Genetic Systems for Condensed Tannin Biotechnology

Gruber, Margaret Y.; Ray, Heather; Auser, Patricia; Skadhauge, Birgitte; Falk, Jon; Thomsen, Kristine Rømer; Stougaard, Jens; Muir, Alister D.; Coulman, Bruce; McKersie, Bryan D.; Bowley, S. R.; Wettstein, Diter von

doi:10.1007/978-1-4615-4139-4_17

Cited by 8 publications

(8 citation statements)

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“…Lignin is usually accumulated within the cell wall, 11,42 whereas PA is usually accumulated in endoplasmic reticulum vesicles or in the plant vacuole. 52 Many variations have been found in lignin polymer composition and in the type of cross-linkage between phenolic components and polysaccharides of the cell wall. 11 Lignin variability may influence seed coat pigment extractability owing to the position of the highly lignified palisade cells adjacent to the inner integument in the seed coat, where pigment is initially deposited.…”

Section: Discussionmentioning

confidence: 99%

Histochemical characterisation of unextractable seed coat pigments and quantification of extractable lignin in the Brassicaceae

Marles

Gruber

2004

J Sci Food Agric

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The differences determined by in situ histochemical staining and thioglycolic lignin analyses provided a new view of seed coat composition in a range of yellow-and brown-seeded germplasm of the Brassicaceae. Unextractable seed coat pigments were composed of proanthocyanidin (condensed tannin) polymers. Anthocyanins were absent in all seed coat tissues. Proanthocyanidin was deposited over the entire seed coat in dark-seeded germplasm and in patches in some yellow-seeded germplasm. The seed coat and hilum of Crambe abyssinica cv Prophet and some yellow-seeded accessions contained an unidentified, unreactive brown pigment. Several new pigmentation patterns, occurring as spots and patches and surrounding the hilum, became apparent from this analysis. Thioglycolic lignin was significantly lower in yellow-seeded samples compared with the dark-seeded accessions, and the majority of the lignin occurred in the seed coat. These discoveries provide new and useful data for plant breeders and indicate the need to use more detailed analytical methods in breeding programmes that have the goal of improving seed meal quality by reducing fibre and phenolics.

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Section: Discussionmentioning

confidence: 99%

Histochemical characterisation of unextractable seed coat pigments and quantification of extractable lignin in the Brassicaceae

Marles

Gruber

2004

J Sci Food Agric

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“…Introduction of an antisense chalcone synthase gene into sainfoin produced plants exhibiting a range of CT concentrations (Gruber et al 1999). The transgene was lost after 15 mo, however, and normal CT concentrations ensued.…”

Section: Factors Affecting Condensed Tanninmentioning

confidence: 99%

“…Antisense is a particularly useful strategy for altering tannin content in tetraploid outcross pollinating forage species in which it has been difficult to produce mutations. Antisense transgenes block transcription or translation of homologous native genes, resulting in reduced levels of transgene product (Carron et al 1994;Gruber et al 1999). Figure 2 depicts the CT biosynthetic pathway in L. corniculatus and the enzymes that are targeted using antisense technology.…”

Section: Factors Affecting Condensed Tanninmentioning

confidence: 99%

“…Several new genetic systems have recently been developed to clone tannin-specific steps in the flavonoid pathway (reviewed in Gruber et al 1999). In addition, genes that regulate the anthocyanin pathway of tannin-free plant species are being inserted into several forage legumes to induce anthocyanins and CT. For example, the anthocyanin-related Can.…”

Section: Bloat Prevention Through Introduction Of Ct Into Foragesmentioning

confidence: 99%

“…The maize regulatory genes, B-Peru, C1 and Lc, have also been inserted into alfalfa (reviewed in Gruber et al 1999), but the limited number of transgenic alfalfa plants analysed to date have not expressed anthocyanins. The unpredictability of outcome using regulatory genes from other plant species to induce flux through the flavonoid pathway of forage legumes underscores the need to isolate strong promoters and regulatory genes from tannin-accumulating forage legume species.…”

Section: Bloat Prevention Through Introduction Of Ct Into Foragesmentioning

confidence: 99%

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A review of the effects of forage condensed tannins on ruminal fermentation and bloat in grazing cattle

McMahon¹,

McAllister²,

Berg³

et al. 2000

Can. J. Plant Sci.

231

176

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[469][470][471][472][473][474][475][476][477][478][479][480][481][482][483][484][485]. Condensed tannins (CT) are polyphenolic secondary plant products that are widespread in the plant kingdom. By definition, CT bind to protein and are regarded as "antinutritional" compounds which reduce protein digestibility. Variations in CT chemistry alter protein binding capacities among polymers from different plant species and developmental stages. Condensed tannins interact with proteins in feed, saliva and microbial cells, with microbial exoenzymes, and with endogenous proteins or other feed components, which alters digestive processes as compared with diets free of CT. Tannin levels exceeding 40 to 50 g kg -1 DM in forages may reduce protein and DM digestibility of the forages by ruminants. At low to moderate levels, CT increase the quantity of dietary protein, especially essential amino acids, flowing to the small intestine. Unlike alfalfa, legumes that contain CT do not cause bloat. Dietary CT may provide a means to beneficially manipulate protein digestion and/or prevent pasture bloat in ruminants. Research efforts are also currently being directed to genetically modify alfalfa to de-repress its CT biosynthetic pathway, or to move genes encoding steps of this pathway into alfalfa from other legumes. The effects of CT in forage legumes on digestion in ruminants and the potential use of tannin-rich forages for preventing bloat in grazing systems are discussed. Les tanins condensés (TC) sont des substances secondaires polyphénoliques répandues dans le règne végétal. Par essence fixés aux protéines, ils sont considérés comme substances antinutritionnelles qui réduisent la digestibilité des protéines. Leur constitution chimique, et par conséquent leur aptitude à se fixer aux protéines, fluctue selon la nature et le stade de croissance des espèces végétales. Les tanins condensés interagissent avec les protéines dans les aliments du bétail, dans la salive et dans les cellules microbiennes; avec les exoenzymes microbiens et avec les protéines endogènes ou avec d'autres composants des aliments du bétail, modifiant ainsi le processus de la digestion par rapport aux aliments sans TC. Des teneurs en tanins de plus de 40 à 50 g kg -1 m.s. dans les fourrages peuvent abaisser la digestibilité des protéines et de la matière sèche chez les ruminants. À des niveaux faibles à moyens, les TC accroissent le flux de protéines alimentaires, en particulier celui des acides aminés essentiels, vers l'intestin grêle. À la différence de la luzerne, les légumineuses qui contiennent des TC ne provoquent pas le météorisme. L'apport de TC dans l'alimentation des animaux peut être un moyen de manipuler positivement la digestion des protéines ou de prévenir le météorisme chez les ruminants au pâturage. Les recherches s'orientent également ves la modification génétique de la luzerne pour contrer l'inhibition de la biosynthèse des TC ou pour introduire dans l'espèce, à partir d'autres légumineuses, des gènes codant pour certaines étapes de cette voie....

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Transport of Flavonoids: From Cytosolic Synthesis to Vacuolar Accumulation

Kitamura

2006

The Science of Flavonoids

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Genetic Systems for Condensed Tannin Biotechnology

Cited by 8 publications

References 91 publications

Histochemical characterisation of unextractable seed coat pigments and quantification of extractable lignin in the Brassicaceae

Histochemical characterisation of unextractable seed coat pigments and quantification of extractable lignin in the Brassicaceae

A review of the effects of forage condensed tannins on ruminal fermentation and bloat in grazing cattle

Transport of Flavonoids: From Cytosolic Synthesis to Vacuolar Accumulation

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