Enhancement of Calibrachoa growth, secondary metabolites and bioactivity using seaweed extracts

Abstract

Background: Calibrachoa x hybrida (Solanaceae) cultivars are widely used in North and South America as ornamental plants. Their potential as a source of antimicrobial compounds might be enhanced by seaweed extract (SWE) applications. Methods: SWE of Ascophyllum nodosum were applied at 5 and 7 ml/L as a soil drench or foliar spray on Calibrachoa cultivars of Superbells® 'Dreamsicle' (CHSD) and Superbells® 'Frost Fireʼ (CHSF). The total phenolics, tannins and antioxidants composition as well as specific flavonols in leaf extracts were determined. Further, the chemical composition of SWE was assessed. Results: The drench and foliar SWE treatments significantly enhanced Calibrachoa cultivars leaf number and area, dry weight, plant height, antioxidant capacity as well as phenolic, flavonols and tannin content. The increased growth and composition of phenols, flavonols and tannins was attributed to the stimulatory effects of SWE mineral composition. The antifungal activity of Calibrachoa cultivars was significantly enhanced following SWE treatments and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were in the range of 0.07-0.31 mg/ml and from 0.16 to 0.56 mg/ml, respectively. Moreover, antibacterial activity was significantly increased and the MIC and minimum bactericidal concentration (MBC) measurements were in the range of 0.06-0. 23 mg/ml and from 0.10 to 0.44 mg/ml, respectively. The most sensitive fungus to SWE treatments was C. albicans and the most sensitive bacterium was E. cloacae. Conclusion:The results suggest that enhanced antifungal and antibacterial activities might be attributed to significant increases of phenolic, flavonols and tannin contents, which ultimately enhance the potential of Calibrachoa as a natural source of alternative antibiotics.

Bioactivities of Traditional Medicinal Plants in Alexandria

“…Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 35210). The microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the plant extracts [ 42 ]. The 96-well microtiter plates were used, and each well of the plate contained known concentration of plant extracts + 100 μ L tryptic soy broth containing bacterial inoculum (1.0 × 10 4 CFU per well).…”

“…Several fungi, including Aspergillus flavus (ATCC 9643), A. ochraceus (ATCC 12066), A. niger (ATCC 6275), Penicillium ochrochloron (ATCC 48663), P. funiculosum (ATCC 56755), and Candida albicans (ATCC 12066), were used to test the antifungal activity of leaf extracts using the microdilution method [ 42 ]. Known concentrations of each leaf extract (2 μ L) were added to microtiter plates (with a capacity of 96 wells) with each well containing broth Malt medium mixed with each fugal inoculum (spore suspension concentration of 1.0 × 10 5 ).…”

Ascophyllum nodosum-Based Biostimulants: Sustainable Applications in Agriculture for the Stimulation of Plant Growth, Stress Tolerance, and Disease Management

“…AlgaeGreen ® , a commercial A. nodosum extract, increased the yield and secondary metabolite content of cabbage ( Brassica oleraceae ) (Lola-Luz et al, 2013). Treatment with ANE significantly enhanced vegetative growth as well as the biosynthesis of bioactive molecules such as phenolics and flavonoids of Calibrachoa hybrid , a medicinal plant (Elansary et al, 2016a). ANE-induced biosynthesis of secondary metabolites further enhanced the antifungal and antibacterial activity of the extract of Calibrachoa (Elansary et al, 2016a).…”

Seaweed Extracts Enhance Salam Turfgrass Performance during Prolonged Irrigation Intervals and Saline Shock

“…Ascophyllum nodosum (Fucaceae) is an important species used for SWE production, and is produced commercially under several names. The SWE from A. nodosum and other algae have been proven to enhance horticultural crops production and performance while increasing antioxidants potential (Kumar et al, 2013 ; Lola-Luz et al, 2014 ; Elansary et al, 2016a ), product quality (Kumari et al, 2011 ; Spann and Little, 2011 ), freezing tolerance (Nair et al, 2012 ), salinity and drought tolerance (Neily et al, 2010 ; Spann and Little, 2011 ; Guinan et al, 2013 ; Elansary et al, 2016b ; Martynenko et al, 2016 ). However, the test of SWE on turfgrass performance has been rarely investigated (e.g., Zhang and Ervin, 2004 ; Zhang et al, 2010 ), although turfgrasses comprise dozens of grass species and hundreds of cultivars or accessions that are key in our daily life, e.g., home lawns, parks, golf courses, and many others (Turgeon, 2008 ; Hanna et al, 2013 ).…”