Detection of Diseased Plants by Analysis of Volatile Organic Compound Emission

Abstract

This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The review also provides an overview of processes that affect the gas balance of plant volatiles, including their loss processes. These processes are considered as important because they contribute to the time-dynamic concentration profiles of plant-emitted volatiles. In addition, we describe the most popular techniques currently in use to measure volatiles emitted from plants, with emphasis on agricultural application. Dynamic sampling coupled with gas chromatography and followed by an appropriate detector is considered as the most appropriate method for application in agriculture. It is recommended to evaluate the state-of-the-art in the fields concerned with this method and to explore the development of a new instrument based on the specific needs for application in agricultural practice. However, to apply such an instrument in agriculture remains a challenge, mainly due to high costs.

Alterations in volatile metabolites profile of fresh tomatoes in response to Alternaria alternata (Fr.) Keissl. 1912 infection

“…From the results presented here, we can mention that specific VMs are released during early stages of infection caused by the fungus in tomatoes, even at low conidia concentration (10 4 conidia mL -1 ). Fungi, plants, and fruits produce a variety of volatile metabolites that could act as signals of plant disease (Jansen et al, 2011), or as signaling molecules that play a vital role in the activation of disease resistance mechanisms. Also, could act as antimicrobial agent (Neri et al, 2015), or could serve as markers for the detection of the spoilage pathogens (Vikram et al, 2004;Moalemiyan et al, 2006).…”

“…Also, volatile metabolites (VM) released during the infection can alter the fruit flavor. Some volatiles act as signals of plant diseases (Jansen et al, 2011), or as an antimicrobial agent (Neri et al, 2015), keeping the inactive state of fungi, and contribute to plant resistance against pathogens (QuintanaRodriguez et al, 2015).…”

Diverse Applications of Electronic-Nose Technologies in Agriculture and Forestry

“…Similarly, new food-analysis e-nose methods are being developed to detect changes in VOCs released from foods and beverages in storage to assess shelf-life [346,397,398] and quality [185,206,399–403], and for chemical analyses [404,405], classifications [227,232,346,406,407], and discriminations [162,218,228,408] of food types, varieties and brands. Electronic-nose applications to detect plant pests in preharvest and postharvest crops and tree species continue to expand to include new insect [54–61] and disease [111,112,339,409–413] pests, primarily microbial plant pathogens, beyond those originally reported by Wilson et al [2,106,107]. In the macroenvironments adjacent to industrial plants and indoor working spaces within associated food- and fiber-production facilities, e-noses increasingly are being utilized to monitor air quality to detect hazardous chemicals [68–70,76,77,80,414–419], explosives and flammable gases [29,64], pollutants [420–422] and other VOCs that threaten human health.…”

Secondary aerosol formation from stress-induced biogenic emissions and possible climate feedbacks

“…Phenolic BVOCs (with MeSa being predominant) originate from the phenylpropanoid pathway (Colquhoun et al, 2010), and the activity of this pathway is induced in particular by pathogen attack (e.g. Jansen et al, 2011, and references cited therein). Emissions of MeSa and SQT during insect infestation were also reported for Eurasian and for a North American conifer species .…”