Enhancing plants with vitamin C could improve both human and crop health, according to New Zealand and Australian researchers. Because most major commodity crops have low levels of vitamin C, the researchers want to take a leaf out of certain superfruits’ DNA (which have high levels) to help fortify staple crops. They say there are many methods to turn on genes that boost vitamin C in plants, so a multi-pronged approach should be taken.
The have published their work in a paper in Current Opinion in Biotechnology 2017 titled Increasing ascorbate levels in crops to enhance human nutrition and plant abiotic stress tolerance (HERE) .
The authors are Richard C Macknight (University of Otago, Department of Biochemistry); William A Laing and Sean M Bulley (Plant & Food Research); Ronan C Broad and Alexander A. T. Johnson (University of Melbourne’s School of BioScience); and Roger P Hellens (Queensland University of Technology’s Centre for Tropical Crops and Biocommodities, Institute for Future Environments).
The abstract says:
Ascorbate (or vitamin C) is an essential human micronutrient predominantly obtained from plants. In addition to preventing scurvy, it is now known to have broader roles in human health, for example as a co-factor for enzymes involved in epigenetic programming and as regulator of cellular iron uptake. Furthermore, ascorbate is the major antioxidant in plants and underpins many environmentally induced abiotic stress responses.
Biotechnological approaches to enhance the ascorbate content of crops therefore have potential to improve both human health and abiotic stress tolerance of crops.
Identifying the genetic basis of ascorbate variation between plant varieties and discovering how some ‘super fruits’ accumulate extremely high levels of ascorbate should reveal new ways to more effectively manipulate the production of ascorbate in crops.
Ascorbate is a major antioxidant produced by plants and its primary role is to protect the cell from the damaging effects of reactive oxygen species that are produced as a result of normal cellular metabolism, especially during photosynthesis. Ascorbate also plays an important protective role under stress conditions where damage to cellular machinery causes increased production of ROS.
Changing global climate patterns are predicted to increase extreme environmental conditions, such as high temperatures and drought. Developing abiotic stress tolerant crops therefore will be critical to ensuring food security for an increasing world population, the paper says.
As plants with increased ascorbate levels are more tolerant to stress, this is a promising way to generate more resilient crops.
Increasing the ascorbate levels of crop plants should also provide a way to improving human nutrition.
The paper reviews recent research efforts to increase ascorbate in leaves (primarily aimed at stress tolerance) and edible plant parts (aimed at improved nutrition).
The work was supported by the University of Otago School of Biomedical Sciences Bequest Fund and a grant from the Australian Research Council (LP130100785).