Auxin biosynthesis maintains embryo identity and growth during BABY BOOM-induced somatic embryogenesis

• DOI: 10.1093/plphys/kiab558
• Publication Date: 2021-11-25T20:16:11Z
• Authors: Mengfan Li; Justyna Wrobel-Marek; Iris Heidmann; Anneke Horstman; Baojian Chen; Ricardo Reis; Gerco C Angenent; Kim Boutilier
• Keywords: Ectopic expression

Abstract Somatic embryogenesis is a type of plant cell totipotency where embryos develop from nonreproductive (vegetative) cells without fertilization. can be induced in vitro by auxins, and ectopic expression embryo-expressed transcription factors like the BABY BOOM (BBM) AINTEGUMENTA-LIKE APETALA2/ETHYLENE RESPONSE FACTOR domain protein. These different pathways are thought to converge promote auxin response biosynthesis, but specific roles endogenous pathway somatic induction have not been well-characterized. Here we show that BBM transcriptionally regulates YUCCA3 (YUC3) YUC8 biosynthesis genes during BBM-mediated Arabidopsis (Arabidopsis thaliana) seedlings. local YUC3 seedlings, which coincided with increased DR5 indole-3-acetic acid (IAA) WOX2 embryo reporter. YUC-driven was required for embryogenesis, as number embryogenic explants reduced ca. 50% yuc3 yuc8 mutants abolished after chemical inhibition YUC enzyme activity. However, detailed inhibitor time-course study revealed YUC-dependent IAA re-initiation totipotent identity Rather, enzymes later development maintenance growth. This resolves long-standing question about role factor-mediated also provides an experimental framework understanding other planta systems.