Down-regulation of lycopene ε-cyclase expression in transgenic sweetpotato plants increases the carotenoid content and tolerance to abiotic stress.
Plant Sci
; 281: 52-60, 2019 Apr.
Article
em En
| MEDLINE
| ID: mdl-30824061
ABSTRACT
Carotenoids are required for many biological processes in plants and humans. Lycopene ε-cyclase (LCY-ε) catalyzes the conversion of lycopene into lutein via the α-branch carotenoid biosynthesis pathway. Down-regulation of IbLCY-ε by RNAi increases carotenoid accumulation and salt stress tolerance in transgenic sweetpotato calli. As the role of IbLCY-ε in carotenoid biosynthesis and environmental stress responses in whole plants is poorly understood, transgenic sweetpotato (RLE plants) with reduced expression of IbLCY-ε were developed. RLE plants contained higher levels of total carotenoid and ß-carotene, due to an elevated ß-carotene/lutein ratio rather than increased de novo biosynthesis. RLE plants showed high reactive oxygen species/radical-scavenging activity. They also exhibited an enhanced tolerance of both salt and drought stress, which was associated with lower membrane permeability and a higher photosynthetic rate, respectively. Elevated carotenoid accumulation in RLE plants mitigated the reductions in leaf photosystem II efficiency and chlorophyll induced by abiotic stress. Expression of the carotenoid cleavage genes 9-cis-epoxycarotenoid dioxygenase, carotenoid cleavage dioxygenase 1 (CCD1) and CCD4 was higher in RLE plants, as was abscisic acid accumulation. IbLCY-ε silencing thus offers an effective approach for developing sweetpotato plants with increased tolerance to abiotic stress that will grow on global marginal lands with no reduction in nutritional value.
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01-internacional
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MEDLINE
Assunto principal:
Carotenoides
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Plantas Geneticamente Modificadas
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Beta Caroteno
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Liases Intramoleculares
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Ipomoea batatas
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Licopeno
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article