Tansley Review No. 111

Abstract

Zinc deficiency is one of the most widespread micronutrient deficiencies in plants and causes severe reductions in crop production. There are a number of physiological impairments in Zn-deficient cells causing inhibition of the growth, differentiation and development of plants. Increasing evidence indicates that oxidative damage to critical cell compounds resulting from attack by reactive O # species (ROS) is the basis of disturbances in plant growth caused by Zn deficiency. Zinc interferes with membrane-bound NADPH oxidase producing ROS. In Zn-deficient plants the iron concentration increases, which potentiates the production of free radicals. The Zn nutritional status of plants influences photooxidative damage to chloroplasts, catalysed by ROS. Zinc-deficient leaves are highly light-sensitive, rapidly becoming chlorotic and necrotic when exposed to high light intensity. Zinc plays critical roles in the defence system of cells against ROS, and thus represents an excellent protective agent against the oxidation of several vital cell components such as membrane lipids and proteins, chlorophyll, SH-containing enzymes and DNA. The cysteine, histidine and glutamate or aspartate residues represent the most critical Znbinding sites in enzymes, DNA-binding proteins (Zn-finger proteins) and membrane proteins. In addition, animal studies have shown that Zn is involved in inhibition of apoptosis (programmed cell death) which is preceded by DNA and membrane damage through reactions with ROS.

Fortification of micronutrients for efficient agronomic production: a review

“…In terms of abiotic stress mitigation, Zn has also been shown to modulate the activity of enzymes, such as the membrane-bound NADPH oxidase (Cakmak 2000) involved in the homeostasis of reactive oxygen species that, at relevant levels, mediate important cellular functions like host defense and signaling during drought or other abiotic stresses (Golldack et al 2014). In agronomic studies conducted under drought conditions with adequate N and P (70:70 kg ha −1 ) supply, Bagci et al (2007) demonstrated that while inadequate water supply under rain-fed systems could decrease average wheat grain yield by as much as 25 %, the addition of Zn (23 kg ha −1 as a foliar application) increased wheat yield by 16 %.…”

Arabidopsis thaliana26S Proteasome Subunits RPT2a and RPT5a Are Crucial for Zinc Deficiency-Tolerance

“…24) We speculated that the Zn deficiency-sensitive rpt mutants suffer strongly from oxidative stress under such conditions. To investigate this possibility, we determined the lipid peroxidation levels and accumulation of oxidized proteins in Zndeficient shoots (Fig.…”

Uptake of seed-applied copper by maize and the effects on seed vigor

“…The initial stages of growth is a crucial phase for the uptake of micronutrients by plants, as higher concentrations of these elements are found in young plant tissues (Cakmak, 2000). A proper supply of micronutrients during this phase may result on a better crop establishment in the field and a faster initial development of plants, which are crucial aspects for obtaining higher grain yields in maize (Dias et al, 2010;Mondo et al, 2013).…”