Hormonal homeostasis associated with effective induction of triticale microspore embryogenesis

Abstract The endogenous level of cytokinins (CKs) and auxins (Auxs) was analyzed in isolated microspores ovaries two doubled haploid (DH) lines triticale (× Triticosecale Wittm.) to better understand the mechanism microspore embryogenesis (ME)—the most efficient widely applied method producing DHs. responsiveness studied ME significantly varied. induced by pre-treating tillers with low temperature (4 °C for 3 weeks) alone or combination synthetic auxin (2,4-D), inhibitor (PCIB) melatonin (MEL) 4 days before isolation. Hormonal profile analyses, accompanied effectiveness evaluation confirmed multi-level crosstalk Auxs/CKs specific hormonal homeostasis required effective reprogramming. It found that contained mainly cis zeatin derivatives: -zeatin- O -glucoside ( c ZOG), -zeatin riboside ZR) Z), as well indole-3-acetic acid (IAA) IAA-aspartate (IAAsp). Increased efficiency associated higher contents identified CKs Auxs, active Aux/active CK ratio. Trans isoforms were detected only ovaries, confirming their importance a source bioactive molecules stimulating embryogenic development. Two pre-treatments tested: 12.5 μM PCIB 50 MEL decreased ratio, which an increase regeneration efficiency.