De novo in vitro shoot morphogenesis from shoot tip-induced callus cultures of Gymnema sylvestre (Retz.) R.Br. ex Sm

Enhanced wedelolactone content in in vitro-raised genetically uniform Wedelia chinensis under the influence of CuSO4

In the present study, we addressed the imperative for potent anticancer agents through Wedelia chinensis, a medicinal plant abundant in the robust antihepatotoxic and antitumor compound wedelolactone. Hindrances in conventional propagation methods due to cross-pollination and habitat degradation prompted us to pioneer in vitro rapid multiplication using plant tissue culture. Optimal outcomes were attained employing Murashige and Skoog (MS) medium supplemented with Indole-3-butyric acid (IBA) (0.5 mg/L) and Kinetin (KN) (5.0 mg/L), yielding 97.67% shoot regeneration and 81.67% rooting from nodal explants. Transplanted plantlets exhibited a 92% survival rate. We established a wedelolactone extraction protocol using toluene:ethyl acetate:formic acid (5:4:1) for High-performance thin-layer chromatography (HPTLC) analysis, trailblazing wedelolactone quantification and 2C DNA analysis in W. chinensis via flow cytometry. Experiments under heavy metal stress with CuSO4 unveiled physiological responses, with peak wedelolactone content [193.90 μg/g dry weight (dw)] in vitro at 75 μM CuSO4, surpassing in vivo levels (89.95 μg/g dw) by 116%. By pioneering successful in vitro rapid multiplication and enhanced wedelolactone content, we bridge a critical gap in the conservation and production of this medicinal plant. Our findings not only offer a sustainable means of propagation but also present a viable strategy for elevating the yield of potent bioactive molecules like wedelolactone, holding immense promise for the development of novel therapeutic interventions and addressing the pressing healthcare challenges of our time.

Development of a highly efficient virus-free regeneration system of Salvia miltiorrhiza from Sichuan using apical meristem as explants

BCAKGROUND

The dry root and rhizome of Salvia miltiorrhiza are used to treat cardiovascular diseases, chronic pain, and thoracic obstruction over 2000 years in Asian countries. For high quality, Sichuan Zhongjiang is regarded as the genuine producing area of S. miltiorrhiza. Given its abnormal pollen development, S. miltiorrhiza from Sichuan (S.m.-SC) relies on root reproduction and zymad accumulation; part of diseased plants present typical viral disease symptoms and seed quality degeneration. This study aim to detected unknown viruses from mosaic-diseased plants and establish a highly efficient virus-free regeneration system to recover germplasm properties.

RESULTS

Tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were detected from mosaic-diseased plants. Primary apical meristem with two phyllo podium in 0.15-0.5 mm peeled from diseased plants were achieved 73.33% virus-free rate. The results showed that the medium containing MS, 0.5 mg/L 6-BA, 0.1 mg/L NAA, 0.1 mg/L GA₃, 30 g/L sucrose and 7.5 g/L agar can achieve embryonic-tissue (apical meristem, petiole and leaf callus) high efficient organogenesis. For callus induction, the optimal condition was detected on the medium containing MS, 2 mg/L TDZ, 0.1 mg/L NAA by using secondary petiole of virus-free plants under 24 h dark/d condition for 21 d. The optimal system for root induction was the nutrient solution with 1/2 MS supplemented with 1 mg/L NAA. After transplant, the detection of agronomic metric and salvianolic acid B content confirmed the great germplasm properties of S.m.-SC virus-free plants.

CONCLUSIONS

A highly efficient virus-free regeneration system of S.m.-SC was established based on the detected viruses to recover superior seed quality. The proposed system laid support to control disease spread, recover good germplasm properties in S.m.-SC.

Natural and synthetic cytokinins and their applications in biotechnology, agrochemistry and medicine

The review is devoted to cytokinins — classical plant hormones known for more than six decades. Nevertheless, different aspects of the action of cytokinins are still being investigated. Relevant studies produced interesting, often unexpected, results, which cast doubt on the old paradigms and open new prospects for the use of these phytohormones. Particular attention is given to recent advances in the applications of natural cytokinins and their synthetic analogues in biotechnology, agriculture, medicine and cosmetics. The chemical synthesis, properties and the possible use of artificial cytokinins are considered in detail. The review is aimed at researchers interested in the development and applications of new biologically active compounds with a wide spectrum of action on diverse biological objects, from plants to humans.

The bibliography includes 233 references.

In vitro shoot multiplication of Rumex vesicarius L., and quantification of ascorbic acid and major phenolics from its leaf derived callus

An optimised method for enhanced in vitro shoot multiplication of Rumex vesicarius (Polygonaceae)-a branched succulent herb-was achieved. The in vitro seed pre-treatment with 4% urea was able to show 95% seed germination on MS medium within 2 weeks of culturing. In vitro shoot bud induction from shoot tip explants was best in the presence of 2 mg L^-1 kinetin on Murashige and Skoog medium (MS medium), wherein 8.3 shoots/explants were observed. Shoot elongation was found to be high (3.75 ± 0.5 cm) in 2 mg L^-1 BA comprising medium. The transfer of micro-shoots on to MS medium comprising 1.5 mg L^-1 IBA and 1% activated charcoal (w/v) supported efficiently in vitro rooting (2.5-4.0 cm) in 3-4 weeks. Upon hardening, 70% rooted plants survived under greenhouse conditions. Though friable callus was produced on MS medium-containing 2 mg L^-1 BA followed by 3 mg L^-1 BA, no organogenesis was noticed. The ascorbic acid content of 78.62 ± 0.25 mg 100 g^-1 FW was recorded in callus cultures grown on medium supplemented with 2 mg L^-1 BA, and it is 1.74-fold more compared to normal ex vitro leaves of the same age. In vitro raised plant leaf showed 1.98-fold more ascorbic acid (89.42 ± 0.18 mg 100 g^-1 FW) to that of ex vitro leaves. The total phenolic content was found to be 60 mg in callus as compared to 610 mg (per 100 g GAE FW) of ex vitro leaves. The major phenolic compounds quantified were synergic, chlorogenic, ferulic, and generic acids, respectively. This optimised protocol will facilitate to pursue scale-up studies for in vitro ascorbic acid production and also to further investigate the kinetics of biosynthetic pathway genes involved.