Essential metal for plants

Abstract

Plant Science Although zinc (Zn) is an essential micronutrient for plants and humans, much of the world's agricultural land is deficient in Zn. Sinclair et al. studied plants that are unable to deliver Zn into their own xylem. The plant shoots were thus internally starved regardless of whether Zn was available from the root. The Zn-starved shoots signaled to roots to increase Zn supplies. In response, the roots up-regulated expression of the genes encoding metal transport/tolerance protein 2 (MTP2) and heavy metal ATPase 2 (HMA2). Local Zn deficiency in roots left these same genes unaffected. It seems that Zn taken up in lateral roots is transported into the endoplasmic reticulum by MTP2, thus gaining access to the intercellular symplastic network. The Zn then progresses from outer epidermal cells toward the core of the root, where it is exported by HMA2 into the xylem for transport to the shoot. The shoot asks for what it needs, and the root delivers. Plant Cell 30 , 2463 (2018).