SUMMARYPlants are highly capable of recognizing and defending themselves against invading microbes. Adapted plant pathogens secrete effector molecules to suppress the host's immune system. These molecules may be recognized by host-encoded resistance proteins, which then trigger defense in the form of the hypersensitive response (HR) leading to programmed cell death of the host tissue at the infection site. The three proteins PEN1, PEN2 and PEN3 have been found to act as central components in cell wall-based defense against the non-adapted powdery mildew Blumeria graminis fsp. hordei (Bgh). We found that loss of function mutations in any of the three PEN genes cause decreased hypersensitive cell death triggered by recognition of effectors from oomycete and bacterial pathogens in Arabidopsis. There were considerable additive effects of the mutations. The HR induced by recognition of AvrRpm1 was almost completely abolished in the pen2 pen3 and pen1 pen3 double mutants and the loss of cell death could be linked to indole glucosinolate breakdown products. However, the loss of the HR in pen double mutants did not affect the plants' ability to restrict bacterial growth, whereas resistance to avirulent isolates of the oomycete Hyaloperonospora arabidopsidis was strongly compromised. In contrast, the double and triple mutants demonstrated varying degrees of run-away cell death in response to Bgh. Taken together, our results indicate that the three genes PEN1, PEN2 and PEN3 extend in functionality beyond their previously recognized functions in cell wallbased defense against non-host pathogens.

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Transitioning from spores to hyphae is pivotal to host invasion by the plant pathogenic fungus Zymoseptoria tritici. This dimorphic switch can be initiated by high temperature in vitro (~27 °C); however, such a condition may induce cellular heat stress, questioning its relevance to field infections. Here, we study the regulation of the dimorphic switch by temperature and other factors. Climate data from wheat-growing areas indicate that the pathogen sporadically experiences high temperatures such as 27 °C during summer months. However, using a fluorescent dimorphic switch reporter (FDR1) in four wild-type strains, we show that dimorphic switching already initiates at 15–18 °C, and is enhanced by wheat leaf surface compounds. Transcriptomics reveals 1261 genes that are up- or down-regulated in hyphae of all strains. These pan-strain core dimorphism genes (PCDGs) encode known effectors, dimorphism and transcription factors, and light-responsive proteins (velvet factors, opsins, putative blue light receptors). An FDR1-based genetic screen reveals a crucial role for the white-collar complex (WCC) in dimorphism and virulence, mediated by control of PCDG expression. Thus, WCC integrates light with biotic and abiotic cues to orchestrate Z. tritici infection.

Background: the aim was to verify the association between Major Depressive Disorders (MDD) and the risk of premature death in people with oncological diseases, and to collect evidence about the causality of a possible association from a longitudinal perspective.Design and Methods: it is a cohort study lasting 9 months, involving people with solid or hematologic cancers. The assessment was conducted by an ad hoc form to collect socio-demographic and clinical-oncological data, the PHQ-9 to screen MDD (cut-off ≥10) and the SF-12 to evaluate HRQoL. Relative Risk (RR) of early death between MDD exposed and not-exposed and Kaplan-Meier survival were carried out.Results: people exposed to MDD during the follow-up were 107/263 (40.7%). Among them, 36 deceased during the observation period. Overtime, having MDD and death’ occurrence showed a strong association (RR=2.15; 95% CI (1.10-4.20); χ²=5.224, p=0.0022), confirmed by Kaplan-Meier survival analysis (χ²=4.357, p=0.037). Among people who died, there was not any association between MDD, age, gender, HRQoL, cancer stage and site.Conclusions: the study confirms the association between MDD and early death in people with cancer. The absence of any association between the onset of MDD and advanced stage of cancer may suggest that it could be due to the consequences of MDD in worsening the clinical conditions related to cancer. The findings point out the relevance of MDD’ early detention among people with cancer.

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