Phenotypic and transcriptomic characterization of an ABA-sensitive mutant generated by microspore embryogenesis in barley

Barley (<i>Hordeum vulgare</i> L.) has been recognized as an ideal model plant to study the mechanism of environmental adaptation for crop improvement owing to its wide adaption to abiotic stresses. Abscisic acid is an essential hormone involved in many abiotic stresses. Here, an ABA-sensitive barley mutant (<i>abas1</i>) was generated by microspore embryogenesis. On exogenous ABA treatment, the seedlings of <i>abas1</i> presented less plant height, root length, shoot and root dry matter than the wild type, and more genes showedigher expressional intensity and up-regulation models by RNA-Seq profiling. The gene ontology analysis revealed that the regulation of DEGs may lead to the activation of the ROS pathway and consumption of more energy in <i>abas1,</i> specifically. Furthermore, the up-regulation of two candidate genes (<i>P450</i> and <i>NsLTP</i>) in <i>abas1</i> may contribute to the variation of ABA sensitivity. Our findings provide more valuable material and information toward the understanding of the mechanism of ABA response in barley.