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Query: UNIPROT:P06889 (
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630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A novel
stigma
-specific class III peroxidase gene, SSP (
Stigma
-Specific Peroxidase), has been isolated from the self-incompatible daisy Senecio squalidus L. (Asteraceae). Expression of SSP in flower buds is developmentally regulated, with maximal levels of expression coinciding with anthesis, when stigmas are most receptive to pollen and when self-incompatibility is fully developed. In situ hybridization revealed SSP expression to be localized exclusively to the specialized secretory epidermal cells (papillae) of the
stigma
, which receive and discriminate pollen. SSP is therefore the first tissue-specific and cell-specific peroxidase gene identified in a plant. SSP belongs to a distinct clade of class III plant peroxidases that possess two introns, instead of the more normal situation of three conserved introns. The deduced amino acid sequence of SSP revealed a 27 amino acid signal peptide, suggesting that the SSP protein is secreted to the cell wall of the stigmatic papillae. In-gel peroxidase activity assays showed that SSP has relatively low peroxidase activity compared to other, as yet uncharacterized, peroxidases present in stigmatic extracts. Six SSP alleles have been cloned from different lines of S. squalidus carrying a range of self-incompatibility (S)-alleles but there was no consistent association between the presence of a particular SSP allele and S-genotype indicating that SSP is not the female determinant of SSI in S. squalidus. Nevertheless, the precise expression of SSP in stigmatic papillae suggests that it may have a more general function in pollen-
stigma
interactions, or alternatively in protection of stigmas from pathogen attack. Extensive database screens have identified homologues of SSP in other plant species, but available expression data for these genes indicates that none are flower-specific, suggesting that SSP represents a new functional type of class III peroxidase specific to the
stigma
. We discuss the possible function(s) of S. squalidus SSP in pollen-
stigma
interactions and in protection of stigmas from pathogen attack.
Plant
Mol
Biol 2005 Mar
PMID:Isolation and characterization of a polymorphic stigma-specific class III peroxidase gene from Senecio squalidus L. (Asteraceae). 1598 62
Alcohol dehydrogenase (ADH) activity in plants is generally associated with glycolytic fermentation, which facilitates cell survival during episodes of low-oxygen stress in water-logged roots as well as chronically hypoxic regions surrounding the vascular core. Work with tobacco and potato has implicated ADH activity in additional metabolic roles, including aerobic fermentation, acetaldehyde detoxification and carbon reutilization. Here a combination of approaches has been used to examine tissue-specific patterns of Adh gene expression in order to provide insight into the potential roles of alcohol dehydrogenases, using Petunia hybrida, a solanaceous species with well-characterized genetics. A reporter-gene study, relying on the promoters of Adh1 and Adh2 to drive expression of the gene for a green fluorescent protein derivative, mgfp5, revealed unexpectedly complex patterns of GFP fluorescence in floral tissues, particularly the
stigma
, style and nectary. Results of GC-MS analysis suggest the association of ADH with production of aromatic compounds in the nectary. Overall the results demonstrate selective recruitment of Adh gene family members in tissues and organs associated with diverse ADH functions.
Plant
Mol
Biol 2005 May
PMID:Selective recruitment of Adh genes for distinct enzymatic functions in Petunia hybrida. 1602 79
Mental disorders cause more disability than any other class of medical illness in Americans between ages 15 and 44 years. The suicide rate is higher than the annual mortality from homicide, AIDS, and most forms of cancer. In contrast to nearly all communicable and most non-communicable diseases, there is little evidence that the morbidity and mortality from mental disorders have changed in the past several decades. Mental health advocates, including psychiatric researchers, have pointed to
stigma
as one of the reasons for the lack of progress with mental illnesses relative to other medical illnesses. This review considers how the expectations and goals of the research community have contributed to this relative lack of progress. In contrast to researchers in cancer and heart disease who have sought cures and preventions, biological psychiatrists in both academia and industry have set their sights on incremental and marketable advances, such as drugs with fewer adverse effects. This essay argues for approaches that can lead to cures and strategies for prevention of schizophrenia and mood disorders.
Mol
Psychiatry 2006 Jan
PMID:Cure therapeutics and strategic prevention: raising the bar for mental health research. 1635 50
A recent investigation found evidence that the transition of Arabidopsis thaliana from ancestral self-incompatibility (SI) to full self-compatibility occurred very recently and suggested that this occurred through a selective fixation of a nonfunctional allele (PsiSCR1) at the SCR gene, which determines pollen specificity in the incompatibility response. The main evidence is the lack of polymorphism at the SCR locus in A. thaliana. However, the nearby SRK gene, which determines
stigma
specificity in self-incompatible Brassicaceae species, has extremely high sequence diversity, with 3 very divergent SRK haplotypes, 2 of them present in multiple strains. Such high diversity is extremely unusual in this species, and it suggests the possibility that multiple, different SRK haplotypes may have been preserved from A. thaliana's self-incompatible ancestor. To study the evolution of S-haplotypes in the A. thaliana lineage, we searched the 2 most closely related Arabidopsis species Arabidopsis lyrata and Arabidopsis halleri, in which most populations have retained SI, and found SRK sequences corresponding to all 3 A. thaliana haplogroup sequences. Our molecular evolutionary analyses of these 3 S-haplotypes provide an independent estimate of the timing of the breakdown of SI and again exclude an ancient transition to selfing in A. thaliana. Comparing sequences of each of the 3 haplogroups between species, we find that 2 of the 3 SRK sequences (haplogroups A and B) are similar throughout their length, suggesting that little or no recombination with other SRK alleles has occurred since these species diverged. The diversity difference between the SCR and SRK loci in A. thaliana, however, suggests crossing-over, either within SRK or between the SCR and SRK loci. If the loss of SI involved fixation of the PsiSCR1 sequence, the exchange must have occurred during its fixation. Divergence between the species is much lower at the S-locus, compared with reference loci, and we discuss two contributory possibilities. Introgression may have occurred between A. lyrata and A. halleri and between their ancestral lineage and A. thaliana, at least for some period after their split. In addition, the coalescence times of sequences of individual S-haplogroups are expected to be less than those of alleles at non-S-loci.
Mol
Biol Evol 2006 Sep
PMID:The transition to self-compatibility in Arabidopsis thaliana and evolution within S-haplotypes over 10 Myr. 1678 60
The plant co-chaperones FK506-binding proteins (FKBPs) are peptidyl prolyl cis-trans isomerases that function in protein folding, signal transduction and chaperone activity. We report the characterization of the Arabidopsis large FKBPs ROF1 (AtFKBP62) and ROF2 (AtFKBP65) expression and protein accumulation patterns. Transgenic plants expressing ROF1 promoter fused to GUS reporter gene reveal that ROF1 expression is organ specific. High expression was observed in the vascular elements of roots, in hydathodes and trichomes of leaves and in
stigma
, sepals, and anthers. The tissue specificity and temporal expression of ROF1 and ROF2 show that they are developmentally regulated. Although ROF1 and ROF2 share 85% identity, their expression in response to heat stress is differentially regulated. Both genes are induced in plants exposed to 37 degrees C, but only ROF2 is a bonafide heat-stress protein, undetected when plants are grown at 22 degrees C. ROF1/ROF2 proteins accumulate at 37 degrees C, remain stable for at least 4 h upon recovery at 22 degrees C, whereas, their mRNA level is reduced after 1 h at 22 degrees C. By protein interaction assays, it was demonstrated, that ROF1 is a novel partner of HSP90. The five amino acids identified as essential for recognition and interaction between the mammalian chaperones and HSP90 are conserved in the plant ROF1-HSP90. We suggest that ROF/HSP90 complexes assemble in vivo. We propose that specific complexes formation between an HSP90 and ROF isoforms depends on their spatial and temporal expression. Such complexes might be regulated by environmental conditions such as heat stress or internal cues such as different hormones.
Plant
Mol
Biol 2007 Jan
PMID:Arabidopsis immunophilins ROF1 (AtFKBP62) and ROF2 (AtFKBP65) exhibit tissue specificity, are heat-stress induced, and bind HSP90. 1708 Feb 88
The white flowers of N. suaveolens emit a complex bouquet of fragrance volatiles. The dominant compounds are benzenoids (e.g. methyl benzoate, methyl salicylate, benzyl benzoate and benzyl salicylate), monoterpenes (1,8-cineole, limonene, sabinene, E-beta-ocimene, beta-beta-myrcene, alpha- and beta-pinene and alpha-terpineole) and sesquiterpenes (e.g. caryophyllene), which are all emitted at higher levels during the night. Here, we show that the simultaneous nocturnal emission of most monoterpenes is realized by a single floral-specific multi-product enzyme (1,8-cineole synthase, CIN), which synthesizes the monoterpenes of the "cineole cassette". Interestingly, N. suaveolens is the only known taxon of the Suaveolentes section to have a flower emitting "cineole cassette of monoterpenes" which is otherwise typical for the Alatae section. Gene sequence analysis of CIN has revealed the highest similarities to other angiosperm monoterpene synthases from Vitis vinifera, Quercus ilex, Citrus unshiu and C. limon, which cluster in the same branch of the terpene synthase B subfamily. However, based on its synthesized products, N. suaveolens CIN shares similarity with enzymes of the Arabidopsis thaliana root and Salvia officinalis leaf. The N. suaveolens CIN gene is only expressed in the
stigma
/style tissue and petals. Thin sections of petals present the enzyme primarily in the adaxial and abaxial epidermis; this facilitates the comprehensive emission of volatiles in all spacial directions. The oscillation of monoterpene emission is a consequence of the regulation of the CIN gene by the circadian clock, with oscillations occurring at the level of transcript and protein accumulations and of enzyme activity. Light/dark or dark/light transition signals synchronize the slow-running endogenous clock. Two strategies for synchronized scent emission have been established in N. suaveolens flowers: (i) the synthesis of volatile organic compounds by a multi-product enzyme and (ii) the coordination of biosynthetic pathways by a circadian clock.
Plant
Mol
Biol 2007 Sep
PMID:Regulation of simultaneous synthesis of floral scent terpenoids by the 1,8-cineole synthase of Nicotiana suaveolens. 1761 97
Self-incompatibility (SI) in Lolium perenne is controlled gametophytically by the S-Z two-locus system. S and Z loci mapped to L. perenne linkage groups 1 and 2, respectively, with their corresponding putative-syntenic regions on rice chromosome 5 (R5) and R4. None of the gene products of S and Z have yet been identified. SI cDNA libraries were developed to enrich for SI expressed genes in L. perenne. Transcripts were identified from the SI libraries that were orthologous to sequences on rice R4 and R5. These represent potential SI candidate genes. Altogether ten expressed SI candidate genes were identified. A rapid increase in gene expression within two minutes after pollen-
stigma
contact was revealed, reaching a maximum between 2 and 10 min. The potential involvement of these genes in the SI reactions is discussed.
Plant
Mol
Biol 2009 Aug
PMID:Identification of genes expressed during the self-incompatibility response in perennial ryegrass (Lolium perenne L.). 1948 89
Within the Gentianaceae-Exaceae, the most species-rich genus Sebaea has received very little attention in terms of phylogenetic or karyological investigations. As a result, the exact number of species remains vague and the relationships with the other members of the Exaceae poorly understood. In this paper, we provide the first comprehensive phylogeny of the Exaceae including most Sebaea species known so far based on four cpDNA sequence regions. In addition, morphological and karyological characters were mapped on the inferred phylogenetic trees to detect possible non-molecular synapomorphies. Our results reveal the paraphyly of Sebaea and highlight new generic relationships within the Exaceae. Sebaea pusilla (lineage S1--Lagenias) forms a highly supported and early diverging clade with Sebaeas.str. (clade S2 -Sebaea). A third clade of the former Sebaea s.l. (clade S3--Exochaenium) contains exclusively tropical African species, and is sister with a large clade containing all the remaining genera of Exaceae. Within the latter, the proposed sister relationships between the recently described Klackenbergia and Ornichia are highly supported. Optimization of several morphological characters onto the inferred phylogenetic trees reveals several synapomorphies for most highly supported clades. In particular, lineage S1 (Lagenias) is supported by medifixed anthers that are inserted at the base of the corolla tube and cubical seeds with polygonal testa cells; clade S2 (Sebaea) is supported by both the presence of secondary stigmas along the style and ridged seeds with rectangular testa cells arranged in row; clade S3 (Exochaenium) is supported by its particular gynoecium (stylar polymorphism and clavate, papillose
stigma
). Finally, karyological reconstructions suggest a basal number of x=7 for the Exaceae and several episodes of dysploidy leading to x=8 and 9.
Mol
Phylogenet Evol 2009 Dec
PMID:The polyphyletic genus Sebaea (Gentianaceae): a step forward in understanding the morphological and karyological evolution of the Exaceae. 1964 40
High throughput screening of stage-specific differentially expressed genes in a Brassica napus two-line Rs1046A/B subtractive library was used to identify the BnQRT3 gene associated with cell wall metabolism. Phylogenetic analysis indicates the protein product of BnQRT3 is polygalacturonase. According to cytological comparisons of Rs1046 sterile and fertile anthers, RT-PCR studies and in situ hybridizations, BnQRT3 is expressed most strongly in floral organs and may play an essential role in pollen maturation. Analysis of the histological staining pattern of BnQRT3 promoter-GUS constructs in transgenic Arabidopsis and Brassica napus revealed that proximal part of 5'-flanking region directed expression in the vascular tissue of filaments, veins in sepal and petals,
stigma
, branch connective and the floral organ abscission zone during the open flower stage. In the meanwhile, Activity of BnQRT3 was detected in the anthers, which commences at the microsporocyte stage and persists as anther approaches dehiscence. Strong GUS expression also can be observed in the vascular tissue of leaves and stem by compression with forceps or excision, suggesting that the BnQRT3 promoter is responsive to wounding.
Mol
Biol Rep 2010 Dec
PMID:Molecular analysis and expression of a floral organ-specific polygalacturonase gene isolated from rapeseed (Brassica napus L.). 2021 7
Stigma
and spikelet characteristics play an essential role in hybrid seed production. A mini-core of 90 accessions developed from USDA rice core collection was phenotyped in field grown for nine traits of
stigma
and spikelet and genotyped with 109 DNA markers, 108 SSRs plus an indel. Three major clusters were built upon Rogers' genetic distance, indicative of indicas, and temperate and tropical japonicas. A mixed linear model combining PC-matrix and K-matrix was adapted for mapping marker-trait associations. Resulting associations were adjusted using false discovery rate technique. We identified 34 marker-trait associations involving 22 SSR markers for eight traits. Four markers were associated with single
stigma
exsertion (SStgE), six with dual exsertion (DStgE) and five with total exsertion. RM5_Chr1 played major role indicative of high regression with not only DStgE but also SStgE. Four markers were associated with spikelet length, three with width and seven with L/W ratio. Numerous markers were co-associated with multiple traits that were phenotypically correlated, i.e. RM12521_Chr2 associated with all three correlated spikelet traits. The co-association should improve breeding efficiency because single marker could be used to assist breeding for multiple traits. Indica entry 1032 (cultivar 50638) and japonica entry 671 (cultivar Linia 84 Icar) with 80.65 and 75.17% of TStgE, respectively are recommended to breeder for improving
stigma
exsertion. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-009-9290-y) contains supplementary material, which is available to authorized users.
Mol
Breed 2009 Oct
PMID:Association mapping of stigma and spikelet characteristics in rice (Oryza sativa L.). 2023 78
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