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Efeitos de herbicidas nos teores de clorofilas de Spirodela punctata
Santos, Durvalina M. M. dos;Pitelli, Robinson A.;Banzatto, David A.;
Planta Daninha , 1999, DOI: 10.1590/S0100-83581999000200001
Abstract: effect of the herbicides on the chlorophyll content of spirodela punctata the aim of this study was to verify the effects of the herbicides butachlor, glyphosate and propanil on content of chlorophyll of aquatic plant spirodela punctata. in order to determine the effect of different concentrations of 0.005; 0.05; 0.5 and 5 mgl-1 (active ingredient) of three herbicides on the contents of chlorophyll a, b and a/b ratio. the bioassays were conducted, for a period of seven full days, in a climatedcontrolled room. chlorophyll content was determined by spectrophotometric absorbency readings at a645 and a663 nm. butachlor reduced chlorophyll b, the glyphosate decrease chlorophyll a, while the propanil reduced chlorophyll a, b and a/b ratio, causing the greatest reduction of the pigments in the species.
Evolution of Genome Size in Duckweeds (Lemnaceae)  [PDF]
Wenqin Wang,Randall A. Kerstetter,Todd P. Michael
Journal of Botany , 2011, DOI: 10.1155/2011/570319
Abstract: To extensively estimate the DNA content and to provide a basic reference for duckweed genome sequence research, the nuclear DNA content for 115 different accessions of 23 duckweed species was measured by flow cytometry (FCM) stained with propidium iodide as DNA stain. The 1C-value of DNA content in duckweed family varied nearly thirteen-fold, ranging from 150 megabases (Mbp) in Spirodela polyrhiza to 1,881?Mbp in Wolffia arrhiza. There is a continuous increase of DNA content in Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia that parallels a morphological reduction in size. There is a significant intraspecific variation in the genus Lemna. However, no such variation was found in other studied species with multiple accessions of genera Spirodela, Landoltia, Wolffiella, and Wolffia. 1. Introduction The Lemnaceae, commonly known as duckweeds, are the smallest, fastest-growing, and simplest of flowering plants. In this globally distributed aquatic monocot family (Figure 1(a)), there are 33 species representing five genera: Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia. Among them, Spirodela is the most ancestral, while Wolffia is the most derived [1]. The individual plants range in size from 1.5?cm long (Spirodela polyrhiza) to less than one millimeter (Wolffia globosa). Therefore, there is a successive reduction of morphological structures in parallel with evolutionary advancement within the family (Figure 1(b)). Duckweeds are not simply miniature versions of larger angiosperms; they represent a highly modified structural organization that resulted from the alteration, simplification, or loss of many morphological and anatomical features [2]. The biomass doubling time of the fastest-growing duckweeds in optimal growth conditions is less than 30 hours, nearly twice as fast as other “fast” growing flowering plants and more than double that of conventional crops [3]. Figure 1: Duckweeds are small aquatic plants that are widely distributed in nature and amenable to culturing in the lab. (a) Duckweeds growing in the Raritan Canal River, Piscataway, NJ, USA. This population of duckweed includes Wolffia, Spirodela, and Lemna. (b) The relative size of Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia in the order of phylogeny as compared to an American Quarter. (c) Sterile Spirodela polyrhiza grown in the Schenk and Hildebrandt basal salt medium. Before the days of Arabidopsis, duckweeds, and more specifically Lemna, were an important model system for plant biology [4]. Since duckweeds are small, morphologically reduced (although with root and
A família Lemnaceae Gray no Pantanal (Mato Grosso e Mato Grosso do Sul), Brasil
POTT, VALI JOANA;CERVI, ARMANDO CARLOS;
Brazilian Journal of Botany , 1999, DOI: 10.1590/S0100-84041999000200007
Abstract: a survey of aquatic plants belonging to the family lemnaceae was carried out in the pantanal wetland (states of mato grosso and mato grosso do sul), represented by nine species, divided into four genera. only two of the reported species had been previously cited for the pantanal, wolffia brasiliensis wedd. and lemna valdiviana phil. the other species are spirodela intermedia w. koch, lemna aequinoctialis welw., l. minuta kunth, in humb., bonp. & kunth, wolffiella welwitschii (hegelm.) monod, w. lingulata (hegelm.) hegelm., w. oblonga (phil.) hegelm., and wolffia columbiana h. karst. lemnaceae occurs in all 10 subregions of the pantanal, with a higher number of species in the nabileque subregion, where soils are more fertile.
A família Lemnaceae Gray no Pantanal (Mato Grosso e Mato Grosso do Sul), Brasil
POTT VALI JOANA,CERVI ARMANDO CARLOS
Brazilian Journal of Botany , 1999,
Abstract: Realizou-se o levantamento de plantas aquáticas da família Lemnaceae no Pantanal do Mato Grosso e Mato Grosso do Sul, a qual está representada por nove espécies, distribuídas em quatro gêneros. Das espécies encontradas somente Wolffia brasiliensis Wedd. e Lemna valdiviana Phil. haviam sido registradas no Pantanal. As demais espécies s o Spirodela intermedia W. Koch, Lemna aequinoctialis Welw., L. minuta Kunth, in Humb., Bonp. & Kunth, Wolffiella welwitschii (Hegelm.) Monod, W. lingulata (Hegelm.) Hegelm., W. oblonga (Phil.) Hegelm. e Wolffia columbiana H. Karst. As Lemnaceae ocorrem em todas as 10 sub-regi es do Pantanal, com o maior número de espécies na sub-regi o do Nabileque, de solos mais férteis.
Chondrodysplasia Punctata  [PDF]
GS Narang,S Arora,MS Khurana,T Singh,Dr Shifali
Journal of Nepal Paediatric Society , 2014, DOI: 10.3126/jnps.v34i1.9110
Abstract: We report a case of two and a half months old male child affected by chondrodysplasia punctata, a rare condition characterized by depressed nasal bridge, hypoplastic distal phalanges and epiphyseal stippling of the bones. DOI: http://dx.doi.org/10.3126/jnps.v34i1.9110 ? J Nepal Paediatr Soc 2014;34(1):57-61
DNA barcoding of the Lemnaceae, a family of aquatic monocots
Wenqin Wang, Yongrui Wu, Yiheng Yan, Marina Ermakova, Randall Kerstetter, Joachim Messing
BMC Plant Biology , 2010, DOI: 10.1186/1471-2229-10-205
Abstract: We developed a simple and rapid DNA-based molecular identification system for the Lemnaceae based on sequence polymorphisms. We compared the barcoding potential of the seven plastid-markers proposed by the CBOL (Consortium for the Barcode of Life) plant-working group to discriminate species within the land plants in 97 accessions representing 31 species from the family of Lemnaceae. A Lemnaceae-specific set of PCR and sequencing primers were designed for four plastid coding genes (rpoB, rpoC1, rbcL and matK) and three noncoding spacers (atpF-atpH, psbK-psbI and trnH-psbA) based on the Lemna minor chloroplast genome sequence. We assessed the ease of amplification and sequencing for these markers, examined the extent of the barcoding gap between intra- and inter-specific variation by pairwise distances, evaluated successful identifications based on direct sequence comparison of the "best close match" and the construction of a phylogenetic tree.Based on its reliable amplification, straightforward sequence alignment, and rates of DNA variation between species and within species, we propose that the atpF-atpH noncoding spacer could serve as a universal DNA barcoding marker for species-level identification of duckweeds.The cost of DNA purification and sequencing has dropped considerably in recent years so that identification of individual species by DNA barcoding has become an independent, subtler method than solely morphological-based classification to distinguish closely related species, which also defines the systematic relationships by analysis of genetic distance. The key element for a robust barcode is a suitable threshold between inter- and intra-specific genetic distances. Sequence variation between species has to be high enough to tell them apart while the distances within species must be low enough for them to cluster together [1]. The mitochondrial coxidase subunit I (COI) gene has proven to be a reliable, cost-effective, and easily recovered barcode marker to
The Mitochondrial Genome of an Aquatic Plant, Spirodela polyrhiza  [PDF]
Wenqin Wang, Yongrui Wu, Joachim Messing
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046747
Abstract: Background Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales. Its complete sequence of the mitochondrial (mt) genome could provide clues for the understanding of the evolution of mt genomes in plant. Methods Spirodela polyrhiza mt genome was sequenced from total genomic DNA without physical separation of chloroplast and nuclear DNA using the SOLiD platform. Using a genome copy number sensitive assembly algorithm, the mt genome was successfully assembled. Gap closure and accuracy was determined with PCR products sequenced with the dideoxy method. Conclusions This is the most compact monocot mitochondrial genome with 228,493 bp. A total of 57 genes encode 35 known proteins, 3 ribosomal RNAs, and 19 tRNAs that recognize 15 amino acids. There are about 600 RNA editing sites predicted and three lineage specific protein-coding-gene losses. The mitochondrial genes, pseudogenes, and other hypothetical genes (ORFs) cover 71,783 bp (31.0%) of the genome. Imported plastid DNA accounts for an additional 9,295 bp (4.1%) of the mitochondrial DNA. Absence of transposable element sequences suggests that very few nuclear sequences have migrated into Spirodela mtDNA. Phylogenetic analysis of conserved protein-coding genes suggests that Spirodela shares the common ancestor with other monocots, but there is no obvious synteny between Spirodela and rice mtDNAs. After eliminating genes, introns, ORFs, and plastid-derived DNA, nearly four-fifths of the Spirodela mitochondrial genome is of unknown origin and function. Although it contains a similar chloroplast DNA content and range of RNA editing as other monocots, it is void of nuclear insertions, active gene loss, and comprises large regions of sequences of unknown origin in non-coding regions. Moreover, the lack of synteny with known mitochondrial genomic sequences shed new light on the early evolution of monocot mitochondrial genomes.
IN VITRO ORGANOGENESIS OF GENTIANA PUNCTATA  [cached]
Anca BUTIUC-KEUL,Alexandra SUTEU,C. DELIU
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2005,
Abstract: Multiplication of Gentiana punctata was obtained from seedlings inoculated into MS medium supplemented with different growth regulators and maize extract. Media supplemented with 2iP or zeatin and IBA ensure a low multiplication. Plant multiplication was slightly improved by addition of maize extract to the culture media. Rhysogenesis was not obtained only on medium supplemented with NAA-1.0 mg/l, 2iP-1.0 mg/l and Me -1.0 mg/l. In vitro plantlets have been transferred to soil after six weeks of culture and acclimatization was successfully obtained.
Keratosis punctata palmaris et plantaris  [cached]
Mohanty Sandip,Gandhi Vijay,Baruah M
Indian Journal of Dermatology, Venereology and Leprology , 1999,
Abstract: A 30-year-old man presented with multiple keratotic papules on palms and soles. The lesions started at the age of 15 from soles. Family history was positive with members in preceding two generations being affected. Cutaneous examination revealed multiple discrete hyperkeratotic papules of variable size on palms and soles. Parakeratosis was absent in histopathology and this ruled out the diagnosis of porokeratosis punctata palmaris et plantaris.
CAROTENOID INVOLVEMENT IN THE REGULATION OF Spirodela polyrhiza (L.) Schleid RESISTANCE TO COLD SHOCK  [PDF]
Sofronova V.E.,Chepalov V.A.,Petrov K.A.
Journal of Stress Physiology & Biochemistry , 2006,
Abstract: Effect of short-time (15 sec, 5, 15, 30 min) cold stress (0,1-0,2oC) at 0,1 μmol photons м-2 s-1 over the Spirodela polyrhiza (L.) Schleid carotenoid composition cultivated under the laboratory conditions has been studied. It is found that the sum of carotenoid pigments of Spirodela polyrhiza (L.) does not change and averages 206,9 ± 11,5 mkg/g in fresh weight. Pool increase of lutein+zeaxanthin (by 5-8%) has been observed in response to a short-time Spirodela polyrhiza cooling with simultaneous decrease of violaxanthin content (by 16%). Violaxanthin de-epoxidation occurs in the minute time spans and the depth of conversion does not depend on the cold shock duration. The data obtained indicate that pigments of the violaxanthin cyclemay participate in realization of transitory emergency protection systems of photosynthetic apparatus by increasing the share of thermal energy dissipation of the absorbed light and preventing singlet oxygenformation.
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