RESUMO
Aims: To characterize the growth, carbon assimilation and quality of Ipomoea aquatica as influenced by magnetic nanoparticles (MNP) application as well as to determine the best rates of iron oxide nanoparticles that give high growth, carbon assimilation and quality of Ipomoea aquatica. Study Design: Ipomoea aquatica plants were exposed to four different treatments of magnetic iron oxide nanoparticles (Fe3O4) (0, 50, 100 and 150 mg L-1). The experiment was conducted in a randomized complete block design (RCBD) with 3 replications. One unit of experiment consisted of 8 plants and there were 96 plants used in the experiment. Place and Duration of Study: Department of Biology, Faculty of Science, Universiti Putra Malaysia, between March 2018 and July 2018. Methodology: The growth parameters measured included: plant height, basal diameter, total leaf number, leaf temperature, total chlorophyll content and plant biomass. The carbon assimilation parameters were measured using IRGA (Infrared Gas Analyzer, LICOR 6400 XT Portable Photosynthesis System). i.e. transpiration rate (E), stomatal conductance and water use efficiency (WUE). The chlorophyll fluorescence were measured by using Pocket PEA that measured maximum efficiency of photosystem ii, (fv/fm), maximum quantum yield of phytochemical and non-photochemical process in photosystem II (fv/fo), minimal fluorescence (fo), performance index (PI) and Density of Reaction Centers Per PSII Antenna Chlorophyll (RC/ABS). Total phenolics and flavonoids contents in leaves were measured using Folin-Ciocalteu method. Results: It was observed that plant height, shoot length, plant temperature, total biomass, and total chlorophyll content were significantly influenced (p≤0.05) by the different concentrations of magnetic nanoparticles. The net photosynthetic rate (A), transpiration rate (E), stomatal conductance (gs), maximum efficiency of photosystem II (Fv/fm), maximum quantum yield of phytochemical and non-photochemical process in photosystem II (Fv/fo), performance index and the density of reaction centers per PSII antenna chlorophyll of Ipomoea aquatica were significantly reduced at higher concentration of magnetic nanoparticles. However, water use efficiency and minimal fluorescence value (Fo) of Ipomoea aquatica increased with increase of MNP concentration. In addition, the application of magnetic nanoparticles significantly influenced (P≤0.05) the total flavonoids and total phenolics content in water spinach. Both of these parameters were increased when higher concentration of magnetic nanoparticles was applied to Ipomoea aquatica. This study showed that MNP affected the growth, carbon assimilation and secondary metabolites production of Ipomoea aquatica. Conclusion: In conclusion, the higher concentration of magnetic nanoparticles reduced the growth rate and carbon assimilation of water spinach and enhanced the production of secondary metabolites.
RESUMO
Aims: This study was conducted to investigate the effect of zinc oxide nanoparticles towards the Persicaria minor that can be used as a guidance for further toxicity investigation of ZnO-NPs. Study Design: A Completely Randomized Block Design (RCBD) was used with three replication. Each unit was consisted with eight plants and the total of 96 plants were used in this study. Place and Duration of Study: This study was conducted in plot 1, Vegetables Field plot for Teaching and Research, Taman Pertanian Universiti, Universiti Putra Malaysia (UPM) Selangor, Malaysia, from May 2018 until August 2018. Methodology: Persicaria minor were exposed to four different concentration of zinc oxide nanoparticles (ZnO-NPs) which were (50,100 and 150 mg/L) and 0 mg/L as a control. The ZnO-NPs was dissolved in distilled water before being applied to plants. 40 mL of ZnO-NPs solution was applied to each plant. The growth, carbon assimilation and also secondary metabolites were measured in this experiment. Results: The results showed that the treatment of zinc oxide nanoparticles enhanced growth of the Persicaria minor as the plant treated with zinc oxide nanoparticles had higher plant height and total biomass when compared to control treatment. However, the analysis revealed that the treatment of zinc oxide nanoparticles highly and significantly influenced the carbon assimilation and quality of this plant as the treated plants showed reduction in chlorophyll content, photosynthesis rate, stomatal conductance and transpiration rate but increased in production of secondary metabolites. The increased in production of plant secondary metabolites may be attributed by the plant protection mechanism due to metabolic stress caused by high concentration of zinc oxide nanoparticles. Conclusion: This research will progressively help in contributing some reliable and valid data on the effect of zinc oxide nanoparticles (ZnO-NPs), towards the Persicaria minor that can be used as guidance for further experimental investigation regarding this field.
RESUMO
Aims: This study was conducted to study the growth, leaf gas exchange and secondary metabolites of Orthosiphon stamineus as affected by Multiwalled carbon nanotubes application (MWCNT). Study Design: Orthosiphon stamineus were exposed to four different multi-walled carbon nanotubes (MWCNTs) concentration (0, 700, 1400 and 2100 mg L-1). The experiment was organized in a randomized complete block (RCBD) design with three replications. Each experimental unit consisted of twelve plants, and there were a total of 144 plants used in the experiment. Place and Duration of Study: Department of Biology, Faculty of Science Universiti Putra Malaysia between November 2016 to March 2017. Methodology: Each plant was watered with 50 mL of MWCNTs solution in week 2 and 9. The leaves number were counted manually and the total plant biomass was taken by calculating the dry weight of root, stem, and leaf per seedling The total chlorophyll content in the leaves was measured using a SPAD chlorophyll meter. The leaf gas exchange was determined using LI-6400XT portable photosynthesis system. Total phenolics and flavonoid were determined using Folin-Ciocalteu reagent. Results: It was found that application of MWCNTs would reduce the growth characteristics of this plant that was shown by decreased leaf numbers, total biomass and total chlorophyll content (TCC). As MWCNTs concentration increases from 0 > 2100 mg L-1, the leaf gas exchange parameter also shows reduced patterns. Generally, as the rate of MWCNTs increased from 700 > 2100 mg L-1 MWCNTs reduce the net photosynthesis (A), stomatal conductance (gs), transpiration rate (E) and increased the plant water use efficiency. The production of the secondary metabolites was directly dependable on MWCNTs concentration. As the rate was enhanced from 0 > 700 > 1400 > 2100 mg L-1 the production of total phenolics and flavonoids was enhanced. Conclusion: The current study revealed that the high application of MWCNTs concentration reduce the growth rate of O. stamineus, leaf gas exchange and simultaneously increase the production of secondary metabolites.