A non-destructive selection method for resistance to fusicoccin in Arabidopsis thaliana

A mutagenised population of seeds of Arabidopsis thaliana was allowed to germinate in the presence of the positively charged aminoglycoside hygromycin (4 μg/ml) and the fungal toxin fusicoccin (5×10^–6 m). This hygromycin concentration, which is non-toxic by itself, becomes toxic when used together with fusicoccin, which stimulates cation uptake. Seeds that had germinated after 3–5 days and produced seedlings with green cotyledons were potentially resistant to fusicoccin and were therefore transferred into sterile Magenta vessels containing 1/2-strength Murashige and Skoog medium. This selection procedure is non-destructive, i.e. it allows the recovery of viable seedlings and their growth into adult plants thus permitting direct physiological characterisation. Received: 16 February 1998 / Revision received: 11 August 1998 / Accepted: 13 August 1998     

An actin-related protein from Dictyostelium discoideum is developmentallyregulated and associated with mitochondria

An actin-related protein (ACLA) has been identified in the cellular slime mould Dictyostelium discoideum. The complete cDNA sequence indicates that within the actin superfamily it belongs to the ARP3 family of actin-related proteins together with Arp66B from Drosophila melanogaster, Actin2 from Bos taurus, act2 from Schizosaccharomyces pombe and possibly act2 from Caenorhabditis elegans. The ACLA mRNA is regulated during development, showing a maximum between 2 and 4 h after starvation. The protein has been expressed in E. coli and antibodies raised against it. Immunofluorescence microscopy shows that ACLA protein co-localises with mitochondria; the protein co-purifies with Dictyostelium mitochondria.