Endophytic fungi (EF) can enhance both plant growth and defense barriers against pests and pathogens, contributing to the reduction of chemical pesticides and fertilizers use in agriculture. Beauveria bassiana is an entomopathogenic fungus showing endophytism in several crops, often associated with a good capacity to limit the development of pests and disease agents. However, the diversity of the protective efficacy and plant response to different strains can be remarkable and needs to be carefully assessed for the successful and predictable use of these beneficial microorganisms. This study aims to select B. bassiana strains able to colonize tomato plants as endophytes as well as to control two important disease agents, Botrytis cinerea and Alternaria alternata, and the pest aphid, Macrosiphum euphorbiae. Nine wild-type isolates and one commercial strain were screened for endophytism, then further characterized for plant-growth promotion plus inhibition of disease development and pest infestation. Four isolates proved to have a good control activity against the biotic stressors tested, but only Bb716 was also able to promote plant growth. This work provides a simple workflow for the selection of beneficial EF, paving the way towards more effective use of B. bassiana in Integrate Pest Management (IPM) of tomato.

RNAi interference (RNAi) for insect pest control is often used to silence genes controlling vital functions, thus generating lethal phenotypes. Here, we propose a novel approach, based on the knockout of an immune gene by dsRNA-expressing bacteria as a strategy to enhance the impact of spray applications of the entomopathogen Bacillus thuringiensis (Bt). The target gene, Sl 102, controls the encapsulation and nodulation responses in the noctuid moth Spodoptera littoralis (Lepidoptera, Noctuidae). To deliver Sl 102 dsRNA, we have developed a bacterial expression system, using HT115 Escherichia coli. This allows a much cheaper production of dsRNA and its protection against degradation. Transformed bacteria (dsRNA-Bac) administered through artificial diet proved to be more effective than dsRNA synthesized in vitro, both in terms of gene silencing and immunosuppression. This is a likely consequence of reduced dsRNA environmental degradation and of its protected release in the harsh conditions of the gut. The combined oral administration with artificial diet of dsRNA-Bac and of a Bt-based biopesticide (Xentari™) resulted in a remarkable enhancement of Bt killing activity, both on 4th and 5th instar larvae of S. littoralis, either when the two components were simultaneously administered or when gene silencing was obtained before Bt exposure. These results pave the way toward the development of novel Bt spray formulations containing killed dsRNA-Bac, which synergize Bt toxins by suppressing the insect immune response. This strategy will preserve the long-term efficacy of Bt-based products and can, in principle, enhance the ecological services provided by insect natural antagonists. Key message• RNAi for insect control requires the development of effective delivery strategies of dsRNA. • Bacteria expressing a dsRNA targeting an immune gene induce its silencing when ingested by larvae of the noctuid moth Spodoptera littoralis. • The resulting immunosuppression enhances the killing activity of a Bt-based biopesticide.• These immune suppressive bacteria can be used as synergistic factors to develop more effective Bt sprays, and to preserve Bt efficacy.Communicated by E. Roditakis.* S. Caccia

It is important, from a prognostic and therapeutic point of view, to make a correct diagnosis between verrucous hemangioma (VH) and angiokeratoma circumscriptum. The former needs a large and deep exeresis, while the latter responds to the common means of physical therapy. Two cases of verrucous hemangioma are reported that have allowed us to review the clinical and histologic differential characteristics of the two forms.

Basal cell carcinoma (BCC) is the most frequent cutaneous neoplasm, with a generally favorable clinical behavior. Sometimes, indeed, it recurs after therapy and/or metastasizes. As point mutations in the coding sequence of the p53 tumor suppressor gene have been implicated in the progression of many human tumors, we studied the expression of p53 protein on this neoplasia. We tested immunohistochemically the positivity for p53 protein (NCL-p53-CM1, YLEM) on 19 cases of morphologically "non aggressive" BCC (BCC1) and on 19 "aggressive" BCC (BCC2), all with one or more relapses and 3 with distant metastases also. Results were related to clinico-pathological and follow-up data. All but one BCC2 were found positive for p53 protein. Conversely, only 2 cases of BCC1 exhibited low immunoreactivity for p53 protein, with high statistical differences between the two groups. No correlation was found between the immunoreactivity, age of patients, and site of the lesions. The availability of immunohistochemistry and the relatively easy interpretation of the results make screening for p53 protein a possibly useful tool in the prognostic evaluation of BCC.