with a maximum of 249% relative standard deviation (RSD) for the pair of [U13C]hexanal and [U13C]hexanol. However, in the tomato population, relative responses of internal standard pairs varied much less, with pairwise RSDs ranging from 8% to 56%. The approach described in this paper could be used to evaluate the suitability of using surrogate standards for HS-SPME-GC-MS studies in other plant populations

SNPs called from the RNA-Seq data of RILs

SNPs called from the RNA-Seq data of RILs and their two parents, S. lycopersicum breeding line NC EBR-1 and S. pimpinellifolium accession LA2093. The file is in vcf format

gene models in non-reference genome

gene models annotated in the non-reference sequences of the tomato pan-genome, in gff3 forma

Data from: The tomato pan-genome uncovers new genes and a rare allele regulating fruit flavor

Modern tomatoes have narrow genetic diversity limiting their improvement potential. We present a tomato pan-genome constructed using genome sequences of 725 phylogenetically and geographically representative accessions, revealing 4,873 genes absent from the reference genome. Presence/absence variation analyses reveal substantial gene loss and intense negative selection of genes and promoters during tomato domestication and improvement. Lost or negatively selected genes are enriched for important traits, especially disease resistance. We identify a rare allele in TomLoxC promoter selected against during domestication. QTL mapping and analysis of transgenic plants reveal a novel role for TomLoxC in apocarotenoid production, which contributes to desirable tomato flavor. In orange-stage fruit, accessions harboring both the rare and common TomLoxC alleles (heterozygotes) have higher TomLoxC expression than those homozygous for either, and are resurgent in modern tomatoes. The tomato pan-genome adds depth and completeness to the reference genome, and is useful for future biological discovery and breeding

Tomato non-reference genome sequences

Non-reference genome sequences of tomato pan-genom