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1.
Alain Delbarre Philippe Muller Viviane Imhoff Jean-Louis Morgat Hélène Barbier-Brygoo 《Planta》1994,195(2):159-167
Uptake and metabolism of exogenous naphthalene-1-acetic acid (NAA) and indole-3-acetic acid (IAA) have been studied in tobacco (Nicotiana tabacum L. cv. Xanthi) mesophyll protoplasts. Both auxins entered protoplasts by diffusion under the action of the transmembrane pH gradient without any detectable participation of an influx carrier. Molecules were accumulated by an anion-trapping mechanism and most of them were metabolized within hours, essentially as glucose-ester and amino-acid conjugates. Protoplasts were equipped with a functional auxin-efflux carrier as evidenced by the inhibitory effect of naphthylphtalamic acid on IAA efflux. Basically, similar mechanisms of NAA and IAA uptake occurred in protoplasts. However, the two auxins differed in their levels of accumulation, due to different membrane-transport characteristics, and the nature of the metabolites produced. This shows the need to estimate the accumulation and the metabolism of auxins when analyzing their effects in a given cell system. The internal auxin concentration could be modulated by changing the transmembrane pH gradient, giving an interesting perspective for discriminating between the effects of intra- and extracellular auxin on physiological processes.Abbreviations BA
benzoic acid
- Ci/Ce
accumulation ratio of auxin
- IAAasp
N-[3-indolylacetyl]-dl-aspartic acid
- NAA
naphthalene-1-acetic acid
- NAAasp
N-[1-naphthylacetyl]-l-aspartic acid
- NPA
N-1-naphthylphthalamic acid
The authors thank Dr. M. Caboche (I.N.R.A, Versailles, France) for his generous gifts of some amide derivatives of 1-NAA, Mr. P. Varennes and Dr. B. Das (I.C.S.N., C.N.R.S., Gif-sur-Yvette, France) for recording and interpreting the mass spectra of NAA glucose ester, and Prof. P. Manigault (Institut des Sciences Végétales, Gif-sur-Yvette) for microscopy measurements of protoplast dimensions. This work was supported by funds from the C.N.R.S, I.N.R.A, and E.E.C. 相似文献
2.
Lakhdar Ghazouani Nesrine Abboud Sonia Ben Hadj Khalifa Claire Perret Viviane Nicaud Wassim Youssef Almawi François Cambien Touhami Mahjoub 《Molecular biology reports》2011,38(1):495-501
P-selectin (SELP) and its counter-receptor, P-selectin glycoprotein ligand-1 (PSGL-1), play key role in the transient attachment
of leukocytes to endothelial cells predisposing to coronary heart disease (CHD). In the current report, 293 angiographically
proven CHD patients and 327 age, gender, and race-matched controls were included. Our aim was to evaluate the contribution
to CHD of the following SNPs: C-2123G, G-1969A and T715P in SELP, Met62Ile and the VNTR variants in PSGL-1 gene in a North African population from Tunisia. While there were no significant differences in the distribution of SELP
or PSGL-1 alleles or genotypes between patients and controls, a trend for a significant association of the C-2123G genotypes
distribution with incident CHD was observed (P = 0.06). Assuming an additive model of transmission, the risk was 74% higher among subjects carrying the GG genotypes in
comparison to those carrying the CC genotype (OR = 1.74 [1.01–2.98], P = 0.04) and 80% higher in the recessive model (OR = 1.80 [1.08–3.01], P = 0.02). Haplotype analysis did not identify any specific SELP or PSGL-1 haplotypes to be associated with CHD. The present
study demonstrated no evidence of association between individual SELP or PSGL-1 SNPs or haplotypes with incident CHD. However,
this study replicates absence of association of the mostly studied SNP, T715P, previously reported in individuals with African
origin. 相似文献
3.
Paulo Bentes de Carvalho-Neto Marcelo dos Santos Marcos Brasilino de Carvalho Ana Maria da Cunha Mercante Viviane Priscila Pina dos Santos Patrícia Severino Eloiza Helena Tajara Iuri Drumond Louro Adriana Madeira álvares da Silva-Conforti 《PloS one》2013,8(7)
FAS/FASL altered expression may cause tumor protecting immunomodulation, with a direct impact on patient prognosis. FAS expression was studied in 60 squamous cell carcinomas of the oral cavity. FAS expression did not show a significant association with tumor histopathological characteristics, but was significantly associated with lymph node positivity. FAS expression was significantly associated with disease specific death and negative FAS expression was an independent risk factor, increasing risk 4 times when compared to positive expression. When FAS and FASL expression results were combined, we were able to define high, intermediate and low risk profiles. Disease-free and disease-specific survival were significantly correlated with FAS/FASL expression profiles. The high risk category was an independent marker for earlier disease relapse and disease-specific death, with approximately 4- and 6-fold increased risk, respectively, when compared to the low risk profile. Risk profiles based on FAS/FASL expression showed that high risk was significantly associated with increased disease relapse and death, as well as shorter disease-free or disease-specific survival. This categorization, added to patient clinical data, may facilitate the choice of therapy, minimizing treatment failure and increasing disease control. 相似文献
4.
Marcelle Bens Sophie Vimont Sanae Ben Mkaddem Cécilia Chassin Jean‐Michel Goujon Viviane Balloy Michel Chignard Catherine Werts Alain Vandewalle 《Cellular microbiology》2014,16(10):1503-1517
Uropathogenic Escherichia coli (UPEC) colonizing kidneys is the main cause of acute pyelonephritis. TLR5 that senses flagellin was shown to be highly expressed in the bladder and to participate in host defence against flagellated UPEC, although its role in kidneys still remains elusive. Here we show that TLR5 is expressed in renal medullary collecting duct (MCD) cells, which represent a preferential site of UPEC adhesion. Flagellin, like lipopolysaccharide, stimulated the production of the chemoattractant chemokines CXCL1 and CXCL2, and subsequent migration capacity of neutrophils in cultured wild‐type (WT) and Tlr4?/? MCDs, but not in Tlr5?/? MCDs. UPEC can translocate across intact MCD layers without altering tight junctions. Strikingly, the invasion capacity and transcellular translocation of the UPEC strain HT7 were significantly lower in Tlr5?/? than in WT MCDs. The non‐motile HT7ΔfliC mutant lacking flagellin also exhibited much lower translocation capacities than the HT7 isolates. Finally, Tlr5?/? kidneys exhibited less infiltrating neutrophils than WT kidneys one day after the transurethral inoculation of HT7, and greater delayed renal bacterial loads in the day 4 post‐infected Tlr5?/? kidneys. Overall, these findings indicate that the epithelial TLR5 participates to renal antibacterial defence, but paradoxically favours the translocation of UPEC across intact MCD cell layers. 相似文献
5.
Ortiga-Carvalho TM Oliveira Kde J Morales MM Martins VP Pazos-Moura CC 《Experimental biology and medicine (Maywood, N.J.)》2003,228(9):1083-1088
Neuromedin B (NB), a bombesin-like peptide, highly concentrated in rat pituitary gland, has been shown to act as an autocrine/paracrine inhibitor of thyrotropin (TSH) release. Here it is shown that a single injection of thyrotropin-releasing hormone (TRH, 1.5 microg/animal, ip), the most important stimulator of thyrotropin secretion, induced approximately 35%-45% decrease in pituitary NB content in rats, as well as an important decrease in NB mRNA at 15 and 30 min (P < 0.05). Acute cold exposure, which induced higher serum TSH with a peak at 30 min, was associated with progressive decrease in pituitary NB, starting at 15 min although only reaching statistical significance after 2 hr (P < 0.05). Although not involved in the early peak, the decrease in NB may be contributing to maintenance of higher serum TSH in cold-exposed animals compared with those at room temperature. Fed rats, 2 hr after being subcutaneously injected with mouse recombinant leptin (8 microg /100 g body wt), showed a x2 increase in serum TSH and 38% reduction in pituitary NB (P < 0.05). In conclusion, TRH and leptin rapidly decreased pituitary NB and it is first proposed that the reduction of the inhibitory tonus of NB on TSH release will ultimately contribute to the amplification of TSH secretion elicited by TSH secretagogues. 相似文献
6.
Schemberger MO Bellafronte E Nogaroto V Almeida MC Schühli GS Artoni RF Moreira-Filho O Vicari MR 《Genetica》2011,139(11-12):1499-1508
Parodon and Apareiodon lack sufficiently consistent morphological traits to be considered a monophyletic group in Parodontidae. Species within this family are either sex-homomorphic or sex-heteromorphic (i.e., lacking a differentiated sex chromosome system, ZZ/ZW or ZZ/ZW(1)W(2)). In this study, a DNA fragment from the heterochromatin segment of the W chromosome of Apareiodon ibitiensis (named WAp) was microdissected and used for in situ mapping of nine Parodontidae species. The species were also characterized using a satellite DNA probe (pPh2004). The species were phylogenetically clustered according to 17 characters, which were examined by both classical and molecular cytogenetic techniques. Given the present results, the single ZZ/ZW sex chromosome system seems to have been derived from a paracentric inversion of a terminal WAp site onto the proximal regions of the short arms of a metacentric chromosome pair, followed by WAp site amplification. We reason that these events restrained recombination and favored differentiation of the W chromosome in some species. Moreover, co-hybridization experiments targeting the WAp and pPh2004 repetitive DNA sites of A. affinis suggest that the ZZ/ZW(1)W(2) sex chromosomes of this species may have arisen from a translocation between the proto-sex chromosome and an autosome. Our phylogenetic analysis corroborates the hypothesis of sex chromosome differentiation and establishes groups of closely related species. The phylogenetic reorganization in response to these new data supports the presence of internal monophyletic groups within Parodontidae. 相似文献
7.
Viviane S. Moreira Virgínia L. F. Soares Raner J. S. Silva Aurizangela O. Sousa Wagner C. Otoni Marcio G. C. Costa 《Physiology and Molecular Biology of Plants》2018,24(3):369-378
Bixa orellana L., popularly known as annatto, produces several secondary metabolites of pharmaceutical and industrial interest, including bixin, whose molecular basis of biosynthesis remain to be determined. Gene expression analysis by quantitative real-time PCR (qPCR) is an important tool to advance such knowledge. However, correct interpretation of qPCR data requires the use of suitable reference genes in order to reduce experimental variations. In the present study, we have selected four different candidates for reference genes in B. orellana, coding for 40S ribosomal protein S9 (RPS9), histone H4 (H4), 60S ribosomal protein L38 (RPL38) and 18S ribosomal RNA (18SrRNA). Their expression stabilities in different tissues (e.g. flower buds, flowers, leaves and seeds at different developmental stages) were analyzed using five statistical tools (NormFinder, geNorm, BestKeeper, ΔCt method and RefFinder). The results indicated that RPL38 is the most stable gene in different tissues and stages of seed development and 18SrRNA is the most unstable among the analyzed genes. In order to validate the candidate reference genes, we have analyzed the relative expression of a target gene coding for carotenoid cleavage dioxygenase 1 (CCD1) using the stable RPL38 and the least stable gene, 18SrRNA, for normalization of the qPCR data. The results demonstrated significant differences in the interpretation of the CCD1 gene expression data, depending on the reference gene used, reinforcing the importance of the correct selection of reference genes for normalization. 相似文献
8.
WOX14 promotes bioactive gibberellin synthesis and vascular cell differentiation in Arabidopsis 下载免费PDF全文
Erwan Denis Nadia Kbiri Viviane Mary Gaëlle Claisse Natalia Conde e Silva Martin Kreis Yves Deveaux 《The Plant journal : for cell and molecular biology》2017,90(3):560-572
Procambial and cambial stem cells provide the initial cells that allow the formation of vascular tissues. WOX4 and WOX14 have been shown to act redundantly to promote procambial cell proliferation and differentiation. Gibberellins (GAs), which have an important role in wood formation, also stimulate cambial cell division. Here we show that the loss of WOX14 function phenocopies some traits of GA‐deficient mutants that can be complemented by exogenous GA application, whereas WOX14 overexpression stimulates the expression of GA3ox anabolism genes and represses GA2ox catabolism genes, promoting the accumulation of bioactive GA. More importantly, our data clearly indicate that WOX14 but not WOX4 promotes vascular cell differentiation and lignification in inflorescence stems of Arabidopsis. 相似文献
9.
10.
Ogaki Mayara B. Coelho Lívia C. Vieira Rosemary Neto Arthur A. Zani Carlos L. Alves Tânia M. A. Junior Policarpo A. S. Murta Silvane M. F. Barbosa Emerson C. Oliveira Jaquelline G. Ceravolo Isabela P. Pereira Patrícia O. Cota Betania B. Viana Roberta O. Alves Viviane S. Rosa Luiz H. 《Extremophiles : life under extreme conditions》2020,24(2):227-238
Extremophiles - We accessed the culturable mycobiota present in marine sediments at different depths in Antarctica Ocean. Acremonium fusidioides, Penicillium allii-sativi, Penicillium chrysogenum,... 相似文献