The Challenges and Opportunities Associated with Biofortification of Pearl Millet (Pennisetum glaucum) with Elevated Levels of Grain Iron and Zinc

Abstract

Deficiencies of essential micronutrients such as iron and zinc are the cause of extensive health problems in developing countries. They adversely affect performance, productivity and are a major hindrance to economic development. Since many people who suffer from micronutrient deficiencies are dependent on staple crops to meet their dietary requirements, the development of crop cultivars with increased levels of micronutrients in their edible parts is becoming increasingly recognized as a sustainable solution. This is largely facilitated by genetics and genomic platforms. The cereal crop pearl millet (Pennisetum glaucum), is an excellent candidate for genetic improvement due to its ability to thrive in dry, semi-arid regions, where farming conditions are often unfavorable. Not only does pearl millet grow in areas where other crops such as maize and wheat do not survive, it contains naturally high levels of micronutrients, proteins and a myriad of other health benefitting characteristics. This review discusses the current status of iron and zinc deficiencies and reasons why interventions such as fortification, supplementation, and soil management are neither practicable nor affordable in poverty stricken areas. We argue that the most cost effective, sustainable intervention strategy is to biofortify pearl millet with enhanced levels of bioavailable iron and zinc. We discuss how naturally occurring genetic variations present in germplasm collections can be incorporated into elite, micronutrient rich varieties and what platforms are available to drive this research. We also consider the logistics of transgenic methods that could facilitate the improvement of the pearl millet gene pool.

Discovery and validation of candidate genes for grain iron and zinc metabolism in pearl millet [Pennisetum glaucum (L.) R. Br.]

“…Pearl millet is a nutritionally important cereal not only for the rural poor but also in arid and semiarid tropics. Scientific research is still limited in comparison with other cereals 30 in this regard. To date, no genes associated with Fe and Zn metabolism genes have been characterized in P. glaucum and also their transport capabilities at the time of grain filling.…”

Conservation priorities for endangered coastal North African Pennisetum glaucum L. landrace populations as inferred from phylogenetic considerations and population structure analysis

“…In some of the driest and hottest regions of India and Africa, where agriculture is almost impossible, pearl millet plays a critical role in food security (Senthilvel et al 2008;Elsadig et al 2016). Pearl millet grains have high nutritional values, especially important amino and fatty acids contents, essential minerals, and vitamins appropriate for human nutrition (Yang et al 2012;Manwaring et al 2016). Additionally, this crop is used in brewing opaque beer and in preparing traditional dishes (Loumerem et al 2008).…”

Antinutritional factors in pearl millet grains: Phytate and goitrogens content variability and molecular characterization of genes involved in their pathways

“…Pearl millet is a staple food for more than 90 million people in Africa and Asia, thus the nutritional quality of the grains has a big impact on the diet of these populations. Efforts to improve this crop are increasing (reviewed by [ 56 – 58 ]) and very recently the sequence of pearl millet genome was released [ 43 ], opening new opportunities for accelerating breeding of this species. With the purpose to contribute to the knowledge needed for breeding programs regarding nutritional traits of pearl millet, here we analysed the content of the major antinutrient phytic acid and of the goitrogenic C-glycosylflavones of the grain and provide information on genes involved in their biosynthesis.…”