Domesticated vs. native vegetation: variation in VOC emissions among Solanum genus plants

MANZUR ME; FERNANDEZ PC; FERNANDEZ CURUTCHET ML; THOMPSON S; LASTRA RA; BALLARE CL

Buenos Aires

Congreso; 6th Congress of the Latin American Association of Chemical Ecology (ALAEQ); 2021

Asociación Latino Americana de Ecología Química

Indirect defenses are resources that plants develop to deal with biotic stress factors and consist mainly of the production and release of volatile organic compounds (VOCs) to attract natural enemies of insect herbivores or to alert neighboring plants. However, plant domestication could affect natural defense processes, as the production of VOCs. In order to identify and quantify the VOCs emitted by cultivated and wild tomato plants, we worked with the commercial species S. lycopersicum (cv Moneymaker) and wild species from South America (S. habrochaites, S. pennellii, S. peruvianum, S. palinacanthum). Also, we characterized the foliar morphology, through a description of the leaves trichomes. The VOC collection technique was fine-tuned, allowing the capture and subsequent analysis and quantification by gas chromatography-mass spectrometry (GC-MS). Trichome morphology was analyzed by scanning electron microscopy. Additionally, a diversity index (DI) was calculated to estimate the change in blend composition. The wild tomato species presented the highest concentration of sesquiterpenes, with Zingiberene, gamma-Elemene and beta-Caryophyllene being the most frequent and abundant within this group. The cultivated species released mainly monoterpenes. Additionally, we evaluated the effect of red light (730 nm) environmental enrichment on VOC emissions and composition in one of the wild species (S. habrochaites LA2167) and on the commercial S. lycopersicum. Our results demonstrate that VOC emissions are less affected in cultivated (24.3±4.0 vs 20.7±5.5 ng.µl-1) than in wild species (121.0±60.2 vs 901.0±97.6 ng.µl-1) by far red light. Conversely, cultivated species showed an increase in DI (0.02 vs 0.03) under far red conditions and the wild species showed a drop (0.04 vs 0.02) under far red light. In conclusion, far red light can affect the blend of VOCs in cultivated and the quantity in wild tomato plants and, consequently, a different chemical signal is released to the environment.