CLAVATA2, a regulator of meristem and organ development in Arabidopsis

Development ◽  
1998 ◽  
Vol 125 (19) ◽  
pp. 3843-3851 ◽  
Author(s):  
J.M. Kayes ◽  
S.E. Clark
Keyword(s):  
Genetic Analysis ◽  
Complete Suppression ◽  
Organ Development ◽  
Light Conditions ◽  
Present Evidence ◽  
Physiological Conditions ◽  
Short Day ◽  
Flower Meristem ◽  
Meristem Development

Mutations at the CLAVATA2 (CLV2) locus of Arabidopsis result in enlarged shoot and flower meristems, as well as alterations in the development of the gynoecia, flower pedicels, and stamens. The shoot and flower meristem phenotypes of clv2 mutants are similar to weak clv1 and clv3 mutants. We present genetic analysis that CLV2 may function in the same pathway as CLV1 and CLV3 in the regulation of meristem development, but function separately in the regulation of organ development. We also present evidence that clv2 phenotypes are altered when the mutants are grown under short-day light conditions. These alterations include flower-to-shoot transformations, as well as a nearly complete suppression of the flower phenotypes, indicating that the requirement for CLV2 changes in response to different physiological conditions. The stm-1 mutation dominantly suppresses clv2, and clv2 mutations suppress the strong stm-1 allele, but not the weak stm-2 allele.

scholarly journals Agronomic Performance and Flowering Behavior in Response to Photoperiod and Vernalization in Barley (Hordeum vulgare L.) Genotypes with Contrasting Drought Tolerance Behavior

2021 ◽  
Author(s):  
Jamal Abu-Elenein ◽  
Rabea Al-Sayaydeh ◽  
Zahera Akkeh ◽  
Zakaria Al-Ajlouni ◽  
AbdRaheem A. Al-Bawalize ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Agronomic Performance ◽  
Short Day ◽  
Drought Tolerant ◽  
Long Day ◽  
Meristem Development ◽  
Rainfed Conditions ◽  
Barley Genotypes

Abstract Background In barley, flowering behavior is a highly regulated and complex process where the appropriate matching of reproductive development with seasonal variation in water availability confer barley adaptation to different environments. In this study, the role of variation in flowering time and drought tolerance in four selected barley genotypes was studied under field and controlled conditions. For this purpose, field trials were conducted for two consecutive seasons at three diverse environments where the studied genotypes were subjected to either rainfed conditions or rainfed plus supplementary irrigation under two different sowing dates. Furthermore, reproductive meristem development in two selected barley genotypes, Rum (drought tolerant) and Steptoe (drought-sensitive) was also assessed in response to both vernalization and water stress under two different photoperiod conditions.Results Variation in the number of days to heading was more pronounced under rainfed conditions than under well water conditions. For agronomic performance, Rum was superior under all tested environments, which assure its general adaptability to multiple environments, while Steptoe was the poorest. The transition to reproductive meristem was faster under vernalized long-day conditions as compared to vernalized short-day conditions. The progress of shoot apical meristem development and heading under long-day conditions was significantly faster in Rum than that of Steptoe. A clear effect of drought stress was observed on shoot apical meristem development in Steptoe. Under short-day conditions, vernalized Rum plants subjected to water deficit showed an advanced meristem development stage a significant earlier HD when compared with non-stressed plants. This early flowering behavior in stressed Rum plants under short-day conditions was accompanied by higher gene expression of the Vrn-H1 gene. Conclusion In conclusion, the integration of vernalization and photoperiod signals in drought-tolerant barley genotypes is associated with early flowering behavior and higher productivity in dry environments.

slimb coordinates wg and dpp expression in the dorsal-ventral and anterior-posterior axes during limb development

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3411-3416 ◽  
Author(s):  
N.A. Theodosiou ◽  
S. Zhang ◽  
W.Y. Wang ◽  
T. Xu
Keyword(s):  
Genetic Analysis ◽  
Limb Development ◽  
Imaginal Disc ◽  
Essential Role ◽  
Present Evidence ◽  
First Time ◽  
Anterior Posterior

In the Drosophila leg disc, wingless (wg) and decapentaplegic (dpp) are expressed in a ventral-anterior and dorsal-anterior stripe of cells, respectively. This pattern of expression is essential for proper limb development. While the Hedgehog (Hh) pathway regulates dpp and wg expression in the anterior-posterior (A/P) axis, mechanisms specifying their expression in the dorsal-ventral (D/V) axis are not well understood. We present evidence that slimb mutant clones in the disc deregulate wg and dpp expression in the D/V axis. This suggests for the first time that their expression in the D/V axis is actively regulated during imaginal disc development. Furthermore, slimb is unique in that it also deregulates wg and dpp in the A/P axis. The misexpression phenotypes of slimb- clones indicate that the regulation of wg and dpp expression is coordinated in both axes, and that slimb plays an essential role in integrating A/P and D/V signals for proper patterning during development. Our genetic analysis further reveals that slimb intersects the A/P pathway upstream of smoothened (smo).

scholarly journals The influence of temperature, light energy and photoperiod on flowering of Brodiaea laxa Wats.

1969 ◽  
Vol 17 (3) ◽  
pp. 176-182
Author(s):  
E.J. Fortanier
Keyword(s):  
Flower Development ◽  
High Light ◽  
Light Energy ◽  
Light Conditions ◽  
Influence Of Temperature ◽  
Flower Production ◽  
Short Day ◽  
Light Intensities ◽  
Light Requirements

Temperature and light requirements for a satisfactory forcing of Brodiaea laxa 'Koningin Fabiola' were studied. Corms were planted under different temperature and light conditions in a phytotron and in different photoperiods in the open. Long days accelerated flower development and the termination of growth and enhanced corm formation. Considering both earliness and number of flowers, the most acceptable results with regard to flower production were obtained at 18 degrees C. in short photoperiods. Forcing at higher temperatures and in longer photoperiods resulted in a reduction in the number of flowers because of bud blasting. This also occurred when the natural short day was extended by high light intensities. Forced and retarded corms reacted similarly but the latter flowered sooner and more satisfactorily. Flowering was preceded under all conditions by corm formation and in longer photoperiods even by senescence of the leaves. Year-round production of flowers is possible if 25 cal./sq.cm./day of light energy or more are available.- Agric. Univ., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Analysis of the structure and function of the tomato Solanum lycopersicum L. MADS-box gene SlMADS5

2021 ◽  
Vol 25 (5) ◽  
pp. 492-501
Author(s):  
A. V. Nezhdanova ◽  
M. A. Slugina ◽  
E. A. Dyachenko ◽  
A. M. Kamionskaya ◽  
E. Z. Kochieva ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Solanum Lycopersicum ◽  
Anthocyanin Biosynthesis ◽  
Phylogenetic Analyses ◽  
Functional Characterization ◽  
Decisive Role ◽  
Flower Meristem ◽  
Meristem Development ◽  
Transgenic Lines ◽  
Gene Transcripts

At all stages of flowering, a decisive role is played by the family of MADS-domain transcription factors, the combinatorial action of which is described by the ABCDE-model of flower development. The current volume of data suggests a high conservatism of ABCDE genes in angiosperms. The E-proteins SEPALLATA are the central hub of the MADS-complexes, which determine the identity of the floral organs. The only representative of the SEPALLATA3 clade in tomato Solanum lycopersicum L., SlMADS5, is involved in determining the identity of petals, stamens, and carpels; however, data on the functions of the gene are limited. The study was focused on the SlMADS5 functional characterization. Structural and phylogenetic analyses of SlMADS5 confirmed its belonging to the SEP3 clade. An in silico expression analysis revealed the absence of gene transcripts in roots, leaves, and shoot apical meristem, and their presence in flowers, fruits, and seeds at different stages of development. Two-hybrid analysis showed the ability of SlMADS5 to activate transcription of the target gene and interact with TAGL1. Transgenic plants Nicotiana tabacum L. with constitutive overexpression of SlMADS5 cDNA flowered 2.2 times later than the control; plants formed thickened leaves, 2.5–3.0 times thicker stems, 1.5–2.7 times shortened internodes, and 1.9 times fewer flowers and capsules than non-transgenic plants. The flower structure did not differ from the control; however, the corolla petals changed color from light pink to magenta. Analysis of the expression of SlMADS5 and the tobacco genes NtLFY, NtAP1, NtWUS, NtAG, NtPLE, NtSEP1, NtSEP2, and NtSEP3 in leaves and apexes of transgenic and control plants showed that SlMADS5 mRNA is present only in tissues of transgenic lines. The other genes analyzed were highly expressed in the reproductive meristem of control plants. Gene transcripts were absent or were imperceptibly present in the leaves and vegetative apex of the control, as well as in the leaves and apexes of transgenic lines. The results obtained indicate the possible involvement of SlMADS5 in the regulation of flower meristem development and the pathway of anthocyanin biosynthesis in petals.

POLTERGEIST functions to regulate meristem development downstream of the CLAVATA loci

Development ◽  
2000 ◽  
Vol 127 (8) ◽  
pp. 1661-1670 ◽  
Author(s):  
L.P. Yu ◽  
E.J. Simon ◽  
A.E. Trotochaud ◽  
S.E. Clark
Keyword(s):  
Receptor Activation ◽  
Complete Suppression ◽  
Wild Type ◽  
Meristem Development ◽  
Undifferentiated Cells ◽  
Partial Suppression ◽  
Floral Meristems

Mutations at the CLAVATA loci (CLV1, CLV2 and CLV3) result in the accumulation of undifferentiated cells at the shoot and floral meristems. We have isolated three mutant alleles of a novel locus, POLTERGEIST (POL), as suppressors of clv1, clv2 and clv3 phenotypes. All pol mutants were nearly indistinguishable from wild-type plants; however, pol mutations provided recessive, partial suppression of meristem defects in strong clv1 and clv3 mutants, and nearly complete suppression of weak clv1 mutants. pol mutations partially suppressed clv2 floral and pedicel defects in a dominant fashion, and almost completely suppressed clv2 phenotypes in a recessive manner. These observations, along with dominant interactions observed between the pol and wuschel (wus) mutations, indicate that POL functions as a critical regulator of meristem development downstream of the CLV loci and redundantly with WUS. Consistent with this, pol mutations do not suppress clv3 phenotypes by altering CLV1 receptor activation.

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.

scholarly journals APT1, but Not APT2, Codes for a Functional Adenine Phosphoribosyltransferase inSaccharomyces cerevisiae

1999 ◽  
Vol 181 (1) ◽  
pp. 347-352 ◽  
Author(s):  
Juan D. Alfonzo ◽  
Timothy R. Crother ◽  
Maria L. Guetsova ◽  
Bertrand Daignan-Fornier ◽  
Milton W. Taylor
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Phylogenetic Analysis ◽  
Gene Duplication ◽  
Genetic Analysis ◽  
Duplication Event ◽  
Cloning And Expression ◽  
Gene Duplication Event ◽  
Adenine Phosphoribosyltransferase ◽  
Physiological Conditions

ABSTRACT The yeast Saccharomyces cerevisiae has two separate genes (APT1 and APT2) that encode two potentially different forms of adenine phosphoribosyltransferase (APRT). However, genetic analysis indicated that only APT1could code for a complementing activity. Cloning and expression of both the APT1 and APT2 genes in Escherichia coli showed that although discrete proteins (APRT1 and APRT2) were made by these genes, only APRT1 had detectable APRT activity. Northern and Western blot analyses demonstrated that onlyAPT1 was transcribed and translated under normal physiological conditions in yeast. Phylogenetic analysis revealed that APRT1 and APRT2 are evolutionary closely related and that they arise from a gene duplication event. We conclude that APT1 is the functional gene in S. cerevisiae and that APT2is a pseudogene.

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