RESUMEN
Seven IN Absentia (SINA) is a small family of genes coding for ubiquitin-ligases that play major roles in regulating various plant growth and developmental processes, as well as in plant response to diverse biotic and abiotic stresses. Here, we studied the SINA genes family in bread wheat Triticum aestivum which is a culture of major importance for food security worldwide. One hundred and forty-one SINA family genes have been identified in bread wheat and showed that their number is very high compared to other plant species such as A. thaliana or rice. The expansion of this family seems to have been more important in monocots than in eudicots. In bread wheat, the chromosome 3 distal region is the site of a massive amplification of the SINA family, since we found that 83 of the 141 SINA genes are located on this chromosome in the Chinese Spring variety. This amplification probably occurred as a result of local duplications, followed by sequences divergence. The study was then extended to 4856 SINA proteins from 97 plant species. Phylogenetic and structural analyses identified a group of putative ancestral SINA proteins in plants containing a 58 aminoacid specific signature. Based on sequence homology and the research of that "Ancestral SINA motif" of 58 amino acids, a methodological process has been proposed and lead to the identification of functional SINA genes in a large family such as the Triticae that might be used for other species. Finally, tis paper gives a comprehensive overview of wheat gene family organization and functionalization taken the SINA genes as an example.
Asunto(s)
Genes de Plantas , Triticum , Pan , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Filogenia , Proteínas de Plantas/genética , Estrés Fisiológico/genéticaRESUMEN
Plant defense inducers (PDIs) are booming and attractive protection agents designed to immunostimulate the plant to reduce subsequent pathogen colonization. The structure-PDI activity relationships of four flavan-3-ols: Epicatechin (EC), Epigallocatechin (EGC), Epicatechin gallate (ECG), Epigallocatechin gallate (EGCG) and Gallotannic acid (GTA) were investigated in both whole plant and suspension cell systems. ECG, EGCG, and GTA displayed elicitor activities. Their infiltration into tobacco leaves induced hypersensitive reaction-like lesions with topical scopoletin and PR-target transcript accumulations. On the contrary, EC and EGC infiltrations fail to trigger the biochemical changes in tobacco tissues. The tobacco BY-2 cells challenged with ECG, EGCG, or GTA led to alkalinization of the BY-2 extracellular medium while EC and EGC did not trigger any pH variation. This work provides evidence that the esterified gallate pattern is as an essential flavonoid entity to induce plant defense reactions in tobacco. The phytoprotective properties of the esterified gallate-free EC and the esterified gallate-rich GTA were evaluated on the tobacco/Phytophthora parasitica var. nicotianae (Ppn) pathosystem. Tobacco treatment with EC did not induce significant protection against Ppn compared to GTA which shows antimicrobial properties on Ppn and decreases the infection on GTA-infiltrated and -sprayed wild-type leaves. GTA protection was impaired in the transgenic NahG tobacco plants, suggesting that protection was mediated by salicylic acid.
Asunto(s)
Flavonoides/química , Flavonoides/farmacología , Nicotiana/efectos de los fármacos , Enfermedades de las Plantas/inmunología , Catequina/análogos & derivados , Catequina/química , Catequina/farmacología , Estructura Molecular , Phytophthora/fisiología , Enfermedades de las Plantas/microbiología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Nicotiana/inmunología , Nicotiana/microbiologíaRESUMEN
This study investigated the environmental fate of myrigalone A, a light absorbing natural herbicide found on leaves and fruits of Myrica gale. Myrigalone A was irradiated in water and as a dry solid deposit to simulate reactions on leaves, alone and in the presence of the terpenes generated by Myrica gale. The phototransformation was fast ( t1/2 = 35 min in water). Analyses by liquid chromatography coupled to high resolution orbitrap electrospray mass spectrometry (MS) and gas chromatography-MS revealed the formation of 11 photoproducts in water and solid and 9 in gaseous phase. Some were detected in the leaf glands and oil covering the fruits of Myrica gale, which suggested that photodegradation occurred in the field. Moreover, myrigalone A photoinduced the oxidation of terpenes that in turn protected it against photolysis. This highlights the need for additional research on the effect of terpenes on the photodegradation of pesticides on vegetation.
Asunto(s)
Chalconas/química , Myrica/efectos de la radiación , Feromonas/química , Chalconas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Cinética , Estructura Molecular , Myrica/química , Myrica/metabolismo , Oxidación-Reducción/efectos de la radiación , Feromonas/metabolismo , Fotólisis/efectos de la radiación , Terpenos/química , Terpenos/metabolismoRESUMEN
Alkyl gallates showed elicitor activities on tobacco in both whole plants and cell suspensions. Methyl gallate (MG), ethyl gallate (EG), and propyl gallate (PG) infiltration into tobacco leaves induced hypersensitive reaction-like lesions and topical production of autofluorescent compounds revealed under UV light. When sprayed on tobacco plants at 5 mM, EG promoted upregulation of defense-related genes such as the antimicrobial PR1, ß-1,3-glucanase PR2, Chitinase PR3, and osmotin PR5 target genes. Tobacco BY-2 cells challenged with EG underwent cell death in 48 h, which was significantly reduced in the presence of the protease inhibitor aprotinin. The three alkyl gallates all caused alkalinization of the BY-2 extracellular medium, whereas gallic acid did not trigger any pH variation. Using EGTA or LaCl3, we showed that Ca2+ mobilization occurred in BY-2 cells elicited with EG. Overall, our findings are the first evidence of alkyl gallate elicitor properties with early perception events on the plasma membrane, potential hypersensitive reactions, and PR-related downstream defense responses in tobacco.
Asunto(s)
Ácido Gálico/análogos & derivados , Nicotiana/efectos de los fármacos , Muerte Celular , Ácido Gálico/farmacología , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nicotiana/citología , Nicotiana/genética , Nicotiana/metabolismoRESUMEN
The plant activator acibenzolar-S-methyl (BTH) undergoes phototransformation when exposed to solar radiation. Here we investigated the changes in its elicitation properties on BY-2 tobacco cells at different stages of the photochemical reaction. Both pure BTH and formulated BTH were irradiated in controlled conditions to achieve different extents of conversion. Both pure BTH (900 µM) and Bion® (0.4 g.L-1) induced BY-2 cell death, but BTH photoconverted to an extent of 25 ± 3% lowered the cell death rate. A kinetic study of ß-1,3-glucanase and chitinase activities was conducted on BY-2 extracellular medium. Exposure of tobacco cells to either pure BTH or Bion® resulted in a significant increase in the activities of both defense enzymes, which peaked 48 h after the treatment. The pathogenesis-related (PR) protein activities were quantified 48 h after elicitation for a range of phototransformed BTH solutions. The enzyme activities were reduced when BY-2 cells were treated with solutions in which BTH conversion was 22 ± 3%, 42 ± 3% and 100 ± 3%, but were not affected by the solution in which BTH was phototransformed at 60%, suggesting that some of the secondary photoproducts also exhibit eliciting properties. Solar irradiation of BTH thus impairs its elicitation properties, but this impairment depends strongly on the extent of phototransformation.
Asunto(s)
Nicotiana/metabolismo , Células Vegetales/metabolismo , Tiadiazoles , Biotransformación , Tiadiazoles/farmacocinética , Tiadiazoles/farmacologíaRESUMEN
Xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl (1), the main product of sulcotrione phototransformation on plant leaves, was slowly hydrolyzed into 2-hydroxy-4-methylsulfonylbenzoic acid (2) and 1,3-cyclohexanedione (3) in aqueous solution. Interestingly, the rate of hydrolysis was significantly enhanced in the presence of roots of monocotyledonous plants, while the same treatment showed adverse effects on broadleaf weeds. Root growth enhancement varied according to the plant species and concentrations of compound 2, as shown with Zea mays roots. Compound 2 is a derivative of salicylic acid that is known to be a plant signaling messenger. Compound 2 was, therefore, able to mimic some known effects of this phytohormone. This work showed that a pesticide like sulcotrione was transformed into a compound exhibiting a positive impact on plant growth. This study exemplified a rarely reported situation where chemical and biological chain reactions transformed a xenobiotic into a compound exhibiting potential beneficial effects.
Asunto(s)
Ciclohexanonas/química , Herbicidas/química , Mesilatos/química , Raíces de Plantas/crecimiento & desarrollo , Zea mays/efectos de los fármacos , Ciclohexanonas/farmacología , Herbicidas/farmacología , Hidrólisis , Mesilatos/farmacología , Estructura Molecular , Fotólisis , Raíces de Plantas/efectos de los fármacos , Zea mays/crecimiento & desarrolloRESUMEN
The cytotoxic effects of 2-chloro-4-mesylbenzoic acid (CMBA) and xanthene-1,9-dione-3,4-dihydro-6-methylsulphonyl (XDD), the two main photoproducts of sulcotrione, were investigated on Allium root meristematic cells at different concentrations. Degradation of sulcotrione was correlated to mitotic index decrease, together with increasing anomaly and c-mitosis frequencies. Mitotic index significantly decreased with increasing XDD and CMBA concentrations. Cell frequency with abnormal chromosomes increased with CMBA or XDD application rates. In contrast, CMBA induced a low micronucleus rate even for high concentrations while XDD increased the micronucleus ratio. C-mitoses, chromosomal aberrations due to an inactivation of the spindle, were enhanced by CMBA treatments but not by XDD. The photochemical degradation process of the pesticide can change the risk for the environment.
Asunto(s)
Allium/efectos de los fármacos , Ciclohexanonas/química , Ciclohexanonas/toxicidad , Herbicidas/química , Mesilatos/química , Mesilatos/toxicidad , Allium/genética , Herbicidas/toxicidad , Pruebas de Micronúcleos , Mitosis/efectos de los fármacos , Índice Mitótico , FotólisisRESUMEN
Grape marc extract (GME) acts as an elicitor of plant defense responses. This study analyzed GME-induced plant defense reactions in NahG transgenic tobacco. Leaf infiltration of NahG leaves revealed HR-like reactions with reduced lesions and weak deployment of autofluorescent compounds in the surrounding infiltrated tissues. The ß-1,3-glucanase PR2-, endochitinase PR3-, and osmotin PR5-target transcript levels were strongly lowered in NahG leaves, and the mutant failed to accumulate the antimicrobial PR1 transcripts. GME-induced protection against Phytophthora parasitica var. nicotianae (Ppn) was evaluated on tobacco leaves. The antimicrobial properties of GME against Ppn were evidenced using a range of in vitro tests. GME-sprayed wild-type leaves showed reduced infection areas, whereas GME failed to induce a protective effect against Ppn in NahG leaves. The results suggest that GME-induced plant defense reactions in tobacco plants was mediated by salicylic acid (SA) and that GME-induced protection against Ppn could be the combined result of antimicrobial and defense actions.
Asunto(s)
Fungicidas Industriales/farmacología , Nicotiana/efectos de los fármacos , Nicotiana/inmunología , Phytophthora/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Extractos Vegetales/farmacología , Plantas Modificadas Genéticamente/inmunología , Vitis/química , Phytophthora/fisiología , Enfermedades de las Plantas/inmunología , Hojas de la Planta/inmunología , Hojas de la Planta/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/inmunología , Plantas Modificadas Genéticamente/efectos de los fármacos , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/microbiología , Nicotiana/genética , Nicotiana/microbiologíaRESUMEN
Water extracts from winery by-products exhibited significant plant defense inducer properties. Experiments were conducted on three marc extracts containing various amounts of polyphenols and anthocyanins. Infiltration of red, white and seed grape marc extracts into tobacco leaves induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining. The infiltration zones and the surrounding areas revealed accumulation of autofluorescent compounds under UV light. Leaf infiltration of the three winery by-product extracts induced defense gene expression. The antimicrobial PR1, ß-1,3-glucanase PR2, and chitinase PR3 target genes were upregulated locally in tobacco plants following grape marc extract treatments. The osmotin PR5 transcripts accumulated as well in red marc extract treated-tobacco leaves. Overall, the winery by-product extracts elicited an array of plant defense responses making the grape residues a potential use of high value compounds.
Asunto(s)
Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Nicotiana/efectos de los fármacos , Fitoquímicos/química , Extractos Vegetales/química , Vitis/química , Antocianinas/química , Muerte Celular , Industria de Alimentos , Fenoles/química , Hojas de la Planta/citología , Hojas de la Planta/efectos de los fármacos , Nicotiana/genética , Aguas Residuales/química , VinoRESUMEN
Contamination by toxic agents in the environment has become matters of concern to agricultural countries. Sulcotrione, a triketone herbicide used to control dicotyledonous weeds in maize culture is rapidly photolyzed on plant foliage and generate two main photoproducts the xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl and 2-chloro-4-mesylbenzoic acid (CMBA). The aim of this study was to analyze the potential toxicity of the herbicide and the irradiated herbicide cocktail. Cytotoxicity and genotoxicity of non irradiated and irradiated sulcotrione were investigated in Allium cepa test. The sulcotrione irradiation was monitored under sunlight simulated conditions to reach 50% of phototransformation. Concentrations of sulcotrione in the range 5 × 10(-)(9)-5 × 10(-)(5)M were tested. Cytological analysis of root tips cells showed that both non irradiated and irradiated sulcotrione caused a dose-dependent decrease of mitotic index with higher cytotoxicity for the irradiated herbicide which can lead to 24.2% reduction of mitotic index compared to water control. Concomitantly, chromosomal aberrations were observed in A.cepa root meristems. Both non irradiated sulcotrione and irradiated sulcotrione induced a dose-dependent increase of chromosomal abnormalities frequencies to a maximal value of 33.7%. A saturating effect in anomaly frequencies was observed in meristems treated with high concentrations of non irradiated sulcotrione only. These data suggest that photolyzed sulcotrione cocktail have a greater cytotoxicity and genotoxicity than parent molecule and question about the impact of photochemical process on environment.
Asunto(s)
Ciclohexanonas/toxicidad , Meristema/efectos de los fármacos , Mesilatos/toxicidad , Cebollas/efectos de los fármacos , Cebollas/genética , Plaguicidas/toxicidad , Aberraciones Cromosómicas/inducido químicamente , Meristema/genética , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genéticaRESUMEN
Plant protection based on novel alternative strategies is a major concern in agriculture to sustain pest management. The marc extract of red grape cultivars reveals plant defence inducer properties. Treatment with grape marc extract efficiently induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining of tobacco leaves. Examination of the infiltration zone and the surrounding areas under UV light revealed the accumulation of autofluorescent compounds. Both leaf infiltration and a foliar spray of the red grape extract on tobacco leaves induced defence gene expression. The PR1 and PR2 target genes were upregulated locally and systemically in tobacco plants following grape marc extract treatment. The grape extract elicited an array of plant defence responses making this natural compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable agriculture and environmentally friendly practices.
Asunto(s)
Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Nicotiana/genética , Extractos Vegetales/toxicidad , Hojas de la Planta/química , Vitis/química , Muerte Celular/efectos de los fármacos , Genes de Plantas , ARN de Planta/genética , Transducción de Señal , Nicotiana/efectos de los fármacos , Nicotiana/metabolismo , Regulación hacia ArribaRESUMEN
Kinetics of stress responses to Cd exposure (50, 100 and 200 µM) expanding from 12 to 48 h were studied in roots of hydroponically cultivated-Vicia faba seedlings. The heavy metal induced toxicity symptoms and growth arrest of Vicia roots gradually to the Cd concentration and duration of the treatment. The intracellular oxidative stress was evaluated with the H(2)O(2) production. The H(2)O(2) content increased gradually with the sequestered Cd and root growth inhibition. Lipid peroxidation-evidenced by malondialdehyde (MDA) content and Evans blue uptake-and genotoxicity-evidenced by mitotic index (MI) and micronuclei (MCN) values-were concomitantly investigated in root tips. By 12 h, root meristematic cells lost 15% of their mitotic activity under 50 or 100 µM Cd treatment and 50% under 200 µM Cd treatment and led cells with MCN, while the MDA content and Evans blue absorption were not affected. The loss of membrane integrity occurred subsequently by 24 h. The increase in MDA content in root cells treated with 50, 100 and 200 µM Cd was significantly higher than the control. By 48 h, the MDA content increased 134, 178 or 208% in root cells treated with 50, 100 and 200 µM Cd, respectively. The Evans blue absorption was also affected by 24 h in roots when treated with 200 µM Cd and gradually increase by 48 h with the Cd concentration of the treatment. The decrease of mitotic activity triggered by 12 h was even higher by 24 h and the MI reduced to 44, 56 or 80% compared to the control in the three different Cd concentrations tested. The different kinetics of early in vivo physiological and cytogenetic responses to Cd might be relevant to the characterization of its toxicity mechanisms in disrupting primarily the mitosis process.
Asunto(s)
Cadmio/toxicidad , Peroxidación de Lípido/efectos de los fármacos , Mutágenos/toxicidad , Raíces de Plantas/efectos de los fármacos , Vicia faba/efectos de los fármacos , Cadmio/metabolismo , División Celular/efectos de los fármacos , Aberraciones Cromosómicas/inducido químicamente , Relación Dosis-Respuesta a Droga , Peróxido de Hidrógeno/metabolismo , Mutágenos/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidad , Vicia faba/crecimiento & desarrollo , Vicia faba/metabolismoRESUMEN
The molecular responses of hydroponically cultivated tomato plants to As(V) or Cr(VI) were assessed by transcript accumulation analysis of genes coding for products potentially involved in heavy metal tolerance. A quantitative real-time PCR experiment was performed with Hsp90-1, MT2- and GR1-like protein genes using RNA isolated from tomato roots or shoots treated for 24h with As(V) or Cr(VI) at concentrations ranging from 80 to 640 microM. Both transient metallic treatments induced Hsp90-1 transcript accumulation in tomato plants. MT2- and GR1-like transcripts accumulated in tomato roots treated with As(V) but were only slightly affected by Cr(VI) treatment. Tomatoes showed phenotypic symptoms to heavy metal toxicity when plants were exposed to Cr(VI) but not As(V). Plant lethality was observed at 1280 microM Cr(VI), indicating that tomatoes were more tolerant to As than Cr stress under the experimental conditions used here.
Asunto(s)
Arsénico/toxicidad , Cromo/toxicidad , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Solanum lycopersicum/efectos de los fármacos , Solanum lycopersicum/genética , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/genética , Bases de Datos de Ácidos Nucleicos , Hidroponía , ARN Mensajero/genética , ARN Mensajero/metabolismo , Homología de Secuencia de Ácido Nucleico , SolucionesRESUMEN
To identify genes expressed during root enlargment during the early vegetative growth of chicory (Cichorium intybus L.), we used the cDNA-AFLP technology. The radial pattern of chicory roots was investigated by histological analysis to determine the spatial vascular cambium setting. In young plantlets, serial root sections showed that differentiation of secondary tissues occurred along a gradient extending from the apex to the crown. The cDNA-AFLP technique was carried out on total mRNAs extracted from root tissues producing secondary structures and root tissues developing primary structures only. This study reports on the isolation of two transcript-derived fragments (TDFs) referred to as Y-16 and Y-21. Sequence analysis at the protein level showed that Y-16 carries a sequence highly homologous (93% identities) to the amino acid transporter-like protein 1 (AATL 1) from Arabidopsis and Y-21 presents 72% identity to AAD25141.1 Arabidopsis protein. The expression pattern of both these TDFs was analysed by northern blot and showed an over-expression during early development of chicory roots.