An automated recording incubator for tube culture of microorganisms

Studies on the development of an automated incubator which can perform the operations commonly required for microbiological experiments are described. This apparatus is able to handle a large number of samples and has the unique shaking mechanism which is to strike the lower part of the test tubes with reciprocally moving bars. Besides fundamental operations, such as injection of samples and medium, inoculation and repeated measurements of bacterial growth, the apparatus allows the addition of samples and removal of culture broth at the desired time during the incubation period without the researcher's attendance. These functions are combined to make the apparatus very versatile for microbiological experiments, saving on night-time and holiday working and increasing efficiency in experiments. Some practical applications of this apparatus for microbioassay and fermentation experiments are described. The automated method is shown to be advantageous in assay precision and in obtaining detailed information.     

An E3 ubiquitin ligase,ERECT LEAF1, functions in brassinosteroid signaling of rice

A spontaneous rice mutant, erect leaf1 (elf1–1), produced a dwarf phenotype with erect leaves and short grains. Physiological analyses suggested that elf1–1 is brassinosteroid-insensitive, so we hypothesized that ELF1 encodes a positive regulator of brassinosteroid signaling. ELF1, identified by means of positional cloning, encodes a protein with both a U-box domain and ARMADILLO (ARM) repeats. U-box proteins have been shown to function as E3 ubiquitin ligases; in fact, ELF1 possessed E3 ubiquitin ligase activity in vitro. However, ELF1 itself does not appear to be polyubiquitinated. Mutant phenotypes of 2 more elf1 alleles indicate that the entire ARM repeats is indispensable for ELF1 activity. These results suggest that ELF1 ubiquitinates target proteins through an interaction mediated by ARM repeats. Similarities in the phenotypes of elf1 and d61 mutants (mutants of brassinosteroid receptor gene OsBRI1), and in the regulation of ELF1 and OsBRI1 expression, imply that ELF1 functions as a positive regulator of brassinosteroid signaling in rice.