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切り花として世界的に人気があるトルコギキョウ（Eustoma grandiflorum (Raf.)Shinn.）は胚が活動し始めてから本葉が4枚展開するまでの幼苗期に高温に遭遇するとロゼット化する（Ohkawa et al．，1991；Harbaugh，1992）．いったんロゼット化すると...
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切り花として世界的に人気があるトルコギキョウ（Eustoma grandiflorum (Raf.)Shinn.）は胚が活動し始めてから本葉が4枚展開するまでの幼苗期に高温に遭遇するとロゼット化する（Ohkawa et al．，1991；Harbaugh，1992）．いったんロゼット化すると低温に遭遇しない限り抽だいしない（Azuma and Inubushi，1988；Ohkawaetal．，1991；Pergola，1992）．そのため，高温期に育苗して秋や冬に切り花を得る作型では，高冷地育苗，夜冷育苗（Kobayashi and Kondo，1990；Miyoshi et al．，1990），冷房育苗（Azuma and Inubushi，1988；Ishimitsu and Asano，1990），種子の低温処理（Kageyama et al．，1990；Tanigawa et al．，1999）によるロゼット回避，幼苗の低温処理によるロゼット打破（Ohkawaetal．，1994；Takeda，1995）などの実用的方法が開発されてきた．
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A bizarre virus-like symptom of a leaf rosette formed by dense small leaves on branches of wild roses (Rosa multifloraThunb.), designated as wild rose leaf rosette disease' (WRLRD), was observed in China. To investigate the presum...
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A bizarre virus-like symptom of a leaf rosette formed by dense small leaves on branches of wild roses (Rosa multifloraThunb.), designated as wild rose leaf rosette disease' (WRLRD), was observed in China. To investigate the presumed causal virus, a wild rose sample affected by WRLRD was subjected to deep sequencing of small interfering RNAs (siRNAs) for a complete survey of the infecting viruses and viroids. The assembly of siRNAs led to the reconstruction of the complete genomes of three known viruses, namely Apple stem grooving virus (ASGV), Blackberry chlorotic ringspot virus (BCRV) and Prunus necrotic ringspot virus (PNRSV), and of a novel virus provisionally named rose leaf rosette-associated virus' (RLRaV). Phylogenetic analysis clearly placed RLRaV alongside members of the genus Closterovirus, family Closteroviridae. Genome organization of RLRaV RNA (17653 nucleotides) showed 13 open reading frames (ORFs), except ORF1 and the quintuple gene block, most of which showed no significant similarities with known viral proteins, but, instead, had detectable identities to fungal or bacterial proteins. Additional novel molecular features indicated that RLRaV seems to be the most complex virus among the known genus members. To our knowledge, this is the first report of WRLRD and its associated closterovirus, as well as two ilarviruses and one capilovirus, infecting wild roses. Our findings present novel information about the closterovirus and the aetiology of this rose disease which should facilitate its control. More importantly, the novel features of RLRaV help to clarify the molecular and evolutionary features of the closterovirus.
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Background The unique ‘mandarin jacket’ leaf shape is the most famous trait of Liriodendron chinense and this characteristic gives L. chinense aesthetic and landscaping value. However, the underlying regulatory mechanism of gene...
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Background The unique ‘mandarin jacket’ leaf shape is the most famous trait of Liriodendron chinense and this characteristic gives L. chinense aesthetic and landscaping value. However, the underlying regulatory mechanism of genes involved in the leaf development of L. chinense has remained unclear. Methods Based on transcriptome data of leaves at different developmental stages from L. chinense, we identified differentially expression genes (DEGs) functioning in leaf development. A candidate gene named LcCUC2-like (LcCUC2L) had high similarity in sequence with Arabidopsis thaliana CUC2, and used for further research. We isolated the full-length LcCUC2L gene and its promoter from L. chinense. Subsequently, we analyzed the function of the LcCUC2L gene and its promoter activity via transformation into A. thaliana. Results In this study, we found that the LcCUC2L and AtCUC2 are homologous in sequence but not homologous in function. Unlike the role of AtCUC2 in leaf serration and SAM formation, the LcCUC2L mainly regulates cotyledon development and rosette leaf number. Histochemical β-glucuronidase (GUS) staining revealed that LcCUC2L was expressed in the cotyledons of A. thaliana seedlings, indicating that the LcCUC2L may play a role in cotyledon development. Ectopic expression of LcCUC2L resulted in long, narrow cotyledons without petioles, abnormal lamina epidermis cells and defective vascular tissue in cotyledons, and these results were consistent with the LcCUC2L expression pattern. Further analysis showed that overexpression of LcCUC2L also induced numerous rosette leaves. Also, LcCUC2L and other related genes showed a severe response in L. chinense by introducing exogenous auxin stimulation, partly revealed that LcCUC2L affects the leaf development by regulating the auxin content. Conclusions These results suggest that LcCUC2L may play a critical role in leaf development and morphogenesis in L. chinense, and our findings provide insight into the molecular mechanisms of leaf development in L. chinense.
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Oenothera L. (evening primrose) has been suggested as a new seed-oil crop, source of gamma-linolenic acid, with uses herbal medicine industries. We compared the critical size for reproduction and the biomass allocation patterns du...
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Oenothera L. (evening primrose) has been suggested as a new seed-oil crop, source of gamma-linolenic acid, with uses herbal medicine industries. We compared the critical size for reproduction and the biomass allocation patterns during three phenological stages of a wild (O. mendoncinensis) and a domesticated species (O. biennis). Rosettes of Oenothera biennis attained a critical size after two years in the field, while the wild species reproduced during the first year. Early bolting is a comprehensive strategy for indeterminate species growing in a short season environment, because it extends the flowering period but at the same time, the short vegetative period limits carbohydrates stores available for reproductive growth, and therefore, yield. Reproductive effort caused in both species a significant depletion of reserves during the flowering. Leaves and roots biomass declined by senescence after bolting in the wild species. In conclusion, yield improvement of wild species of Oenothera could be obtained by selecting plants with higher accumulation of vegetative biomass and delayed senescence that guarantees greater photosynthetic capacity after flowering. (C) 2014 Elsevier B.V. All rights reserved.
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Plant cells are surrounded by cell walls playing many roles during development and in response to environmental constraints. Cell walls are mainly composed of polysaccharides (cellulose, hemicelluloses and pectins), but they also ...
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Plant cells are surrounded by cell walls playing many roles during development and in response to environmental constraints. Cell walls are mainly composed of polysaccharides (cellulose, hemicelluloses and pectins), but they also contain proteins which are critical players in cell wall remodeling processes. Today, the cell wall proteome of Arabidopsis thaliana, a major dicot model plant, comprises more than 700 proteins predicted to be secreted (cell wall proteinsCWPs) identified in different organs or in cell suspension cultures. However, the cell wall proteome of rosettes is poorly represented with only 148 CWPs identified after extraction by vacuum infiltration. This new study allows enlarging its coverage. A destructive method starting with the purification of cell walls has been performed and two experiments have been compared. They differ by the presence/absence of protein separation by a short 1D-electrophoresis run prior to tryptic digestion and different gradient programs for peptide separation before mass spectrometry analysis. Altogether, the rosette cell wall proteome has been significantly enlarged to 361 CWPs, among which 213 newly identified in rosettes and 57 newly described. The identified CWPs fall in four major functional classes: 26.1% proteins acting on polysaccharides, 11.1% oxido-reductases, 14.7% proteases and 11.7% proteins possibly related to lipid metabolism.
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The rare plant Rheum palaestinum (Polygonaceae)
is a perennial hemicryptophyte that grows during the rainy winter in desert mountainous areas in Israel and Jordan that receive an average annual rainfall of ca. 75 mm. It produces ...
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The rare plant Rheum palaestinum (Polygonaceae)
is a perennial hemicryptophyte that grows during the rainy winter in desert mountainous areas in Israel and Jordan that receive an average annual rainfall of ca. 75 mm. It produces between one and four large round leaves that are tightly attached to the ground and form large rosettes of up to 1 m~2. These leaves differ markedly from the typical small leaves of most desert plants. Moreover, they have a unique 3D morphology resembling a scaled-down mountainous area with well-developed steep drainage systems, raising the question which selective agents were involved in their evolution. We propose that the large leaves collect rainwater that then infiltrates the soil surrounding the root. We measured the seasonal course of leaf growth, examined the area of wet soil surrounding the root after actual and simulated rain, and modeled the water harvesting capacity using the plant leaf area and the weekly precipitation. We show that even in the slightest rains, water flows above the veins to the leaf's base where it irrigates the vertical root. A typical plant harvests more than 4,100 cm~3 of water per year, and enjoys a water regime of about 427 mm/year, equivalent to the water supply in a Mediterranean climate. This is the
first example of self-irrigation by large leaves in a desert plant, creating a leaf-made mini oasis.
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The tank-bromeliad Guzmania monostachia is a heteroblastic epiphyte with great photosynthetic plasticity; however, few studies have investigated the potential relevance of variations in density and structure of trichomes during th...
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The tank-bromeliad Guzmania monostachia is a heteroblastic epiphyte with great photosynthetic plasticity; however, few studies have investigated the potential relevance of variations in density and structure of trichomes during the ontogenesis of tank bromeliads. This study hypothesized that both number and cellular organization of trichomes vary according to tank development in G. monostachia rosettes. The frequency of trichomes and their cellular organization were evaluated in younger, intermediate, and older leaves of both atmospheric and mature-tank rosettes. Both adaxial and abaxial surfaces of different portions along the leaf blade of all the leaves were analyzed. Complementary histochemical analyses were performed with trichomes displaying the highest degree of structural specialization. Atmospheric plants presented the most uniform pattern of trichome distribution and cellular organization, while mature-tank plants showed a greater number of trichomes on the adaxial leaf surface and their cellular structures varied both along the leaf blade and during rosette development. Unlike the simpler arrangement of trichome cells covering all leaves of atmospheric plants, mature-tank rosettes had trichome shields typically formed by more cells, with the portions with the highest degree of specialization in trichome structure being the base of intermediate and older leaves. Histochemical evidence revealed living cells in both ring and wing cells of trichome shields, with specific cell types potentially displaying varied absorptive functions. Therefore, with the tank establishment, there is a shift in which the distribution of trichomes changes and shields of trichomes reach the maximum potential complexity in number of cells.
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Conyza bonariensis (L.) Cronq. is a problematic weed in crop and non-crop areas of California. This problem has been further aggravated by the discovery of herbicide-resistant biotypes. Experiments were conducted in 2012 and 2013 ...
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Conyza bonariensis (L.) Cronq. is a problematic weed in crop and non-crop areas of California. This problem has been further aggravated by the discovery of herbicide-resistant biotypes. Experiments were conducted in 2012 and 2013 in fall and spring, respectively, to determine the efficacy of glyphosate, saflufenacil, and a tank-mixture of saflufenacil + glyphosate on glyphosate-susceptible (GS), glyphosate-resistant (GR), and glyphosate-paraquat-resistant (GPR) biotypes of C. bonariensis. Efficacy of the herbicides were evaluated at three growth stages (5- to 8-leaf seedling, rosette, and bolting); and three day/night temperature regimes (15/10 degrees C, 25/20 degrees C, 35/30 degrees C). Results differed between experiments conducted in the fall and spring. Saflufenacil-alone was more effective in the fall than in spring. All the GS, GR and GPR plants were controlled by saflufenacil-alone at the 5-to 8-leaf stage and rosette stage, but level of control declined at the bolting stage. Better control with saflufenacil-alone and glyphosate-alone was obtained at the 15/10 degrees C and 25/20 degrees C than at the 35/30 degrees C temperature regime. However, a tank mixture of saflufenacil + glyphosate provided good control of the plants at 35/30 degrees C. Efficacy of saflufenacil-alone was inconsistent in spring and varied between the biotypes, but the control with saflufenacil + glyphosate was excellent and consistent between seasons. Glyphosate-alone provided good control of all three biotypes at the 5- to 8-leaf stage in the fall, but the control was poor in spring. Therefore, saflufenacil-alone can provide excellent control of C. bonariensis plants prior to the bolting stage in the fall; but in spring, it will be more effective when applied with glyphosate. (C) 2015 Elsevier Ltd. All rights reserved.
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? 2020 Elsevier B.V.Hydropotes are specialized trichomes in aquatic plants, especially in species of the Nympaeaceae and Cabombaceae; yet their function remains controversial. In this paper, we present data on the hydropotes forme...
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? 2020 Elsevier B.V.Hydropotes are specialized trichomes in aquatic plants, especially in species of the Nympaeaceae and Cabombaceae; yet their function remains controversial. In this paper, we present data on the hydropotes formed on the abaxial surface of young etiolated leaves tightly packed in the rosette at the rhizome flattened apex in Nuphar lutea (L.) Sm. and Nymphaea alba L. (Nymphaeaceae). The edges of the leaf blade are twisted in 3–5 scrolls. In N. lutea, long glandular hydropotes secreting mucilage are formed on the leaf abaxial surface and inside scrolls. In N. alba, non-glandular three-celled hydropotes are present but each leaf inside the rosette is enclosed by a thin film without mucilage. Only three-celled hydropotes are formed on the abaxial epidermis of green floating leaves of both species. Based on the similarity in initiation and first development of glandular hydropotes and hydropotes, we propose to distinguish two types of hydropotes: type I consisting of an apical cell that continues to divide and type II – an apical cell terminating division. This is well demonstrated by the presence of both types of hydropotes in N. lutea. We assume the function of type I is the secretion of mucilage to protect and facilitate growth of young etiolated leaves inside the rosette and that of type II the accumulation and removal of substances of endogenic and exogenic origin, perhaps residuals of metabolism and/or toxins, in green submerged growing and floating mature leaves. Phylogenetic implications of these morphological structures in Nymphaeales are discussed.
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