The transcriptional landscape of microspore embryogenesis induction in barley
The effectiveness of microspore embryogenesis and plant formation from in vitro cultivated microspores is determined by a complex network of internal and environmental factors. Plant breeding and genetic engineering widely use haploids/doubled haploids (DHs) derived from in vitro-cultured microspores, but the mechanism of ME induction remains poorly defined. Here, RNA-sequencing was used to characterize the transcriptional landscapes of four early stages of ME in two barley cultivars (Golden Promise and Igri) that are contrastingly responsive in the microspore-derived plant formation. Our experimental setup revealed fundamental regulatory networks, key marker genes of ME (628 stage-specific markers), and 160 candidate genes crucial for genotype-dependent responsiveness/resistance to ME. We found that transcription factors probably give rise to embryo-like structure and callus formation at stage III and determine their further development. Our high-resolution temporal transcriptome atlas provides an important resource for future functional studies aiming at unravelling the genetic control of microspore transition. Overall design: Microspores isolated at four developmental stages of microspore embryogenesis; species barley (Hordeum vulgare) ; Microspores isolated from two cultivars: Golden Promise and Igri; each stage - four biological replicates