Biofortification for high Fe and Zn in various Poaceae crops by using different molecular breeding and biotechnological approaches

Nicotianamine: A Key Player in Metal Homeostasis and Hyperaccumulation in Plants

“…Nutrient deficiency is known to be a limiting factor that reduces crop productivity and a widespread cause of human disease and child mortality [ 131 , 242 , 243 ]. One of the ways to solve this problem is biofortification; that is, the development of approaches to increase the level of bioavailable elements, primarily of Fe and Zn, in agricultural plants, mainly in various Poaceae crops [ 242 , 244 , 245 ]. Nicotianamine could play an important role in enhancing the nutritional value of these plants, being a candidate for biofortification technology [ 242 , 245 , 246 , 247 , 248 ].…”

“…One of the ways to solve this problem is biofortification; that is, the development of approaches to increase the level of bioavailable elements, primarily of Fe and Zn, in agricultural plants, mainly in various Poaceae crops [ 242 , 244 , 245 ]. Nicotianamine could play an important role in enhancing the nutritional value of these plants, being a candidate for biofortification technology [ 242 , 245 , 246 , 247 , 248 ]. Notably, NA can play a pivotal role in Fe trafficking in the mammalian intestine, as Fe(II)–NA can be absorbed by proton-coupled amino acid transporter 1 (PAT1) in the proximal jejunum [ 53 , 249 ].…”

“…Numerous studies using transgenic plants have shown that the increase in the expression of NAS genes and in the NA and DMA concentrations is an important factor determining Fe and Zn supply to cereal grains [ 121 , 131 , 132 , 243 , 244 , 245 , 246 , 251 , 252 , 253 ]. Conventional, agronomic and transgenic approaches have been used for the biofortification of cereals as reviewed by [ 242 , 245 , 254 ], and NAS-encoding genes have been recognized as valuable targets for generating metal-enriched crops. For example, overexpression of the OsNAS genes increased NA, Fe and Zn concentrations in O. sativa grains [ 129 , 130 , 131 , 211 , 253 , 255 ], and rice glutelin B1 promoter-driven OsNAS1 increased Fe concentrations in leaves and polished grains [ 256 ].…”

Plant adaptation to nutrient stress

“…The micronutrients, Fe and Zn play crucial roles not only in the plant growth, but are also important from the biofortification point of view when accumulated in significant amount in edible organs such as seeds and grains. Negi et al (2021) reviewed the biotechnological and molecular breeding approaches employed to improve the Fe and Zn content in grains of cereal crops. The knowledge on agronomic, genetic, and molecular approaches and future prospects to increase the mineral contents in the edible organs have been discussed.…”