BUSCADOR RECOLECTA

Vector transmission from DSF grapevines data set Data from vector transmission experiment for Xylella fastidiosa from DSF transgenic grapevines. File is an .rds file for loading directly into R. The file is a list of length 2. The first item in the list is metadata describing each variable of the data set, including total sample size. The second item is the data set itself. zeilinger_dsf_transmission_dataset.rds, Effective management of vector-borne plant pathogens often relies on disease-resistant cultivars. While heterogeneity in host resistance and in pathogen population density at the host population level play important and well-recognized roles in epidemiology, the effects of resistance traits on pathogen distribution at the individual host level, and the epidemiological consequences in turn, are poorly understood. Transgenic disease-resistant plants that produce bacterial Diffusible Signaling Factor (DSF) could provide resistance to the vector-borne bacterium Xylella fastidiosa by impeding plant colonization and reducing virulence. However, the effects of constitutive in planta production of DSF on insect vector transmission has remained unresolved. We investigated the transmission biology of X. fastidiosa in DSF and wild-type (WT) grapevines with the efficient vector Graphocephala atropunctata. We also developed a novel Bayesian hierarchical model to improve statistical inference on the multiple components of the vector transmission process. We found that insect vectors had a greater colonization efficiency on DSF plants—meaning they acquired a greater population size of X. fastidiosa—than on WT plants. However, DSF plants also maintained much lower X. fastidiosa populations. These apparently conflicting processes resulted in a lower but highly variable probability of transmission from DSF plants compared to WT plants. Our Bayesian model improved statistical inference compared to widely used frequentist statistics in part by estimating and correcting for imperfect detection of X. fastidiosa in plant and insect tissues. Overall, our results support current models on the roles that DSF plays in vector transmission of X. fastidiosa. In line with our hypothesis, DSF production reduced mean X. fastidiosa population density but increased heterogeneity within host plants. While DSF-producing plants could potentially improve disease management, our results suggest that they could, under some conditions, facilitate X. fastidiosa spread., Peer reviewed

S1 Video. Correlation between cibarial pump movement and related EPG waveform (Xi). (MP4), The meadow spittlebug Philaenus spumarius plays a key role in the transmission of the bacterium Xylella fastidiosa to olive in Apulia (South Italy). Currently, available data on P. spumarius feeding behavior is limited, and a real-time observation of the different steps involved in stylet insertion, exploratory probes, and ingestion, has never been carried out. Therefore, we performed an EPG-assisted characterization of P. spumarius female feeding behavior on olive, in order to detect and analyze the main EPG waveforms describing their amplitude, frequency, voltage level, and electrical origin of the traces during stylet penetration in plant tissues. Thereafter, each of the main waveforms was correlated with specific biological activities, through video recording and analysis of excretion by adults and excretion/secretion by nymphs. Furthermore, the specific stylet tips position within the plant tissues during each of the waveforms observed was assessed by microcomputer tomography (micro-CT). Additional EPG-recordings were carried out with males of P. spumarius on olive, in order to assess possible sex-related differences. P. spumarius feeding behavior can be described by five main distinct waveforms: C (pathway), Xc (xylem contact/pre-ingestion), Xi (xylem sap ingestion), R (resting), N (interruption within xylem phase). Compared to males, females require shorter time to begin the first probe, and their Xi phase is significantly longer. Furthermore, considering the single waveform events, males on olive exhibit longer np and R compared to females., Peer reviewed

S2 Video. Video obtained from micro-CT showing P. spumarius stylets in xylem vessel. (MKV), The meadow spittlebug Philaenus spumarius plays a key role in the transmission of the bacterium Xylella fastidiosa to olive in Apulia (South Italy). Currently, available data on P. spumarius feeding behavior is limited, and a real-time observation of the different steps involved in stylet insertion, exploratory probes, and ingestion, has never been carried out. Therefore, we performed an EPG-assisted characterization of P. spumarius female feeding behavior on olive, in order to detect and analyze the main EPG waveforms describing their amplitude, frequency, voltage level, and electrical origin of the traces during stylet penetration in plant tissues. Thereafter, each of the main waveforms was correlated with specific biological activities, through video recording and analysis of excretion by adults and excretion/secretion by nymphs. Furthermore, the specific stylet tips position within the plant tissues during each of the waveforms observed was assessed by microcomputer tomography (micro-CT). Additional EPG-recordings were carried out with males of P. spumarius on olive, in order to assess possible sex-related differences. P. spumarius feeding behavior can be described by five main distinct waveforms: C (pathway), Xc (xylem contact/pre-ingestion), Xi (xylem sap ingestion), R (resting), N (interruption within xylem phase). Compared to males, females require shorter time to begin the first probe, and their Xi phase is significantly longer. Furthermore, considering the single waveform events, males on olive exhibit longer np and R compared to females., Peer reviewed