Use of hydrogen peroxide in acclimation of basil (Ocimum basilicum L.) to salt stress

Abstract

The aim of this study was to verify the effects of application of H 2 O 2 on salt tolerance and oil production in basil cv. 'Gennaro de Menta' grown in a hydroponic system. Seedlings were subjected to 3 levels of H 2 O 2 (0, 1, and 1000 μM) in a nutrient solution during 2 different exposure periods (24 and 48 h) and 2 levels of NaCl (0 and 80 mM). The plants were harvested at preflowering (at 15 days) and postflowering (at 25 days). At 25 days, the application of 1 μM H 2 O 2 /48 h and its reapplication at preflowering increased leaf dry mass production compared to the other salt treatments. Relative water content decreased while leaf succulence and sclerophylly index increased with salinity. The increase of succulence was more pronounced with the application of H 2 O 2. Salinity increased the chlorophylls content only in plants without the application of H 2 O 2. Salinity increased Cl-, Na + , and organic solutes content, this effect being more pronounced in salt treatments that received H 2 O 2. Essential oil content, yield, and productivity were induced by salinity and H 2 O 2. This study shows that H 2 O 2 application in nutrient solution for basil cultivation in hydroponic systems using brackish water is a viable technique for promoting biomass or essential oil yield.

Salt-tolerance induced by leaf spraying with H2O2 in sunflower is related to the ion homeostasis balance and reduction of oxidative damage

“…In contrast, the increase observed at 35 days, in H 2 O 2 -primed plants may be because the chloroplast protein associated with chlorophyll is unexcited, facilitating the process of chlorophyll extraction under salt stress conditions (Liang et al, 2018). Cova et al (2019) and Silva et al (2019) also found that salinity increased the Chl a content in noni (Morinda citrifolia) and basil (Ocimum basilicum) plants, respectively.…”

“…As a consequence of this mechanism, there is also an increase in SUC, which is a variable that indicates the amount of water per unit leaf area. Some authors claim that the increase in SUC, besides maintaining water storage, can be an important mechanism for diluting toxic ions (Cova et al, 2016;Silva et al, 2019).…”

“…However, in H 2 O 2primed plants, the decrease in Na þ and Cl À levels and the increase in K þ content in both leaves and roots suggests that H 2 O 2 was able to trigger physiological mechanisms of Na þ and Cl À exclusion and reduction of K þ efflux from tissues, improving the ion homeostasis and increasing the salt tolerance in sunflower plants. Some studies have stated that H 2 O 2 can induce an increase in the K þ /Na þ ratio and reduce the Cl À content in plants under salt stress (Silva et al, 2019). H 2 O 2 can activate Ca 2þ input channels to the cytosol and this, in turn, is one of the main mechanism responsible for the activation of the SOS (salt overly sensitive) pathway, formed by the SOS1, SOS2 and SOS3 proteins and responsible for the extrusion of Na þ from cytosol (Niu and Liao, 2016).…”

“…Several articles have stated that H 2 O 2 can act as a key regulator in modulating the defense response of plants to various environmental stresses, such as salt stress (Silva et al, 2019), drought (Hossain and Fujita, 2013), high temperatures (Wu et al, 2015) and heavy metals (Wen et al, 2013). However, few studies show how they establish the criteria for selecting concentrations for exogenous application and what are the main mechanisms responsible for the increase in plant tolerance induced by H 2 O 2 priming.…”

Cultivo De Manjericão Utilizando Efluente Doméstico Tratado Em Sistemas Hidropônicos Sob Diferentes Espaçamentos Entre Plantas

“…Conforme Bione et al (2014) (SANTOS et al, 2019;SILVA et al, 2019), as plantas foram espaçadas nos canais hidropônicos em 0,25; 0,30 e 0,10 m, respectivamente.…”