WM5: Isolation and characterisation of a gene expressed during early meiosis and shoot meristem development in wheat

2005 ◽  
Vol 32 (3) ◽  
pp. 249 ◽  
Author(s):  
Chongmei Dong ◽  
Stephen Thomas ◽  
Dirk Becker ◽  
Horst Lörz ◽  
Ryan Whitford ◽  
...  
Keyword(s):  
Triticum Aestivum L ◽  
Shoot Meristem ◽  
Cdna Subtraction ◽  
Significant Similarity ◽  
Functional Roles ◽  
Flower Meristem ◽  
Homoeologous Chromosome Pairing ◽  
Meristem Development ◽  
Mother Cells ◽  
Allohexaploid Wheat

Wheat Meiosis 5 (WM5), isolated from an early meiosis anther cDNA library of wheat by cDNA subtraction encodes a novel glycine–serine–proline–alanine-rich protein. The corresponding homologous genes are located on the short arms of chromosomes 3A, 3B and 3D of allohexaploid wheat (Triticum aestivum L.). The copy on 3DS is located within the region deleted in the wheat mutant ph2a that displays increased homoeologous chromosome pairing in crosses with alien species. While WM5 is expressed primarily in young flower buds during early meiosis it is also expressed in shoot meristems, thus indicating functional roles in both meiosis and meristem development. Overall, the WM5 amino acid sequence shares no significant similarity with other known proteins in the NCBI database. However, the carboxyl-terminal region does have similarity with the Arabidopsis PDF1 (Protodermal Factor 1) protein. Comparing WM5 and PDF1 reveals that the two proteins share 33% identity and have similar hydropathy plots and predicted secondary structures. In situ immuno-staining locates the protein to the nuclei of pollen mother cells undergoing meiosis and the epidermal layer of the shoot and flower meristem, including the cell wall and cuticle. We propose that the WM5 protein has a role in shoot and flower development within this economically important cereal crop.

NONSTRUCTURAL CHROMOSOME DIFFERENTIATION AMONG WHEAT CULTIVARS, WITH SPECIAL REFERENCE TO DIFFERENTIATION OF CHROMOSOMES IN RELATED SPECIES

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 391-414
Author(s):  
Jan Dvořák ◽  
Patrick E McGuire
Keyword(s):  
Chinese Spring ◽  
Structural Changes ◽  
Wheat Cultivar ◽  
Chromosome Complement ◽  
Triticum Aestivum L ◽  
Substitution Lines ◽  
Structural Differentiation ◽  
Chromosome Differentiation ◽  
Mother Cells ◽  
Homoeologous Chromosomes

ABSTRACT Wheat cultivar Chinese Spring (Triticum aestivum L. em. Thell.) was crossed with cultivars Hope, Cheyenne and Timstein. In all three hybrids, the frequencies of pollen mother cells (PMCs) with univalents at metaphase I (MI) were higher than those in the parental cultivars. No multivalents were observed in the hybrids, indicating that the cultivars do not differ by translocations. Thirty-one Chinese Spring telosomic lines were then crossed with substitution lines in which single chromosomes of the three cultivars were substituted for their Chinese Spring homologues. The telosomic lines were also crossed with Chinese Spring. Data were collected on the frequencies (% of PMCs) of pairing of the telesomes with their homologues at MI and the regularity of pairing of the remaining 20 pairs of Chinese Spring chromosomes in the monotelodisomics obtained from these crosses. The reduced MI pairing in the intercultivar hybrids was caused primarily by chromosome differentiation, rather than by specific genes. Because the differentiation involved a large part of the chromosome complement in each hybrid, it was concluded that it could not be caused by structural changes such as inversions or translocations. In each case, the differentiation appeared to be unevenly distributed among the three wheat genomes. It is proposed that the same kind of differentiation, although of greater magnitude, differentiates homoeologous chromosomes and is responsible, together with structural differentiation, for poor chromosome pairing in interspecific hybrids.

LEAFY expression and flower initiation in Arabidopsis

Development ◽  
1997 ◽  
Vol 124 (19) ◽  
pp. 3835-3844 ◽  
Author(s):  
M.A. Blazquez ◽  
L.N. Soowal ◽  
I. Lee ◽  
D. Weigel
Keyword(s):  
Life Cycle ◽  
Floral Induction ◽  
Shoot Meristem ◽  
Flower Initiation ◽  
Gradual Change ◽  
Vegetative Phase ◽  
Flower Meristem ◽  
Reproductive Phase ◽  
Plant Life Cycle ◽  
Short Days

During the initial vegetative phase, the Arabidopsis shoot meristem produces leaves with associated lateral shoots at its flanks, while the later reproductive phase is characterized by the formation of flowers. The LEAFY gene is an important element of the transition from the vegetative to the reproductive phase, as LEAFY is both necessary and sufficient for the initiation of individual flowers. We have analyzed in detail the expression of LEAFY during the plant life cycle, and found that LEAFY is extensively expressed during the vegetative phase. In long days, Arabidopsis plants flower soon after germination, and this is paralleled by rapid upregulation of LEAFY. In short days, Arabidopsis plants flower several weeks later than in long days, but LEAFY expression increases gradually before flowering commences. Application of the plant hormone gibberellin, which hastens flowering in short days, enhances the gradual change in LEAFY expression observed in short days. Changes in LEAFY expression before the transition to flowering suggest that the time point of this transition is at least partly controlled by the levels of LEAFY activity that are prevalent at a given time of the life cycle. This assumption is borne out by the finding that increasing the copy number of endogenous LEAFY reduces the number of leaves produced before the first flower is formed. Thus, LEAFY combines properties of flowering-time and flower-meristem-identity genes, indicating that LEAFY is a direct link between the global process of floral induction and the regional events associated with the initiation of individual flowers.

scholarly journals KNOX HOMOLOGS SHOOT MERISTEMLESS (STM) and KNAT6 are epistatic to CLAVATA3 (CLV3) during embryonic meristem development in Arabidopsis thaliana

2020 ◽  
Author(s):  
Sharma Nidhi ◽  
Liu Tie
Keyword(s):  
Arabidopsis Thaliana ◽  
Shoot Apex ◽  
Double Mutant ◽  
Genetic Interaction ◽  
Homeobox Gene ◽  
The Other ◽  
Shoot Meristem ◽  
Published Data ◽  
Meristem Development ◽  
Shoot Meristemless

AbstractIn Arabidopsis, the genes SHOOT MERISTEMLESS (STM) and CLAVATA3 (CLV3) antagonistically regulate shoot meristem development. STM is essential for both development and maintenance of the meristem, as stm mutants fail to develop a shoot meristem during embryogenesis. CLV3, on the other hand, negatively regulates meristem proliferation, and clv3 mutants possess an enlarged shoot meristem. Genetic interaction studies revealed that stm and clv3 dominantly suppress each other’s phenotypes. STM works in conjunction with its closely related homologue KNOTTED1-LIKE HOMEOBOX GENE 6 (KNAT6) to promote meristem development and organ separation, as stm knat6 double mutants fail to form a meristem and produce a fused cotyledon. In this study, we show that clv3 fails to promote post-embryonic meristem formation in stm-1 background if we also remove KNAT6. stm-1 knat6 clv3 triple mutants result in early meristem termination and produce fused cotyledons similar to stm knat6 double mutant. Notably, the stm-1 knat6 and stm-1 knat6 clv3 alleles lack tissue in the presumed region of SAM. stm knat6 clv3 also showed reduced inflorescence size and shoot apex size as compared to clv3 single or stm clv3 double mutants. In contrast to previously published data, these data suggest that stm is epistatic to clv3 in postembryonic meristem development.HighlightSTM and KNAT6 genes determine post-embryonic meristem formation and activity in Arabidopsis. clv3 mutation is unable to rescue the stm knat6 meristemless phenotype.

A WHEAT MUTATION CONDITIONING AN INTERMEDIATE LEVEL OF HOMOEOLOGOUS CHROMOSOME PAIRING

1982 ◽  
Vol 24 (6) ◽  
pp. 715-719 ◽  
Author(s):  
E. R. Sears
Keyword(s):  
Chromosome Pairing ◽  
Triticum Aestivum L ◽  
Terminal Segment ◽  
Intermediate Level ◽  
Homoeologous Pairing ◽  
Homoeologous Chromosome ◽  
X Ray ◽  
Homoeologous Chromosome Pairing ◽  
Homozygous Line ◽  
A Minor

An X-ray-induced mutation in common wheat (Triticum aestivum L.), designated ph2, conditions an intermediate level of homoeologous chromosome pairing in hybrids with Triticum kotschyi var. variabilis. The number of chromosomes paired averaged 9.2 per sporocyte, compared with 2.0 in the control and 27.9 in the same hybrid involving ph1b, an apparent deficiency for Ph1 obtained in the same mutation experiment. The ph2 mutation is located on chromosome 3D and is believed to be a deficiency for a terminal segment of the short arm that includes the locus of Ph2, a minor suppressor of homoeologous pairing. Although no pairing of the ph2-carrying chromosome with telosome 3DS was observed, the mutation is clearly not a deficiency for the entire arm. It has little effect on pairing in wheat itself. Male transmission of the mutation is approximately normal, and fertility, while reduced, is sufficient for easy maintenance of the homozygous line.

An Electron Microscopic Study of Double Fertilization in Allohexaploid Wheat Triticum aestivum L.

1992 ◽  
Vol 70 (6) ◽  
pp. 561-568 ◽  
Author(s):  
XIAOPING GAO ◽  
DENNIS FRANCIS ◽  
JOHN C. ORMROD ◽  
MICHAEL D. BENNETT
Keyword(s):  
Triticum Aestivum ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Triticum Aestivum L ◽  
Double Fertilization ◽  
Electron Microscopic ◽  
Allohexaploid Wheat

scholarly journals The maize heterotrimeric G protein β subunit controls shoot meristem development and immune responses

2019 ◽  
Vol 117 (3) ◽  
pp. 1799-1805 ◽  
Author(s):  
Qingyu Wu ◽  
Fang Xu ◽  
Lei Liu ◽  
Si Nian Char ◽  
Yezhang Ding ◽  
...  
Keyword(s):  
G Protein ◽  
Cross Talk ◽  
Normal Growth ◽  
Shoot Meristem ◽  
Β Subunit ◽  
Subunit Gene ◽  
Α Subunit ◽  
Knock Out ◽  
Meristem Size ◽  
Meristem Development

Heterotrimeric G proteins are important transducers of receptor signaling, functioning in plants with CLAVATA receptors in controlling shoot meristem size and with pathogen-associated molecular pattern receptors in basal immunity. However, whether specific members of the heterotrimeric complex potentiate cross-talk between development and defense, and the extent to which these functions are conserved across species, have not yet been addressed. Here we used CRISPR/Cas9 to knock out the maize G protein β subunit gene (Gβ) and found that the mutants are lethal, differing from those in Arabidopsis, in which homologous mutants have normal growth and fertility. We show that lethality is caused not by a specific developmental arrest, but by autoimmunity. We used a genetic diversity screen to suppress the lethal Gβ phenotype and also identified a maize Gβ allele with weak autoimmune responses but strong development phenotypes. Using these tools, we show that Gβ controls meristem size in maize, acting epistatically with G protein α subunit gene (Gα), suggesting that Gβ and Gα function in a common signaling complex. Furthermore, we used an association study to show that natural variation in Gβ influences maize kernel row number, an important agronomic trait. Our results demonstrate the dual role of Gβ in immunity and development in a cereal crop and suggest that it functions in cross-talk between these competing signaling networks. Therefore, modification of Gβ has the potential to optimize the trade-off between growth and defense signaling to improve agronomic production.

EFFECT OF RYE ON HOMOEOLOGOUS CHROMOSOME PAIRING IN WHEAT × RYE HYBRIDS

1977 ◽  
Vol 19 (3) ◽  
pp. 549-556 ◽  
Author(s):  
J. Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Triticum Aestivum L ◽  
Homoeologous Chromosome ◽  
Wheat Genotype ◽  
Hybrid Plants ◽  
Homoeologous Chromosome Pairing ◽  
Secale Cereale L ◽  
Polygenic System

The number of chiasmata per cell at metaphase I was scored in eight haploid plants of Triticum aestivum L. emend. Thell. cv. 'Chinese Spring' and 100 hybrid plants of Chinese Spring × Secale cereale L. Mean chiasma frequency per cell ranged from 0.00 to 3.59 in the hybrids and from 0.17 to 0.35 in the haploids. Since the same wheat genotype was present in both the haploids and hybrids, it is concluded that some of the rye genotypes promoted homoeologous chromosome pairing. The absence of distinct segregation classes among the hybrids suggests that these genes constitute a polygenic system.

scholarly journals Influence of homoeologous chromosomes on gene-dosage effects in allohexaploid wheat (Triticum aestivum L.).

1978 ◽  
Vol 75 (3) ◽  
pp. 1446-1450 ◽  
Author(s):  
C. Aragoncillo ◽  
M. A. Rodriguez-Loperena ◽  
G. Salcedo ◽  
P. Carbonero ◽  
F. Garcia-Olmedo
Keyword(s):  
Triticum Aestivum ◽  
Gene Dosage ◽  
Triticum Aestivum L ◽  
Gene Dosage Effects ◽  
Dosage Effects ◽  
Allohexaploid Wheat ◽  
Homoeologous Chromosomes

Histological studies of cellular differentiation during somatic embryogenesis of coconut plumule-derived calli

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
K. Lakshmi Jayaraj ◽  
U. Bhavyashree ◽  
T.P. Fayas ◽  
K.K. Sajini ◽  
M.K. Rajesh ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Somatic Embryos ◽  
Callus Formation ◽  
Histological Study ◽  
Shoot Meristem ◽  
Vascular Bundles ◽  
Histological Studies ◽  
Meristematic Cells ◽  
Meristem Development

<div><table cellspacing="0" cellpadding="0" align="center"><tbody><tr><td align="left" valign="top"><p>Since coconut is   one of the most recalcitrant species to generate <em>in vitro</em>, it is   necessary to study in detail about the cellular changes that occur during   somatic embryogenesis to enhance our knowledge about this phenomenon. In the   present study, coconut plumular tissues, the shoot meristem including leaf   primordia, were used as explants for <em>in vitro </em>regeneration studies.   Histological studies were carried out in different stages of plumule culture.   No noticeable growth was observed in 15 days old cultures. After 30 days,   meristematic cells could be identified. Abundance of meristematic cells,   foremost to the development of callus structures, was observed after 45 days.   After 75 days, globular friable calli were formed and histological studies   revealed the presence of meristematic centers which eventually formed somatic   embryos. The histological study of matured somatic embryos formed after 120   days of callus initiation showed a clear meristematic zone of parenchyma   cells, surrounded by vascular bundles. Histological studies, carried out for   certain abnormalities like compact calli, abnormal somatic embryoids with   rudimentary shoots and multiplied roots, revealed the presence of intact   cotyledonary leaves which seemed to inhibit the apical meristem development   of somatic embryoids. The presence of vascular bundles in the early stages of   callus formation might lead to the direct formation of meristemoids. These   results could aid future studies leading to enhanced control of the somatic   embryogenic process and greater efficiency of somatic embryo and plantlet   formation in coconut.</p></td></tr></tbody></table></div>

scholarly journals Molecular and phylogenetic characterization of the homoeologous EPSP Synthase genes of allohexaploid wheat, Triticum aestivum (L.)

BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Attawan Aramrak ◽  
Kimberlee K. Kidwell ◽  
Camille M. Steber ◽  
Ian C. Burke
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Epsp Synthase ◽  
Phylogenetic Characterization ◽  
Allohexaploid Wheat
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