Journal Article

Terpene Down-Regulation in Orange Reveals the Role of Fruit Aromas in Mediating Interactions with Insect Herbivores and Pathogens

López, María M, Alquezar, Berta, Palou, Lluís, Rodrigo, María J, Shimada, Takehiko, Zacarias, Lorenzo, Redondo, Ana, San-Andrés, Victoria, Rodriguez, Ana, Pena, Leandro, Gadea, Jose, Cervera, Magdalena, Castanera, Pedro

2011

Overview

Plants use volatile terpene compounds as odor cues for communicating with the environment. Fleshy fruits are particularly rich in volatiles that deter herbivores and attract seed dispersal agents. We have investigated how terpenes in citrus fruit peels affect the interaction between the plant, insects, and microorganisms. Because limonene represents up to 97% of the total volatiles in orange (Citrus sinensis) fruit peel, we chose to down-regulate the expression of a limonene synthase gene in orange plants by introducing an antisense construct of this gene. Transgenic fruits showed reduced accumulation of limonene in the peel. When these fruits were challenged with either the fungus Penicillium digitatum or with the bacterium Xanthomonas citri subsp. citri, they showed marked resistance against these pathogens that were unable to infect the peel tissues. Moreover, males of the citrus pest medfly (Ceratitis capitata) were less attracted to low limonene-expressing fruits than to control fruits. These results indicate that limonene accumulation in the peel of citrus fruit appears to be involved in the successful trophic interaction between fruits, insects, and microorganisms. Terpene down-regulation might be a strategy to generate broad-spectrum resistance against pests and pathogens in fleshy fruits from economically important crops. In addition, terpene engineering may be important for studying the basic ecological interactions between fruits, herbivores, and pathogens.

• Publisher: American Society of Plant Biologists
• Subject: Acyclic Monoterpenes / analysis / Animals / bacteria / Biological and medical sciences / Ceratitis capitata / Ceratitis capitata - physiology / chemistry / citrus peels / Citrus sinensis / Citrus sinensis - drug effects / Citrus sinensis - genetics / Citrus sinensis - microbiology / Citrus sinensis - parasitology / crops / Cyclohexenes / Cyclohexenes - pharmacology / Down regulation / Down-Regulation - drug effects / drug effects / entomopathogens / Feeding Behavior / Feeding Behavior - drug effects / Feeding Behavior - physiology / Fruit / Fruit - chemistry / Fruit - drug effects / Fruit - microbiology / Fruit - parasitology / Fruits / Fundamental and applied biological sciences. Psychology / Fungal spores / fungi / Gene Expression Regulation, Plant / Gene Expression Regulation, Plant - drug effects / genes / genetics / growth & development / herbivores / Host-Pathogen Interactions / Host-Pathogen Interactions - drug effects / Host-Pathogen Interactions - genetics / Inoculation / Limonene / Male / males / metabolism / microbiology / Molecular Sequence Data / Monoterpenes / odor compounds / Odorants / Odorants - analysis / odors / parasitology / Pathogens / Peels / Penicillium / Penicillium - drug effects / Penicillium - growth & development / Penicillium digitatum / pest resistance / pests / pharmacology / Phenotype / physiology / Plant Diseases / Plant Diseases - genetics / Plant Diseases - microbiology / Plant Diseases - parasitology / Plant physiology and development / Plants / PLANTS INTERACTING WITH OTHER ORGANISMS / Plants, Genetically Modified / seed dispersal / Terpenes / Terpenes - metabolism / Terpenes - pharmacology / terpenoids / Transgenic plants / Volatile Organic Compounds / Volatile Organic Compounds - analysis / Xanthomonas / Xanthomonas citri