Highlighted article: Dmitry Lapin, Rhonda C. Meyer, Hideki Takahashi, Ulrike Bechtold, Guido Van den Ackerveken (2012) Broad-spectrum resistance of Arabidopsis C24 to downy mildew is mediated by different combinations of isolate-specific loci. New Phytologist DOI: 10.1111/j.1469-8137.2012.04344.x
It is a mark of how effective plant immune systems are that most bacteria, fungi, and viruses do not affect plants at all either because plant tissues are not suitable for them to live in, or they are fended off. Of course there are pathogens that are compatible with plants – and within species that share compatibility, there are pockets of resistance. Some sub-groups are resistant to specific pathogen isolates, and this is caused by dominant resistant genes. A much broader, more complicated, and less common form of resistance occurs when a particular accession is resistant to a whole pathogen species, or several species. This is broad-spectrum resistance, and it can be caused by a simple dominant gene or multiple genes. Natural broad-spectrum resistance is not simple to transfer from its origin to a commercial crop because it can come from a complex set of genes which are not necessarily all dominant. (more…)