•Crocus is a medicinally important plant and it is costliest spice of the world.•An efficient microprapogation protocol of five Turkish Crocus species was developed.•Crocus species: C. specious ssp. ...Specious, C. oliveri spp. Oliveri, C. pestalozzae, C. abantensis, and C. paschei..•Different combinations and concentrations of auxins and cytokinins were used.•Plant regeneration was developed via somatic embryogenesis.
Callus induction, somatic embryogenesis and plant regeneration were initiated in selected five species of Turkish crocus using three diffrent explants (leaf, stem and corm) cultured on four different media (MS, GB5, LS and CHE). The highest frequencies of callus induction (100%) and shoot regeneration (70%, with 7.2 shoots/callus) were found in the crocus species Crocus oliveri ssp. Oliveri, using the MS medium containing 5% (w/v) sucrose supplemented with (4mg/L NAA+4mg/L TDZ) and (2mg/L IAA+2mg/L TDZ+2mg/L BAP). When the embryogenic calli were transferred into the four nutrient media containing (2mg/L IAA+2mg/L TDZ) and 100mg/L ABA, these further developed into cotyledonary embryos. Maximum number of somatic embryos (2.9 embryos per leaf explant, with a frequency 46.6%) was obtained in C. oliveri ssp. Oliveri. During subculture using the half strength media, cotyledonary embryos gradually developed into plantlets.
Long periods of high temperature or transitory increased temperature, a widespread agricultural problem, may lead to a drastic reduction in economic yield, affecting plant growth and development in ...many areas of the world. Heat stress causes many anatomical and physiological changes in plants. Its unfavorable effects can be alleviated by thermotolerance induced by exogenous application of plant growth regulators and osmoprotectants or by gradual application of temperature stress. Digitalis trojana Ivanina is an important medicinal plant species well known mainly for its cardenolides. The production of cardenolides via traditional agriculture is commercially inadequate. In this study, elicitation strategies were employed for improving crop thermotolerance and accumulation of cardenolides. For these purposes, the effects of salicylic acid (SA) and/or high temperature treatments in inducing cardenolide accumulation and thermotolerance were tested in callus cultures of D. trojana. Considerable increases in the production of cardenolides (up to 472.28 μg.g−1 dry weight, dw) and induction of thermotolerance capacity were observed when callus cultures were exposed to high temperature for 2 h after pretreating with SA. High temperature treatments (2 h and 4 h) caused a marked reduction in superoxide dismutase (SOD; EC 1.15.1.1) and catalase (CAT; EC 1.11.1.6) activities, while SA pretreatment increased their activities. High temperature and/or SA appeared to increase the levels of proline, total phenolic, and flavonoid content. Elevated phenolic accumulation could be associated with increased stress protection. These results indicated that SA treatments induced synthesis of antioxidants and cardenolides, which may play a significant role in resistance to high temperature stress.
•SA alleviates inhibitory effects of heat stress.•SA induces thermotolerance and cardenolide accumulation in Digitalis trojana.•SA activated antioxidant responses in D. trojana.
The effect of hydrogen peroxide (H2O2) on callus cultures of four Digitalis species (Digitalis lamarckii, Digitalis trojana, Digitalis davisiana and Digitalis cariensis) increased catalase (CAT), ...superoxide dismutase (SOD), total phenolic, proline activity and cardiotonic glycoside production. Callus derived from hypocotyl explants was cultured on Murashige and Skoog medium supplemented with 0.25 mg L−1 indole-3-acetic acid (IAA) and 0.5 mg L−1 thidiazuron (TDZ). After a month of culture, callus was transferred to MS medium containing 10 mM H2O2 and then incubated for 6 h. The amount of five cardenolides (Lanatoside C, Digitoxin, Digoxigenin, Gitoxigenin and Digoxin) as well as CAT, SOD, total phenolic, proline activity from Digitalis species were compared. No digoxin was detected in all treatments and control groups. The total cardenolides estimated were in the order of D. lamarckii (586.65 μg g−1 dw), D. davisiana (506.79 μg g−1 dw), D. cariensis (376.60 μg g−1 dw) and D. trojana (282.39 μg g−1 dw). It was clear that H2O2 pre-treatment resulted in an increase in enzymatic and nonenzymatic antioxidants. However, a significant negative relationship between cardenolides production and overall activities of CAT, SOD, total phenolic and proline was evident. The described protocol here will be useful for the development of new strategies for a large-scale production of cardenolides.
•Exposure of H2O2 resulted in the highest level of cardiac glycosides.•The predominant cardiac glycoside was lanatoside C.•Oxidative stress increases activities of CAT and SOD in cultures.•Treatment of callus with H2O2 drastically increased phenolic and proline content.
Exogenous pretreatment of oxidative stress on callus cultures of
L. (common daisy) induced catalase (CAT), superoxide dismutase (SOD), total phenolic, total flavonoid, total protein and selected ...commercial phenolic compounds production and accumulation.
The callus culture obtained from
pedicel explants was incubated on Murashige and Skoog medium (MS) containing 10 mM H
O
or 0 mM H
O
(for control group) for 10 hours. Twenty phenolic compounds (apigenin, caffeic acid,
-coumaric acid, gallic acid, genistein, kaempferol, luteolin, myricetin, procyanidin-
, quercetin, rutin hydrate, vanillic acid, ferulic acid, salicylic acid, sinapic acid, chlorogenic acid, hesperedin, naringenin, rosmarinic acid and isorhamnetin) were detected by LC-ESI-MS/MS analysis in methanolic extracts of 10 mM H
O
and control treatments.
A predominant phenolic compound was chlorogenic acid followed by rutin hydrate, caffeic acid, luteoline, isorhamnetin, quercetin, myricetin, apigenin,
-coumaric acid and kaempferol. No gallic acid, genistein, procyanidin-
, vanillic acid, sinapic acid, hesperidin and naringenin were detected in H
O
treatment and control groups of
. The total phenolic contents estimated were in the order of H
O
treatment (285.36 μg/g dw) and control (220.79 μg/g dw) groups. The biosynthesis and accumulation of kaempferol, myricetin, quercetin and isorhamnetin were only determined in H
O
treatment callus materials. The H
O
pretreatment clearly showed in a raise in enzymatic and non-enzymatic antioxidant activities. Finally, a significant positive correlation between phenolic accumulation and comprehensive activities of CAT, SOD, total phenolic, total flavonoid and proline was accessible.
The present results suggest that using H
O
as an elicitor or a stimulant plays a significant enhancement role in special phenolic molecules biosynthesis and activation of antioxidant metabolism on callus cultures of
.
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