Wood-destroyer sequenced

In a beautifully understated opening sentence – worthy of Watson and Crick’s famous 1953 seminal paper describing the structure of DNA – Robin Ohmi et al. (Nature Biotechnology, doi:10.1038/nbt.1643) remind us that ‘much remains to be learned about the biology of mushroom-forming fungi, which are an important source of food, secondary metabolites and industrial enzymes’.

As pathogens, and mycorrhiza, such organisms are also sometimes the scourge and life-saving partner, respectively, of plants. Good news, then, that the genome of one lignovore has now been sequenced.

Hopes are high that analysis of the 13,210 genes of Schizophyllum commune’s 38.5 megabase genome will lead to better understanding of toadstool biology using this ‘genetically tractable model for studying mushroom development’. Furthermore – and making a virtue out of the fungus’ wood-devouring activity – unravelling this ability might help us to develop more efficient wood-degradation processes with concomitant industrial applications.

We continue the DNA theme with news of two more plant-relevant genome sequences, wheat and apple. A UK team has recently produced a draft of the genome of bread wheat (Triticum aestivum) variety ‘Chinese Spring’, which has been made freely available at http://www.cerealsdb.uk.net/.

Although acknowledged to be but a first step towards a fully annotated genome, wheat is one of the major staple food crops of the world and this landmark is viewed as a significant contribution to efforts to support global food security. And the result is no mean feat since the hexaploid wheat genome is five times the size of the human genome and the cereal has a very tangled evolutionary history involving much incorporation of genetic material from ancestral grasses.

Meanwhile, on the other side of the Atlantic (but published in a UK-based journal), another group has produced ‘a high-quality draft genome sequence of the domesticated apple (Malus × domestica)’ (Nature Genetics, doi:10.1038/ng.654). The task of sequencing the genome of the ‘Golden Delicious’ cultivar – which at approx. 750 megabases and containing an estimated 57,386 genes is bigger even than wheat’s – took Riccardo Velasco and >80 named co-workers 2 years.

Although apples are not a staple food in the same stable as wheat, as a woody member of the Rosaceae, which includes many important fruit crops, unravelling its genetic secrets will be extremely useful for further exploitation of those crops, and constitutes a significant addition to the growing list of plant genome sequences.