Effect of salt stress on the antimicrobial activity of Ruta chalepensis essential oils

• Published in: Acta physiologiae plantarum Vol. 38; no. 6
• Main Authors: Amdouni, Thouraya, Ben Abdallah, Saoussen, Msilini, Najoua, Merck, Florence, Chebbi, Mohamed, Lachâal, Mokhtar, Karray-Bouraoui, Najoua, Ouerghi, Zeineb, Fernandez, Xavier
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2016
• Subjects: Agriculture; Biomedical and Life Sciences; Life Sciences; Original Article; Plant Anatomy/Development; Plant Biochemistry; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Essential oils; Antimicrobial activity; Salt stress
• ISSN: 0137-5881; 1861-1664
• DOI: 10.1007/s11738-016-2167-x

In the current investigation, the biological activities of essential oils obtained from organs of
Ruta chalepensis
plants grown under salt stress (0, 50 and 100 mM NaCl) were analyzed. Their chemical composition was often investigated by GC/FID and GC–MS and the antimicrobial activities towards eight bacteria (
Salmonella All
,
Salmonella K
,
Escherichia coli
45AG,
Escherichia coli
45AI,
Staphylococcus aureus
9402,
Staphylococcus aureus
02B145,
Listeria
477 and
Pseudomonas aeruginosa
ATCC 10145) and five fungi strains (
Aspergillus,
Saccharomycee crvisiale, Streptomyces griseus, Fusarium solani and Penicillium thomii
) were studied. Results revealed that salt increased essential oil production in leaves at 50 and 100 mM NaCl. A total of 20 compounds were identified in leaves, undecan-2-one, nonan-2-one and geijerene being the dominant ones. In stems, 21 compounds were found; they were dominated by decan-2-one, geijerene, nonan-2-one and undecan-2-one. In contrast, roots exhibited a large variation with 25 volatile compounds and octyl acetate, methyl decanoate, phytyl acetate were the major ones. Salt stress induced significant antibacterial activity changes, mainly in leaves and stems. In leaves, the minimum inhibitory and bactericidal concentration decreased at 100 mM NaCl against
Listeria
477, the two strains of
E. coli
(45AG and 45AI) and
P. aeruginosa
but it increased versus other bacteria. In stems, salt increased oil antibacterial activity against all strains except
P. aeruginosa
ATCC 10145. Root oil showed the least antibacterial activity under saline conditions versus
Listeria
477 and
P. aeruginosa
ATCC 10145. As regards antifungal activity, NaCl reduced the antifungal activity of essential oils against the majority of fungi strains.