Linking the key physiological functions of essential micronutrients to their deficiency symptoms in plants.

In this review, we untangle the physiological key functions of the essential micronutrients and link them to the deficiency responses in plants. Knowledge of these responses at the mechanistic level, and the resulting deficiency symptoms, have improved over the last decade and it appears timely to review recent insights for each of them. A proper understanding of the links between function and symptom is indispensable for an accurate and timely identification of nutritional disorders, thereby informing the design and development of sustainable fertilization strategies.

The molecular-physiological functions of mineral macronutrients and their consequences for deficiency symptoms in plants.

The visual deficiency symptoms developing on plants constitute the ultimate manifestation of suboptimal nutrient supply. In classical plant nutrition, these symptoms have been extensively used as a tool to characterise the nutritional status of plants and to optimise fertilisation. Here we expand this concept by bridging the typical deficiency symptoms for each of the six essential macronutrients to their molecular and physiological functionalities in higher plants.

Temporal and Spatial Patterns of Zinc and Iron Accumulation during Barley ( L.) Grain Development.

Breeding and engineering of biofortified crops will benefit from a better understanding of bottlenecks controlling micronutrient loading within the seeds. However, few studies have addressed the changes in micronutrient concentrations, localization, and speciation occurring over time. Therefore, we studied spatial patterns of zinc and iron accumulation during grain development in two barley lines with contrasting grain zinc concentrations.

Optimising the foliar uptake of zinc oxide nanoparticles: Do leaf surface properties and particle coating affect absorption?

Foliar absorption of zinc (Zn) is limited by several barriers, the first of which is the leaf cuticle. In this study, we investigated the absorption of Zn from Zn oxide nanoparticles (ZnO-NPs) in wheat (Triticum aestivum cv Gladius) and sunflower (Helianthus annuus cv Hyoleic 41) to determine the importance of NP surface coating for Zn absorption. Fourier transform infrared (FTIR) spectroscopy showed a higher polysaccharide content in the wheat cuticle than sunflower, indicated by a more pronounced glycosidic bond at 1020 cm , but wax and cutin content were similar.

Bioimaging Techniques Reveal Foliar Phosphate Uptake Pathways and Leaf Phosphorus Status.

Global demand for phosphorus (P) requires new agronomic practices to address sustainability challenges while increasing food production. Foliar P fertilization could increase P use efficiency; however, leaf entry pathways for inorganic phosphate ion (Pi) uptake remain unknown, and it is unclear whether foliar P applications can meet plant nutrient demands. We developed two techniques to trace foliar P uptake in P-deficient spring barley () and to monitor the effectiveness of the treatment on restoring P functionality.

The search for candidate genes associated with natural variation of grain Zn accumulation in barley.

Combating hidden hunger through molecular breeding of nutritionally enriched crops requires a better understanding of micronutrient accumulation. We studied natural variation in grain micronutrient accumulation in barley ( L.) and searched for candidate genes by assessing marker-trait associations (MTAs) and by analyzing transcriptional differences between low and high zinc (Zn) accumulating cultivars during grain filling.

The impact of silicon on cell wall composition and enzymatic saccharification of .

Background: Plants and in particular grasses benefit from a high uptake of silicon (Si) which improves their growth and productivity by alleviating adverse effects of biotic and abiotic stress. However, the silicon present in plant tissues may have a negative impact on the processing and degradation of lignocellulosic biomass. Solutions to reduce the silicon content either by biomass engineering or development of downstream separation methods are therefore targeted.

A laser ablation ICP-MS based method for multiplexed immunoblot analysis: applications to manganese-dependent protein dynamics of photosystem II in barley (Hordeum vulgare L.).

Manganese (Mn) constitutes an essential co-factor in the oxygen-evolving complex of photosystem II (PSII). Consequently, Mn deficiency reduces photosynthetic efficiency and leads to changes in PSII composition. In order to study these changes, multiplexed protein assays are advantageous.

Golgi localized barley MTP8 proteins facilitate Mn transport.

Many metabolic processes in plants are regulated by manganese (Mn) but limited information is available on the molecular mechanisms controlling cellular Mn homeostasis. In this study, a yeast assay was used to isolate and characterize two genes, MTP8.1 and MTP8.

Multiplexed quantification of plant thylakoid proteins on Western blots using lanthanide-labeled antibodies and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

We have developed a novel calibration method that allows concurrent quantification of multiple proteins by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) after Western blotting. Calibrants were made of nitrocellulose membranes doped with lanthanide standards. Excellent linearity was obtained in the interval from 0 to 24 ng lanthanide cm(-2).

Barley metallothioneins: MT3 and MT4 are localized in the grain aleurone layer and show differential zinc binding.

Metallothioneins (MTs) are low-molecular-weight, cysteine-rich proteins believed to play a role in cytosolic zinc (Zn) and copper (Cu) homeostasis. However, evidence for the functional properties of MTs has been hampered by methodological problems in the isolation and characterization of the proteins. Here, we document that barley (Hordeum vulgare) MT3 and MT4 proteins exist in planta and that they differ in tissue localization as well as in metal coordination chemistry.

Elevated phosphorus impedes manganese acquisition by barley plants.

The occurrence of manganese (Mn) deficiency in cereal crops has increased in recent years. This coincides with increasing phosphorus (P) status of many soils due to application of high levels of animal manure and P-fertilizers. In order to test the hypothesis that elevated P my lead to Mn deficiency we have here conducted a series of hydroponics and soil experiments examining how the P supply affects the Mn nutrition of barley.

The effects of the loss of TIP1;1 and TIP1;2 aquaporins in Arabidopsis thaliana.

Loss of aquaporin TIP1;1 in Arabidopsis has been suggested to result in early senescence and plant death. This was based on the fact that a partial reduction of TIP1;1 by RNA interference (RNAi) led to gradual phenotypes, ranging from indistinguishable from wild type to lethality, depending on the degree of downregulation of the target messenger, and displaying pleiotropic effects in primary metabolism and cell signalling. A hypothesis was put forward to suggest that TIP1;1, apart from its transport function, may play an essential role in vesicle routing.