Efficacy of Lippia alba Essential Oil in Alleviating Osmotic and Oxidative Stress in Salt-Affected Bean Plants

• Published in: Horticulturae Vol. 11; no. 5; p. 457
• Main Authors: Borromeo, Ilaria, Giordani, Cristiano, Forni, Cinzia
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2025
• Subjects: Abiotic stress; Acclimation; Acclimatization; Agricultural research; antioxidant activity; Antioxidants; Ascorbic acid; Beans; biostimulant; Biotechnology; Calcium ions; Catalase; Common beans; Comparative analysis; Crop diseases; Crops; Drought; Environmental aspects; Essences and essential oils; Essential oils; Fungicides; Germination; Growth; Homeostasis; Horticultural crops; Hydrocarbons; Indigenous plants; L-Ascorbate peroxidase; Lipid peroxidation; Lippia alba; Oils & fats; osmolytes; Oxidative stress; P. acutifolius; Peroxidase; Pharmacology; Physiological aspects; Plant growth; Plant protection; Polyphenol oxidase; ROS overproduction; Salinity; Salinity effects; Salinity tolerance; Salt; Salt stress (Botany); Salt tolerance; Seedlings; Seeds; Sodium chloride; Superoxide dismutase; Testing; Toxicity; Verbena; Water shortages; Water uptake; Italy; Colombia; Mexico
• ISSN: 2311-7524; 2311-7524
• DOI: 10.3390/horticulturae11050457

Lippia alba (Mill.) N.E.Br. ex Britton and P. Wilson is a native plant of Colombia, widespread throughout Central and South America, used for thousands of years by pre-Columbian populations, who already knew the many beneficial properties of this species (e.g., antifungal, antibacterial, antiviral and anti-inflammatory activities). The essential oil of L. alba is rich in phytochemicals with antioxidant activity that could be very useful both for pharmacology and biotechnology application, such as the protection of horticultural crops sensitive to salinity. To enhance salt tolerance, seed-priming treatment with the essential oil of L. alba was performed. We evaluated the effect of this biostimulant on the response to salt stress in a sensitive bean species, Phaseolus acutifolius L. (cv Blue Tepary), native to Mexico, and used by pre-Columbians as well as nowadays. Bean seeds were primed in a solution of 0.5 mL/L of essential oil of L. alba, germinated and after 2 weeks of acclimation, the seedlings were subjected to salt stress, by watering with 40 mM and 80 mM NaCl solutions. Four weeks later, many biochemical parameters were evaluated in order to test the effects of the treatments on plant fitness. Primed seeds showed an increase in salt tolerance during germination, as well as primed plants revealing a higher water uptake, increased chlorophylls, proline content and salt tolerance index. The treatments also improved the Ca2+ concentration in the shoots of stressed primed plants, more quickly activating enzymatic responses to salinity—in particular superoxide dismutase, polyphenol oxidase, catalase, peroxidase and ascorbate peroxidase—compared to unprimed stressed plants. In conclusion, L. alba was found to be a strong elicitor of responses against osmotic and oxidative stress, as induced by salinity, suggesting the possibility of its future utilization in agriculture.