This demonstrates the potential of chemical genetic screening in combination with reverse genetics to assign specific capabilities to individual members of a giant protein household. A bigger screen was carried out for subtilisin-like serine proteases , which contains fifty six members in Arabidopsis. Here a hundred and forty four T-DNA insertion traces for 55 subtilase genes have been identified. With the exception of SDD1, not considered one of the lines displayed an apparent seen phenotype in the homozygous state .