Induction of systemic acquired resistance in cotton by BTH has a negligible effect on phytophagous insects

• Published in: Entomologia experimentalis et applicata Vol. 99; no. 1; pp. 65 - 70
• Main Authors: Inbar, Moshe, Doostdar, Hamed, Gerling, Dan, Mayer, Richard T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-04-2001; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; BTH; cotton; Fundamental and applied biological sciences. Psychology; Genetics and breeding of economic plants; induced resistance; pathogenesis-related; Pest animals; Pest resistance; plant defense; systemic acquired resistance; Varietal selection. Specialized plant breeding, plant breeding aims; whitefly; Malvaceae; Induction; Insecta; Systemic; Fiber crop; Pest; Phytophagous; Homoptera; Animal plant relation; Efficiency; Helicoverpa zea; Arthropoda; Dicotyledones; Bemisia tabaci; Insect resistance; Angiospermae; Lepidoptera; Defense mechanism; Aleyrodidae; Spermatophyta; Gossypium hirsutum; Noctuidae; Invertebrata
• ISSN: 0013-8703; 1570-7458
• DOI: 10.1046/j.1570-7458.2001.00802.x

Whether or not chemical changes in plants in response to pests (insects and pathogens) are general or specific remains unclear. Some evidence indicates that an induced response (IR) to arthropods via the octadecanoid pathway represents a distinct mechanism from the salicylic acid‐based pathway of systemic acquired resistance (SAR) to pathogens. To further test this hypothesis, young cotton seedlings were activated with benzo (1,2,3) thiadiazole‐7‐carbothioic acid (S) methyl ester (BTH), an elicitor of SAR. The enzymatic activities of a number of pathogenesis‐related (PR) proteins in young and old leaves of control and BTH treated plants were measured. BTH applications elicited marked increases in the activity levels of chitinase, peroxidase, and β‐1,3‐glucanase both locally and systemically. The highest levels of induction were detected systemically in young leaves. Except for some local effects on whitefly oviposition, the induction of SAR by BTH had no effect on either host preference of whiteflies Bemisia tabaci (Gennadius) or on feeding efficiency of cotton bollworms Helicoverpa armigera (Hübner). We conclude that SAR induction via the salicylic acid pathway in ‘Acala’ cotton has negligible effect on the tested insect herbivores.