Mass spectrometric imaging as a high-spatial resolution tool for functional genomics: Tissue-specific gene expression of TT7 inferred from heterogeneous distribution of metabolites in Arabidopsis flowers

TitleMass spectrometric imaging as a high-spatial resolution tool for functional genomics: Tissue-specific gene expression of TT7 inferred from heterogeneous distribution of metabolites in Arabidopsis flowers
Publication TypeJournal Article
Year of Publication2012
AuthorsKorte AR, Song ZH, Nikolau BJ, Lee YJ
Journal TitleAnalytical Methods
Volume4
Pages474-481
Date Published02
Type of ArticleArticle
ISBN Number1759-9660
Accession NumberWOS:000300038900025
Keywordsambient conditions, brain, lipids, MATRIX, metabolomics, methodology, MS, silver, thaliana
Abstract

Laser desorption/ionization (LDI) mass spectrometry imaging (MSI) was used to acquire chemical images of flavonoid metabolites on the surface of wild-type and mutant (tt7) Arabidopsis thaliana flowers. Flavonoids were localized to the petals and carpels of flowers, with tissue heterogeneity in the petals. Specifically, kaempferol and/or its glycosides were abundant in the distal region of petals and quercetin and its downstream flavonoids were highly enriched in the more proximal region of petals. As a result of a mutation in the TT7 gene which blocks the conversion of dihydrokaempferol to dihydroquercetin, the downstream metabolites, quercetin, isohamnetin, and their glycosides, were not observed in the mutant flowers. Instead, the metabolites in an alternative pathway, kaempferol and/or its glycosides, were as highly abundant on the proximal region of the petals as in the distal region. In addition, the combined flavonoid amounts on the proximal region of petals in the wild-type are almost equivalent to the amounts of kaempferol and/or its glycosides in the mutant. This strongly suggests that the expression of the TT7 gene is localized on the proximal part of the petal while the other genes in the upper stream pathway are evenly expressed throughout the petal. Most importantly, this work demonstrates MSI of metabolites can be utilized for the localization of gene expression.

URL<Go to ISI>://WOS:000300038900025http://pubs.rsc.org/en/content/articlepdf/2012/ay/c2ay05618f
DOI10.1039/c2ay05618f
Alternate JournalAnal. Methods