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The electrical activity of tomato plants subjected to fruit herbivory was investigated. The study aimed to test the hypothesis that tomato fruits transmit long-distance electrical signals to the shoot when subjected to herbivory. For such, time series classification by machine learning techniques and analyses related to the oxidative response were employed. Tomato plants (cv. “Micro-Tom”) were placed into a Faraday's cage and an electrode pair was inserted in the fruit's peduncle. Helicoverpa armigera caterpillars were placed on the fruit (either green and ripe) for 24 h. The time series were recorded before and after the fruit's exposure of the caterpillars. The plant material for chemical analyses was collected 24 and 48 h after the end of the acquisition of electrophysiological data. The time series were analyzed by the following techniques: Fast Fourier Transform (FFT), Wavelet Transform, Power Spectral Density (PSD), and Approximate Entropy. The following features from FFT, PSD, and Wavelet Transform were used for PCA (Principal Component Analysis): average, maximum and minimum value, variance, skewness, and kurtosis. Additionally, these features were used in Machine Learning (ML) analyses for looking for classifiable patterns between tomato plants before and after fruit herbivory. Also, we compared the electrome before and after herbivory in the green and ripe fruits. To evaluate an oxidative response in different organs, hydrogen peroxide, superoxide anion, catalase, ascorbate peroxidase, guaiacol peroxidase, and superoxide dismutase activity were evaluated in fruit and leaves. The results show with 90% of accuracy that the electrome registered in the fruit's peduncle before herbivory is different from the electrome during predation on the fruits. Interestingly, there was also a sharp difference in the electrome of the green and ripe fruits' peduncles before, but not during, the herbivory, which demonstrates that the signals generated by the herbivory stand over the others. Biochemical analysis showed that herbivory in the fruit triggered an oxidative response in other parts of the plant. Here, we demonstrate that the fruit perceives biotic stimuli and transmits electrical signals to the shoot of tomato plants. This study raises new possibilities for studies involving electrical signals in signaling and systemic response, as well as for the applicability of ML to classify electrophysiological data and its use in early diagnosis.

Photosynthetic process of common bean plants (Phaseolus vulgaris L.) was evaluated from short-term root flooding and recovery conditions. Common bean plants (BRS Expedito genotype) were grown in single plastic pots (1 L), containing soil as substrate. At the early reproductive stage (R1), distilled water was added up to 20 mm above the soil surface to flood the root system of plants for 1 day. The flooding was maintained by fitting a second pot without holes. After 1 day of flooding, the pots without holes were removed to drain water and recover the plants. Control plants were kept under normoxia. Chlorophyll a fluorescence transient, gas exchange, glycolate oxidase, antioxidative enzymes, reactive oxygen species (ROS) and lipid peroxidation were measured in leaves upon flooding (1 day) and recovery (1, 3 and 7 days) conditions. Root flooding (1 day) induced decrease (two-fold) in CO 2 assimilation rate and did not recover even after 7 days of normoxic conditions was re-established, besides limited transpiration rate and decreases in stomatal conductance. Moreover, the continuous light energy absorption by chlorophylls induced an increase in fluorescence and heat and impaired the connectivity between photosystems I and II, leading to ROS formation. The antioxidative enzyme system induced upon flooding and recovery conditions did not deal efficiently with ROS, which led to oxidative damage (lipid peroxidation) in leaves of common bean. Therefore, short-term root flooding impairs photosynthetic process recovery of common bean plants upon re-establishment of normoxic conditions. Keywords Antioxidative enzymes Á Oxidative damage Á Phaseolus vulgaris L. Á Photosynthesis Á Waterlogging 1 Introduction Climate changes are increasing flooding events since the 1950 0 s worldwide (Bailey-Serres et al. 2012; Limami et al. 2014; Pedersen et al. 2017), especially in the 28 million hectares of flood-prone located in Cerrado and lowlands in the South of Brazil (Jackson and Colmer 2005), due to increases in heavy rainfall (IPCC 2014). Currently, the lowland areas are mainly occupied with rice cropping system (Garcia et al. 2020), and food production by small farmers, such as common bean (Phaseolus vulgaris L.). Common bean

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In this study, we tested whether waterlogging priming at the vegetative stage would mitigate a subsequent waterlogging event at the reproductive stage in soybean [Glycine max (L.) Merr.]. Plants (V3 stage) were subjected to priming for 7 days and then exposed to waterlogging stress for 5 days (R2 stage) with non-primed plants. Roots and leaves were sampled on the fifth day of waterlogging and the second and fifth days of reoxygenation. Overall, priming decreased the H2O2 concentration and lipid peroxidation in roots and leaves during waterlogging and reoxygenation. Priming also decreased the activity of antioxidative enzymes in roots and leaves and increased the foliar concentration of phenols and photosynthetic pigments. Additionally, priming decreased fermentation and alanine aminotransferase activity during waterlogging and reoxygenation. Finally, priming increased the concentration of amino acids, sucrose, and total soluble sugars in roots and leaves during waterlogging and reoxygenation. Thus, primed plants were higher and more productive than non-primed plants. Our study shows that priming alleviates oxidative stress, fermentation, and carbohydrate consumption in parallel to increase the yield of soybean plants exposed to waterlogging and reoxygenation.