Effects of karrikins and the strigolactone analogue GR24 on the transcriptome of Brachypodium distachyon seedlings. Effects of karrikins and the strigolactone analogue GR24 on the transcriptome of Brachypodium distachyon seedlings

Objective: to compare and contrast the effects of exogenous application of karrikins KAR1 and KAR2, and the strigolatone analogue rac-GR24, on gene expression in shoot tissue of seedlings of Brachpodium distachyon (false brome). The experiment compared the effects on three genotypes: wild type Bd21-3, and two mutant alleles for the Brachypodium orthoologue of the karrikin receptor KARRIKIN INSENSITIVE2 (KAI2; Bradi1g15880.1). These alleles were designated Bdkai2-1 and Bdkai2-2. Overall design: Four treatments (mock, 1 µM KAR1, 1 µM KAR2, 10 µM rac-GR24) were applied to three genotypes (WT Bd21-3, Bdkai2-1, Bdkai2-2) in triplicate, for a total of 36 samples. Three-day-old seedlings were transferred to liquid growth medium in 250 mL conical flasks for 24 hours, and then treated by addition of 1:1000 dilution of acetone (mock), 1 mM KAR1, 1 mM KAR2 or 10 mM rac-GR24 (all dissolved in acetone). Shoot material was collected after four hours of treatment and frozen in liquid nitrogen prior to extraction of total RNA.