The Biologist’s Palette: Genetic Engineering of Anthocyanin Biosynthesis and Flower Color

665

327

There is growing recognition that many phenolic secondary metabolites present in foodstuffs may possibly exert beneficial effects on human health. This may to some degree be mediated via antioxidant actions, but a range of more specific pharmacological effects have also been proposed. Given this background, there may be favourable consequences for the general health of Western populations as a result of optimising the phenolic content of the diet. This paper reviews what is known of the function of phenolics both in the plant and in man. It also describes current understanding of the biosynthesis of phenolics in plants, with emphasis on where potential controlling steps may exist. Finally, advances in identification and isolation of the genes coding for phenolic biosynthetic enzymes or regulatory proteins are also summarised. Taken together, this information provides a basis for attempts to modify and optimise the phenolic content of food crops, using either conventional plant breeding along with manipulation of agronomic practices, or else the more targeted approaches of modern molecular biology. © 2000 Society of Chemical Industry

Section: Geneticsmentioning

confidence: 99%

Phenols in the plant and in man. The potential for possible nutritional enhancement of the diet by modifying the phenols content or profile

Parr

Bolwell

2000

665

327

“…Anthocyanins are next to the chlorophyll as the most important group of plant pigments visible to the human eye. These compounds accumulate in leaves, fruits and in flowers of all higher plants where they are considered to act as ‘nectar guides’ for pollinating insects 109. Flavones, flavonols and cinnamic acid derivatives are considered to be the main UV protectants for plants because they strongly absorb in the UV‐B and UV‐A regions of the light spectrum.…”

Section: Organic Compounds Affecting the Bioavailability Of Fe Zn Anmentioning

confidence: 99%

Potential for increasing the content and bioavailability of Fe, Zn and Ca in plants for human nutrition

Frossard¹,

Bucher²,

Mächler³

et al. 2000

443

112

This paper reviews the possibility and limits for increasing the content and bioavailability of iron (Fe), zinc (Zn) and calcium (Ca) in edible parts of staple crops, such as cereals, pulses, roots and tubers as a way to combat mineral deficiencies in human populations. Theoretically, this could be achieved by increasing the total level of Fe, Zn and Ca in the plant foods, while at the same time increasing the concentration of compounds which promote their uptake (ascorbic acid), and/or by decreasing the concentration of compounds which inhibit their absorption (phytic acid or phenolic compounds). The content of Zn and Ca in grains and fruits can in some cases be increased through soil and/or foliar applications of Zn and Ca fertilisers. Plant breeding and genetic engineering techniques, however, have the greatest potential to increase Fe and Zn content in grains, roots and tubers. The possibility of enhancing Ca and ascorbic acid content in plant foods by plant breeding and genetic engineering remained to be explored. The critical factor is to ensure that the extra minerals have an adequate bioavailability for man. Given the important role of phytic acid and polyphenols in plant physiology, reducing the levels of these compounds in the edible parts of plants does not appear to be wise although introduction of phytases which are active during digestion is an exciting possibility. © 2000 Society of Chemical Industry

“…This subject has been extensively reviewed recently. 126,253,272 There has been considerable biotechnological interest in the manipulation of¯avonoids both qualitatively and quantitatively. Attempts to identify and overexpress key genes in pathways have had limited success where there is a wild-type background expression.…”

Section: Potential Strategiesmentioning

confidence: 99%

Phenols in the plant and in man. The potential for possible nutritional enhancement of the diet by modifying the phenols content or profile

Parr¹,

Bolwell²

2000

There is growing recognition that many phenolic secondary metabolites present in foodstuffs may possibly exert bene®cial effects on human health. This may to some degree be mediated via antioxidant actions, but a range of more speci®c pharmacological effects have also been proposed. Given this background, there may be favourable consequences for the general health of Western populations as a result of optimising the phenolic content of the diet. This paper reviews what is known of the function of phenolics both in the plant and in man. It also describes current understanding of the biosynthesis of phenolics in plants, with emphasis on where potential controlling steps may exist. Finally, advances in identi®cation and isolation of the genes coding for phenolic biosynthetic enzymes or regulatory proteins are also summarised. Taken together, this information provides a basis for attempts to modify and optimise the phenolic content of food crops, using either conventional plant breeding along with manipulation of agronomic practices, or else the more targeted approaches of modern molecular biology.