ABSTRACT
Given the effects of salicylic acid (SA) on enhancing the phenolic compounds, flavonoids, and especially anthocyanins at higher doses in grapes as well as some toxic effects of SA at higher doses, the use of nano-carriers and nano-forms could assist SA in enhancing the accumulation of these compounds while reducing its toxic activity. Chitosan (CTS) has gained attention as a safe transporter and control releaser for a variety of chemicals, particularly in the agriculture industry. In this regard, the nano-form combination of SA and CTS (CTS-SA NPs) could boost the effectiveness of SA, particularly at lower dosages. Therefore, in the present study, SA (10, 20 mM), CTS (0.1%), and CTS-SA NPs (10, 20 mM) were applied on grape (Vitis vinifera L.) berries cv. Red Sultana at the pre-véraison stage to evaluate their actions on phenolic compounds, particularly anthocyanins. The CTS-SA NPs treatments provided the highest results in terms of the total phenolic compounds, flavonoids (10 mM), anthocyanins (in particular oenin, the main anthocyanin of red grapes) (10 and 20 mM), and PAL enzyme activity (20 mM). In conclusion, the CTS-SA NPs could be applied as a potential effective elicitor for phenolics, particularly anthocyanin enhancement of grape berries at pre- véraison stage with synergistic effects between SA and CTS in nano-forms predominantly at lower doses.
ABSTRACT
In view of damaging impacts of cadmium (Cd) toxicity on various vital processes of plants and strategies for alleviating these effects, selenium (Se) application has been recently achieved great attention. In addition, chitosan (CS) and its nano-form, besides many positive effects on plants, could be considered as an excellent adsorption matrix and a carrier for a wide range of materials like Se with various applications in agricultural sector. For that point, the combination nano-form of Se and CS (CS-Se NPs), using CS as a carrier and control releaser for Se, could enhance Se efficiency particularly at lower doses under stress conditions. Therefore, Se (10 mg L-1), CS (0.1%) and CS-Se NPs (in two concentrations; 5 and 10 mg L-1) were applied on Moldavian balm plant under 0, 2.5 and 5 mg kg-1 Cd-stress conditions. The results demonstrated that mostly Se and CS-Se NPs treatments could lessen negative effects of Cd-stress conditions through enhancing agronomic traits, photosynthetic pigments, chlorophyll fluorescence parameters and SPAD, proline, phenols, antioxidant enzymes activities and some dominant constituents of essential oils and decreasing MDA and H2O2. These encouraging impacts were more significant at lower dose of CS-Se NPs (5 mg L-1) introducing it as the best treatment to ameliorate Moldavian balm performance under Cd-stress conditions. In conclusion, CS-Se NPs could be considered as a supportive approach in plant production mainly under different heavy metal stressful conditions and probably a potential plant growth promoting and stress protecting agent with new outlooks for applying in agricultural sector.
Subject(s)
Chitosan , Nanoparticles , Oils, Volatile , Selenium , Antioxidants , Cadmium/toxicity , Hydrogen Peroxide , Photosynthesis , Selenium/pharmacologyABSTRACT
Regarding destructive impacts of salinity on different vital processes of plants, many strategies have been developed to alleviate salinity effects. Amongst, nanoparticles (NPs) application has been achieved great attention. For that point, considering positive effects of graphene oxide NPs (GO) and glycine betaine (GB) on different plant processes, GO-GB NPs were primarily synthesized to use GO as a carrier for GB. Then, GO, GB and GO-GB (each in three concentrations; 0, 50 and 100 mg L-1) were applied on sweet basil (Ocimum basilicum L.) plants under 0, 50 and 100 mM salinity stress conditions. The results demonstrated that GO-GB NPs could lessen negative effects of salinity by enhancing agronomic traits, photosynthetic pigments, chlorophyll fluorescence parameters, membrane stability index (MSI), proline, phenols, antioxidant enzymes activities and dominant constituents of essential oils and decreasing MDA and H2O2. These positive effects were more considerable at its lower dose (50 mg L-1) introducing it as the best treatment to ameliorate sweet basil performance especially essential oil compounds under salt stress. GO application at its higher dose (100 mg L-1) demonstrated toxicity by negative impacts on the measured parameters. In conclusion, the positive response of sweet basil to GO-GB NPs under non-stress and salt stress conditions cause to consider the NPs as potential novel plant growth promoting and stress protecting agent with innovative outlooks for its use in agriculture.
Subject(s)
Nanoparticles , Ocimum basilicum , Betaine , Graphite , Hydrogen Peroxide , Salt StressABSTRACT
BACKGROUND: Grape berries produce significant amounts of phenolic compounds. These are an essential qualitative factor due to their nutritional value and effect on berry color and texture. Salicylic acid (SA) and its derivatives usually lead to enhancement of phenolic content in plant tissues. The present study was conducted to evaluate the effect of different levels of SA (0.0, 50.0, 100.0, and 200.0 mM) on the production of phenolic compounds and the derivatives (anthocyanin and flavonoid) in the grape berries, with emphasis on malvidin-3-O-ß glucoside as a regular anthocyanin in red grapes. RESULT: The results showed that total phenolics content were significantly enhanced in SA-treated (100.0 and 200.0 mM) berries compared to untreated ones. Salicylic acid treatment at all concentrations considerably improved the anthocyanin content in the berries and, compared with untreated berries, the accumulation of malvidin-3-O-ß glucoside was higher in SA-treated fruits. In particular, the 200.0 mM concentration caused approximately two times more malvidin-3-O-ß glucoside than the control. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity of the fruits treated with SA were significantly higher than those of the untreated berries. The activity of phenylalanine ammonia-lyase (PAL) in SA treated fruits significantly increased as compared with the untreated clusters. CONCLUSION: A general evaluation of the current results leads us to the conclusion that SA is a suitable and recommendable treatment for improving and increasing the phenolic and antioxidant capacity of grape berries. Spraying grape berries at pre-véraison stage with SA could therefore be a convenient strategy to increase quality and nutritional value of grape berries considerably. © 2019 Society of Chemical Industry.