Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0277787 (stigma)
 13,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gynoecium is the most complex floral organ, designed to protect the ovules and ensure their fertilization. Correct patterning and tissue specification in the developing gynoecium involves the concerted action of a host of genetic factors. In addition, apical-basal patterning into different domains, stigma and style, ovary and gynophore, appears to depend on the establishment and maintenance of asymmetric auxin distribution, with an auxin maximum at the apex. Here, we show that a small subfamily of the B3 transcription factor superfamily, the NGATHA (NGA) genes, act redundantly to specify style development in a dosage-dependent manner. Characterization of the NGA gene family is based on an analysis of the activation-tagged mutant named tower-of-pisa1 (top1), which was found to overexpress NGA3. Quadruple nga mutants completely lack style and stigma development. This mutant phenotype is likely caused by a failure to activate two auxin biosynthetic enzymes, YUCCA2 and YUCCA4, in the apical gynoecium domain. The NGA mutant phenotypes are similar to those caused by multiple combinations of mutations in STYLISH1 (STY1) and additional members of its family. NGA3/TOP1 and STY1 share almost identical patterns of expression, but they do not appear to regulate each other at the transcriptional level. Strong synergistic phenotypes are observed when nga3/top1 and sty1 mutants are combined. Furthermore, constitutive expression of both NGA3/TOP1 and STY1 induces the conversion of the ovary into style tissue. Taken together, these data suggest that the NGA and STY factors act cooperatively to promote style specification, in part by directing YUCCA-mediated auxin synthesis in the apical gynoecium domain.
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PMID:The NGATHA genes direct style development in the Arabidopsis gynoecium. 1943 37

Carpels are a distinctive feature of angiosperms, the ovule-bearing female reproductive organs that endow them with multiple selective advantages likely linked to the evolutionary success of flowering plants. Gene regulatory networks directing the development of carpel specialized tissues and patterning have been proposed based on genetic and molecular studies carried out in Arabidopsis thaliana. However, studies on the conservation/diversification of the elements and the topology of this network are still scarce. In this work, we have studied the functional conservation of transcription factors belonging to the SHI/STY/SRS family in two distant species within the eudicots, Eschscholzia californica and Nicotiana benthamiana. We have found that the expression patterns of EcSRS-L and NbSRS-L genes during flower development are similar to each other and to those reported for Arabidopsis SHI/STY/SRS genes. We have also characterized the phenotypic effects of NbSRS-L gene inactivation and overexpression in Nicotiana. Our results support the widely conserved role of SHI/STY/SRS genes at the top of the regulatory network directing style and stigma development, specialized tissues specific to the angiosperm carpels, at least within core eudicots, providing new insights on the possible evolutionary origin of the carpels.
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PMID:The Role of SHI/STY/SRS Genes in Organ Growth and Carpel Development Is Conserved in the Distant Eudicot Species Arabidopsis thaliana and Nicotiana benthamiana. 2858 95