Effects of silver nitrate (AgNO3) on growth and anatomical structure of vegetative organs of liquorice (Glycyrrhiza glabra L.) under in vitro condition

Abstract

Liquorice (Glycyrrhiza glabra L.) has been used worldwide as a medicine for a long time. In this research, the effect of silver nitrate (AgNO 3 ) as a growth regulator and anti-ethylene in in vitro culture was investigated on growth and anatomical structure of vegetative organs (root, hypocotyl, shoot, leaf) as well as the number of stomata and trichomes in the leaves of liquorice under vitro culture condition. The seeds were cultured in MS culture media containing different concentrations of AgNO 3 (0, 2, 4, 8, and 10 mg L -1 ). Investigations on 20-day seedlings after three replications showed a significant increase in length and growth of roots, hypocotyls and shoots, and decreased number of stomata and trichomes in the samples treated with AgNO 3 (P≤0.05). The effects of AgNO 3 on anatomical structures of the organs included the increased cell division in root and shoot tips, reduced vascular tissues and sclerenchyma-fiber (with lignified cell walls), increased thickness of Casparian strip and cell walls of endodermis, reduced thickness of epidermis and increased intercellular spaces in mesophyll. The leaf area was measured in the 4-month plantlets, showing a significant increase in the samples treated with AgNO 3 . Furthermore, there was significant difference in increased leaf area applying 10 mg L -1 treatment and other concentrations as well as between the concentrations of 2 and 8 mg L -1 . It seems that these results are due to the inhibitory effects of AgNO 3 on the production and function of ethylene and the plant strategy to increase the tolerance against silver metal.

Barley somatic embryogenesis-an attempt to modify variation induced in tissue culture

“…However, overstepping bounds of toxic doses may imbalance the chloroplast redox state altering photosynthesis [ 19 – 21 ], and inducing oxidative stress [ 22 ]. Another ion utilized in tissue culture media is silver [ 23 ]. The positive effect of AgNO 3 on somatic embryogenesis, shoot growth, and direct organogenesis is well established [ 24 ].…”

The Imbibition of Pea (Pisum sativum L.) Seeds in Silver Nitrate Reduces Seed Germination, Seedlings Development and Their Metabolic Profile

“…Additionally, previously it was shown that silver nitrate affects callus induction as well as shoot and root formation in wheat [ 36 ]. AgNO 3 also accelerated the growth of licorice seedlings [ 37 ] but at low doses also enhanced the growth of pea seedlings [ 38 ]. The results obtained in our study show that high concentrations of AgNO 3 had toxic effects on growing pea seedlings.…”

“…Silver nitrate affects callus induction as well as shoot and root formation in wheat [ 36 ]. Licorice ( Glycyrrhiza glabra L.) seeds after germination in Murashige and Skooge (MS) medium containing AgNO 3 had increased root, hypocotyl and shoot growth, and decreased stomata and trichomes in 20-day-old seedlings [ 37 ]. AgNO 3 also increased cell divisions in root and shoot tips, decreasing the number of vascular tissues, the epidermal thickness, and intercellular spaces in the mesophyll [ 37 ].…”

Effect of Silver Nitrate on in Vitro Regeneration and Antioxidant Responses of Oilseed Rape Cultivars (Brassica Napus L.)

“…Ethylene is a plant hormone that regulates many developmental processes and modulate stress responses (Polko and Kieber, 2019). An accumulation of ethylene in tissue cultures is often accompanied by reduced growth and morphological changes (Roshanfekrrad et al, 2017;Tahoori et al, 2018). Moreover, ethylene is associated with formation of reactive oxygen species (ROS) (Zhang et al, 2016).…”

“…At low concentration, AgNO3 stimulates plant regeneration while at higher concentration promotes oxidative stress (Qin and Zhang, 2005;Baťková et al, 2008;Barbasz et al, 2016). AgNO3 is considered an ethylene inhibitor in in vitro culture of many plant tissues (Ghobeishavi et al, 2015;Sarropoulou et al, 2016;Jaberi et al, 2018;Tahoori et al, 2018). Its inhibitory effect consists in preventing of ethylene-induced plant responses by substituting Cu ions in ethylene receptors (Zhao et al 2002 We aimed to investigate a stimulatory effect of AgNO3 at concentration of 5 mg.L -1 on shoot organogenesis of five commercial oilseed rape cultivars Ability, Lagonda, Lancia, Menthal and Mirakel.…”