scholarly journals A Petunia Twist on the ABC Model of Floral Organ Specification

2012 ◽  
Vol 24 (6) ◽  
pp. 2237-2237 ◽  
Author(s):  
Jennifer Mach
Keyword(s):  
Floral Organ ◽  
Abc Model ◽  
Floral Organ Specification

scholarly journals Spatio-temporal Dynamics of the Patterning of Arabidopsis Flower Meristem

2020 ◽  
Author(s):  
José Díaz ◽  
Elena R. Álvarez-Buylla
Keyword(s):  
Flower Development ◽  
Apical Meristem ◽  
Temporal Dynamics ◽  
Positional Information ◽  
Floral Organ ◽  
Necessary Condition ◽  
Sufficient Condition ◽  
Abc Model ◽  
Flower Meristem ◽  
Spatio Temporal

AbstractThe qualitative model presented in this work recovers the onset of the four fields that correspond to those of each floral organ whorl of Arabidopsis flower, suggesting a mechanism for the generation of the positional information required for the differential expression of the A, B and C identity genes according to the ABC model for organ determination during early stages of flower development. Our model integrates a previous model for the emergence of WUS pattern in the apical meristem, and shows that this pre-pattern is a necessary but not sufficient condition for the posterior information of the four fields predicted by the ABC model. Furthermore, our model predicts that LFY diffusion along the L1 layer of cells is not a necessary condition for the patterning of the floral meristem.

Identification and fine mapping of lemma-distortion1, a single recessive gene playing an essential role in the development of lemma in rice

2016 ◽  
Vol 154 (6) ◽  
pp. 989-1001 ◽  
Author(s):  
D. W. YANG ◽  
X. F. YE ◽  
X. H. ZHENG ◽  
C. P. CHENG ◽  
N. YE ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Rice Genome ◽  
Recessive Gene ◽  
Floral Organ ◽  
Formation Mechanisms ◽  
Single Recessive Gene ◽  
New Gene ◽  
Genome Annotations ◽  
Floral Organ Specification

SUMMARYFloral organ development influences plant reproduction and crop yield. The mechanism of floral organ specification is generally conserved in angiosperms as demonstrated by the ‘ABC’ model. However, mechanisms underlying the development of floral organs in specific groups of species such as grasses remain unclear. In the genus Oryza (rice), a spikelet consists of a fertile floret sub-tended by a lemma, a palea, two sterile lemmas and rudimentary glumes. To understand how the lemma is formed, a curve-shaped lemma-distortion1 (ld1) mutant was identified. Genetic analysis confirmed that the ld1 mutant phenotype was due to a single recessive gene mutation. Using a large F2 population, the LD1 gene was mapped between markers Indel-7-15 and Indel-7-18, which encompassed a region of 15·6 kilo base pairs (kbp). According to rice genome annotations, two putative genes, LOC_Os07g32510 and LOC_Os07g32520, were located in this candidate region. However, DNA sequencing results indicated only 1 base pair (bp) substitution (T⇨C) was found in LOC_Os07g32510 between the wild-type and the ld1 mutant. Thus LOC_Os07g32510, encoding a DNA binding with one zinc finger (DoF) containing protein, was the candidate gene for LD1. Further analysis showed that mutation of the amino acid cysteine (C) to arginine (R) was likely to lead to zinc finger protein deactivation. Phylogenetic and conservation analysis of the gene from different species revealed that cysteine was critical to LD1 function. As a new gene controlling lemma development, the study of LD1 could provide insights into rice floral organ formation mechanisms.

scholarly journals Control of flower development in Arabidopsis thaliana by APETALA1 and interacting genes

Development ◽  
1993 ◽  
Vol 119 (3) ◽  
pp. 721-743 ◽  
Author(s):  
J. L. Bowman ◽  
J. Alvarez ◽  
D. Weigel ◽  
E. M. Meyerowitz ◽  
D. R. Smyth
Keyword(s):  
Arabidopsis Thaliana ◽  
In Situ Hybridization ◽  
Flower Development ◽  
Floral Organ ◽  
Allelic Series ◽  
Flower Meristem ◽  
Petal Development ◽  
Two Phases ◽  
Floral Organ Specification

Mutations in the APETALA1 gene disturb two phases of flower development, flower meristem specification and floral organ specification. These effects become manifest as a partial conversion of flowers into inflorescence shoots and a disruption of sepal and petal development. We describe the changes in an allelic series of nine apetala1 mutants and show that the two functions of APETALA1 are separable. We have also studied the interaction between APETALA1 and other floral genes by examining the phenotypes of multiply mutant plants and by in situ hybridization using probes for several floral control genes. The results suggest that the products of APETALA1 and another gene, LEAFY, are required to ensure that primordia arising on the flanks of the inflorescence apex adopt a floral fate, as opposed to becoming an inflorescence shoot. APETALA1 and LEAFY have distinct as well as overlapping functions and they appear to reinforce each other's action. CAULIFLOWER is a newly discovered gene which positively regulates both APETALA1 and LEAFY expression. All functions of CAULIFLOWER are redundant with those of APETALA1. APETALA2 also has an early function in reinforcing the action of APETALA1 and LEAFY, especially if the activity of either is compromised by mutation. After the identity of a flower primordium is specified, APETALA1 interacts with APETALA2 in controlling the development of the outer two whorls of floral organs.

scholarly journals A nucleostemin-like GTPase required for normal apical and floral meristem development in Arabidopsis

2012 ◽  
Vol 23 (8) ◽  
pp. 1446-1456 ◽  
Author(s):  
Xiaomin Wang ◽  
Daniel K. Gingrich ◽  
Yunfei Deng ◽  
Zonglie Hong
Keyword(s):  
Flower Development ◽  
Cell Cycle Progression ◽  
Floral Organ ◽  
Regulatory Proteins ◽  
Cycle Progression ◽  
New Class ◽  
Meristem Development ◽  
Promote Cell Cycle Progression ◽  
Floral Primordia ◽  
Floral Organ Specification

Mammalian nucleostemin (NS) is preferentially expressed in stem cells and acts to promote cell cycle progression. In plants, stem cell activities have to be terminated during flower development, and this process requires the activation of AGAMOUS (AG) gene expression. Here, a nucleostemin-like 1 gene, NSN1, is shown to be required for flower development in Arabidopsis. The NSN1 mRNA was found in the inflorescence meristem and floral primordia, and its protein was localized to the nucleoli. Both heterozygous and homozygous plants developed defective flowers on inflorescences that were eventually terminated by the formation of carpelloid flowers. Overexpression of NSN1 resulted in loss of apical dominance and formation of defective flowers. Expression of the AG gene was found to be up-regulated in nsn1. The carpelloid flower defect of nsn1 was suppressed by the ag mutation in the nsn1 ag double mutant, whereas double mutants of nsn1 apetala2 (ap2) displayed enhanced defective floral phenotypes. These results suggest that in the delicately balanced regulatory network, NSN1 acts to repress AG and plays an additive role with AP2 in floral organ specification. As a midsize nucleolar GTPase, NSN1 represents a new class of regulatory proteins required for flower development in Arabidopsis.

The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis

Development ◽  
2001 ◽  
Vol 128 (14) ◽  
pp. 2735-2746
Author(s):  
Dazhong Zhao ◽  
Qilu Yu ◽  
Min Chen ◽  
Hong Ma
Keyword(s):  
Ubiquitin Ligase ◽  
Floral Organ ◽  
Abc Model ◽  
Gene Encoding ◽  
Genetic Studies ◽  
Organ Identity ◽  
F Box Protein ◽  
In Situ Hybridizations ◽  
Floral Regulatory Genes

The Arabidopsis floral regulatory genes APETALA3 (AP3) and PISTILLATA (PI) are required for the B function according to the ABC model for floral organ identity. AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes. UFO encodes an F-box protein, and we have shown previously that UFO genetically interacts with the ASK1 gene encoding a SKP1 homologue; both the F-box containing protein and SKP1 are subunits of ubiquitin ligases. We show here that the ask1-1 mutation can enhance the floral phenotypes of weak lfy and ap3 mutants; therefore, like UFO, ASK1 also interacts with LFY and AP3 genetically. Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression. These results support the idea that UFO and ASK1 together positively regulate AP3 and PI expression. We propose that the UFO and ASK1 proteins are components of a ubiquitin ligase that mediates the proteolysis of a repressor of AP3 and PI expression. Our genetic studies also indicate that ASK1 and UFO play a role in regulating the number of floral organ primordia, and we discuss possible mechanisms for such a regulation.

HvLEAFY controls the early stages of floral organ specification and inhibits the formation of multiple ovaries in barley

2021 ◽  
Author(s):  
C. Selva ◽  
N. Shirley ◽  
K. Houston ◽  
R. Whitford ◽  
U. Baumann ◽  
...  
Keyword(s):  
Floral Organ ◽  
Early Stages ◽  
Floral Organ Specification
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