Recently, a novel iron-regulated transporter ZmIRT2 in maize has been discovered by the Biotechnology Research Institute and Qingdao Agricultural University. ZmIRT2 involves in the regulation of iron and zinc balance in maize, which provides genetic resources and theoretical basis for breeding new crop varieties with high iron contents. These findings were published in Plant & Cell Physiology.

Iron is an essential micronutrient for the growth and development of animals and plants. Iron deficiency in humans can lead to anemia, and about one-third of the world's population are of iron deficiency to some extent. Therefore, it is of great significance to elucidate the mechanism of iron absorption in plants for the development of new crop varieties with high iron contents and improvement the iron-deficiency anemia in humans. At present, several iron transporters have been discovered, including maize Yellow Stripe 1 (ZmYS1), which has been reported to transport ferric iron into cells, and ZmIRT1 was previously identified by this team. However, the relationship and function of different iron transporters in maize are not well studied.

In this research, a novel iron-regulated transporter ZmIRT2 in maize was identified, which reversed growth defects involving Zn and Fe uptake in mutant yeast. Moreover, overexpression of ZmIRT2 in maize led to enhanced Zn and Fe accumulation in roots, shoots, and seeds of transgenic maize. The expression levels of ZmIRT2, ZmIRT1 and ZmYS1 genes in maize were further analyzed. The results imply that ZmIRT1, ZmIRT2, and ZmYS1 function cooperatively to maintain Zn and Fe homeostasis. ZmIRT2 could be used in fortification efforts to elevate the Zn and Fe levels in crop plants, which provides a new genetic resource and research approach for breeding new crop varieties with high iron contents.

Subcellular localization of ZmIRT2

Overexpression of ZmIRT2 enhanced accumulation of Zn and Fe in transgenic seeds

Dr. Li Suzhen is the first author of the paper, and Professor Chen Rumei and Professor Chen Jingtang are the co-corresponding authors. This work was supported by the National Special Program for GMO Development of China (grant number 2016ZX08003-002), the National Natural Science Foundation of China (grant number 31671768), and the National Natural Science Foundation of China (grant number 32001550).

Standard link:

https://academic.oup.com/pcp/advance-article-abstract/doi/10.1093/pcp/pcab177/6523264

By Li Suzhen (lisuzhen@caas.cn)