Spontaneous Mutations in KNOX Genes Give Rise to a Novel Floral Structure in Antirrhinum

@article{Golz2002SpontaneousMI,
  title={Spontaneous Mutations in KNOX Genes Give Rise to a Novel Floral Structure in Antirrhinum},
  author={John F. Golz and Emma Keck and Andrew Hudson},
  journal={Current Biology},
  year={2002},
  volume={12},
  pages={515-522}
}

Figures from this paper

Characterization of Linaria KNOX genes suggests a role in petal-spur development.

A model in which KNOX gene expression during early petal-spur development promotes and maintains further morphogenetic potential of the petal, as previously described, is proposed, indicating that petal spurs could have evolved by changes in regulatory gene expression that cause rapid and potentially saltational phenotypic modifications.

A role for the Auxin Response Factors ARF6 and ARF8 homologs in petal spur elongation and nectary maturation in Aquilegia.

This study provides the first evidence of ARF6/8 homolog-mediated petal development outside the core eudicots, and the genes appear to be specifically required for cell elongation and nectary maturation in the Aquilegia petal spur.

Identification of the Key Regulatory Genes Involved in Elaborate Petal Development and Specialized Character Formation in Nigelladamascena (Ranunculaceae).

The results of extensive transcriptomic and functional studies on Nigella damascena provide the first portrait of elaborate petal development and pave the way to understanding the mechanisms underlying lateral organ diversification in plants.

Molecular framework underlying floral bilateral symmetry and nectar spur development in Tropaeolum, an atypical member of the Brassicales.

Tropaeolum specific duplications in the TCP3/4L and STM gene lineages, which are critical for spur formation in other taxa are identified, and TM6 (MADS-box), RL2 (RAD-like7), and KN2/6L2 and OSH6L (KNOX1 genes), have been lost in core Brassicales but retained in Tropaeolums.

Identification of the Key Regulatory Genes Involved in Elaborate Petal Development and Specialized Character Formation in Nigella damascena (Ranunculaceae)[OPEN]

30 genes that are responsible for the marginal/ventral elaboration of petals and the initiation of several highly specialized morphological characters are identified, providing the first portrait of elaborate petal development.

Chicken Toes-Like Leaf and Petalody Flower (CTP) is a novel regulator that controls leaf and flower development in soybean

CTP is a novel and critical pleiotropic regulator of leaf and flower development that participates in multiple regulation pathways, and may play key roles in lateral organ differentiation as a putative novel transcription regulator.

Premature arrest of the male flower meristem precedes sexual dimorphism in the dioecious plant Silene latifolia

The results make SlSTM and SlCUC strong candidates for being involved in sex determination in S. latifolia strong candidates, and phylogenetic analyses suggest that they are true orthologs for both types of genes.

Duplicated STM-like KNOX I genes act in floral meristem activity in Eschscholzia californica (Papaveraceae)

The data suggest that some aspects of STM function present in Arabidopsis evolved already before the basal eudicots diverged from core eudicot, and that both EcSTM genes are required for the formation of reproductive organs.

KNOX overexpression in transgenic Kohleria (Gesneriaceae) prolongs the activity of proximal leaf blastozones and drastically alters segment fate

It is concluded that KNOX-mediated perpetuation of marginal blastozones in Kohleria is sufficient to induce a set of processes that result in highly dissected leaflets, which are unusual in this plant family.

Molecular basis for three-dimensional elaboration of the Aquilegia petal spur

Findings indicate that the production of this three-dimensional form is an example of organ sculpting via localized cell division with novel contributions from hormone signalling, rather than a product of prolonged indeterminacy.
...

References

SHOWING 1-10 OF 78 REFERENCES

Floral homeotic mutations produced by transposon-mutagenesis in Antirrhinum majus.

It is shown that the deficiens (def) gene (class 2) acts throughout organ development, but its action may be different at various developmental stages, accounting for the intermediate phenotypes conferred by certain def alleles.

A dominant mutation in the maize homeobox gene, Knotted-1, causes its ectopic expression in leaf cells with altered fates.

Kn1 functions in its wild-type context as a regulator of cell determination and apparently alters the fates of leaf cells in which it is ectopically expressed from an early stage of leaf development.

The barley Hooded mutation caused by a duplication in a homeobox gene intron

It is concluded that homeotic genes of the Knox gene family are involved in floral evocation and the study of polarity of reproductive organs in K and related mutants can now focus on homeobox genes.

Shoot meristem size is dependent on inbred background and presence of the maize homeobox gene, knotted1.

Analysis of limited shoot plants during embryogenesis indicated a role forkn1 in shoot meristem maintenance, and a model for kn1 in maintenance of the morphogenetic zone of the shoot apical meristems is discussed.

Ectopic expression of the maize kn1 gene phenocopies the Hooded mutant of barley.

It is suggested that the inverse polarity of the ectopic flowers seen in Hooded and transgenic kn1 plants results from the transformation of the awn into reiterative inflorescence axes, suggesting posttranscriptional regulation.

Overexpression of the maize homeo box gene, KNOTTED-1, causes a switch from determinate to indeterminate cell fates.

It is proposed that the KN1 homeo box gene plays a role in determining cell fate in maize and tobacco, and the consequences of KN1 overexpression appear to depend on the concentration ofKN1 and the timing of its expression during organogenesis.

Ectopic expression of the knox homeo box gene rough sheath1 alters cell fate in the maize leaf.

Ectopic expression in Rs1-O plants suggests the ligular [corrected] region is more competent to respond to rs1 than blade or sheath tissues, suggesting a possible role for rs1 in patterning the placement of lateral organs along the axis of the shoot.

An epigenetic mutation responsible for natural variation in floral symmetry

It is shown that a naturally occurring mutant of Linaria vulgaris carries a defect in Lcyc, a homologue of the cycloidea gene which controls dorsoventral asymmetry in Antirrhinum, indicating that epigenetic mutations may play a more significant role in evolution than has hitherto been suspected.

Mutator-suppressible alleles of rough sheath1 and liguleless3 in maize reveal multiple mechanisms for suppression.

Characterization of five dominant Mu-suppressible alleles of the knox (knotted1-like homeobox) genes liguleless3 and rough sheath1, which exhibit neomorphic phenotypes in the leaves suggests that whether an allele is suppressible or not may depend upon the site of insertion.

Knots in the family tree: evolutionary relationships and functions of knox homeobox genes

Preliminary data from the analysis of class I knox gene expression illustrates the evolution of complex patterns of knox expression is likely to have occurred through loss and gain of domains of gene expression.
...