The AP2 transcription factors DORNRÖSCHEN and DORNRÖSCHEN-LIKE redundantly controlArabidopsisembryo patterning via interaction with PHAVOLUTA

Abstract

DORNRÖSCHEN (DRN) (also known as ENHANCER OF SHOOT REGENERATION1; ESR1)and DRN-LIKE (DRNL; also known as ESR2) are two linked paralogues encoding AP2 domain-containing proteins. drn mutants show embryo cell patterning defects and, similarly to drnl mutants, disrupt cotyledon development at incomplete penetrance. drn drnl double mutants with weak or strong drnl alleles show more highly penetrant and extreme phenotypes, including a pin-like embryo without cotyledons, confirming a high degree of functional redundancy for the two genes in embryo patterning. Altered expression of PIN1::PIN1-GFP and DR5::GFP in drn mutant embryos places DRN upstream of auxin transport and response. A yeast two-hybrid screen with DRN followed by coimmunoprecipitation and bimolecular fluorescence complementation revealed PHAVOLUTA (PHV) to be a protein interaction partner in planta. drn phv double mutants show an increased penetrance of embryo cell division defects. DRNL can also interact with PHV and both DRN and DRNL can heterodimerise with additional members of the class III HD-ZIP family, PHABULOSA, REVOLUTA, CORONA and ATHB8. Interactions involve the PAS-like C-terminal regions of these proteins and the DRN/DRNL AP2 domain.

Of Blades and Branches: Understanding and Expanding the Arabidopsis Ad/Abaxial Regulatory Network through Target Gene Identification

“…Chandler et al (2007) found that the HD-ZIPIII protein PHAVOLUTA interacts with the AP2 family DORNRÖ SCHEN and DORNRÖ SCHEN-LIKE transcription factors. Moreover, dornröschen dornröschenlike double mutants fail to make cotyledons indicating that the interaction has biological relevance.…”

Embryogenesis: Pattern Formation from a Single Cell

“…The single mutants dornroschen (drn) and dornoschen-like (drnl) display a variety of cotyledon defects such as single or fused cotyledons, some aberrant divisions in the embryo and in rare instances a phenotype similar to mp (Chandler et al, 2007). Mutant drn embryos are also disturbed in auxin responsiveness (Chandler et al, 2007).…”

“…Mutant drn embryos are also disturbed in auxin responsiveness (Chandler et al, 2007). In a double mutant combining a strong drn allele with a weak drnl, the penetrance of all three phenotypes is greatly increased, whereas a homozygous double mutant combining a strong drn allele and a strong drnl allele shows a pinlike phenotype (Chandler et al, 2007).…”

“…Mutant drn embryos are also disturbed in auxin responsiveness (Chandler et al, 2007). In a double mutant combining a strong drn allele with a weak drnl, the penetrance of all three phenotypes is greatly increased, whereas a homozygous double mutant combining a strong drn allele and a strong drnl allele shows a pinlike phenotype (Chandler et al, 2007). DRN and DRNL encode AP2-like transcription factors and have been shown to interact with PHAVOLUTA (PHV) and BES interacting Myc-like protein 1 (BIM1) (Chandler et al, 2007;, two other transcription factors involved in embryo patterning.…”

“…In a double mutant combining a strong drn allele with a weak drnl, the penetrance of all three phenotypes is greatly increased, whereas a homozygous double mutant combining a strong drn allele and a strong drnl allele shows a pinlike phenotype (Chandler et al, 2007). DRN and DRNL encode AP2-like transcription factors and have been shown to interact with PHAVOLUTA (PHV) and BES interacting Myc-like protein 1 (BIM1) (Chandler et al, 2007;, two other transcription factors involved in embryo patterning. DRN itself has also been (A) Auxin accumulates in certain cells through coordinated transport mediated by the PIN proteins and this accumulation leads to the activation of the ARFs.…”