Exploring the evolutionary ecology of fungal endophytes in agricultural systems: using functional traits to reveal mechanisms in community processes

All plants, including crop species, harbor a community of fungal endophyte species, yet we know little about the biotic factors that are important in endophyte community assembly. We suggest that the most direct route to understanding the mechanisms underlying community assembly is through the study of functional trait variation in the host and its fungal consortium. We review studies on crop endophytes that investigate plant and fungal traits likely to be important in endophyte community processes. We focus on approaches that could speed detection of general trends in endophyte community assembly: (i) use of the ‘assembly rules’ concept to identify specific mechanisms that influence endophyte community dynamics, (ii) measurement of functional trait variation in plants and fungi to better understand endophyte community processes and plant–fungal interactions, and (iii) investigation of microbe–microbe interactions, and fungal traits that mediate them. This approach is well suited for research in agricultural systems, where pair-wise host–fungus interactions and mechanisms of fungal–fungal competition have frequently been described. Areas for consideration include the possibility that human manipulation of crop phenotype and deployment of fungal biocontrol species can significantly influence endophyte community assembly. Evaluation of endophyte assembly rules may help to fine-tune crop management strategies

Antioxydant response to biotic and abiotic inducers for the resistance against Fusarium wilt disease in eggplant (Solanum melongena L.)

Acibenzolar-S-methyl as an abiotic plant activator and a non-host isolate of Fusarium oxysporum on eggplant (F. oxysporum f. sp. melonis) as a biotic inducer were applied to eggplant seedlings in order to confer increased resistance to F. oxysporum f. sp. melongenae, the causal agent of Fusarium wilt of eggplant. Acibenzolar-S-methyl and F. oxysporum f. sp. melonis were applied 72 h before pathogen inoculation and the development of disease symptoms was assessed with a Fusarium yellow rating at 7th, 11th, 14th, 17th and 21th day after inoculation. Pretreatment of eggplants with Acibenzolar-S-methyl and F. oxysporum f. sp. melonis significantly reduced the severity of Fusarium wilt disease. The severity of the disease in positive control plants reached to 92.50% whereas that of acibenzolar-S-methyl and F. oxysporum f. sp. melonis-pretreated seedlings of eggplants was only 32.21% and 21.13%, respectively, 21 days after inoculation. Acibenzolar-S-methyl and F. oxysporum f. sp. melonis pretreatments resulted in a hypersensitive reaction and triggered the elaboration of histological barriers such as callose and H2O2 synthesis. In situ studies demonstrated that the hydrogen peroxide (H2O2) accumulation and the callose deposition as responses to the pathogen attack started 24 h after inoculation. Acibenzolar- S-methyl and F. oxysporum f. sp. melonis-pretreated plants also showed significant increases in the activity of catalase and polyphenol oxidase enzymes along with the increase of proline and H2O2 content when compared to F. oxysporum f. sp. melongenae-infected plants

Individuazione e caratterizzazione di sequenze genomiche in un batterio endosimbionte del fungo micorrizico arbuscolare Gigaspora margarita

Dottorato di ricerca in scienze ambientali: acque interne, agroecosistemi. 12. ciclo. Relatoree coordinatore Graziella Berta. Co-relatore Paola BonfanteConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal