Establishment of a method to collect root exudates from olive plants and its validation by determining the effect of root exudates against Verticillium dahliae

• Published in: Plant and soil Vol. 483; no. 1-2; pp. 625 - 642
• Main Authors: López-Moral, Ana, Sánchez-Rodríguez, Antonio Rafael, Trapero, Antonio, Agustí-Brisach, Carlos
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.02.2023; Springer; Springer Nature B.V
• Subjects: Agriculture; Biomedical and Life Sciences; Carbon; Collection; Conidia; Cultivars; Deionization; Diseases and pests; Dissolved organic carbon; Distilled water; Ecology; Environmental aspects; Exudates; Exudates and transudates; Exudation; Flowers & plants; Fungi; Germination; Infections; Life Sciences; Microorganisms; Olive; Pathogens; Physiological aspects; Plant Physiology; Plant Sciences; Research Article; Roots; Roots (Botany); Soil ecology; Soil Science & Conservation; Verticillium dahliae; Spain; Rhizosphere; Plant-pathogen interactions; Soilborne pathogen; Verticillium wilt
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-022-05770-1

Aims The aim of this study was to establish a method to collect root exudates from olive plants. The method was validated by determining the effect of root exudates on the viability of Verticillium dahliae conidia and microsclerotia. Methods Three collection media (deionized distilled water, 0.01 M CaSO 4 solution, Hoagland nutrient solution) and four collection periods (2, 4, 6, 12 h) were assessed to identify the most appropriate combination for root exudate collection in olive plants (‘Picual’). To validate the method, root exudates were collected from olive cultivars with different susceptibilities to V. dahliae [‘Frantoio’ (resistant); ‘Arbequina’ (moderately susceptible), and ‘Picual’ (highly susceptible)] and treated or not treated with two microorganisms ( Bacillus amyloliquefaciens PAB-024; Aureobasidium pullulans AP08) or two phosphite salts (Naturfos®; Phoscuprico®). The effect of root exudates on the germination of V. dahliae conidia and microsclerotia was evaluated in vitro. The dissolved organic carbon in the root exudates was estimated. Results A 0.01 M CaSO 4 solution and 4 h were confirmed to be the preferred medium and timing combination to collect root exudates from olive. Root exudates from ‘Arbequina’ and ‘Picual’ significantly induced conidia and microsclerotia germination in comparison with the control without exudates. AP08 was the most effective treatment to enhance the effectiveness of root exudates in decreasing conidia and microsclerotia viability. Root exudates from ‘Picual’ or, ‘Frantoio’ treated with AP08 showed the highest levels of organic carbon. Conclusions The collection method for root exudates developed herein was useful to assess the effect of root exudates from olive plants and the olive- V. dahliae interaction.