Post-Embryonic Lateral Organ Development and Adaxial—Abaxial Polarity Are Regulated by the Combined Effect of ENHANCER OF SHOOT REGENERATION 1 and WUSCHEL in Arabidopsis Shoots

Abstract

The development of above-ground lateral organs is initiated at the peripheral zone of the shoot apical meristem (SAM). The coordination of cell fate determination and the maintenance of stem cells are achieved through a complex regulatory network comprised of transcription factors. Two AP2/ERF transcription factor family genes, ESR1/DRN and ESR2/DRNL/SOB/BOL, regulate cotyledon and flower formation and de novo organogenesis in tissue culture. However, their roles in post-embryonic lateral organ development remain elusive. In this study, we analyzed the genetic interactions among SAM-related genes, WUS and STM, two ESR genes, and one of the HD-ZIP III members, REV, whose protein product interacts with ESR1 in planta. We found that esr1 mutations substantially enhanced the wus and stm phenotypes, which bear a striking resemblance to those of the wus rev and stm rev double mutants, respectively. Aberrant adaxial–abaxial polarity is observed in wus esr1 at relatively low penetrance. On the contrary, the esr2 mutation partially suppressed stm phenotypes in the later vegetative phase. Such complex genetic interactions appear to be attributed to the distinct expression pattern of two ESR genes because the ESR1 promoter-driving ESR2 is capable of rescuing phenotypes caused by the esr1 mutation. Our results pose the unique genetic relevance of ESR1 and the SAM-related gene interactions in the development of rosette leaves.

Dynamic chromatin regulatory programs during embryogenesis of hexaploid wheat

“…Thus, chromatin accessibility and H3K27me3 coordinately regulate the organ identity gene's activation potential, while chromatin accessibility but not H3K27me3 mediates repression is indispensable for totipotency gene silencing. Indeed, several regeneration-related factors, such as REV [39], SAUR41 [40], CKX7 [41], and DDM1 [42], were gradually diminished during embryo maturation along with closing chromatin status but activated during the callus induction process (Fig. 6d).…”

ESR2–HDA6 complex negatively regulates auxin biosynthesis to delay callus initiation in Arabidopsis leaf explants during tissue culture

“…To identify HDA6-interacting proteins, we carried out yeast two-hybrid (Y2H) screening using a commercial cDNA library ( Matiolli and Melotto, 2018 ). Preliminary results suggested that HDA6 interacts with ESR2, which is involved in in vitro plant regeneration ( Ikeda et al., 2006 , 2021 ; Nag et al., 2007 ; Matsuo et al., 2011 ). To validate this observation, we designed and co-expressed the GAL4 DNA-binding domain–HDA6 fusion construct with a construct comprising the GAL4 activation domain fused to full-length ESR2 coding sequence.…”

An updated model of shoot apical meristem regulation by ERECTA family and CLAVATA3 signaling pathways

“…Out of ten genes upregulated in response to EPFL6, none were upregulated when EPFL6 was applied with CHX, suggesting that upregulation of these genes is an indirect response to EPFL6. Two upregulated genes with the lowest FDR were DORNROSCHEN (DRN)/ ENHANCER OF SHOOT REGENERATION (ESR1) (AT1G12980) and DRN-LIKE ( DRNL )/ ESR2 (AT1G24590) (Fig 2A), both APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factors that regulate meristem maintenance and organ initiation (Kirch et al, 2003; Ikeda et al, 2006; Ikeda et al, 2021). But both of these genes were downregulated by EPFL6 in the presence of CHX (Fig.…”