New plant genes are being discovered at a rapid pace. Yet, in most cases, their precise function remains elusive. The recent advent of recombinational cloning techniques has significantly improved our ability to investigate gene functions systematically. For example, proteins fused with diverse fluorescent tags can be expressed at will using versatile cloning cassettes. In addition, novel binary T-DNA vectors are now available to assemble multiple DNA fragments simultaneously, which greatly facilitate plant cell and protein engineering.