Biodiversity and Plant SystematicsDr. Anja Schmidt

To gain an understanding of the gene regulatory programs governing the formation and development of plant reproductive tissues, we are combining laser assisted microdissection with RNA-Seq for transcriptome analyses at high spatial and temporal resolution. As model systems, we are using Arabidopsis thaliana and sexual and apomictic accessions of the closely related genus Boechera. This has recently identified a number of new candidate genes for apomixis and substantiated previous evidence of RNA helicases to be crucial for development of the reproductive lineages in plants, resembling conserved features of animal germlines. Interestingly, the coding regions of many RNA helicases remain highly conserved and under purifying selection also in apomicts, in agreement with their importance in fundamental cellular or developmental processes. In support of this notion, we recently uncovered crucial roles of different novel RNA helicases for germline development. Importantly, we demonstrated that in Arabidopsis lines carrying mutant alleles of a single RNA helicase, RH17, show phenotypes resembling different elements of apomixis. We further identified additional RNA helicases causing severe defects during reproductive development. Current directions aim at the elucidation of the molecular processes and regulatory networks they are involved in to control aspects of gene activity, genome integrity, and stress response during reproductive development.