Increase of the tocochromanol content in transgenic Brassica napus seeds by overexpression of key enzymes involved in prenylquinone biosynthesis

Raclaru, Mirela; Gruber, Jens; Kumar, Rajeev; Sadre, Radin; Lühs, W.; Zarhloul, M. Karim; Friedt, Wolfgang; Frentzen, Margrit; Weier, Dagmar

doi:10.1007/s11032-006-9014-5

Cited by 58 publications

(47 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2A and Fig. S1), combined with the increased PC-8 levels in plants overexpressing Arabidopsis or corn TC (20,21), support this conclusion. All plants contain TC and PQ-9 and thus have the potential to produce PC-8.…”

Section: Discussionsupporting

confidence: 52%

“…Compared with vte2 vte1, the presence of PC-8 in vte2-1 prevented lipid oxidation during seed desiccation (15)(16)(17)(18)(19)(20) and early quiescence (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). Lipid oxidation is enhanced in vte2-1 seed (and seedlings derived thereof) only after extended quiescence (60 DAP; Figs.…”

Section: Discussionmentioning

confidence: 91%

“…Despite the absence of tocotrienols in Anabaena and Arabidopsis, their respective TCs also can convert geranylgeranyl-benzoquinols into tocotrienols, indicating a relatively broad substrate specificity of TCs (17)(18)(19). Given the structural similarities between dimethylsolanesyl-benzoquinol [plastoquinone-9 (PQ-9)] and dimethylphytyl-(or geranylgeranyl)-benzoquinol, it had been suggested that TC may also cyclize PQ-9 into PC-8, a third type of tocochromanol with a 40 carbon unsaturated side chain derived from solanesyl (20,21). The lack of PC-8 in the Arabidopsis vte1 mutant and in its orthologous corn mutant sxd1 (13, 14) ( Fig.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Plastochromanol-8 and tocopherols are essential lipid-soluble antioxidants during seed desiccation and quiescence in Arabidopsis

Mène-Saffrané¹,

Jones

DellaPenna³

2010

Proc. Natl. Acad. Sci. U.S.A.

124

102

View full text Add to dashboard Cite

Given their essential role as vitamin E, tocopherols and tocotrienols have been studied extensively in animals and plants. In contrast, our understanding of the function of plastochromanol-8 (PC-8), a third type of tocochromanol with a longer side chain, is very limited despite the wide distribution of PC-8 in the plant kingdom, including species consumed by humans. To investigate PC-8 function in vivo, we combined the Arabidopsis vte1 mutation that eliminates tocopherols and PC-8 and causes the accumulation of 2,3-dimethyl-6-phytyl-1,4-benzoquinol (DMPBQ), a redox-active tocopherol precursor, and the vte2 mutation that eliminates tocopherols without affecting PC-8. The vte2 vte1 double mutant lacks tocopherols, PC-8, and DMPBQ, and exhibits the most severe physiological and biochemical phenotypes of any tocochromanol-affected genotype isolated to date, most notably a severe seedling developmental phenotype associated with massive lipid oxidation initiated during seed desiccation and amplified during seed quiescence. In contrast, the presence of PC-8 in vte2 suppresses or attenuates all of the developmental and biochemical phenotypes observed in vte2 vte1, demonstrating that PC-8 is a lipid antioxidant in vivo. Finally, the low relative fitness of vte2 vte1 demonstrates that tocopherols and PC-8 are in vivo lipid antioxidants essential for seed plant survival.eed-bearing plants (spermatophytes) first appeared in the fossil record during the late Devonian period (about 370 mya) and represent 90% of the extant terrestrial flora (1). One of the key innovations for this evolutionary success is the capacity of seed to maintain a viable desiccated embryo for extended periods (quiescence), thereby allowing seed plants to occupy ecosystems experiencing temporary nonpermissive growth conditions (e.g., drought, frost). Extreme examples of the ability of seed to preserve plant genetic resources are demonstrated by the germination and development of plants from 2,000-y-old date seed, 1,300-y-old lotus seed, and 600-y-old canna seed (2). More commonly, seed viability gradually decreases during quiescence as a function of storage conditions (e.g., temperature, humidity, oxygen) and initial seed quality (e.g., moisture, pathogens) (3).Genetic factors underlying seed longevity have been studied only recently (reviewed in ref. 2). Protein repair and folding during seed development, maturation, and storage have been shown to be important factors affecting seed longevity. Overexpression of L-isoaspartyl O-methyltransferase 1, an enzyme that repairs damaged aspartate residues in proteins, reduced seed protein L-isoaspartyl levels, and enhanced germination compared with WT in accelerated aging tests, which subject dry seed to heat and high humidity (4). Similarly, overexpression of the heat stress transcription factor HaHSFA9 increased several heat-shock proteins in seed and improved resistance to accelerated aging treatments (5). Proper development and maturation of the seed coat (testa) also impacts seed longevity. For example, Ar...

show abstract

Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Plastochromanol-8 and tocopherols are essential lipid-soluble antioxidants during seed desiccation and quiescence in Arabidopsis

Mène-Saffrané¹,

Jones

DellaPenna³

2010

Proc. Natl. Acad. Sci. U.S.A.

124

102

View full text Add to dashboard Cite

show abstract

“…The most plausible candidate for such a secondarily limiting enzyme seems to be the tocopherol cyclase that acts downstream of HPT in the pathway ( Fig. 1) (24). To test this possibility, we decided to combine all three chloroplast enzymes of the tocopherol biosynthetic pathway (HPT, TCY, and TMT) in a synthetic operon.…”

Section: Expression Of Three Enzymes Of Thementioning

confidence: 99%

Efficient metabolic pathway engineering in transgenic tobacco and tomato plastids with synthetic multigene operons

Rijzaani

Karcher

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

172

137

View full text Add to dashboard Cite

The engineering of complex metabolic pathways requires the concerted expression of multiple genes. In plastids (chloroplasts) of plant cells, genes are organized in operons that are coexpressed as polycistronic transcripts and then often are processed further into monocistronic mRNAs. Here we have used the tocochromanol pathway (providing tocopherols and tocotrienols, collectively also referred to as "vitamin E") as an example to establish principles of successful multigene engineering by stable transformation of the chloroplast genome, a technology not afflicted with epigenetic variation and/or instability of transgene expression. Testing a series of single-gene constructs (encoding homogentisate phytyltransferase, tocopherol cyclase, and γ-tocopherol methyltransferase) and rationally designed synthetic operons in tobacco and tomato plants, we (i) confirmed previous results suggesting homogentisate phytyltransferase as the limiting enzymatic step in the pathway, (ii) comparatively characterized the bottlenecks in tocopherol biosynthesis in transplastomic leaves and tomato fruits, and (iii) achieved an up to tenfold increase in total tocochromanol accumulation. In addition, our results uncovered an unexpected light-dependent regulatory link between tocochromanol metabolism and the pathways of photosynthetic pigment biosynthesis. The synthetic operon design developed here will facilitate future synthetic biology applications in plastids, especially the design of artificial operons that introduce novel biochemical pathways into plants.

show abstract

“…The cloning of Arabidopsis VTE genes allowed the core tocochromanol pathway to be engineered for improved nutritional content and composition in various plants (Shintani and DellaPenna, 1998;Savidge et al, 2002;Collakova and DellaPenna, 2003;Karunanandaa et al, 2005;Kumar et al, 2005;Raclaru et al, 2006;Hunter and Cahoon, 2007;Li et al, 2010;DellaPenna and Mène-Saffrané, 2011;Lu et al, 2013;Zhang et al, 2013). Altering the expression of the pathway methyltransferase genes, vte3 and vte4, has profound impacts on the qualitative profiles of specific tocopherols and tocotrienols in leaves and seed without affecting total tocochromanol levels (Shintani and DellaPenna, 1998;Cheng et al, 2003;Van Eenennaam et al, 2003;Karunanandaa et al, 2005;DellaPenna and Mène-Saffrané, 2011;Lu et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Novel Loci Underlie Natural Variation in Vitamin E Levels in Maize Grain

et al. 2017

View full text Add to dashboard Cite

Tocopherols, tocotrienols, and plastochromanols (collectively termed tocochromanols) are lipid-soluble antioxidants synthesized by all plants. Their dietary intake, primarily from seed oils, provides vitamin E and other health benefits. Tocochromanol biosynthesis has been dissected in the dicot Arabidopsis thaliana, which has green, photosynthetic seeds, but our understanding of tocochromanol accumulation in major crops, whose seeds are nonphotosynthetic, remains limited. To understand the genetic control of tocochromanols in grain, we conducted a joint linkage and genome-wide association study in the 5000-line U.S. maize (Zea mays) nested association mapping panel. Fifty-two quantitative trait loci for individual and total tocochromanols were identified, and of the 14 resolved to individual genes, six encode novel activities affecting tocochromanols in plants. These include two chlorophyll biosynthetic enzymes that explain the majority of tocopherol variation, which was not predicted given that, like most major cereal crops, maize grain is nonphotosynthetic. This comprehensive assessment of natural variation in vitamin E levels in maize establishes the foundation for improving tocochromanol and vitamin E content in seeds of maize and other major cereal crops.

show abstract

Increase of the tocochromanol content in transgenic Brassica napus seeds by overexpression of key enzymes involved in prenylquinone biosynthesis

Cited by 58 publications

References 51 publications

Plastochromanol-8 and tocopherols are essential lipid-soluble antioxidants during seed desiccation and quiescence in Arabidopsis

Plastochromanol-8 and tocopherols are essential lipid-soluble antioxidants during seed desiccation and quiescence in Arabidopsis

Efficient metabolic pathway engineering in transgenic tobacco and tomato plastids with synthetic multigene operons

Novel Loci Underlie Natural Variation in Vitamin E Levels in Maize Grain

Contact Info

Product

Resources

About