1. Construction of transplastomic lettuce (Lactuca sativa) dominantly producing astaxanthin fatty acid esters and detailed chemical analysis of generated carotenoids
- Author
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Hisashi Harada, Jun-ichiro Hattan, Norihiko Misawa, Kazutoshi Shindo, Toshihiko Otomatsu, Ayako Osawa, Takashi Maoka, and Hirosuke Kanamoto
- Subjects
Lutein ,Palmitates ,Germination ,Lactuca ,Xanthophylls ,Mixed Function Oxygenases ,chemistry.chemical_compound ,Astaxanthin ,Botany ,Genetics ,Cloning, Molecular ,Carotenoid ,Alphaproteobacteria ,DNA Primers ,chemistry.chemical_classification ,Haematococcus pluvialis ,Myristates ,Singlet Oxygen ,biology ,food and beverages ,Fatty acid ,Lettuce ,Plants, Genetically Modified ,biology.organism_classification ,Carotenoids ,Blotting, Southern ,chemistry ,Animal Science and Zoology ,Green algae ,Agronomy and Crop Science ,Plasmids ,Biotechnology ,Transplastomic plant - Abstract
The plastid genome of lettuce (Lactuca sativa L.) cv. Berkeley was site-specifically modified with the addition of three transgenes, which encoded β,β-carotenoid 3,3′-hydroxylase (CrtZ) and β,β-carotenoid 4,4′-ketolase (4,4′-oxygenase; CrtW) from a marine bacterium Brevundimonas sp. strain SD212, and isopentenyl diphosphate isomerase from a marine bacterium Paracoccus sp. strain N81106. Constructed transplastomic lettuce plants were able to grow on soil at a growth rate similar to that of non-transformed lettuce cv. Berkeley and generate flowers and seeds. The germination ratio of the lettuce transformants (T0) (98.8 %) was higher than that of non-transformed lettuce (93.1 %). The transplastomic lettuce (T1) leaves produced the astaxanthin fatty acid (myristate or palmitate) diester (49.2 % of total carotenoids), astaxanthin monoester (18.2 %), and the free forms of astaxanthin (10.0 %) and the other ketocarotenoids (17.5 %), which indicated that artificial ketocarotenoids corresponded to 94.9 % of total carotenoids (230 μg/g fresh weight). Native carotenoids were there lactucaxanthin (3.8 %) and lutein (1.3 %) only. This is the first report to structurally identify the astaxanthin esters biosynthesized in transgenic or transplastomic plants producing astaxanthin. The singlet oxygen-quenching activity of the total carotenoids extracted from the transplastomic leaves was similar to that of astaxanthin (mostly esterified) from the green algae Haematococcus pluvialis.
- Published
- 2013