Colonization by arbuscular mycorrhizal and endophytic fungi enhanced terpene production in tomato plants and their defense against a herbivorous insect
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Terpenoids serve as an important form of chemical defense for plants. A greenhouse study was conducted to investigate the effects of two types of beneficial fungi on the accumulation of terpenoids in tomato plants and on defense against herbivorous insects. Control tomato plants without any fungal inoculation constitutively made monoterpenes and sesquiterpenes. Inoculation by Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) C. Walker & A. Schüßler, an arbuscular mycorrhizal fungus, and Beauveria bassiana (Bals.-Criv.) Vuill., an endophytic entomopathogenic fungus, individually or in combination, led to enhanced levels of monoterpenes and sesquiterpenes, which included new monoterpenes not found in the control plants. Herbivore feeding assays using beet armyworm (Spodoptera exigua Hübner) were performed to compare the levels of defense in tomato plants with or without fungal inoculation. Beet armyworm larvae fed on tomato plants inoculated by either or both types of fungi were found to gain significantly less weight than those fed on control non-inoculated plants. This suggests that fungus-inoculated tomato plants had a stronger defense response against beet armyworm than control plants, which may be partly attributed to the difference in the levels of terpenoids.
KeywordsBeauveria bassiana Chemical profiling Glomus/Rhizophagus intraradices Insect herbivory Spodoptera exigua
This project was supported by the University of Tennessee Institute of Agriculture.
- Broughton S, Harrison J (2012) Evaluation of monitoring methods for thrips and the effect of trap colour and semiochemicals on sticky trap capture of thrips (Thysanoptera) and beneficial insects (Syrphidae, Hemerobiidae) in deciduous fruit trees in Western Australia. Crop Prot 42:156–163CrossRefGoogle Scholar
- Forgy D (2012) Arbuscular mycorrhizal fungi can benefit heavy metal tolerance and phytoremediation. Nat Sci Educ 41:23–26Google Scholar
- Griffin MR (2007) Beauveria bassiana, a cotton endophyte with biocontrol activity against seedling disease. Dissertation, University of Tennessee, Knoxville, TennesseeGoogle Scholar
- McGonigle TP, Miller MH, Evans DG, Fairchild GL, Swan JA (1990) A new method which gives an objective measure of colonization of roots by vesicular-arbuscular mycorrhizal fungi. New Phytol 15:490–501Google Scholar
- Megido RC, Haubruge E, Verheggen FJ (2014) Pheromone-based management strategies to control the tomato leafminer, tuta absoluta (Lepidoptera: Gelechiidae): a review. Biotechnol Agron Soc Environ 17:475–482Google Scholar
- Migiro LN, Maniania NK, Chabi-Olaye A, Vandenberg J (2010) Pathogenicity of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana (Hypocreales:Clavicipitaceae) isolates to the adult pea leafminer (Diptera: Agromyzidae) and prospects of an autoinoculation device for infection in the field. Environ Entomol 39:468–475CrossRefPubMedGoogle Scholar
- Onstad DW (2014) Insect resistance management: biology, economics, and prediction, 2nd edn. Elsevier, NYGoogle Scholar
- Ownley BH, Griffin MR (2012) Dual biological control of insect pests and plant pathogens with fungi in the order Hypocreales. In: Brar SK (ed) Biocontrol: management, processes, and challenges. Nova, Hauppauge, pp 133–152Google Scholar
- Smith SE, Read D (2008) Mycorrhizal symbiosis. Elsevier, AmsterdamGoogle Scholar
- Toussaint JP, Kraml M, Nell M, Smith SE, Smith FA, Steinkellner S, Schmiderer C, Vierheilig H, Novak J (2008) Effect of Glomus mosseae on concentrations of rosmarinic and caffeic acids and essential oil compounds in basil inoculated with Fusarium oxysporum f. sp. basilica. Plant Pathol 57:1109–1116CrossRefGoogle Scholar
- Walker V, Couillerot O, Von Felten A, Bellvert F, Jansa J, Maurhofer M, Bally R, Moenne-Loccoz Y, Comte G (2012) Variation of secondary metabolite levels in maize seedling roots induced by inoculation with Azospirillum, Pseudomonas and Glomus consortium under field conditions. Plant Soil 356:151–163CrossRefGoogle Scholar