Alterações na dinâmica eletrofisiológica em tomateiro induzidas por Oidium sp.

Abstract

Plants and pathogens coexist in the same environment a millions of years and this coexistence favored the development of a complex communication system between them. This communication occurs mainly by the exchange of chemical signals, which is considered as the first stage of plant-pathogen communication. One of the first effects of this interaction on plants is cytosolic calcium influxes, which may be directly related to bioelectrical changes in plant cell membranes. The electrical signaling in plants has been known for a long time, but it has been gaining prominence recently with the establishment of relations with several physiological processes. The objective of this dissertation was to verify the existence of patterns of electrophysiological responses in tomato plants inoculated with the pathogenic fungus Oidium sp. For the realization of this study, we used Micro-Tom plants, which were inoculated with Oidium sp. In a controlled environment was performed an inoculation of the plants, as well as was obtained electrical signal data before and after, inoculation plants using the technique eletrofitografia (EPG). The temporal series obtained were analyzed using statistical and computational tools to determine Frequency Spectral Density (PSD), Autocorrelation of values and Multiscalar Entropy. In order to verify the existence of patterns in the series were used classification algorithms used in machine learning. Through the results obtained in the analysis of the temporal series, it was shown that the electrical signals collected from plants presented oscillatory dynamics with frequency distribution pattern in power law. The results of the classification algorithms reached a higher accuracy of detection of the infection only in the initial phase of recognition of the pathogen by the plant. However, the analysis of the multiscale entropy revealed a constancy of regularity in the electrical signals before and after the inoculation of the plants. Once the inoculum was applied to the leaves of the plants and the signal was captured in the stem, this study brought evidence that the electrical signaling is involved in long-distance signaling in the plant-pathogen interaction.