SummaryTo cope with manganese (Mn) deficiency, plants have evolved an efficient transport system to uptake and redistribute Mn. However, the underlying molecular mechanisms remain to be demonstrated.We carried out a forward genetic screen in a root high-affinity Mn transporter nramp1 mutant background in Arabidopsis thaliana and identified an uncharacterized Mn transport NRAMP2. We investigated the effect of nramp2 mutation on root growth and reactive oxygen species (ROS) accumulation and we also examined the NRAMP2 expression pattern, and the subcellular localization and transport activity of NRAMP2.Mutation of NRAMP2 impaired plant growth, while overexpression of NRAMP2 improved plant growth under low Mn conditions. In the nramp2-1nramp1 double mutant, Mn deficiency inhibited root cell elongation and root hair development, which was associated with increased hydrogen peroxide (H 2 O 2 ) accumulation. NRAMP2 is preferentially localized to the trans-Golgi network. NRAMP2 has Mn influx transport activity in yeast, and mutation of NRAMP2 led to greater Mn retention in roots.Our results suggest that under Mn-deficient conditions, increased accumulation of H 2 O 2 is partially responsible for the root growth inhibition and NRAMP2 is involved in remobilization of Mn in Golgi for root growth.

Adaptive infrared (IR) electrochromic devices driven by electrical energy have considerable potential use in intelligent IR thermal management application in the future.

Background Metal homeostasis is critical for plant growth, development and adaptation to environmental stresses and largely governed by a variety of metal transporters. The plant ZIP ( Z n-regulated transporter, I ron-regulated transporter-like P rotein) family proteins belong to the integral membrane transporters responsible for uptake and allocation of essential and non-essential metals. However, whether the ZIP family members mediate metal efflux and its regulatory mechanism remains unknown. Results In this report, we provided evidence that OsZIP1 is a metal-detoxified transporter through preventing excess Zn, Cu and Cd accumulation in rice. OsZIP1 is abundantly expressed in roots throughout the life span and sufficiently induced by excess Zn, Cu and Cd but not by Mn and Fe at transcriptional and translational levels. Expression of OsZIP-GFP fusion in rice protoplasts and tobacco leaves shows that OsZIP1 resides in the endoplasmic reticulum (ER) and plasma membrane (PM). The yeast ( Saccharomyces cerevisiae ) complementation test shows that expression of OsZIP1 reduced Zn accumulation. Transgenic rice overexpressing OsZIP1 grew better under excess metal stress but accumulated less of the metals in plants. In contrast, both oszip1 mutant and RNA interference (RNAi) lines accumulated more metal in roots and contributed to metal sensitive phenotypes. These results suggest OsZIP1 is able to function as a metal exporter in rice when Zn, Cu and Cd are excess in environment. We further identified the DNA methylation of histone H3K9me2 of OsZIP1 and found that OsZIP1 locus, whose transcribed regions imbed a 242 bp sequence, is demethylated, suggesting that epigenetic modification is likely associated with OsZIP1 function under Cd stress. Conclusion OsZIP1 is a transporter that is required for detoxification of excess Zn, Cu and Cd in rice. Electronic supplementary material The online version of this article (10.1186/s12870-019-1899-3) contains supplementary material, which is available to authorized users.

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In laboratory experiments, we show that naupliar survival and egg production by the copepod Acartia tonsa was significantly lower when they were fed iron-depleted algal cells than when they were fed a diet of Fe-replete cells that had two orders of magnitude higher Fe levels. Naupliar survival after 1 week was reduced from 60% for copepods feeding on Fe-replete diatoms (Thalassiosira oceanica) to 0% for those feeding on Fe-depleted cells. The decline of egg production rate was greatest (83%) when T. oceanica was used as prey and smaller (20-30%) when the cryptophyte Rhodomonas salina and the prymnesiophyte Isochrysis galbana were used as food. The assimilation rates of Fe and C from Fe-replete and Fe-depleted algae were determined using radioisotopes. Egg production was hyperbolically dependent on the Fe assimilation rate (r 2 5 0.71). The effect of Fe on copepod reproduction rates could not be explained by changes in ingestion rate and the rate of carbon assimilated, because there was no significant difference of ingestion rate and C assimilation between Fe-replete and Fe-depleted treatments. Iron might limit zooplankton productivity in high-nutrient, low-chlorophyll regions.

In this study, a WO 3 film with controllable crystallinity has been prepared by radio frequency magnetron sputtering. The WO 3 film with about 400 nm thickness and controllable crystallinity not only has the advantages of amorphous WO 3 with large transmittance modulation and short switching response time but also has the outstanding cyclic stability of crystalline WO 3 . Therefore, this WO 3 film exhibits superior electrochromic performances including large transmittance modulation in the near infrared regime (72.5% at λ = 1000 nm), short coloration/bleaching switching response time (5.3 s for coloration and 3.0 s for bleaching), high coloration efficiency at λ = 1000 nm (80.5 cm 2 C −1 ), and excellent cycle stability. The strategy of preparing a WO 3 film with controllable crystallinity by a simple magnetron sputtering method presents an innovative direction to obtain high-performance WO 3 electrochromic materials applied in the fields of smart windows, spacecraft thermal control, and infrared camouflage.

Vanadium dioxide (VO2)-based thermochromic coatings has attracted considerable attention in the application of smart windows as a result of their intriguing property of metal–insulator transition at moderate temperatures. However, the practical requirements of smart windows, i.e., the high luminous transmittance of T lum > 60% and large solar modulating ability of ΔT sol > 10%, are competing to a large extent and hardly satisfied simultaneously. Here, we proposed a facile and universal method to prepare VO2 coatings for exceeding the criteria above using double-sided localized surface plasmon resonances (LSPRs), which are excited by the VO2 nanoparticles dispersed evenly on both surfaces of the fused silica substrate. With subtle engineering of the sol–gel and heat treatment processes, the morphology of as-prepared VO2 nanoparticles and corresponding LSPRs are controlled to achieve a high luminous transmittance (T lum = 68.2%) and solar modulating ability (ΔT sol = 11.7%) simultaneously. Further simulation suggests that the double-sided LSPRs can collectively enhance the performance of VO2 smart coatings. Moreover, the double-sided VO2 nanoparticle coatings demonstrate stable performance with no more than 1% degradation of T lum and ΔT sol after 1500 cycles. This study provides an alternative strategy to obtain high-quality VO2 (M) solar modulating coatings.

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