reported an escalating trend (but statistically insignificant) in total chlorophyll content material in cucumber (Cucumis sativus) treated with 400 and 800 mg/kg bare-ZnO NP in soil (Zhao et al., 2013b). Zinc is an vital micronutrient in plants (Hansch and Mendel, 2009) but above a “threshold” concentration, the element can create toxicity in BML-275 dihydrochloride site unique plant species (Broadley et al., 2007; Zhao et al., 2013b). For example, Kupper et al. (1996) reported that zinc can substitute the central metal atom magnesium (Mg2+ ) in chlorophyll, causing a breakdown with the photosynthetic process. It has been reported that above 200 mg/kg (threshold value) in leaf tissues, Bacopa monniera and Lolium perenne L. cv Apollo showed phytotoxicological responses (Ali et al., 2000; Bonnet, 2000). In our study, the maximum Zn concentration in leaf was <300 mg/kg DW. This value is likely less than the threshold Zn tolerance value (not determined here) for green pea leavesFrontiers in Plant Science | http://www.frontiersin.orgJanuary 2016 | Volume 6 | ArticleMukherjee et al.Nanoparticle Doping Impacts Phytotoxicityunder our particular growth condition. Moreover, at 1000 mg/kg, carotenoid concentrations increased up to 9 fold, compared to control. Carotenoids are photo-absorbing pigments which might have protected Chl-a from photooxidation (Lichtenthaler, 1987). In leaf tissues, the unchanged (Chl-b) or increased (Chla, carotenoids) pigment content clearly suggests little or no toxicity to photosynthetic pigment production with Zn exposure. However, these findings may not exclude the possibility of damage to other components of the photosynthetic apparatus, e.g., electron transport chains and photosynthetic enzyme activities. Further biochemical investigations are warranted to evaluate the effects of ZnO NP exposure on other complex photosynthetic components.Effects of NPs on Green Pea Seed QualityExposure to Zn, regardless of type, generally had little effect on the green pea pod characteristics. The pod length, pod weight, and number of seeds per pod did not change as a function of treatment, with the exception of doped 250 mg/kg nanoparticles (data not shown). Here, the number of seeds per pod decreasedby 33 compared to that of bare ZnO NP treatment. Unlike bulk treatments, bare, fpsyg.2014.00726 doped, and coated NPs showed enhance in Zn uptake at 250 mg/kg remedy, compared to manage (Figure 6). At 1000 mg/kg, the Zn content material increased by 2?.five occasions in all NP and bulk treatment options as in comparison with handle. The ionic treatment options did not show any considerable transform in Zn uptake at 5 mg/kg or 20 mg/kg. Concentrations of Cu, Mg, and K inside the seed did not modify drastically with Zn exposure (information not shown). The Fe level was drastically elevated by the coated (250 mg/kg) and doped (1000 mg/kg) treatments. Furthermore, at 1000 mg/ kg coated therapy, P and Mn were significantly improved (Figures 6B ). All round, Zn exposure, regardless of kind or concentration, had little effect around the protein or carbohydrate profile with the green pea seeds. The level of acid-soluble (glutelin), salt-soluble (globulin), water-soluble (albumin), and alcoholsoluble (prolamin) protein fractions remained unaltered in dar.12324 all therapies (Figure S6). There was a reduce in glutelin quantity (50 ) at 1000 mg/kg doped remedy, compared to manage, but on account of significant variability and modest replica.