The genome sequence and gene prediction of Blumeria graminis f. sp. hordei Race1 have not been determined by the Joint Genome Institute (JGI), but were obtained from Lamprinos Frantzeskakis. In order to allow comparative analyses with other fungal genomes sequenced by the JGI, a copy of this genome is incorporated into Mycocosm. Please note that this copy of the genome is not maintained by Frantzeskakis et. al. and is therefore not automatically updated. JGI tools were used to automatically annotate predicted proteins.
Blumeria graminis causes powdery mildews in grasses, including the common cereals wheat and barley. Host specificity of the “formae specialis” is high: for example f. sp. hordei is capable of infecting barley but not wheat, whist the f. sp. tritici grows only on wheat. Like all powdery mildew fungi, B. graminis is an obligate biotroph: it requires a living host to grow and reproduce. No significant development has been ever observed in axenic culture. On a host, the mildew fungi conidium germinates to produce a hypha that differentiates an appressorium and a peg that penetrates directly into the epidermal cell. Once inside the cell, the hypha develops a multidigitate haustorium, surrounded by a matrix and a membrane continuous with the host plasma membrane. The haustorium takes up nutrients from the host and is believed to deliver effectors to target the plant’s metabolism and immune system. The haustoria effectively feed the rest of the colony which expands on the surface of the plant, first as a network of branched hyphae (which produce further, secondary haustoria and then develops conidiophores which grow perpendicular to the leaf surface and generate masses of conidiophores that are visible as a white powdery mass (hence the name of the disease). The conidia are dispersed by air currents.
Genome Reference(s)
Frantzeskakis L, Kracher B, Kusch S, Yoshikawa-Maekawa M, Bauer S, Pedersen C, Spanu PD, Maekawa T, Schulze-Lefert P, Panstruga R
Signatures of host specialization and a recent transposable element burst in the dynamic one-speed genome of the fungal barley powdery mildew pathogen.
BMC Genomics. 2018 May 22;19(1):381. doi: 10.1186/s12864-018-4750-6