Unraveling new genes associated with seed development and metabolism in Bixa orellana L. by expressed sequence tag (EST) analysis.
The tropical tree Bixa orellana L. produces a range of secondary metabolites which biochemical and molecular biosynthesis basis are not well understood. In this work we have characterized a set of ESTs from a non-normalized cDNA library of B. orellana seeds to obtain information about the main developmental and metabolic processes taking place in developing seeds and their associated genes. After sequencing a set of randomly selected clones, most of the sequences were assigned with putative functions based on similarity, GO annotations and protein domains. The most abundant transcripts encoded proteins associated with cell wall (prolyl 4-hydroxylase), fatty acid (acyl carrier protein), and hormone/flavonoid (2OG-Fe oxygenase) synthesis, germination (MADS FLC-like protein) and embryo development (AP2/ERF transcription factor) regulation, photosynthesis (chlorophyll a-b binding protein), cell elongation (MAP65-1a), and stress responses (metallothionein- and thaumatin-like proteins). Enzymes were assigned to 16 different metabolic pathways related to both primary and secondary metabolisms. Characterization of two candidate genes of the bixin biosynthetic pathway, BoCCD and BoOMT, showed that they belong, respectively, to the carotenoid-cleavage dioxygenase 4 (CCD4) and caffeic acid O-methyltransferase (COMT) families, and are up-regulated during seed development. It indicates their involvement in the synthesis of this commercially important carotenoid pigment in seeds of B. orellana. Most of the genes identified here are the first representatives of their gene families in B. orellana.
Soares
Virgínia L F
VL
Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, BA, Brazil.
Rodrigues
Simone M
SM
de Oliveira
Tahise M
TM
de Queiroz
Talisson O
TO
Lima
Lívia S
LS
Hora-Júnior
Braz T
BT
Gramacho
Karina P
KP
Micheli
Fabienne
F
Cascardo
Júlio C M
JC
Otoni
Wagner C
WC
Gesteira
Abelmon S
AS
Costa
Marcio G C
MG
D031212:Bixaceae / Q000235:genetics*; D049308:Dioxygenases / Q000235:genetics*; D020224:Expressed Sequence Tags; D015723:Gene Library; D017343:Genes, Plant; D008780:Methyltransferases / Q000235:genetics*; D008957:Models, Genetic; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013997:Time Factors
D010940:Plant Proteins; D049308:Dioxygenases; C431939:carotenoid cleavage dioxygenase 1; D008780:Methyltransferases