Control of Carotenoid Gene Expression in Bixa orellana L. Leaves Treated with Norflurazon
Bixa orellana (annatto or lipstick tree) is a perennial tropical plant that stores and produces considerable quantities of the apocarotenoid bixin, a culturally and economically important pigment used worldwide. However, the mechanisms underlying the gene regulation and pigment accumulation of bixin and carotenoids in annatto remain unknown. Bixin is present in the different tissues of the plant, although this pigment is primarily accumulated in the seed coat. Thus, the leaves are useful organs for understanding carotenoid and bixin production, thereby facilitating the study of this pigment, which would otherwise be difficult in ligneous adult plants. To study the regulation of bixin synthesis and to determine which genes are important regulatory molecules at the transcription level, the herbicide norflurazon (NF) was used to block carotenoid synthesis and bixin concentrations in B. orellana leaves. The genes activated in the early stages of the carotenoid pathway are involved in lycopene production (dxs, psy and pds), and those induced in the later stages of the carotenoid pathway, such as β and ε-lycopene cyclases and boccd1, were differentially expressed compared with the control. The expression of some genes was more susceptible to certain concentrations of NF, potentially reflecting the roles of these genes in carotenoid synthesis in B. orellana. These results suggest that apocarotenoids, such as bixin, are synthesized using alternative precursors through the actions of genes that have not yet been identified.
Main Author: | |
---|---|
Format: | info:eu-repo/semantics/article biblioteca |
Subjects: | info:eu-repo/classification/cti/2, |
Online Access: | http://cicy.repositorioinstitucional.mx/jspui/handle/1003/38 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Bixa orellana (annatto or lipstick tree) is a perennial
tropical plant that stores and produces considerable quantities
of the apocarotenoid bixin, a culturally and economically
important pigment used worldwide. However, the mechanisms
underlying the gene regulation and pigment accumulation
of bixin and carotenoids in annatto remain unknown.
Bixin is present in the different tissues of the plant, although
this pigment is primarily accumulated in the seed coat. Thus,
the leaves are useful organs for understanding carotenoid and
bixin production, thereby facilitating the study of this pigment,
which would otherwise be difficult in ligneous adult
plants. To study the regulation of bixin synthesis and to
determine which genes are important regulatory molecules at
the transcription level, the herbicide norflurazon (NF) was
used to block carotenoid synthesis and bixin concentrations
in B. orellana leaves. The genes activated in the early stages of
the carotenoid pathway are involved in lycopene production
(dxs, psy and pds), and those induced in the later stages of the
carotenoid pathway, such as β and ε-lycopene cyclases and
boccd1, were differentially expressed compared with the control.
The expression of some genes was more susceptible to
certain concentrations of NF, potentially reflecting the roles of
these genes in carotenoid synthesis in B. orellana. These
results suggest that apocarotenoids, such as bixin, are synthesized
using alternative precursors through the actions of genes
that have not yet been identified. |
---|