title: Comparative deep transcriptional profiling of four developing oilseeds.
abstract: Transcriptome analysis based on deep expressed sequence tag (EST) sequencing allows quantitative comparisons of gene expression across multiple species. Using pyrosequencing, we generated over 7 million ESTs from four stages of developing seeds of Ricinus communis, Brassica napus, Euonymus alatus and Tropaeolum majus, which differ in their storage tissue for oil, their ability to photosynthesize and in the structure and content of their triacylglycerols (TAG). The larger number of ESTs in these 16 datasets provided reliable estimates of the expression of acyltransferases and other enzymes expressed at low levels. Analysis of EST levels from these oilseeds revealed both conserved and distinct species-specific expression patterns for genes involved in the synthesis of glycerolipids and their precursors. Independent of the species and tissue type, ESTs for core fatty acid synthesis enzymes maintained a conserved stoichiometry and a strong correlation in temporal profiles throughout seed development. However, ESTs associated with non-plastid enzymes of oil biosynthesis displayed dissimilar temporal patterns indicative of different regulation. The EST levels for several genes potentially involved in accumulation of unusual TAG structures were distinct. Comparison of expression of members from multi-gene families allowed the identification of specific isoforms with conserved function in oil biosynthesis. In all four oilseeds, ESTs for Rubisco were present, suggesting its possible role in carbon metabolism, irrespective of light availability. Together, these data provide a resource for use in comparative and functional genomics of diverse oilseeds. Expression data for more than 350 genes encoding enzymes and proteins involved in lipid metabolism are available at the 'ARALIP' website (http://aralip.plantbiology.msu.edu/).
authors.affiliation: Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Manuel A
authors.initials: MA
authors.lastname: Troncoso-Ponce
authors.forename: Aruna
authors.initials: A
authors.lastname: Kilaru
authors.forename: Xia
authors.initials: X
authors.lastname: Cao
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Durrett
authors.forename: Jilian
authors.initials: J
authors.lastname: Fan
authors.forename: Jacob K
authors.initials: JK
authors.lastname: Jensen
authors.forename: Nick A
authors.initials: NA
authors.lastname: Thrower
authors.forename: Markus
authors.initials: M
authors.lastname: Pauly
authors.forename: Curtis
authors.initials: C
authors.lastname: Wilkerson
authors.forename: John B
authors.initials: JB
authors.lastname: Ohlrogge
mesh_terms: D000215:Acylation; D000217:Acyltransferases / Q000378:metabolism; D029688:Brassica napus / Q000235:genetics; D029756:Euonymus / Q000235:genetics; D020224:Expressed Sequence Tags; D005227:Fatty Acids / Q000096:biosynthesis*; D015870:Gene Expression; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000502:physiology; D006019:Glycolysis; D010938:Plant Oils / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D012278:Ricinus / Q000235:genetics; D012639:Seeds / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D014280:Triglycerides / Q000096:biosynthesis*; D032388:Tropaeolum / Q000235:genetics
chemical_list: D005227:Fatty Acids; D010938:Plant Oils; D014280:Triglycerides; D019289:Pyruvic Acid; D000217:Acyltransferases