Increasing ascorbate levels in crops to enhance human nutrition and plant abiotic stress tolerance

Macknight, Richard C.; Laing, William A.; Bulley, Sean; Broad, Ronan C.; Johnson, Alexander; Hellens, Roger P.

doi:10.1016/j.copbio.2017.01.011

Cited by 81 publications

(77 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a major antioxidant, AsA can protect cells in living organisms from the threat of reactive oxygen species (ROS) under abiotic stress. At the same time, AsA is also a cofactor for dioxygenase and plays a vital role in most metabolic processes ( Macknight et al 2017 ). Ascorbic acid is present in a wide range of plant tissues, and is a multifunctional metabolite linked to many physiological processes like regulating photosynthesis, growth and development, cell wall biosynthesis, regulating seed germination, flowering time, fruit softening and aging, postharvest storage, mediating signal transduction and enhancing plant resistance to adverse environments ( Gallie 2013 ; Mellidou et al 2017 ; Fenech et al 2018 ).…”

Section: Introductionmentioning

confidence: 99%

Molecular evolution of GDP-L-galactose phosphorylase, a key regulatory gene in plant ascorbate biosynthesis

2020

View full text Add to dashboard Cite

Ascorbic acid (AsA) is a widespread antioxidant in living organisms, and plays essential roles in the growth and development of animals and plants as well as in the response to abiotic stress tolerance. The GDP-L-galactose phosphorylase (GGP) is a key regulatory gene in plant AsA biosynthesis that can regulate the concentration of AsA at the transcriptional and translational levels. The function and regulation mechanisms of GGP have been well understood; however, the molecular evolutionary patterns of the gene remain unclear. In this study, a total of 149 homologous sequences of GGP were sampled from 71 plant species covering the major groups of Viridiplantae, and the phylogenetic relationships, gene duplication and molecular evolution analyses of the genes were systematically investigated. Results showed that GGP genes are present throughout the plant kingdom and five shared whole-genome duplications and several lineage-specific whole-genome duplications were found, which led to the rapid expansion of GGPs in seed plants, especially in angiosperms. The structure of GGP genes was more conserved in land plants, but varied greatly in green algae, indicating that GGP may have undergone great differentiation in the early stages of plant evolution. Most GGP proteins had a conserved motif arrangement and composition, suggesting that plant GGPs have similar catalytic functions. Molecular evolutionary analyses showed that GGP genes were predominated by purifying selection, indicating that the gene is functionally conserved due to its vital importance in AsA biosynthesis. Most of the branches under positive selection identified by the branch-site model were mainly in the chlorophytes lineage, indicating episodic diversifying selection may contribute to the evolution of GGPs, especially in the chlorophyte lineage. The conserved function of GGP and its rapid expansion in angiosperms maybe one of the reasons for the increase of AsA content in angiosperms, enabling angiosperms to adapt to changing environments.

show abstract

Section: Introductionmentioning

confidence: 99%

Molecular evolution of GDP-L-galactose phosphorylase, a key regulatory gene in plant ascorbate biosynthesis

2020

View full text Add to dashboard Cite

show abstract

“…Ascorbic acid (known as Vitamin C, AsA), one of the essential vitamins for human beings, also has important roles in growth and development [ 1 , 2 ]. As the most abundant antioxidant of plants, AsA is involved widely in scavenging reactive oxygen species (ROS) during the photosynthetic electron transfer and stress responses [ 2 ]. Therefore, the synthesis of AsA is related closely to environmental stresses [ 2 , 3 ].…”

Section: Introductionmentioning

confidence: 99%

“…As the most abundant antioxidant of plants, AsA is involved widely in scavenging reactive oxygen species (ROS) during the photosynthetic electron transfer and stress responses [ 2 ]. Therefore, the synthesis of AsA is related closely to environmental stresses [ 2 , 3 ].…”

Section: Introductionmentioning

confidence: 99%

The Synthesis of Ascorbic Acid in Rice Roots Plays an Important Role in the Salt Tolerance of Rice by Scavenging ROS

Wang

Zhao

Qin

et al. 2018

IJMS

View full text Add to dashboard Cite

The root plays an important role in the responses of plants to stresses, but the detailed mechanisms of roots in stress responses are still obscure. The GDP-mannose pyrophosphate synthetase (GMPase) OsVTC1-3 is a key factor of ascorbic acid (AsA) synthesis in rice roots. The present study showed that the transcript of OsVTC1-3 was induced by salt stress in roots, but not in leaves. Inhibiting the expression of OsVTC1-3 by RNA interfering (RI) technology significantly impaired the tolerance of rice to salt stress. The roots of OsVTC1-3 RI plants rapidly produced more O2−, and later accumulated amounts of H2O2 under salt stress, indicating the impaired tolerance of OsVTC1-3 RI plants to salt stress due to the decreasing ability of scavenging reactive oxygen species (ROS). Moreover, exogenous AsA restored the salt tolerance of OsVTC1-3 RI plants, indicating that the AsA synthesis in rice roots is an important factor for the response of rice to salt stress. Further studies showed that the salt-induced AsA synthesis was limited in the roots of OsVTC1-3 RI plants. The above results showed that specifically regulating AsA synthesis to scavenge ROS in rice roots was one of important factors in enhancing the tolerance of rice to salt stress.

show abstract

“…Enhancement strategies have focused on increasing the activity of key biosynthetic enzymes, and elevation of the activity of GGP has had the greatest effect on concentrations of vitamin C giving 6.2-fold more in tomato fruit (up to 111 mg g À1 FW), 3.0fold more in potato tubers (up to 36 mg g À1 FW), 2.1-fold more in strawberries (up to 131 mg g À1 FW) (Bulley et al, 2012) and 2.5fold more in rice (Zhang et al, 2015a). Combined expression of GGP/vtc2 and the gene encoding GDP-mannose epimerase (GME/ vtc4) has been attempted to overcome the problem of GME becoming rate-limiting in plants with high GGP activity, but without very strong effects on ascorbate concentrations in leaves (Imai et al, 2012;Macknight et al, 2017). Recent results showing post-transcriptional regulation of GGP production via an untranslated open reading frame (ORF) in the 5 0 untranslated region of the GGP/vtc2 gene in response to ascorbate concentrations, suggest that removal of this homeostatic regulatory unit (by mutation or genome editing) could elevate ascorbate synthesis substantially (Laing et al, 2015).…”

Section: Enhancing Vitamin C (Ascorbate) Concentrations In Food Cropsmentioning

confidence: 99%

“…Recent results showing post-transcriptional regulation of GGP production via an untranslated open reading frame (ORF) in the 5 0 untranslated region of the GGP/vtc2 gene in response to ascorbate concentrations, suggest that removal of this homeostatic regulatory unit (by mutation or genome editing) could elevate ascorbate synthesis substantially (Laing et al, 2015). Transient assays of deregulated GGP and GME in Nicotiana benthamiana leaves suggest that increases in ascorbate concentrations of the order of 12-fold (up to 300 mg g À1 FW) might be achievable (Laing et al, 2015;Macknight et al, 2017).…”

Section: Enhancing Vitamin C (Ascorbate) Concentrations In Food Cropsmentioning

confidence: 99%

Medicine is not health care, food is health care: plant metabolic engineering, diet and human health

Martin

2017

New Phytologist

105

View full text Add to dashboard Cite

Contents 699I.699II.700III.700IV.706V.707VI.714714References714 Summary Plants make substantial contributions to our health through our diets, providing macronutrients for energy and growth as well as essential vitamins and phytonutrients that protect us from chronic diseases. Imbalances in our food can lead to deficiency diseases or obesity and associated metabolic disorders, increased risk of cardiovascular diseases and cancer. Nutritional security is now a global challenge which can be addressed, at least in part, through plant metabolic engineering for nutritional improvement of foods that are accessible to and eaten by many. We review the progress that has been made in nutritional enhancement of foods, both improvements through breeding and through biotechnology and the engineering principles on which increased phytonutrient levels are based. We also consider the evidence, where available, that such foods do enhance health and protect against chronic diseases.

show abstract

Increasing ascorbate levels in crops to enhance human nutrition and plant abiotic stress tolerance

Cited by 81 publications

References 64 publications

Molecular evolution of GDP-L-galactose phosphorylase, a key regulatory gene in plant ascorbate biosynthesis

Molecular evolution of GDP-L-galactose phosphorylase, a key regulatory gene in plant ascorbate biosynthesis

The Synthesis of Ascorbic Acid in Rice Roots Plays an Important Role in the Salt Tolerance of Rice by Scavenging ROS

Medicine is not health care, food is health care: plant metabolic engineering, diet and human health

Contact Info

Product

Resources

About