Bioengineering secreted proteases convert divergent Rcr3 orthologs and paralogs into extracellular immune co-receptors.

Secreted immune proteases Rcr3 (Required for Cladosporium resistance-3) and Pip1 (Phytophthora- inhibited protease-1) of tomato (Solanum lycopersicum) are both inhibited by Avr2 from the fungal plant pathogen Cladosporium fulvum. However, only Rcr3 acts as a decoy co-receptor that detects Avr2 in the presence of the Cf-2 immune receptor. Here, we identified crucial residues in tomato Rcr3 that are required for Cf-2-mediated signalling and bioengineered various proteases to trigger Avr2/Cf-2-dependent immunity. Despite substantial divergence in Rcr3 orthologs from eggplant (Solanum melongena) and tobacco (Nicotiana spp.), minimal alterations were sufficient to trigger Avr2/Cf-2-mediated immune signalling. By contrast, tomato Pip1 was bioengineered with 16 Rcr3-specific residues to initiate Avr2/Cf-2-triggered immune signalling. These residues cluster on one side of the protein next to the substrate-binding groove, indicating a potential Cf-2 interaction site. Our findings also revealed that Rcr3 and Pip1 have distinct substrate preferences determined by two variant residues, and that both are suboptimal for binding Avr2. This study advances our understanding of Avr2 perception and opens avenues to bioengineer proteases to broaden pathogen recognition in other crops.

Evolution of a guarded decoy protease and its receptor in solanaceous plants.

Rcr3 is a secreted protease of tomato that is targeted by fungal effector Avr2, a secreted protease inhibitor of the fungal pathogen Cladosporium fulvum. The Avr2-Rcr3 complex is recognized by receptor-like protein Cf-2, triggering hypersensitive cell death (HR) and disease resistance. Avr2 also targets Rcr3 paralog Pip1, which is not required for Avr2 recognition but contributes to basal resistance. Thus, Rcr3 acts as a guarded decoy in this interaction, trapping the fungus into a recognition event. Here we show that Rcr3 evolved > 50 million years ago (Mya), whereas Cf-2 evolved <6Mya by co-opting the pre-existing Rcr3 in the Solanum genus. Ancient Rcr3 homologs present in tomato, potato, eggplants, pepper, petunia and tobacco can be inhibited by Avr2 with the exception of tobacco Rcr3. Four variant residues in Rcr3 promote Avr2 inhibition, but the Rcr3 that co-evolved with Cf-2 lacks three of these residues, indicating that the Rcr3 co-receptor is suboptimal for Avr2 binding. Pepper Rcr3 triggers HR with Cf-2 and Avr2 when engineered for enhanced inhibition by Avr2. Nicotiana benthamiana (Nb) is a natural null mutant carrying Rcr3 and Pip1 alleles with deleterious frame-shift mutations. Resurrected NbRcr3 and NbPip1 alleles were active proteases and further NbRcr3 engineering facilitated Avr2 inhibition, uncoupled from HR signalling. The evolution of a receptor co-opting a conserved pathogen target contrasts with other indirect pathogen recognition mechanisms.

The use of advertising appeals in breast cancer detection messages: a web content analysis.

We explored the use of different advertising appeals in breast cancer detection messages. We analyzed the extent to which emotional appeals were applied in advertisements that promoted two forms of breast cancer detection behaviors: breast self-examination (BSE) and mammographic screening. Findings of a content analysis of 456 breast cancer-related advertisements gathered in February 2016 indicated that textual fear appeals, humor appeals and erotic appeals were more likely to be featured in BSE-promoting advertisements than in breast cancer-related advertisements with other message purposes. While shame-guilt appeals were more likely to be used in mammography-promoting messages, humor and erotic appeals were less likely to be applied. Regarding hybrid message appeals, combinations of humor appeals with erotic, fear and shame-guilt appeals, as well as combined erotic-fear appeals were found more in BSE-promotion messages. Mammography-promoting messages made less use of hybrid messages with a humorous touch as compared to breast cancer advertisements with other message purposes. The results are in contrast to research findings on the effectiveness of message appeals and thus allow to some extent the evaluation of whether scientific findings on the effectiveness of message appeals are reflected in the current advertising practice.

Insights into the impact of online physician reviews on patients' decision making: randomized experiment.

BACKGROUND: Physician-rating websites combine public reporting with social networking and offer an attractive means by which users can provide feedback on their physician and obtain information about other patients' satisfaction and experiences. However, research on how users evaluate information on these portals is still scarce and only little knowledge is available about the potential influence of physician reviews on a patient's choice. OBJECTIVE: Starting from the perspective of prospective patients, this paper sets out to explore how certain characteristics of physician reviews affect the evaluation of the review and users' attitudes toward the rated physician. We propose a model that relates review style and review number to constructs of review acceptance and check it with a Web-based experiment. METHODS: We employed a randomized 2x2 between-subject, factorial experiment manipulating the style of a physician review (factual vs emotional) and the number of reviews for a certain physician (low vs high) to test our hypotheses. A total of 168 participants were presented with a Web-based questionnaire containing a short description of a dentist search scenario and the manipulated reviews for a fictitious dental physician. To investigate the proposed hypotheses, we carried out moderated regression analyses and a moderated mediation analysis using the PROCESS macro 2.11 for SPSS version 22. RESULTS: Our analyses indicated that a higher number of reviews resulted in a more positive attitude toward the rated physician. The results of the regression model for attitude toward the physician suggest a positive main effect of the number of reviews (mean [low] 3.73, standard error [SE] 0.13, mean [high] 4.15, SE 0.13). We also observed an interaction effect with the style of the review­if the physician received only a few reviews, fact-oriented reviews (mean 4.09, SE 0.19) induced a more favorable attitude toward the physician compared to emotional reviews (mean 3.44, SE 0.19), but there was no such effect when the physician received many reviews. Furthermore, we found that review style also affected the perceived expertise of the reviewer. Fact-oriented reviews (mean 3.90, SE 0.13) lead to a higher perception of reviewer expertise compared to emotional reviews (mean 3.19, SE 0.13). However, this did not transfer to the attitude toward the physician. A similar effect of review style and number on the perceived credibility of the review was observed. While no differences between emotional and factual style were found if the physician received many reviews, a low number of reviews received lead to a significant difference in the perceived credibility, indicating that emotional reviews were rated less positively (mean 3.52, SE 0.18) compared to fact-oriented reviews (mean 4.15, SE 0.17). Our analyses also showed that perceived credibility of the review fully mediated the observed interaction effect on attitude toward the physician. CONCLUSIONS: Physician-rating websites are an interesting new source of information about the quality of health care from the patient's perspective. This paper makes a unique contribution to an understudied area of research by providing some insights into how people evaluate online reviews of individual doctors. Information attributes, such as review style and review number, have an impact on the evaluation of the review and on the patient's attitude toward the rated doctor. Further research is necessary to improve our understanding of the influence of such rating sites on the patient's choice of a physician.