Lycopene beta cyclase

Metrics details. Carotenoids are a group of C40 isoprenoid lycopene beta cyclase that play diverse biological and ecological roles in plants. Genes encoding enzymes involved in carotenoid biosynthetic pathway have been cloned. However, regulation of genes involved in carotenoid biosynthetic pathway and accumulation of specific carotenoid in chromoplasts are not well understood.

Carotenoids are important isoprenoids produced in the plastids of photosynthetic organisms that play key roles in photoprotection and antioxidative processes. Xanthi resulted in increased levels of abscisic acid ABA and especially gibberellins GAs , resulting in increased plant yield. In order to understand this phenomenon prior to exporting this genetic strategy to crops, we generated tobacco Nicotiana tabacum cv. Transplastomic plants expressing DcLCYB1 at high levels showed a wild-type-like growth, even though their pigment content was increased and their leaf GA 1 content was reduced. Remarkably, drastic changes in phytohormone content also occurred in the RNAi lines. However, external application of phytohormones was not sufficient to rescue these phenotypes, suggesting that altered photosynthetic efficiency might be another important factor explaining their reduced biomass. These results show that LCYB expression influences plant biomass by different mechanisms and suggests thresholds for LCYB expression levels that might be beneficial or detrimental for plant growth.

Lycopene beta cyclase

However, the roles and underlying mechanisms of the LCYB gene in plant responses to abiotic stresses are rarely known. This gene has not been used to improve carotenoid contents of sweetpotato, Ipomoea batatas L. Shangshu 19 plants. The genes involved in carotenoid and abscisic acid ABA biosynthesis pathways and abiotic stress responses were up-regulated in the transgenic plants. The ABA and proline contents and superoxide dismutase SOD activity were significantly increased, whereas malonaldehyde MDA and H 2 O 2 contents were significantly decreased in the transgenic plants under abiotic stresses. The overall results indicate that the IbLCYB2 gene enhances carotenoid contents and abiotic stress tolerance through positive regulation of carotenoid and ABA biosynthesis pathways in sweetpotato. This gene has the potential to improve carotenoid contents and abiotic stress tolerance in sweetpotato and other plants. Published by Elsevier B. All rights reserved. Substances Carotenoids Intramolecular Lyases lycopene cyclase-isomerase.

Article Navigation. The carotenoid biosynthetic pathway is controlled by a complex regulatory mechanism that includes transcriptional, post transcriptional and feed-back inhibition by end-products [ 822 — 24 ], lycopene beta cyclase.

Federal government websites often end in. The site is secure. We also aimed to obtain more information about the endogenous carotenoid biosynthetic pathway and thus provide experimental support for carotenoid metabolic engineering in wheat. The cyclization activity of the encoded protein was demonstrated by heterologous complementation analysis. In addition, changes in TaLCYB expression also affected the expression of several endogenous carotenogenic genes to varying degrees. Our attempt to silence it not only contributes to elucidating the mechanism of carotenoid accumulation in wheat but may also help in breeding wheat varieties with high provitamin A content through RNA interference RNAi to block specific carotenogenic genes in the wheat endosperm.

Federal government websites often end in. The site is secure. The composition of carotenoids, along with anthocyanins and chlorophyll, accounts for the distinctive range of colour found in the Actinidia kiwifruit species. Lutein and beta-carotene are the most abundant carotenoids found during fruit development, with beta-carotene concentration increasing rapidly during fruit maturation and ripening. In addition, the accumulation of beta-carotene and lutein is influenced by the temperature at which harvested fruit are stored. Plants accumulate a huge variety of secondary metabolites.

Lycopene beta cyclase

Metrics details. We also aimed to obtain more information about the endogenous carotenoid biosynthetic pathway and thus provide experimental support for carotenoid metabolic engineering in wheat. The cyclization activity of the encoded protein was demonstrated by heterologous complementation analysis. In addition, changes in TaLCYB expression also affected the expression of several endogenous carotenogenic genes to varying degrees. Our attempt to silence it not only contributes to elucidating the mechanism of carotenoid accumulation in wheat but may also help in breeding wheat varieties with high provitamin A content through RNA interference RNAi to block specific carotenogenic genes in the wheat endosperm. Carotenoids are important natural isoprenoid pigments synthesized in plants that have essential roles in protecting against excess light energy and oxidative damage, and in light-harvesting [ 1 , 2 ]. Their provitamin A activity and antioxidant properties are their most attractive functions. In higher plants, although the main pathway of carotenoid biosynthesis has been studied extensively [ 6 - 8 ], the regulatory mechanisms of carotenoid biosynthesis are still not well known.

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Therefore, these changes may partially account for the phenotypes observed in line R1 and R2 compared with the wild type Coles et al. Both vectors included a chimeric aadA gene, including aadA and plastid expression elements Svab and Maliga, , for selection of transformed plants. This qualitative GUS assay revealed that the full-length ShCYC-B promoter as well as its deletion fragments were able to drive the expression of reporter gene in different developmental stages of tomato fruit. These experiments were repeated three times in different Petri dishes. Trends in Plant Science 15 , — Journal Article. Journal of Molecular Biology , — GUS activity was apparently not detectable by visual observations in transgenic roots Fig. S4C, D. GA metabolism was also affected in the transplastomic lines.

Metrics details. Carotenoids are a group of C40 isoprenoid molecules that play diverse biological and ecological roles in plants. Genes encoding enzymes involved in carotenoid biosynthetic pathway have been cloned.

Junli Chang, Email: nc. Sorry, a shareable link is not currently available for this article. Reduced NtLCYB expression causes decreases in plant growth, pigment content, and gene expression in tobacco plants. Carotenoid biosynthesis has been extensively studied in plants such as tomato, Arabidopsis and pepper [ 2 ]. Peaks were annotated based on an accurate mass and elution profile of secondary metabolites, previously characterized in Nicotiana attenuata Li et al. The Plant Cell 15 , — Figure S5. A tool for rapid functional analysis of transgenes directly in fruit. The same phenomenon has been observed with the other wheat carotenoid biosynthetic genes, such as the different expression patterns of TaHYD1 and TaHYD2 in vegetative tissues and developing grains of wheat. Bramley PM. Sambrook J, Fritsch E. Abstract Background Carotenoids are a group of C40 isoprenoid molecules that play diverse biological and ecological roles in plants. Nat Biotechnol.