Abstract
The regulation of floral organ identity was investigated using a forward genetic approach in five floral homeotic mutants of Thalictrum, a noncore eudicot. We hypothesized that these mutants carry defects in the floral patterning genes. Mutant characterization comprised comparative floral morphology and organ identity gene expression at early and late developmental stages, followed by sequence analysis of coding and intronic regions to identify transcription factor binding sites and protein-protein interaction (PPI) motifs. Mutants exhibited altered expression of floral MADS-box genes, which further informed the function of paralogs arising from gene duplications not found in reference model systems. The ensuing modified BCE models for the mutants supported instances of neofunctionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (E-class), or subfunctionalization (C-class) of paralogs. A lack of deleterious mutations in the coding regions of candidate floral MADS-box genes suggested that cis-regulatory or trans-acting mutations are at play. Consistent with this hypothesis, double-flower mutants had transposon insertions or showed signs of transposon activity in the regulatory intron of AGAMOUS (AG) orthologs. Single amino acid substitutions were also found, yet they did not fall on any of the identified DNA binding or PPI motifs. In conclusion, we present evidence suggesting that transposon activity and regulatory mutations in floral homeotic genes likely underlie the striking phenotypes of these Thalictrum floral homeotic mutants.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 9
Claim · model-written summary
Floral mutants showed altered expression of floral MADS-box genes.
Verbatim
t0“a ranunculid”
e0“Mutants exhibited altered expression of floral MADS-box genes, which further informed the function of paralogs arising from gene duplications not found in reference model systems.”
Claim · model-written summary
Modified BCE models supported neofunctionalization of B-class paralogs.
Verbatim
t0“a ranunculid”
e1“The ensuing modified BCE models for the mutants supported instances of neofunctionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (E-class), or subfunctionalization (C-class) of paralogs.”
Claim · model-written summary
Modified BCE models supported partial redundancy of E-class paralogs.
Verbatim
t0“a ranunculid”
e1“The ensuing modified BCE models for the mutants supported instances of neofunctionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (E-class), or subfunctionalization (C-class) of paralogs.”
Claim · model-written summary
Modified BCE models supported subfunctionalization of C-class paralogs.
Verbatim
t0“a ranunculid”
e1“The ensuing modified BCE models for the mutants supported instances of neofunctionalization (e.g., B-class genes expressed ectopically in sepals), partial redundancy (E-class), or subfunctionalization (C-class) of paralogs.”
Claim · model-written summary
Candidate floral MADS-box genes lacked deleterious coding-region mutations.
Verbatim
t0“a ranunculid”
e2“A lack of deleterious mutations in the coding regions of candidate floral MADS-box genes suggested that cis-regulatory or trans-acting mutations are at play.”
Claim · model-written summary
The absence of coding mutations suggested cis-regulatory or trans-acting mutations.
Verbatim
t0“a ranunculid”
e2“A lack of deleterious mutations in the coding regions of candidate floral MADS-box genes suggested that cis-regulatory or trans-acting mutations are at play.”
Claim · model-written summary
Double-flower mutants had transposon insertions or activity in regulatory introns of AG orthologs.
Verbatim
t0“a ranunculid”
e3“double-flower mutants had transposon insertions or showed signs of transposon activity in the regulatory intron of AGAMOUS (AG) orthologs.”
Claim · model-written summary
Single amino acid substitutions were found outside identified DNA-binding and PPI motifs.
Verbatim
t0“a ranunculid”
e4“Single amino acid substitutions were also found, yet they did not fall on any of the identified DNA binding or PPI motifs.”
Claim · model-written summary
The authors infer transposon activity and regulatory mutations likely underlie floral homeotic phenotypes.
Verbatim
t0“a ranunculid”
e5“transposon activity and regulatory mutations in floral homeotic genes likely underlie the striking phenotypes of these Thalictrum floral homeotic mutants.”