Effects of 24-epibrassinolide on root-knot nematode, Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae) in tomatoes

Abstract

In this study conducted in 2020, three concentrations (1, 5 and 10 µM) of 24-epibrassinolide were applied to seedlings of Lycopersicon esculentum Mill. (Solanales: Solanaceae) cv. H2274, which is susceptible to root-knot nematodes, by immersion, spray and irrigation, and its effects against root-knot nematode Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae) were investigated. One-thousand second stage juveniles of M. incognita, collected from cucumber roots in a greenhouse located in Çardak, Çanakkale were inoculated on the roots of the plants per pot. After eight weeks, stem fresh weight, stem dry weight, root diameter and longest root length values, in addition to the stem length and stem diameter measured at the beginning and end of the experiment, were recorded. 24-Epibrassinolide, applied by an immersion method, gave similar or better results than the control even in the presence of nematodes. Distilled water plus nematode application showed the highest gall index whereas 5 µM 24-epibrassinolide plus nematode application gave the lowest gall index. The lowest number of egg mass was also obtained from the same concentration of 24-epibrassinolide applied by immersion. As a result, 24-epibrassinolide showed a beneficial effect in terms of reducing the damage caused by the nematodes in tomato plants, depending on the concentration and application method.

Roles of Brossinosteroids Signaling in Biotic and Abiotic Stresses

“…One previous study has shown that exogenous application of 0.2 μM 2,4-Epibrassinolide (EBR) on tomato leaf significantly increased its resistance to Meloidogyne incognita , as is the case with cucumber, melon and watermelon . In tomato and cucumber, weekly foliar application of 0.2 μM EBR could completely prevent the occurrence of nematode galls in root . Subsequently, a research study further revealed that the positive role of BRs in the resistance against root-knot nematode is mainly attribute to RESPIRATORY BURST OXIDASE HOMOLOGUE (RBOH)-dependent activation of MAPKs .…”

“…72 In tomato and cucumber, weekly foliar application of 0.2 μM EBR could completely prevent the occurrence of nematode galls in root. 73 Subsequently, a research study further revealed that the positive role of BRs in the resistance against root-knot nematode is mainly attribute to RESPIRA-TORY BURST OXIDASE HOMOLOGUE (RBOH)-dependent activation of MAPKs. 74 However, in rice, BRs suppressed the defense against root-knot nematodes (Meloidogyne graminicola) by antagonizing JA.…”

Influence of 24-Epibrassinolide on Physiological Characteristics of Tomato Seedlings Infested with Root-knot Nematode Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae)

“…Increases in resistance after brassinosteroid application against viruses have also been shown by Ali et al (2014) in Hordeum vulgare, and by Zhang et al (2015) in Arabidopsis thaliana. In recent years, responses against root-knot nematode damage in plants have also been carried out and positive results have been reported by Jasrotia and Ohri (2014;, Kaur et al (2013;, Song et al (2017) andGözel (2021) against Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949.…”