Pattern formation and growth during floral organogenesis: HUELLENLOS and AINTEGUMENTA are required for the formation of the proximal region of the ovule primordium in Arabidopsis thaliana

Development ◽  
1998 ◽  
Vol 125 (14) ◽  
pp. 2555-2563 ◽  
Author(s):  
K. Schneitz ◽  
S.C. Baker ◽  
C.S. Gasser ◽  
A. Redweik
Keyword(s):  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Molecular Mechanisms ◽  
Embryo Sac ◽  
Typical Feature ◽  
Proximal Region ◽  
Ovule Development ◽  
Linear Arrangement ◽  
Floral Organogenesis ◽  
Temporal And Spatial

Our understanding of the molecular mechanisms that regulate and integrate the temporal and spatial control of cell proliferation during organ ontogenesis, particularly of floral organs, continues to be primitive. The ovule, the progenitor of the seed, of Arabidopsis thaliana has been used to develop an effective model system for the analysis of plant organogenesis. A typical feature of a generalized ovule is the linear arrangement of at least three distinct elements, the funiculus, chalaza and nucellus, along a proximal-distal axis. This pattern is supposed to be established during the early proliferative phase of ovule development. We provide genetic evidence that the young ovule primordium indeed is a composite structure. Two genes, HUELLENLOS and AINTEGUMENTA have overlapping functions in the ovule and differentially control the formation of the central and proximal elements of the primordium. The results indicate that proximal-distal pattern formation in the Arabidopsis ovule takes place in a sequential fashion, starting from the distal end. Furthermore, we show that HUELLENLOS also regulates the initiation and/or maintenance of integument and embryo sac ontogenesis and interestingly prevents inappropriate cell death in the young ovule.

NOZZLE regulates proximal-distal pattern formation, cell proliferation and early sporogenesis during ovule development in Arabidopsis thaliana

Development ◽  
2000 ◽  
Vol 127 (19) ◽  
pp. 4227-4238 ◽  
Author(s):  
S. Balasubramanian ◽  
K. Schneitz
Keyword(s):  
Cell Proliferation ◽  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Initial Phase ◽  
Growth Control ◽  
Cell Number ◽  
Outer Function ◽  
Ovule Development ◽  
Floral Organogenesis ◽  
Downstream Target

With the characterisation of the NOZZLE gene we aim at a better understanding of the molecular and genetic mechanism underlying pattern formation and growth control during floral organogenesis. Our data indicate that NOZZLE links these processes during ovule development. In the ovule primordium NOZZLE plays a central role in the formation of the nucellus through antagonizing the activities of BELL, AINTEGUMENTA and INNER NO OUTER, all encoding putative transcription factors, in the prospective nucellar region. We provide evidence that NOZZLE and BELL are chalaza identity genes that share overlapping functions in establishing the prospective chalaza of the ovule. In addition, NOZZLE plays a role in controlling the cell number and by this means the length of the funiculus, again through antagonizing AINTEGUMENTA and INNER NO OUTER function. NOZZLE is also required for the development of the integuments. We show that during the initial phase of this process NOZZLE is transcriptionally regulated by AINTEGUMENTA and INNER NO OUTER. NOZZLE thus represents a downstream target of these two genes in the integument development pathway.

A series of novel mutants of Arabidopsis thaliana that are defective in the formation of continuous vascular network: calling the auxin signal flow canalization hypothesis into question

Development ◽  
2000 ◽  
Vol 127 (15) ◽  
pp. 3197-3204 ◽  
Author(s):  
K. Koizumi ◽  
M. Sugiyama ◽  
H. Fukuda
Keyword(s):  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Genetic Analysis ◽  
Molecular Mechanisms ◽  
Vascular Tissue ◽  
Early Stage ◽  
Diffusion Reaction ◽  
Signal Flow ◽  
Vein Formation ◽  
Mutant Lines

For the genetic analysis of molecular mechanisms underlying temporal and spatial regulation of vascular pattern formation, we isolated mutants of Arabidopsis thaliana that are impaired in vascular patterning. Microscopic examination of the cotyledonary venation of 3,400 M(3) lines led to the identification of 12 mutant lines. Genetic analysis of 8 of these mutant lines indicated that vein pattern formation in these lines resulted from monogenic recessive mutations in 7 different genes, designated VAN1 through VAN7. Mutations in VAN1 through VAN6 genes caused fragmentation (disconnection or partial loss) of lateral veins of the cotyledon and tertiary veins of the rosette leaf whereas they were less injurious to the formation of major veins. Detailed characterization of the van3 mutant using pAthb8::GUS and pTED3::GUS, as molecular markers for the early stage of vascular tissue formation showed that the provascular tissue of the cotyledonary lateral veins was differentiated in fragments during late embryogenesis. These phenotypes of the van mutants are discussed in relation to the auxin signal flow canalization hypothesis and the diffusion-reaction prepattern hypothesis, with the fragility of the continuity in the minor vein formation favoring the latter hypothesis.

scholarly journals Interactions Among Genes Regulating Ovule Development in Arabidopsis thaliana

Genetics ◽  
1997 ◽  
Vol 145 (4) ◽  
pp. 1109-1124 ◽  
Author(s):  
Shawn C Baker ◽  
Kay Robinson-Beers ◽  
Jacinto M Villanueva ◽  
J Christopher Gaiser ◽  
Charles S Gasser
Keyword(s):  
Arabidopsis Thaliana ◽  
Surface Topography ◽  
Flower Development ◽  
Outer Integument ◽  
Embryo Sac ◽  
Ovule Development ◽  
Regulatory Pathways ◽  
Altered Surface ◽  
Further Development

The INNER NO OUTER (INO) and AINTEGUMENTA (ANT) genes are essential for ovule integument development in Arabidopsis thaliana. Ovules of ino mutants initiate two integument primordia, but the outer integument primordium forms on the opposite side of the ovule from the normal location and undergoes no further development. The inner integument appears to develop normally, resulting in erect, unitegmic ovules that resemble those of gymnosperms. ino plants are partially fertile and produce seeds with altered surface topography, demonstrating a lineage dependence in development of the testa. ant mutations affect initiation of both integuments. The strongest of five new ant alleles we have isolated produces ovules that lack integuments and fail to complete megasporogenesis. ant mutations also affect flower development, resulting in narrow petals and the absence of one or both lateral stamens. Characterization of double mutants between ant, ino and other mutations affecting ovule development has enabled the construction of a model for genetic control of ovule development. This model proposes parallel independent regulatory pathways for a number of aspects of this process, a dependence on the presence of an inner integument for development of the embryo sac, and the existence of additional genes regulating ovule development.

Dissection of sexual organ ontogenesis: a genetic analysis of ovule development in Arabidopsis thaliana

Development ◽  
1997 ◽  
Vol 124 (7) ◽  
pp. 1367-1376 ◽  
Author(s):  
K. Schneitz ◽  
M. Hulskamp ◽  
S.D. Kopczak ◽  
R.E. Pruitt
Keyword(s):  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Large Scale ◽  
Control Level ◽  
Three Dimensional ◽  
Flowering Plant ◽  
Ovule Development ◽  
Cellular Processes ◽  
Mature Ovule ◽  
And Control

Understanding organogenesis remains a major challenge in biology. Specification, initiation, pattern formation and cellular morphogenesis, have to be integrated to generate the final three-dimensional architecture of a multicellular organ. To tackle this problem we have chosen the ovules of the flowering plant Arabidopsis thaliana as a model system. In a first step towards a functional analysis of ovule development, we performed a large-scale genetic screen and isolated a number of sterile mutants with aberrant ovule development, We provide indirect genetic evidence for the existence of proximal-distal pattern formation in the Arabidopsis ovule primordium. The analysis of the mutants has identified genes that act at an intermediate regulatory level and control initiation of morphogenesis in response to proximal-distal patterning. A second group of genes functions at a subordinate control level and regulates general cellular processes of morphogenesis. A large group of male and female sterile mutants shows defects restricted to early or late gametogenesis. In addition, we propose that the mature ovule obtains its overall curved shape by at least three different processes that act in only one domain of the ovule.

scholarly journals Ancestral duplicated DL/CRC orthologs display function on orchid reproductive organ innovation

2020 ◽  
Author(s):  
You-Yi Chen ◽  
Yu-Yun Hsiao ◽  
Chung-I Li ◽  
Chuan-Ming Yeh ◽  
Nobutaka Mitsuda ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Reproductive Organ ◽  
Abnormal Development ◽  
Organ Development ◽  
Ovule Development ◽  
Accessible Information ◽  
Display Function ◽  
Temporal And Spatial ◽  
Transient Overexpression ◽  
Orchid Flower

ABSTRACTThe orchid flower is renowned for complexity of flower organ morphogenesis and has attracted great interest from scientists. The YABBY genes encode plant-specific transcription factors with important roles in vegetative and reproductive development in seed plants. DROOPING LEAF/CRABS CLAW (DL/CRC) orthologs are involved in reproductive organ development (especially carpels) of angiosperms. Orchid gynostemium (the fused organ of the androecium and gynoecium) and ovule development are unique developmental processes. Understanding the DL/CRC-like genes controlling the developmental program of the gynostemium and ovule could provide accessible information for reproductive organ molecular regulation in orchids. Two DL/CRC-like genes, named PeDL1 and PeDL2, were cloned from Phalaenopsis equestris. The orchid DL/CRC forms a monophyletic clade with two subclades including AshDL, PeDL1 and DcaDL1 in subclade I, and PeDL2 and DcaDL2 in subclade II. The temporal and spatial expression analysis indicated PeDL genes are specifically expressed in the gynostemium and at the early stages of ovule development. Both PeDLs could partially complement an Arabidopsis crc-1 mutant. Transient overexpression of PeDL1 in Phalaenopsis orchids caused abnormal development of ovule and stigmatic cavity of gynostemium. PeDL1, instead of PeDL2, could form a heterodimer with PeCIN8. Paralogue retention and subsequent divergence of the gene sequence of PeDL1 and PeDL2 in P. equestris might result in the differentiation of function and protein behaviors. These results reveal the important roles of PeDLs involved in orchid gynostemium and ovule development and provide new insights for further understanding the molecular mechanisms underlying orchid reproductive organ development.

scholarly journals NOZZLE links proximal-distal and adaxial-abaxial pattern formation during ovule development in Arabidopsis thaliana

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4291-4300
Author(s):  
Sureshkumar Balasubramanian ◽  
Kay Schneitz
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factor ◽  
Pattern Formation ◽  
Vital Role ◽  
Regulatory Control ◽  
Homeodomain Protein ◽  
Ovule Development ◽  
Temporal Expression ◽  
Aberrant Testa Shape ◽  
Ap2 Domain

The ovules of Arabidopsis show polarity along the proximal-distal and the adaxial-abaxial axis. NOZZLE, a gene that encodes a novel protein and BELL1, encoding a homeodomain protein, play a vital role in pattern formation along the proximal-distal axis. INNER NO OUTER, which encodes a member of the YABBY family of transcription factors and SUPERMAN, encoding a zinc finger transcription factor, are essential for the establishment and maintenance of adaxial-abaxial polarity. To date, the co-ordination of patterning along these two axes is unclear. Here we show that NOZZLE plays a vital role in pattern formation along the adaxial-abaxial axis as well. We investigated the expression of INNER NO OUTER in various mutant backgrounds and have identified ABERRANT TESTA SHAPE and NOZZLE as spatial regulators of INNER NO OUTER expression. In addition, we show that NOZZLE and AINTEGUMENTA, which encodes an AP2 domain transcription factor, regulate the temporal expression of INNER NO OUTER and that BELL1 is essential for INNER NO OUTER expression. We further analysed the expression of BELL1 and AINTEGUMENTA in inner no outer mutants and show that the positive auto-regulatory control of INNER NO OUTER expression involves AINTEGUMENTA. Based on our results we propose a model for adaxial-abaxial pattern formation during ovule development. Our results indicate that NOZZLE plays a central role in patterning both the proximal-distal and the adaxial-abaxial axes. Furthermore, negatively regulating INO expression in a temporal manner, ensures that the adaxial-abaxial polarity is established after the specification of the chalaza, a proximal-distal axis pattern element. It therefore serves as a molecular link between these processes during ovule development in Arabidopsis thaliana.

scholarly journals Temporal and spatial domain-specific transcriptomic analysis of a vital reproductive meristem in Arabidopsis thaliana

2015 ◽  
Author(s):  
Gonzalo H Villarino ◽  
Miguel Flores-Vergara ◽  
Qiwen Hu ◽  
Bhupinder Sehra ◽  
Linda Robles ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Reproductive Organ ◽  
Differentially Expressed ◽  
Switching Behavior ◽  
Expression Domain ◽  
Data Set ◽  
Domain Specific ◽  
Temporal And Spatial

Background Plant meristems are analogous to animal stem cell niches as they maintain a pool of undifferentiated cells that divide and differentiate to give rise to organs. The carpel margin meristem is a vital, multi-potent structure located in the medial domain of the Arabidopsis thaliana gynoecium, the female floral reproductive organ. The carpel margin meristem generates ovules that upon fertilization become seeds. The molecular mechanisms that specify this meristematic region and regulate its organogenic potential are poorly understood. Here, we present an analysis of the transcriptional profile of the medial domain of the Arabidopsis gynoecium highlighting the developmental stages that immediately proceed ovule initiation, the earliest stages of seed development. Results Using a floral synchronization system and a SHATTERPROOF2 domain-specific reporter, paired with fluorescence-activated cell sorting and RNA sequencing, we assayed the transcriptome of the gynoecial medial domain with temporal and spatial precision. This analysis reveals a set of genes that are differentially expressed within the SHATTERPROOF2 expression domain that marks portions of the developing medial domain. Many members of this gene set have been shown previously to function during the development of medial domain-derived structures, including the ovules, thus validating our approach. Other uncharacterized members including differentially expressed cis-natural antisense transcripts, are potential novel regulators of medial domain development. Members of the REPRODUCTIVE MERISTEM (REM) family of transcriptional regulators were enriched in the SHATTERPROOF2-expressing cell population including a previously unrecognized REM family member. Finally, the analysis transcriptional isoforms in the medial domain identified genes that may exhibit 'isoform switching' behavior during gynoecial development. Conclusions This data set provides genome-wide transcriptional insight into the development of the gynoecial medial domain that contains the carpel margin meristem, a vital reproductive structure that gives rise to the ovules in Arabidopsis thaliana.

scholarly journals Pattern formation during early ovule development in Arabidopsis thaliana

2004 ◽  
Vol 273 (2) ◽  
pp. 321-334 ◽  
Author(s):  
Patrick Sieber ◽  
Jacqueline Gheyselinck ◽  
Rita Gross-Hardt ◽  
Thomas Laux ◽  
Ueli Grossniklaus ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pattern Formation ◽  
Ovule Development

scholarly journals Orchid Bsister gene PeMADS28 displays conserved function in ovule integument development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ching-Yu Shen ◽  
You-Yi Chen ◽  
Ke-Wei Liu ◽  
Hsiang-Chia Lu ◽  
Song-Bin Chang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Protein Interaction ◽  
Ectopic Expression ◽  
Flowering Plants ◽  
Complementation Test ◽  
Ovule Development ◽  
Mads Box ◽  
Temporal Expression ◽  
Protein Protein Interaction ◽  
Silique Length

AbstractThe ovules and egg cells are well developed to be fertilized at anthesis in many flowering plants. However, ovule development is triggered by pollination in most orchids. In this study, we characterized the function of a Bsister gene, named PeMADS28, isolated from Phalaenopsis equestris, the genome-sequenced orchid. Spatial and temporal expression analysis showed PeMADS28 predominantly expressed in ovules between 32 and 48 days after pollination, which synchronizes with integument development. Subcellular localization and protein–protein interaction analyses revealed that PeMADS28 could form a homodimer as well as heterodimers with D-class and E-class MADS-box proteins. In addition, ectopic expression of PeMADS28 in Arabidopsis thaliana induced small curled rosette leaves, short silique length and few seeds, similar to that with overexpression of other species’ Bsister genes in Arabidopsis. Furthermore, complementation test revealed that PeMADS28 could rescue the phenotype of the ABS/TT16 mutant. Together, these results indicate the conserved function of BsisterPeMADS28 associated with ovule integument development in orchid.

scholarly journals The mac1 Gene: Controlling the Commitment to the Meiotic Pathway in Maize

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 1009-1020 ◽  
Author(s):  
William F Sheridan ◽  
Nadezhda A Avalkina ◽  
Ivan I Shamrov ◽  
Tatyana B Batyea ◽  
Inna N Golubovskaya
Keyword(s):  
Female Gametophyte ◽  
Embryo Sac ◽  
Flowering Plants ◽  
Normal Female ◽  
Ovule Development ◽  
Partial Sterility ◽  
Embryo Sac Formation ◽  
Female Gametophyte Development ◽  
Normal Meiosis ◽  
Pleiotropic Mutation

Abstract The switch from the vegetative to the reproductive pathway of development in flowering plants requires the commitment of the subepidermal cells of the ovules and anthers to enter the meiotic pathway. These cells, the hypodermal cells, either directly or indirectly form the archesporial cells that, in turn, differentiate into the megasporocytes and microsporocytes. We have isolated a recessive pleiotropic mutation that we have termed multiple archesporial cells1 (macl) and located it to the short arm of chromosome 10. Its cytological phenotype suggests that this locus plays an important role in the switch of the hypodermal cells from the vegetative to the meiotic (sporogenous) pathway in maize ovules. During normal ovule development in maize, only a single hypodermal cell develops into an archesporial cell and this differentiates into the single megasporocyte. In macl mutant ovules several hypodermal cells develop into archesporial cells, and the resulting megasporocytes undergo a normal meiosis. More than one megaspore survives in the tetrad and more than one embryo sac is formed in each ovule. Ears on mutant plants show partial sterility resulting from abnormalities in megaspore differentiation and embryo sac formation. The sporophytic expression of this gene is therefore also important for normal female gametophyte development.

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