CHORIPETALA and DESPENTEADO: general regulators during plant development and potential floral targets of FIMBRIATA-mediated degradation

Development ◽  
2000 ◽  
Vol 127 (17) ◽  
pp. 3725-3734
Author(s):  
M. Wilkinson ◽  
E. de Andrade Silva ◽  
S. Zachgo ◽  
H. Saedler ◽  
Z. Schwarz-Sommer

Two Antirrhinum majus mutants, choripetala (cho) and despenteado (desp), exhibit identical highly pleiotropic phenotypes including petaloid transformation of first whorl floral organs, narrowing of both vegetative and floral organs, reduction in carpel size and fertility and delayed germination. The petaloid first whorl results from ectopic expression of the class B genes DEFICIENS and GLOBOSA and is correlated with the ectopic expression of the proposed class B/C gene regulator FIMBRIATA (FIM). Ectopic class B gene expression is apparent from the earliest point at which class B gene transcription can be detected in the wild type, indicating that the pre-patterning of the class B domain has been disrupted in these mutants. Single and double mutant analyses indicate that CHO and DESP also play a role in regulation of the class C domain. Interestingly, the cho and desp mutations partially suppress the phenotype of fim null mutants, suggesting that the F-box protein FIM may target a member of the CHO/DESP pathway for degradation. We propose that CHO and DESP are members of a ‘basal regulatory function’ influencing many processes throughout plant development and in particular are directly or indirectly required for the repression of class B and C genes during early stages of flower development.


2013 ◽  
Vol 14 (12) ◽  
pp. 24643-24655
Author(s):  
Xin Li ◽  
Chen Liu ◽  
Fengjiao Da ◽  
Ning Ma ◽  
Huolin Shen


2013 ◽  
Vol 12 (11) ◽  
pp. 1530-1537 ◽  
Author(s):  
Jae-Sook Park ◽  
Yuuya Okumura ◽  
Hiroyuki Tachikawa ◽  
Aaron M. Neiman

ABSTRACT The creation of haploid gametes in yeast, termed spores, requires the de novo formation of membranes within the cytoplasm. These membranes, called prospore membranes, enclose the daughter nuclei generated by meiosis. Proper growth and closure of prospore membranes require the highly conserved Vps13 protein. Mutation of SPO71 , a meiosis-specific gene first identified as defective in spore formation, was found to display defects in membrane morphogenesis very similar to those seen in vps13 Δ cells. Specifically, prospore membranes are smaller than in the wild type, they fail to close, and membrane vesicles are present within the prospore membrane lumen. As in vps13 Δ cells, the levels of phophatidylinositol-4-phosphate are reduced in the prospore membranes of spo71 Δ cells. SPO71 is required for the translocation of Vps13 from the endosome to the prospore membrane, and ectopic expression of SPO71 in vegetative cells results in mislocalization of Vps13. Finally, the two proteins can be coprecipitated from sporulating cells. We propose that Spo71 is a sporulation-specific partner for Vps13 and that they act in concert to regulate prospore membrane morphogenesis.



2021 ◽  
Vol 22 (13) ◽  
pp. 7025
Author(s):  
Francesca Lucibelli ◽  
Maria Carmen Valoroso ◽  
Günter Theißen ◽  
Susanne Nolden ◽  
Mariana Mondragon-Palomino ◽  
...  

The molecular basis of orchid flower development is accomplished through a specific regulatory program in which the class B MADS-box AP3/DEF genes play a central role. In particular, the differential expression of four class B AP3/DEF genes is responsible for specification of organ identities in the orchid perianth. Other MADS-box genes (AGL6 and SEP-like) enrich the molecular program underpinning the orchid perianth development, resulting in the expansion of the original “orchid code” in an even more complex gene regulatory network. To identify candidates that could interact with the AP3/DEF genes in orchids, we conducted an in silico differential expression analysis in wild-type and peloric Phalaenopsis. The results suggest that a YABBY DL-like gene could be involved in the molecular program leading to the development of the orchid perianth, particularly the labellum. Two YABBY DL/CRC homologs are present in the genome of Phalaenopsis equestris, PeDL1 and PeDL2, and both express two alternative isoforms. Quantitative real-time PCR analyses revealed that both genes are expressed in column and ovary. In addition, PeDL2 is more strongly expressed the labellum than in the other tepals of wild-type flowers. This pattern is similar to that of the AP3/DEF genes PeMADS3/4 and opposite to that of PeMADS2/5. In peloric mutant Phalaenopsis, where labellum-like structures substitute the lateral inner tepals, PeDL2 is expressed at similar levels of the PeMADS2-5 genes, suggesting the involvement of PeDL2 in the development of the labellum, together with the PeMADS2-PeMADS5 genes. Although the yeast two-hybrid analysis did not reveal the ability of PeDL2 to bind the PeMADS2-PeMADS5 proteins directly, the existence of regulatory interactions is suggested by the presence of CArG-boxes and other MADS-box transcription factor binding sites within the putative promoter of the orchid DL2 gene.



2003 ◽  
Vol 23 (9) ◽  
pp. 3031-3042 ◽  
Author(s):  
Maria Dahlén ◽  
Per Sunnerhagen ◽  
Teresa S.-F. Wang

ABSTRACT We investigated the effects of fission yeast replication genes on telomere length maintenance and identified 20 mutant alleles that confer lengthening or shortening of telomeres. The telomere elongation was telomerase dependent in the replication mutants analyzed. Furthermore, the telomerase catalytic subunit, Trt1, and the principal initiation and lagging-strand synthesis DNA polymerase, Polα, were reciprocally coimmunoprecipitated, indicating these proteins physically coexist as a complex in vivo. In a polα mutant that exhibited abnormal telomere lengthening and slightly reduced telomere position effect, the cellular level of the Trt1 protein was significantly lower and the coimmunoprecipitation of Trt1 and Polα was severely compromised compared to those in the wild-type polα cells. Interestingly, ectopic expression of wild-type polα in this polα mutant restored the cellular Trt1 protein to the wild-type level and shortened the telomeres to near-wild-type length. These results suggest that there is a close physical relationship between the replication and telomerase complexes. Thus, mutation of a component of the replication complex can affect the telomeric complex in maintaining both telomere length equilibrium and telomerase protein stability.



2006 ◽  
Vol 19 (6) ◽  
pp. 588-596 ◽  
Author(s):  
Candace E. Elliott ◽  
Barbara J. Howlett

Agrobacterium tumefaciens-mediated random mutagenesis was used to generate insertional mutants of the fungus Leptosphaeria maculans. Of 91 transformants screened, only one (A3) produced lesions of reduced size on cotyledons of canola (Brassica napus). Genes flanking the T-DNA insertion had the best matches to an alcohol dehydrogenase class 4 (ADH4)-like gene (Adh4L) and a 3-ketoacyl-CoA thiolase gene (Thiol) and were expressed in mutant A3 in vitro and in planta at significantly higher levels than in the wild type. This is the first report of a T-DNA insertion in fungi causing increased gene expression. Transformants of the wild-type isolate expressing both Adh4L and Thiol under the control of a heterologous promoter had similar pathogenicity to mutant A3. Ectopic expression of only thiolase resulted in loss of pathogenicity, suggesting that thiolase overexpression was primarily responsible for the reduced pathogenicity of the A3 isolate. The thiolase gene encoded a functional protein, as shown by assays in which a nontoxic substrate (2, 4 dichlorophenoxybutyric acid) was converted to a toxic product. The use of a translational fusion with a reporter gene showed thiolase expressed in organelles that are most likely peroxisomes.



Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5083-5092 ◽  
Author(s):  
M. Yamada ◽  
T. Murata ◽  
S. Hirose ◽  
G. Lavorgna ◽  
E. Suzuki ◽  
...  

FTZ-F1, a member of the nuclear receptor superfamily, has been implicated in the activation of the segmentation gene fushi tarazu during early embryogenesis of Drosophila melanogaster. We found that an isoform of FTZ-F1, betaFTZ-F1, is expressed in the nuclei of almost all tissues slightly before the first and second larval ecdysis and before pupation. Severely affected ftz-f1 mutants display an embryonic lethal phenotype, but can be rescued by ectopic expression of betaFTZ-F1 during the period of endogenous betaFTZ-F1 expression in the wild type. The resulting larvae are not able to molt, but this activity is rescued again by forced expression of betaFTZ-F1, allowing progression to the next larval instar stage. On the other hand, premature expression of betaFTZ-F1 in wild-type larvae at mid-first instar or mid-second instar stages causes defects in the molting process. Sensitive periods were found to be around the time of peak ecdysteroid levels and slightly before the start of endogenous betaFTZ-F1 expression. A hypomorphic ftz-f1 mutant that arrests in the prepupal stage can also be rescued by ectopic, time-specific expression of betaFTZ-F1. Failure of salivary gland histolysis, one of the phenotypes of the ftz-f1 mutant, is rescued by forced expression of the ftz-f1 downstream gene BR-C during the late prepupal period. These results suggest that betaFTZ-F1 regulates genes associated with ecdysis and metamorphosis, and that the exact timing of its action in the ecdysone-induced gene cascade is important for proper development.



2019 ◽  
Vol 20 (9) ◽  
pp. 2165 ◽  
Author(s):  
Mei-Li Zhao ◽  
Jun Ni ◽  
Mao-Sheng Chen ◽  
Zeng-Fu Xu

Trehalose-6-phosphate (T6P) phosphatase (TPP), a dephosphorylating enzyme, catalyzes the dephosphorylation of T6P, generating trehalose. In Jatropha, we found six members of the TPP family. Five of them JcTPPA, JcTPPC, JcTPPD, JcTPPG, and JcTPPJ are highly expressed in female flowers or male flowers, or both, suggesting that members of the JcTPP family may participate in flower development in Jatropha. The wide expression of JcTPPJ gene in various organs implied its versatile roles and thus was chosen for unraveling its biological functions during developmental process. We constructed an overexpression vector of JcTPPJ cDNA driven by the cauliflower mosaic virus (CaMV) 35S promoter for genetic transformation. Compared with control Arabidopsis plants, 35S:JcTPPJ transgenic Arabidopsis plants presented greater sucrose contents in their inflorescences and displayed late-flowering and heterostylous phenotypes. Exogenous application of sucrose to the inflorescence buds of wild-type Arabidopsis repressed the development of the perianth and filaments, with a phenocopy of the 35S:JcTPPJ transgenic Arabidopsis. These results suggested that the significantly increased sucrose level in the inflorescence caused (or induced) by JcTTPJ overexpression, was responsible for the formation of heterostylous flower phenotype. However, 35S:JcTPPJ transgenic Jatropha displayed no obvious phenotypic changes, implying that JcTPPJ alone may not be sufficient for regulating flower development in Jatropha. Our results are helpful for understanding the function of TPPs, which may regulate flower organ development by manipulating the sucrose status in plants.



2019 ◽  
Vol 116 (28) ◽  
pp. 14319-14324 ◽  
Author(s):  
Jingbo Duan ◽  
Hong Yu ◽  
Kun Yuan ◽  
Zhigang Liao ◽  
Xiangbing Meng ◽  
...  

Strigolactones (SLs), a group of terpenoid lactones derived from carotenoids, are plant hormones that control numerous aspects of plant development. Although the framework of SL signaling that the repressor DWARF 53 (D53) could be SL-dependently degraded via the SL receptor D14 and F-box protein D3 has been established, the downstream response genes to SLs remain to be elucidated. Here we show that the cytokinin (CK) content is dramatically increased in shoot bases of the rice SL signaling mutantd53. By examining transcript levels of all the CK metabolism-related genes after treatment with SL analog GR24, we identifiedCYTOKININ OXIDASE/DEHYDROGENASE 9(OsCKX9) as a primary response gene significantly up-regulated within 1 h of treatment in the wild type but not ind53. We also found that OsCKX9 functions as a cytosolic and nuclear dual-localized CK catabolic enzyme, and that the overexpression ofOsCKX9suppresses the browning ofd53calli. Both the CRISPR/Cas9-generatedOsCKX9mutants andOsCKX9-overexpressing transgenic plants showed significant increases in tiller number and decreases in plant height and panicle size, suggesting that the homeostasis ofOsCKX9plays a critical role in regulating rice shoot architecture. Moreover, we identified the CK-inducible rice type-A response regulatorOsRR5as the secondary SL-responsive gene, whose expression is significantly repressed after 4 h of GR24 treatment in the wild type but not inosckx9. These findings reveal a comprehensive plant hormone cross-talk in which SL can induce the expression ofOsCKX9to down-regulate CK content, which in turn triggers the response of downstream genes.



2019 ◽  
Vol 99 (2) ◽  
pp. 210-220 ◽  
Author(s):  
Yong Zhou ◽  
Lifang Hu ◽  
Shuifeng Ye ◽  
Lunwei Jiang ◽  
Shiqiang Liu

MADS-box proteins are important transcription factors that play essential roles in various aspects of plant development, particularly in flower development. In this study, we performed the identification and functional characterization of CsMADS09 isolated from cucumber (Cucumis sativus L.). CsMADS09 contains a 648-bp open reading frame encoding 215 amino acid residues, and shares high sequence identities with the members of the AP1/FUL family of MADS-box proteins, especially the euAPETALA1 (euAP1) subclade. Many cis-elements related to plant development, stress response, and hormones were identified in the promoter region of CsMADS09. Quantitative real-time polymerase chain reaction results showed that CsMADS09 was mainly expressed in reproductive tissues such as male flowers and unexpanded ovaries, while its expression was low in roots and only traceable in fertilized ovaries. Moreover, the results revealed that CsMADS09 expression tended to decline during male flower development and stayed nearly constant during female flower development. Ectopic expression of CsMADS09 resulted in earlier flowering and abnormal leaf development in transgenic Arabidopsis. This study is the first functional analysis of an AP1-like gene from cucumber and provides some clues for revealing the molecular mechanisms of flower development in cucumber.



Author(s):  
Thecan Caesar-Ton That ◽  
Lynn Epstein

Nectria haematococca mating population I (anamorph, Fusarium solani) macroconidia attach to its host (squash) and non-host surfaces prior to germ tube emergence. The macroconidia become adhesive after a brief period of protein synthesis. Recently, Hickman et al. (1989) isolated N. haematococca adhesion-reduced mutants. Using freeze substitution, we compared the development of the macroconidial wall in the wild type in comparison to one of the mutants, LEI.Macroconidia were harvested at 1C, washed by centrifugation, resuspended in a dilute zucchini fruit extract and incubated from 0 - 5 h. During the incubation period, wild type macroconidia attached to uncoated dialysis tubing. Mutant macroconidia did not attach and were collected on poly-L-lysine coated dialysis tubing just prior to freezing. Conidia on the tubing were frozen in liquid propane at 191 - 193C, substituted in acetone with 2% OsO4 and 0.05% uranyl acetate, washed with acetone, and flat-embedded in Epon-Araldite. Using phase contrast microscopy at 1000X, cells without freeze damage were selected, remounted, sectioned and post-stained sequentially with 1% Ba(MnO4)2 2% uranyl acetate and Reynold’s lead citrate. At least 30 cells/treatment were examined.



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