Elucidation of the polyamine biosynthesis pathway during Brazilian pine (Araucaria angustifolia) seed development.
Polyamines (PAs), such as spermidine and spermine, as well as amino acids that are substrates for their biosynthesis, are known to be essential for plant development. However, little is known about the gene expression and metabolic switches associated with the ornithine/arginine and PA biosynthetic pathway during seed development in conifers. To understand these metabolic switches, the enzyme activity of arginine decarboxylase and ornithine decarboxylase, as well as the contents of PAs and amino acids were evaluated in three Araucaria angustifolia (Bertol. Kuntze) seed developmental stages in combination with expression profile analyses of genes associated with the ornithine/arginine and PA biosynthetic pathway. Twelve genes were selected for further analysis and it was shown that the expression profiles of AaADC and AaSAMDC were up-regulated during zygotic embryo development. Polyamines and amino acids were found to accumulate differently in embryos and megagametophytes, and the transition from the globular to the cotyledonary stage was marked by an increase in free and conjugated spermidine and spermine contents. Putrescine is made from arginine, which was present at low content at the late embryogenesis stage, when high content of citrulline was observed. Differences in amino acids, PAs and gene expression profiles of biosynthetic genes at specific seed stages and at each seed transition stage were investigated, providing insights into molecular and physiological aspects of conifer embryogenesis for use in future both basic and applied studies.
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
Leandro F
LF
de Oliveira
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
Paula
P
Elbl
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
Bruno V
BV
Navarro
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
Amanda F
AF
Macedo
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
André L W
AL
Dos Santos
Laboratory of Plant Cell Biology, Department of Botany, Institute of Biosciences, University of São Paulo, Rua do Matão, São Paulo, Brazil.
Eny I S
EI
Floh
Janice
J
Cooke
D000596:Amino Acids / Q000378:metabolism*; D053898:Biosynthetic Pathways; D002262:Carboxy-Lyases / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D009955:Ornithine Decarboxylase / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017422:Sequence Analysis, DNA; D064028:Tracheophyta / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
D000596:Amino Acids; D010940:Plant Proteins; D011073:Polyamines; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; C019722:arginine decarboxylase
amino acids; arginine decarboxylase; conifer; embryogenesis; ornithine decarboxylase; polyamine biosynthesis