Uncovering the post-embryonic functions of gametophytic- and embryonic-lethal genes.

An estimated 500-1 000 Arabidopsis (Arabidopsis thaliana) genes mutate to embryonic lethality. In addition, several hundred mutations have been identified that cause gametophytic lethality. Thus, a significant fraction of the ∼25,000 protein-coding genes in Arabidopsis are indispensable to the early stages of the diploid phase or to the haploid gametophytic phase. The expression patterns of many of these genes indicate that they also act later in development but, because the mutants die at such early stages, conventional methods limit the study of their roles in adult diploid plants. Here, we describe the toolset that allows researchers to assess the post-embryonic functions of plant genes for which only gametophytic- and embryonic-lethal alleles have been isolated.