Antibacterial potential of Caesalpinia bonducella extracts and their isolated phytoconstituents: in vitro and in silico analysis

The antimicrobial activity of Caesalpinia bonducella extracts such as CLC, CLE, CSC, and CSE and thephytoconstituents such as β-Sitosterol (LC3) isolated from CLC and methyl (4E)-5-{2-[(1E)-buta-1,3-dien-1-yl]-4,6-dihydroxyphenyl} pent-4-enoate (SC2) isolated from CSC were evaluated on gram-positive and gram-negativebacteria. The extracts and isolated compounds were found to have moderate-to-significant bacterial inhibition. Thesignificant activity was observed in the inhibition of Pseudomonas aeruginosa by CLC extract (16.10 ± 1.10 mm),whereas the isolated phytocomponent SC2 showed the highest inhibition (16.50 ± 0.58 mm). Further, the isolatedcompounds were subjected to molecular docking studies of the bacterial DNA Gyrase. The in silico study showedthe docking energy of −6.4 and three hydrogen bonding. This in vitro and in silico analysis of extracts and isolatedphytocomponents of C. bonducella helps to understand and evaluate the therapeutic efficacy to cure infectiousdiseases and also supports the traditional medicinal claim as an antibiotic.

Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. Puttabale micropropagated clones.

An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 ± 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 ± 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5–15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, β-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

Direct and indirect method of plant regeneration from root explants of Caesalpinia bonduc (L.) Roxb.— A threatened medicinal plant of Western Ghats.

An in vitro regeneration protocol has been standardized via direct and indirect methods from excised root explants of C. bonduc, a threatened woody legume used for the treatment of contagious diseases, inflammation, leprosy, antiperiodic, febrifuge, anthelmenthic, urinary disorders, leucorrhoea, piles and to heal wounds. MS medium supplemented with 17.75 µmol BAP and 2.46 µmol IBA, induced a mean of 3.40 ± 1.07 shoots directly from the surface of excised root explant. Subsequently, the shoots rooted readily on MS half strength medium with out growth regulators. In indirect organogenesis, callogenic frequency was optimized (96.66%) at the concentration of 9.04 µmol 2, 4-D and 0.88 µmol BAP. An average, 15.30 ± 5.25 shoots were differentiated from the root callus at the concentration of 17.57 µmol BAP and 2.85 µmol IAA. Shoots regenerated through callus were rooted well on MS half strength medium with growth regulators at 2.95 µmol IBA. Rooted plantlets were transferred to the pots containing sterilized soil and were successfully hardened at greenhouse condition for three weeks then exposed to the natural environment. Survival rate was more (95%) in plantlets derived through direct organogenesis than (60%) the plantlets regenerated through root calli.

Regeneration of plantlets from mature embryo calli of Western Ghats land race cultivar of rice, Oryza sativa L.

The Malnad region located in the Western Ghats of Karnataka is known for the cultivation of indigenous rain fed land race cultivar of rice. The present study was to investigate the callogenic and caulogenic potentialities of the two indigenous rice cultivar namely Karimundaga and Kanadatumba using dehusked mature embryo explants. For callus and shoot bud differentiation, the explants were cultured on Murashige and Skoog (MS) medium supplemented with 2,4-D (1–3 mg/L), IAA (1–2 mg/L), Kn (1–4 mg/L) and BAP (1–4 mg/L). The morphogenic potentialities of the two rice cultivar differed in texture of callus. In both the cultivar callogenic frequency was optimized at 1 mg/L 2,4-D concentration, it was 94% in Karimundaga and 58% in Kanadatumba. Supplementation of IAA either alone (1–2 mg/L) or in combination with Kn or BAP at 1 to 4 mg/L concentration of each induces shoot bud differentiation from the calli. In the cultivar Karimundaga caulogenic frequency was highest (10.60±2.55) at 1.0 mg/L IAA and 4.0 mg/L BAP concentration. While in the cultivar Kanadatumba highest number of shoot buds (7.90±2.69) was differentiated at 1.0 mg/L IAA and 4.0 mg/L Kn concentration. The calli derived regenerants were successfully acclimatized in the greenhouse and agro-morphological variations were evaluated. The growth characteristics and yield related parameters exhibited by in vitro plants were lower than the in vivo plants.