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

The S locus glycoprotein (SLG) gene of Brassica encodes stigmatic glycoproteins that are implicated in the pollen-stigma interaction of self-incompatibility. We have transformed the related plant Arabidopsis thaliana with a chimaeric gene consisting of the promoter region of an SLG gene fused to the reporter gene beta-glucuronidase (GUS). In transgenic plants the gene was expressed in two cell types of the flower. In stigmas, the timing and distribution of GUS activity was similar to that previously described for SLG expression in Brassica. In anthers, expression was detected at an earlier stage of flower development with GUS activity restricted to the tapetal cell layer. The novel finding of SLG-promoter activity in the anther supports the hypothesis that sporophytic control of self-incompatibility is a result of SLG-gene expression in the tapetum.
 ...
PMID:A Brassica S locus gene promoter directs sporophytic expression in the anther tapetum of transgenic Arabidopsis. 199 65

Deletions were made in the promoter of the acyl carrier protein (ACP) Acll.2 gene from Arabidopsis to investigate the nature of the cis-acting elements that direct its expression. These constructs, which included the untranslated leader region, were fused to a reporter gene coding for beta-glucuronidase (GUS) and transformed into tobacco. Quantitative fluorometric analysis of GUS activity in transgenic plants showed that expression in young leaves drops to a basal level when a 85 bp domain, from -320 to -236 relative to transcription initiation, is deleted. Maximum promoter activity in roots also depends on this domain, but two other regions are also important. In total, deletion of the sequences from -466 to -55 caused an ca. 80-fold reduction in Acl1.2 promoter activity in roots. The -320 to -236 domain forms a complex with a protein factor found in leaves and roots, which was not detectable in seeds. The formation of this protein-DNA complex was abolished by mutation of a bZIP core motif, ACGT, found within the context AAGACGTAG, which is dissimilar to the other bZIP-binding sites thus far characterized in plants. Previously we showed that Acl1.2 promoter activity is highest in seeds [2]. Here we find, in contrast to leaves and roots, that deletion to position -236 has no effect on GUS levels in seeds. However, nearly a 100-fold drop was observed when the -235 to -55 region was removed. Hence, this 180 bp domain contains all the cis-acting information necessary for Acl1.2 promoter activity in seeds. The same region is necessary for Acl1.2 activity in the receptacle, stigma, tapetum and pollen of the flower, as demonstrated by histochemical staining.
 ...
PMID:Identification of domains in an Arabidopsis acyl carrier protein gene promoter required for maximal organ-specific expression. 785 29

The promoter of the S Locus Glycoprotein (SLG) gene of Brassica is a tightly regulated promoter that is active specifically in reproductive organs. In transgenic tobacco, this promoter is active exclusively in cells of the pistil and in pollen. We transformed tobacco with truncated versions of the SLG13 promoter fused to the beta-glucuronidase reporter gene. We show that the promoter has a modular organization and consists of separable DNA elements that independently specify pistil- and pollen-specific expression. A 196-bp region (-339 to -143) is sufficient to confer stigma and style specificity to the marker gene. Two distinct, but functionally redundant, domains (-415 to -291 and -117 to -8) allow specific expression of the gene in pollen. The functional domains identified within the SLG13 promoter contain sequence elements that are highly conserved in different alleles of the SLG gene and in the S Locus Related SLR1 gene.
 ...
PMID:Distinct cis-acting elements direct pistil-specific and pollen-specific activity of the Brassica S locus glycoprotein gene promoter. 840 Aug 68

The expression of two closely related peroxidase isogenes, Shpx6a and Shpx6b, of the legume Stylosanthes humilis was studied using isogene-specific reverse transcriptase PCR techniques. Results indicated that transcripts of both genes were rapidly induced following inoculation with the fungal pathogen Colletotrichum gloeosporioides, wounding and treatment with the defense regulator methyl jasmonate (MeJA). In contrast treatment of leaves of S. humilis with abscisic acid (ABA) and salicylic acid (SA) did not induce transcripts of either isogene. A genomic clone containing the Shpx6b gene was isolated and 594 bp of 5' sequence upstream of the translation start was fused in frame to the coding region of the uidA reporter gene and introduced into tobacco. Expression from the Shpx6b promoter in transgenic plants was determined by histochemical staining and quantitative assays of beta-glucuronidase (GUS). In transgenic tobacco, GUS expression was detected in cotyledons, vascular cells of young leaves, anthers, pollen, and the stigma and style. Wounding of the tobacco plants produced very localized GUS staining. Much more extensive staining for GUS was observed following inoculation of tobacco leaves with conidia of the fungal pathogen Cercospora nicotianae and the inoculation of wound sites with mycelium of the Oomycete pathogen Phytophthora parasitica var. nicotianae. Treatment of mature leaves with methyl jasmonate induced GUS activity while treatment with ABA, SA, and H2O2 had no effect. A similar strong induction of GUS activity was measured in young transgenic seedlings germinated on MeJA while some, but much weaker, induction of GUS activity was observed in seedlings treated with SA. The sequence of the promoter contained motifs homologous to putative cis elements in other plant genes responsive to MeJA. The Shpx6b gene is the first plant peroxidase gene shown to be induced by both microbial pathogens and MeJA and its promoter will be useful for investigations of signaling processes during fungal infection and for the expression of foreign gene products at infection sites.
 ...
PMID:A peroxidase gene promoter induced by phytopathogens and methyl jasmonate in transgenic plants. 910 Mar 78

The fruit is a highly specialized plant organ that occurs in diverse forms among the angiosperms. Fruits of Arabidopsis thaliana, which are typical of the > 3000 species of Brassicaceae, develop from a gynoecium that consists of two fused carpels. The mature gynoecium of Arabidopsis is composed of an apical stigma, a short style, and a basal ovary that contains the developing ovules. After the ovules are fertilized, the fruit elongates and differentiates a number of distinct cell types, allowing for the successful maturation and the eventual dispersal of the seeds. Although the processes involved in carpel and fruit morphogenesis are not well understood, recent studies have identified a large number of mutants that display abnormal gynoecium and fruit development. The detailed phenotypic description of these mutants together with recent cloning of many of these genes has begun to shed light on this interesting and complex developmental process. Here we review the growing collection of Arabidopsis genes known to control the initiation and development of the gynoecium and resulting fruit.
 ...
PMID:Control of carpel and fruit development in Arabidopsis. 1087 53

The carpel is the female reproductive organ of flowering plants. In Arabidopsis, congenital fusion of two carpels leads to the formation of an enclosed gynoecium. The margins of the two fused carpels are meristematic in nature and give rise to placentas, ovules, septa, abaxial repla, and the majority of the stylar and stigmatic tissues. Thus, understanding how the marginal tissues are specified and identifying genes that direct their development may provide important insight into higher plant reproductive development. In this study, we show that LEUNIG and AINTEGUMENTA are two critical regulators of marginal tissue development. Double mutants of leunig aintegumenta fail to develop placentas, ovules, septa, stigma, and style. This effect is specific to the leunig aintegumenta double mutant and is not found in other double mutant combinations such as leunig apetala2 or aintegumenta apetala2. Additional analyses indicate that the absence of marginal tissues in leunig aintegumenta double mutants is not mediated by ectopic AGAMOUS. We propose that LEUNIG and AINTEGUMENTA act together to control the expression of common target genes that regulate cell proliferation associated with marginal tissue development.
 ...
PMID:Regulation of gynoecium marginal tissue formation by LEUNIG and AINTEGUMENTA. 1104 83

The interactions between pollen and stigma are essential for plant reproduction and are made possible by compounds, such as proteins and lipids, located on their surfaces. The pollen coat is formed in part by compounds synthesized in, and released from, the tapetum, which become transferred to the pollen coat late in pollen development. In the Brassicaceae the predominant proteins of the mature pollen coat are the tapetal oleosin-like proteins, which are highly expressed in, and ultimately transferred from, the tapetum. Here we report the modification of the protein composition of the pollen coat by the addition of an active enzyme which was synthesized in the tapetum. The marker enzyme beta-glucuronidase (GUS) was successfully targeted to the pollen coat in transgenic Brassica carinata plants expressing GUS translationally fused to a B. napus tapetal oleosin-like protein (BnOlnB;4). To our knowledge this is the first demonstration of the targeting of an enzyme to the pollen coat.
 ...
PMID:Modifying the pollen coat protein composition in Brassica. 1218 5

A chimeric toxic gene consisting of the diphtheria toxin A chain gene fused to a promoter previously shown to direct pistil- and anther-specific expression was used to genetically target cell killing in transgenic Arabidopsis. Flowers of Arabidopsis transformants that carried the toxic gene fusion had distinct structural defects. The papillar cells at the stigma surface were stunted and were biosynthetically inactive. Anther development was also impaired by toxic gene expression, leading to abnormalities in anther dehiscence, pollen morphology, and pollen germination. The combined defects of pistil and anther rendered transformants that carried the toxic gene fusion self-sterile. However, the transformants were cross-fertile with untransformed plants: the viable pollen of ablated plants was rescued by wild-type stigmas, and, strikingly, the ablated papillar cells allowed the growth of wild-type pollen.
 ...
PMID:Genetic Ablation of Floral Cells in Arabidopsis. 1227 Oct 62

The pollen-stigma interaction of self-incompatibility in crucifers is correlated with glycoproteins localized in the cell wall of the stigmatic papillae that are encoded by the S locus glycoprotein (SLG) gene. When fused to the [beta]-glucuronidase (GUS) reporter gene, the 5[prime] upstream regulatory region of SLG directed high level expression in the papillae of transgenic Brassica plants. Histochemical and fluorometric assays revealed that, in addition to its primary site of expression in the stigmatic papillae, the SLG-GUS fusion was also expressed in the transmitting tissue of stigma, style, and ovary, and in anthers. This conclusion was verified by the detection of transgene-encoded GUS transcripts and endogenous SLG-homologous transcripts by RNA gel blot analysis. Significantly, in anthers, the SLG promoter was active not only sporophytically in the nurse cells of the tapetum, but also in the haploid microspores. Because self-incompatibility systems exhibiting sporophytic control of pollen phenotype are thought to have evolved from systems with gametophytic control, we suggest that sporophytic control was acquired without loss of gametophytic function.
 ...
PMID:Activity of an S Locus Gene Promoter in Pistils and Anthers of Transgenic Brassica. 1232 20

The genomic clone encoding the pistil-specific thaumatin/PR5-like protein (PsTL1) was isolated from Japanese pear (Pyrus serotina). Sequence analysis showed that the genomic clone contained the 5'-flanking sequence of 2.4 kb, the 3'-flanking sequence of 648 bp and the coding region interrupted by a intron of 351 bp. A sequence motif conserved in some pistil self-incompatibility gene promoters of solanaceous and brassicaceous species was located in the 5'-flanking region of the PsTL1 gene. The 2.4 kb 5'-flanking region was fused to the GUS coding sequence and transferred to tobacco. Transgenic tobacco showed GUS activity in pistil and, at low level, in anther, but not in other floral organs and leaf. Histochemical analysis localized GUS activity to stigma, transmitting tissue, anther and pollen of transgenic tobacco.
 ...
PMID:A pistil-specific thaumatin/PR5-like protein gene of Japanese pear (Pyrus serotina): sequence and promoter activity of the 5' region in transgenic tobacco. 1236 14


1 2 3 4 Next >>