Genetic and genomic interventions in crop biofortification: Examples in millets

Abstract

Micronutrient malnutrition is a serious threat to the developing world’s human population, which largely relies on a cereal-based diet that lacks diversity and micronutrients. Besides major cereals, millets represent the key sources of energy, protein, vitamins, and minerals for people residing in the dryland tropics and drought-prone areas of South Asia and sub-Saharan Africa. Millets serve as multi-purpose crops with several salient traits including tolerance to abiotic stresses, adaptation to diverse agro-ecologies, higher productivity in nutrient-poor soils, and rich nutritional characteristics. Considering the potential of millets in empowering smallholder farmers, adapting to changing climate, and transforming agrifood systems, the year 2023 has been declared by the United Nations as the International Year of Millets. In this review, we highlight recent genetic and genomic innovations that can be explored to enhance grain micronutrient density in millets. We summarize the advances made in high-throughput phenotyping to accurately measure grain micronutrient content in cereals. We shed light on genetic diversity in millet germplasm collections existing globally that can be exploited for developing nutrient-dense and high-yielding varieties to address food and nutritional security. Furthermore, we describe the progress made in the fields of genomics, proteomics, metabolomics, and phenomics with an emphasis on enhancing the grain nutritional content for designing competitive biofortified varieties for the future. Considering the close genetic-relatedness within cereals, upcoming research should focus on identifying the genetic and genomic basis of nutritional traits in millets and introgressing them into major cereals through integrated omics approaches. Recent breakthroughs in the genome editing toolbox would be crucial for mainstreaming biofortification in millets.

The power of magnesium: unlocking the potential for increased yield, quality, and stress tolerance of horticultural crops

“…Traditional breeding methods have capitalized on vast natural genetic variations associated with Mg 2+ absorption and utilization. Diverse germplasm collections serve as a rich reservoir, where researchers have identified genotypes exhibiting superior nutrient uptake or resilience under nutrient-deficient scenarios ( Kudapa et al., 2023 ). Complementing this approach is Quantitative Trait Locus (QTL) Mapping.…”

Revealing Consequences of the Husking Process on Nutritional Profiles of Two Sorghum Races on the Male Sterility Line

“…On the other hand, the grain color profile is crucial since it directly impacts the grain's nutritional composition [20]. Sorghum exhibits variations in pericarp color, involving white, black, and red, which might affect the nutritional and antioxidant characteristics due to the flavonoid concentration in the aleurone layer and seed coat of the grain [26]. The color of the grain is mostly governed by genetic regulation, with several alleles controlling the grain's color [24].…”

Finger millet (Eleusine coracana) improvement: Challenges and prospects—A review

“…It has a C 4 photosynthesis and is adapted to growing in the semi‐arid tropics. The crop has exceptional genetic plasticity with tolerance to extreme temperatures (Kudapa et al, 2023; Yogeesh et al, 2016), moisture stress (Ceasar et al, 2018; Hittalmani et al, 2017), aluminium toxicity (Brhane, Fikiru, et al, 2017) and salinity (Divya et al, 2022; Rahman et al, 2014). The gluten‐free grain has multiple uses, such as food and beverage preparations.…”

“…The stalk is used as livestock feed, thatching and bedding material. The grain has extended storage quality (Ceasar et al, 2018), with unique nutritional composition, including high levels of Ca, Fe, Zn, K, Mg, Mn, dietary fibre, phenolic compounds, essential amino acids (e.g., cystine, methionine and tryptophan) (Backiyalakshmi et al, 2023; Devi et al, 2011; Kudapa et al, 2023; Maharajan et al, 2022). Finger millet food products are believed to lower blood cholesterol levels and blood pressure (Anitha, Botha, et al, 2021) and possess anti‐cancer (Chandrasekara & Shahidi, 2011; Devi et al, 2011); and anti‐ageing properties (Puranik et al, 2020; Kumar, Rani, et al, 2021).…”