Effect of SiO₂ nanoparticles on drought resistance in hawthorn seedlings

Abstract

Drought is a significant factor limiting crop production in arid regions while hawthorns (Crataegus sp.) are an important component of such region’s forests. Therefore, treatments that increase hawthorn drought resistance may also increase transplanting success. Thus, the physiological and biochemical responses of hawthorn seedlings to a factorial combination of different concentrations of silica nanoparticles (SNPs at 0, 10, 50 and 100 mg L−1) and three soil moisture treatments (without stress, moderate stress and severe stress) were investigated. Seedlings were irrigated with one of the four concentrations of SNPs for 45 days before exposing them to drought stress. Photosynthesis parameters, malondialdehyde (MDA), relative water content (RWC), membrane electrolyte leakage (ELI) as well as chlorophyll, carotenoid, carbohydrate and proline content were determined. At the end of the experiment, positive effects by SNP pre-treatment on physiological indexes were observed during drought stress. Under drought conditions, the effect of SNPs on photosynthetic rate and stomatal conductance was evident. Although the SNPs increased plant biomass, xylem water potential and MDA content, especially under drought conditions, RWC and ELI were not affected by the SNP pre-treatments. Seedlings pre-treated with SNPs had a decreased carbohydrate and proline content under all water regimes, but especially so under drought. Total chlorophyll content and carotenoid content did not change among the treatments. Generally, the findings imply that SNPs play a positive role in maintaining critical physiological and biochemical functions in hawthorn seedlings under drought stress conditions. However, more studies are needed before the physiological and biochemical basis of induced drought resistance can be determined.

Response of Jatropha integerrima Plants Irrigated with Different Levels of Saline Water to Nano Silicon and Gypsum

“…However the combined treatments were more effective in enhancing the synthesis and accumulation of total chlorophylls, total carbohydrates and K% in leaves than individual one. The results of increasing total carbohydrates, N% or K% as a result of gypsum treatments are in conformity with that demonstrated by prior studies (Mora et al 1999;Arafa et al 2002;Lee and Mudge, 2013), while increasing in total chlorophylls, N% or K% as a result of nano silicon treatments are consistent with those reported by other studies (Bao-shan et al 2004;Li et al 2012;Xie et al 2012;Ashkavand et al 2015;Janmohammadi et al 2016, Sharifi-Rad et al 2016. The results of increasing total carbohydrates as a result of nano silicon treatments are disagreement with findings of Ashkavand et al (2015) who reported decreasing in carbohydrate contents due to application of SiO 2 nanoparticles.…”

“…Also it was clear that there is no significant difference between application of nano silicon at 1 or 2 mM concentration in most cases. Similar increases in growth and flowers parameters as a result of gypsum treatments have been reported by prior studies (Arafa et al 2002;Kakaraparthi et al 2013;Kumar et al 2014) , also such increases due to nano silicon treatments confirmed the reports of other researches (Bao-shan et al 2004;Ashkavand et al 2015;Janmohammadi et al 2016;Sharifi-Rad et al 2016 andKhalaki et al 2016). Additionally, previous studies (Kamenidou andCavins, 2008 &Sivanesan et al 2013) reported that application of Si in bulk materials (potassium silicate or sodium silicate) increased plants growth and flowering parameters.…”

Application of SiO2 nanoparticles as pretreatment alleviates the impact of drought on the physiological performance of Prunus mahaleb (Rosaceae)

“…So, SNPs aided plants to maintain root length and decreased the impact on XWP but not on RWR. In this respect, Zhang et al (2013) found that silicon application did not enhance leaf RWC of Chestnut plants subjected to water deficit as well as it was found by Ashkavand et al (2015) on hawthorn seedlings. Curiously, it seems that SNPs application did not aid to improve leaf RWC in woody plants (eg.…”

“…Curiously, it seems that SNPs application did not aid to improve leaf RWC in woody plants (eg. Zhang et al, 2013;Ashkavand et al, 2015) but it does it in herbaceous crop species such as sorghum (Kafi et al, 2011), cotton, canola, and wheat (Mehrabanjoubani et al, 2015). Gadallah (2000) proposed that RWC improvement could be due to (i) an enhanced water uptake resulting from a more developed root system and (ii) a reduction of water loss by transpiration.…”

“…In previous research, investigators have shown that silicon enhances plants resistance to drought, salinity, cold, heat, and metal toxicity. For example, Ashkavand et al (2015) found that SNPs play a positive role in maintaining critical physiological and biochemical functions in Hawthorn seedlings subjected to drought stress. Thus, it seems that the application of silicon nanoparticles looks promising (and non-expensive) agronomic practice to reduce detrimental environmental effects due to drought (Xie et al, 2015;Balakhnina & Borkowska, 2013).…”