The evolution of vitamin C biosynthetic pathways in plants and algae

2015 ◽  
Vol 86 ◽  
pp. S10
Author(s):  
Nick Smirnoff
eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Glen Wheeler ◽  
Takahiro Ishikawa ◽  
Varissa Pornsaksit ◽  
Nicholas Smirnoff

Ascorbic acid (vitamin C) is an enzyme co-factor in eukaryotes that also plays a critical role in protecting photosynthetic eukaryotes against damaging reactive oxygen species derived from the chloroplast. Many animal lineages, including primates, have become ascorbate auxotrophs due to the loss of the terminal enzyme in their biosynthetic pathway, l-gulonolactone oxidase (GULO). The alternative pathways found in land plants and Euglena use a different terminal enzyme, l-galactonolactone dehydrogenase (GLDH). The evolutionary processes leading to these differing pathways and their contribution to the cellular roles of ascorbate remain unclear. Here we present molecular and biochemical evidence demonstrating that GULO was functionally replaced with GLDH in photosynthetic eukaryote lineages following plastid acquisition. GULO has therefore been lost repeatedly throughout eukaryote evolution. The formation of the alternative biosynthetic pathways in photosynthetic eukaryotes uncoupled ascorbate synthesis from hydrogen peroxide production and likely contributed to the rise of ascorbate as a major photoprotective antioxidant.


2008 ◽  
Vol 25 (No. 3) ◽  
pp. 101-118 ◽  
Author(s):  
J. Velíšek ◽  
K. Cejpek

This review article gives a survey of the biosynthetic pathways that lead to water-soluble vitamins in microorganisms, plants and some animals. The biosynthetic pathways leading to some the B-group vitamins (biotin, folacin, cobalamins) and to vitamin C are described in detail using reaction schemes and mechanisms with enzymes involved and detailed explanations based on chemical principles and mechanisms.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242833
Author(s):  
Asaad M. Mahmood ◽  
Jim M. Dunwell

L-Ascorbic acid (ascorbate, Vitamin C) is an essential human micronutrient that is predominantly obtained from plants. It is known to work as the major antioxidant in plants, and it underpins several environmentally induced stresses due to its use as a co-factor by certain 2-oxoglutarate-dependent (2-OG) dioxygenases [2(OG)-dioxygenases]. It is important to understand the role of 2(OG)-dioxygenases in the biosynthesis of ascorbate. The present study examined contents of ascorbate and protein-protein interaction in nine T-DNA mutants of Arabidopsis containing an insert in their respective (2-OG) dioxygenase genes (At1g20270, At1g68080, At2g17720, At3g06290, At3g28490, At4g35810, At4g35820, At5g18900, At5g66060). In this study, the amount of ascorbate in five of the mutants was shown to be almost two-fold or more than two-fold higher than in the wild type. This result may be a consequence of the insertion of the T-DNA. The prediction of possible protein interactions between 2(OG)-dioxygenases and relevant ascorbate-function players may indicate the oxidative effects of certain dioxygenase proteins in plants. It is expected that certain dioxygenases are actively involved in the metabolic and biosynthetic pathways of ascorbate. This involvement may be of importance to increase ascorbate amounts in plants for human nutrition, and to protect plant species against stress conditions.


2011 ◽  
Vol 81 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Rahime Bedir Findik ◽  
Nurcihan Karakurt Hascelik ◽  
Kadir Okhan Akin ◽  
Ayse Nurcan Unluer ◽  
Jale Karakaya

Background: Striae gravidarum, a clinical condition commonly seen in pregnant women, produces serious cosmetic problems and may lead to psychological problems. Aim: The present study investigated whether there was any relation between the presence of striae in primigravid pregnant women and blood vitamin C levels, and factors thought to contribute to the formation of striae such as family history, weight gained during pregnancy, smoking status, abdominal and thigh circumference, and age. Methods: Overall, 69 primigravid women attending routine antenatal follow-up and, using prophylactic iron and vitamin preparations, underwent investigation. All were pregnant 36 or more weeks. Scoring was based on striae examination and whether striae were present. The relation between the presence of striae, vitamin C blood levels, and other factors was investigated. Results and Conclusions: Multiple logistic regression analysis showed a significant relation between the presence of striae and blood vitamin C levels (p = 0.046) and between the presence of striae and family history (p = 0.023). No significant relation was found between the presence of striae and age, weight gained during pregnancy, abdominal and thigh circumference, or smoking status. It was concluded that further, more comprehensive studies on the issue are required.


2006 ◽  
Vol 76 (6) ◽  
pp. 359-366 ◽  
Author(s):  
Rodríguez-Rodríguez ◽  
Ortega ◽  
López-Sobaler ◽  
Aparicio ◽  
Bermejo ◽  
...  

This study investigated the relationship between the intake of antioxidant nutrients and the suffering of cataracts in 177 institutionalized elderly people (61 men and 116 women) aged ≥ 65 years. Dietary intake was monitored for 7 consecutive days using a "precise individual weighing" method. Subjects, who during their earlier years were exposed by their work to sunlight, had a greater risk of suffering cataracts (OR = 3.2; Cl: 1.1–9.3, P < 0.05) than those who worked indoors. A relationship was found between increased vitamin C intake and a reduced prevalence of cataracts (i.e., when comparing those above P95 for vitamin C intake with those below P5; (OR = 0.08; Cl: 0.01–0.75, P 0.05). Among subjects with cataracts, 12.1% had vitamin C intakes of < 61 mg/day (P10) and only 2.2% had intakes of > 183 mg/day (P95) (p < 0.01). Subjects who consumed > 3290 μg/day (P95) of lutein were less likely to have cataracts (OR = 0.086; Cl: 0.007–1.084; p < 0.05) than those whose consumption was < 256 μg/day (P5). In men, high intakes of zeaxanthin seemed to provide a protective effect against the problem (OR = 0.96; Cl: 0.91–0.99; p < 0.05). The results suggest an association exists between exposure to sunlight and the development of cataracts, and that vitamin C, lutein, and zeaxanthin offer some protection against this disorder.


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