Expression data from microdissected endosperm transfer cells (ETCs) of barley seeds during different developmental stages

Endosperm transfer cells (ETCs) of barley grains/seeds are located at the maternal-filial boundary in seeds and fascilitate nutrient transfer from the mother plant into the filial endosperm tissue. Due to the difficult accessibility of ETCs inside the seed, signalling and metabolic pathways involved in differentiation processes of ETCs are poorly understood. To analyse ETC differentiation, we applied laser microdissection pressure catapulting (LMPC) coupled to transcriptome analysis at various developmental stages from cellularization to full functionality and ongoing modifications. ETC-specific transcriptome data identified candidate genes and associated pathways involved in distinct differentiation processes. Barley grains were harvested at 5, 7, 10 and 12 days after flowering/pollination (DAF) and immediately frozen in liquid nitrogen. In a cryostat (-20°C), middle parts were cut by a razor blade, glued onto sample plates by Tissue-Tek® O.C.T™ and 20 µm sections were mounted on PEN membrane slides (PALM, Bernried, Germany). Cryosections were stored for 7 days at -20°C until complete dryness. LMPC-based isolation of ETC tissue from cryosections has been done using the PALM® MicroBeam laser system. For each biological replicate, 50-70 sections from three independent grains were collected. Three biological replicates were generated from each time point (total number of samples = 12).