How do some plants tolerate low levels of soil zinc? Mechanisms of zinc efficiency in crop plants

Abstract

Summary Researchers are beginning to understand how some plant genotypes can maintain reasonable growth and yields under low soil Zn, a trait termed zinc efficiency (ZE). Several studies have shown no correlation between ZE and root Zn uptake, Zn translocation to shoot, or shoot Zn accumulation. Furthermore, it has not been possible to conclusively link differences in leaf subcellular Zn compartmentation with ZE. However, biochemical Zn utilization, including the ability to maintain the activity of Zn requiring enzymes in response to Zn deficiency may be a key component of ZE. The next logical step in investigations of this trait is research on the genetic and molecular basis for ZE, in order to better understand the relationship between Zn utilization and ZE, and to identify the gene(s) controlling ZE. Progress in this research area could provide the knowledge to facilitate the engineering of Zn‐efficient plant varieties, which could help both crop production on marginal soils as well as possibly improve the micronutrient density of food crops to help address significant human nutrition problems related to micronutrient deficiency.

Evaluation of Soil and Foliar Applied Zinc Sources on Rice (Oryza sativa) Genotypes in Saline Environments

“…The mechanisms for improved internal Zn distribution in crop plants are due to increased phloem mobility and root to shoot Zn translocation, subcellular Zn compartmentation, and biochemical Zn use (Hacisalihoglu and Kochian, 2003;White and Broadly, 2011). Plant Zn concentration decreased and of Na and Cl increased significantly in the shoot Potassium concentrations in rice decreased with increasing NaCl levels and an increase was observed by Zn fertilization.…”

Can silicon partially alleviate micronutrient deficiency in plants? a review

“…Similarly to Fe(III), which has even lower solubility, Zn solubility in the rhizosphere should be controlled through growth media acidification and low-molecular-weight chelating agents excretion by roots (Sinclair and Krämer 2012;von Wiren et al 1996). However, some authors consider that the enhancement of Zn soil availability induced by root changes not seem to play a key role in Zn efficiency mechanism and that Zn-efficient genotypes utilize Zn more efficiently through enzymes such as Cu/ZnSOD and carbonic anhydrase (Hacisalihoglu and Kochian 2003).…”

Mapping QTLs for mineral accumulation and shoot dry biomass under different Zn nutritional conditions in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

“…However, both Zn deficiency and Zn toxicity occur worldwide, including in China, depending on Zn content and availability in the soils (Nan and Zhao 2000;Hacisalihoglu and Kochian 2003;Liu et al 2005). In addition to reduced yield due to Zn deficiency or toxicity, the transfer of excess Zn from soils to plants is an important contribution to human health exposure to Zn and more importantly to Cd that goes along with it (Friberg and Nordberg 1986).…”