Lycopene beta cyclase

Federal government websites often end in. The site is secure. We also aimed to lycopene beta cyclase more information about the endogenous carotenoid biosynthetic pathway and thus provide experimental support for carotenoid metabolic engineering in wheat.

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.

Lycopene beta cyclase

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. Carotenoids are carbon isoprenoids with polyene chains containing up to 15 conjugated double bonds Hirschberg, In plants, carotenoids have many important functions, such as chlorophyll protection from UV light, and multiple antioxidant activities, including the ability to scavenge reactive oxygen species ROS , such as singlet oxygen, and peroxyl radicals Krinsky, As membrane-bound compounds, they provide membrane stabilization Frank and Cogdell, , ; Demmig-Adams et al. Moreover, they are precursors of the apocarotenoid phytohormone abscisic acid ABA , which is involved in developmental processes and adaptive stress responses to environmental stimuli such as drought-induced stomatal closure in plants Nambara and Marion-Poll, ; Taylor et al. Overexpression of LCYB leads to increased tolerance to abiotic stresses e. This was shown under fully controlled constant and fluctuating light regimes and non-controlled climate conditions Moreno et al. However, unexpectedly, transgenic DcLCYB1 lines also showed increased transcript levels of key genes involved in several metabolic pathways related to isoprenoid metabolism, resulting in increased biosynthesis of ABA and especially of different gibberellins GAs; Fig.

Journal of Plant Growth Regulation 24— Chloroplasts of 20 cells per line were counted. Figure S2.

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. However, regulation of genes involved in carotenoid biosynthetic pathway and accumulation of specific carotenoid in chromoplasts are not well understood. One of the approaches to understand regulation of carotenoid metabolism is to characterize the promoters of genes encoding proteins involved in carotenoid metabolism. To identify promoter region necessary for regulating developmental expression of the ShCYC-B gene, the full-length promoter and its three different 5' truncated fragments were cloned upstream to the initiation codon of GUS reporter cDNA in binary vectors.

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 ].

El dia de los albañiles 3 reparto

For growth-related measurements plant height, leaf surface, flower and leaf numbers , sampling, and seed production, plants were grown under greenhouse conditions. Copy to clipboard. To improve the carotenoid or provitamin A content in wheat, the detailed regulation of carotenoid biosynthesis must be clarified. However, in the leaves of our transgenic lines Figure 6 B , carotenogenic gene transcripts and carotenoid content and composition did not show dramatic changes. GUS activity was expressed as pmol 4-MU mg protein -1 min However, some changes were consistently significant in all lines: steady state accumulation of deoxyxylulose 5-phosphate synthase2 DXS2 transcripts was highly increased, 3. Issue Section:. Apel W , Bock R. The visual observations made by histochemical GUS staining in leaf, flower and different developmental stages of fruit, were quantified by fluorometric MUG 4-methylumbelliferone glucuronide assay. Xanthi Moreno et al. Metabolic Engineering 14 , 19 — Niyogi KK. A phylogenetic tree was constructed by the Neighbor—Joining method [ 51 ] included in the ClustalW program [ 52 ] and bootstrap re-sampling analysis replicates was performed. While expression levels of carotenoid biosynthesis enzymes in the range of several percent of soluble leaf protein is certainly not required to manipulate carotenoid biosynthesis, the appropriate choice of expression elements for chloroplast transformation allows the generation of mutants covering a wide range of transgene expression levels. Xiatian Wang, Email: moc.

Metrics details.

Bock R. The Plant Cell 15 , — Federal government websites often end in. M, 1 kb Mol. Trends in Plant Science 8 , — Although gene cloning will become easier and more precise after sequencing is completed in the future, there is still plenty of work to be done and many difficulties to be overcome. At least independent transgenic events from each construct were examined for stable integration of transgene and its copy number by Southern hybridization Additional file 1 , Figure S1. RNA interference for wheat functional gene analysis. Open in a separate window. This was shown under fully controlled constant and fluctuating light regimes and non-controlled climate conditions Moreno et al.