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1.
Plant Mol Biol ; 103(1-2): 113-128, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32086696

RESUMO

KEY MESSAGE: Using a time-course RNA-seq analysis we identified transcriptomic changes during formation of nodule-like structures (NLS) in rice and compared rice RNA-seq dataset with a nodule transcriptome dataset in Medicago truncatula. Plant hormones can induce the formation of nodule-like structures (NLS) in plant roots even in the absence of bacteria. These structures can be induced in roots of both legumes and non-legumes. Moreover, nitrogen-fixing bacteria can recognize and colonize these root structures. Therefore, identifying the genetic switches controlling the NLS organogenesis program in crops, especially cereals, can have important agricultural implications. Our recent study evaluated the transcriptomic response occurring in rice roots during NLS formation, 7 days post-treatment (dpt) with auxin, 2,4-D. In this current study, we investigated the regulation of gene expression occurring in rice roots at different stages of NLS formation: early (1-dpt) and late (14-dpt). At 1-dpt and 14-dpt, we identified 1662 and 1986 differentially expressed genes (DEGs), respectively. Gene ontology enrichment analysis revealed that the dataset was enriched with genes involved in auxin response and signaling; and in anatomical structure development and morphogenesis. Next, we compared the gene expression profiles across the three time points (1-, 7-, and 14-dpt) and identified genes that were uniquely or commonly differentially expressed at all three time points. We compared our rice RNA-seq dataset with a nodule transcriptome dataset in Medicago truncatula. This analysis revealed there is some amount of overlap between the molecular mechanisms governing nodulation and NLS formation. We also identified that some key nodulation genes were not expressed in rice roots during NLS formation. We validated the expression pattern of several genes via reverse transcriptase polymerase chain reaction (RT-PCR). The DEGs identified in this dataset may serve as a useful resource for future studies to characterize the genetic pathways controlling NLS formation in cereals.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/genética , RNA de Plantas , RNA-Seq , Conjuntos de Dados como Assunto , Perfilação da Expressão Gênica , Ontologia Genética , Medicago truncatula/genética , Oryza/anatomia & histologia , Oryza/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Proteínas de Plantas/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Proteínas Quinases/genética , Fatores de Transcrição/metabolismo , Transcriptoma
2.
PLoS One ; 14(12): e0226783, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31869401

RESUMO

Cassava production in Africa is constrained by cassava mosaic disease (CMD) that is caused by the Cassava mosaic virus (CMV). The aim of this study was to evaluate the responses of a range of commonly cultivated West African cassava cultivars to varying inoculum doses of African cassava mosaic virus (ACMV). We grafted 10 cultivars of cassava plants with different inoculum doses of CMV (namely two, four, or six CMD-infected buds) when the experimental plants were 8, 10, or 12 weeks old, using non-inoculated plants as controls. Three cultivars showed disease symptoms when grafted with two buds, and four cultivars showed disease symptoms when grafted with four or six buds. Most cultivars became symptomatic six weeks after inoculation, but one ('TMS92/0326') was symptomatic two weeks after inoculation, and two ('Ntollo' and 'Excel') were symptomatic after four weeks. Root weight tended to be lower in the six-bud than in the two-bud dose, and disease severity varied with plant age at inoculation. These results indicate that the level of CMD resistance in cassava cultivars varies with inoculum dose and timing of infection. This will allow appropriate cultivars to be deployed in each production zone of Africa in accordance with the prevalence of CMD.


Assuntos
Begomovirus/fisiologia , Manihot/fisiologia , Manihot/virologia , Doenças das Plantas/virologia , África , Resistência à Doença , Manihot/anatomia & histologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia , Raízes de Plantas/virologia
3.
Molecules ; 24(17)2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31470508

RESUMO

Viola betonicifolia (Violaceae) is commonly recognized as "Banafsha" and widely distributed throughout the globe. This plant is of great interest because of its traditional, pharmacological uses. This review mainly emphases on morphology, nutritional composition, and several therapeutic uses, along with pharmacological properties of different parts of this multipurpose plant. Different vegetative parts of this plant (roots, leaves, petioles, and flowers) contained a good profile of essential micro- and macronutrients and are rich source of fat, protein, carbohydrates, and vitamin C. The plant is well known for its pharmacological properties, e.g., antioxidant, antihelminthic, antidepressant, anti-inflammatory, analgesic, and has been reported in the treatment of various neurological diseases. This plant is of high economic value. The plant has potential role in cosmetic industry. This review suggests that V. betonicifolia is a promising source of pharmaceutical agents. This plant is also of significance as ornamental plant, however further studies needed to explore its phytoconstituents and their pharmacological potential. Furthermore, clinical studies are needed to use this plant for benefits of human beings.


Assuntos
Analgésicos/química , Anti-Helmínticos/química , Anti-Inflamatórios/química , Antidepressivos/química , Antioxidantes/química , Fármacos Neuroprotetores/química , Viola/química , Analgésicos/isolamento & purificação , Analgésicos/farmacologia , Anti-Helmínticos/isolamento & purificação , Anti-Helmínticos/farmacologia , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Antidepressivos/isolamento & purificação , Antidepressivos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Humanos , Micronutrientes/classificação , Micronutrientes/isolamento & purificação , Fármacos Neuroprotetores/isolamento & purificação , Fármacos Neuroprotetores/farmacologia , Nutrientes/classificação , Nutrientes/isolamento & purificação , Fitoterapia/métodos , Componentes Aéreos da Planta/anatomia & histologia , Componentes Aéreos da Planta/química , Extratos Vegetais/análise , Extratos Vegetais/química , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/química , Plantas Medicinais , Viola/anatomia & histologia
4.
Mar Pollut Bull ; 149: 110536, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31543481

RESUMO

Heavy metal stress changes the morphological and anatomical structure of plant organs. In this study, we determined the anatomical changes and Cd distribution in the roots of Aegiceras corniculatum (L.) Blanco (Black mangrove) under Cd stress. The results showed that Cd levels in A. corniculatum root tissues decreased in the following order: endodermis > pith > xylem > epidermis and exodermis > phloem > cortex. The endodermis secondary casparian strip replaces exodermis casparian strip and plays a role in the "retardation mechanism", which sort of compensates for the missing exodermis retardation effect. The xylem and pith both show high affinity for Cd and contain enriched Cd. This creates a low-Cd environment for phloem and protects the nutrient transport function of the vasculature against Cd toxicity. The present study provides new evidences suggesting that Cd regional enrichment and anatomical structure changes are an adaptive strategy of mangrove plants to HM tolerance.


Assuntos
Cádmio/farmacocinética , Cádmio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Primulaceae/efeitos dos fármacos , Adaptação Biológica/efeitos dos fármacos , Cádmio/análise , Microscopia Eletrônica de Varredura , Epiderme Vegetal/efeitos dos fármacos , Epiderme Vegetal/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/metabolismo , Primulaceae/anatomia & histologia , Primulaceae/metabolismo , Espectrometria por Raios X , Estresse Fisiológico , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Áreas Alagadas , Xilema/efeitos dos fármacos , Xilema/metabolismo
5.
PLoS One ; 14(7): e0214182, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329591

RESUMO

Pearl millet is able to withstand dry and hot conditions and plays an important role for food security in arid and semi-arid areas of Africa and India. However, low soil fertility and drought constrain pearl millet yield. One target to address these constraints through agricultural practices or breeding is root system architecture. In this study, in order to easily phenotype the root system in field conditions, we developed a model to predict root length density (RLD) of pearl millet plants from root intersection densities (RID) counted on a trench profile in field conditions. We identified root orientation as an important parameter to improve the relationship between RID and RLD. Root orientation was notably found to depend on soil depth and to differ between thick roots (more anisotropic with depth) and fine roots (isotropic at all depths). We used our model to study pearl millet root system response to drought and showed that pearl millet reorients its root growth toward deeper soil layers that retain more water in these conditions. Overall, this model opens ways for the characterization of the impact of environmental factors and management practices on pearl millet root system development.


Assuntos
Pennisetum/fisiologia , Raízes de Plantas/fisiologia , Água/metabolismo , Agricultura , Secas , Modelos Biológicos , Pennisetum/anatomia & histologia , Raízes de Plantas/anatomia & histologia , Solo/química , Estresse Fisiológico
6.
Planta ; 250(5): 1461-1474, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31321496

RESUMO

MAIN CONCLUSION: Sesame harbors a large diversity in root morphological and anatomical traits and a high root biomass improves the plant aboveground biomass as well as the seed yield. Sesame provides one of the most nutritious and healthy vegetable oils, sparking an increasing demand of its seeds. However, with the low yield and productivity of sesame, there is still a huge gap between the seed demand and supply. Improving the root system has a high potential to increase crop productivity, but information on the diversity of the sesame root systems is still lacking. In this study, 40 diverse sesame varieties were grown in soil and hydroponics systems and the diversity of the root system was investigated. The results showed that sesame holds a large root morphological and anatomical diversity, which can be harnessed in breeding programmes. Based on the clustering of the genotypes in hydroponics and soil culture systems, we found that similar genotypes were commonly clustered either in the small-root or in the big-root group, indicating that the hydroponics system can be employed for a large-scale root phenotyping. Our results further revealed that the root biomass positively contributes to increased seed yield in sesame, based on multi-environmental trials. By comparing the root transcriptome of two contrasting genotypes, 2897 differentially expressed genes were detected and they were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, stilbenoid, diarylheptanoid and gingerol biosynthesis, flavonoid biosynthesis, suggesting that these pathways are crucial for sesame root growth and development. Overall, this study sheds light on the diversity of sesame root system and offers the basis for improving root traits and increasing sesame seed yield.


Assuntos
Sesamum/genética , Transcriptoma , Biomassa , Genótipo , Fenótipo , Óleos Vegetais/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Sesamum/anatomia & histologia , Sesamum/crescimento & desenvolvimento
7.
Planta ; 250(5): 1423-1432, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31290031

RESUMO

MAIN CONCLUSION: Nitrogen and CO2 supply interactively regulate whole plant nitrogen partitioning and root anatomical and morphological development in tomato plants. Nitrogen (N) and carbon (C) are the key elements in plant growth and constitute the majority of plant dry matter. Growing at CO2 enrichment has the potential to stimulate the growth of C3 plants, however, growth is often limited by N availability. Thus, the interactive effects of CO2 under different N fertilization rates can affect growth, acclimation to elevated CO2, and yield. However, the majority of research in this field has focused on shoot traits, while neglecting plants' hidden half-the roots. We hypothesize that elevated CO2 and low N effects on transpiration will interactively affect root vascular development and plant N partitioning. Here we studied the effects of elevated CO2 and N concentrations on greenhouse-grown tomato plants, a C3 crop. Our main objective was to determine in what manner the N fertilization rate and elevated CO2 affected root development and nitrogen partitioning among plant organs. Our results indicate that N interacting with the CO2 level affects the development of the root system in terms of the length, anatomy, and partitioning of the N concentration between the roots and shoot. Both CO2 and N concentrations were found to affect xylem size in an opposite manner, elevated CO2 found to repressed, whereas ample N stimulated xylem development. We found that under limiting N and eCO2, the N% increase in the root, while it decreased in the shoot. Under eCO2, the root system size increased with a coordinated decrease in root xylem area. We suggest that tomato root response to elevated CO2 depends on N fertilization rates, and that a decrease in xylem size is a possible underlying response that limits nitrogen allocation from the root into the shoot. Additionally, the greater abundance of root amino acids suggests increased root nitrogen metabolism at eCO2 conditions with ample N.


Assuntos
Aclimatação , Dióxido de Carbono/metabolismo , Lycopersicon esculentum/fisiologia , Nitrogênio/metabolismo , Transporte Biológico , Carbono/metabolismo , Lycopersicon esculentum/anatomia & histologia , Lycopersicon esculentum/crescimento & desenvolvimento , Fotossíntese , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Transpiração Vegetal , Xilema/anatomia & histologia , Xilema/crescimento & desenvolvimento , Xilema/fisiologia
8.
BMC Plant Biol ; 19(1): 331, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31357955

RESUMO

BACKGROUND: Salt stress is one of the environmental factors that greatly limits crop production worldwide because high salt concentrations in the soil affect morphological responses and physiological and metabolic processes, including root morphology and photosynthetic characteristics. Soil aeration has been reported to accelerate the growth of plants and increase crop yield. The objective of this study was to examine the effects of 3 NaCl salinity levels (28, 74 and 120 mM) and 3 aeration volume levels (2.3, 4.6 and 7.0 L/pot) versus non-aeration and salinity treatments on the root morphology, photosynthetic characteristics and chlorophyll content of potted tomato plants. RESULTS: The results showed that both aeration volume and salinity level affected the root parameters, photosynthetic characteristics and chlorophyll content of potted tomato plants. The total length, surface area and volume of roots increased with the increase in aeration volume under each NaCl stress level. The effect was more marked in the fine roots (especially in ≤1 mm diameter roots). Under each NaCl stress level, the photosynthetic rate and chlorophyll content of tomato significantly increased in response to the aeration treatments. The net photosynthetic rate and chlorophyll a and t content increased by 39.6, 26.9, and 17.9%, respectively, at 7.0 L/pot aeration volume compared with no aeration in the 28 mM NaCl treatment. We also found that aeration could reduce the death rate of potted tomato plants under high salinity stress conditions (120 mM NaCl). CONCLUSIONS: The results suggest that the negative effect of NaCl stress can be offset by soil aeration. Soil aeration can promote root growth and increase the photosynthetic rate and chlorophyll content, thus promoting plant growth and reducing the plant death rate under NaCl stress conditions.


Assuntos
Lycopersicon esculentum/fisiologia , Fotossíntese , Raízes de Plantas/anatomia & histologia , Clorofila/metabolismo , Lycopersicon esculentum/anatomia & histologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Raízes de Plantas/fisiologia , Salinidade , Estresse Salino , Solo
9.
BMC Plant Biol ; 19(1): 242, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174465

RESUMO

BACKGROUND: Recurrent drought associated with climate change is a major constraint to wheat (Triticum aestivum L.) productivity. This study aimed to (i) quantify the effects of addition/substitution/translocation of chromosome segments from wild relatives of wheat on the root, physiological and yield traits of hexaploid wheat under drought, and (ii) understand the mechanism(s) associated with drought tolerance or susceptibility in wheat-alien chromosome lines. METHODS: A set of 48 wheat-alien chromosome lines (addition/substitution/translocation lines) with Chinese Spring background were used. Seedling root traits were studied on solid agar medium. To understand the influence of drought on the root system of adult plants, these 48 lines were grown in 150-cm columns for 65 d under full irrigation or withholding water for 58 d. To quantify the effect of drought on physiological and yield traits, the 48 lines were grown in pots under full irrigation until anthesis; after that, half of the plants were drought stressed by withholding water for 16 d before recording physiological and yield-associated traits. RESULTS: The alien chromosome lines exhibited altered root architecture and decreased photochemical efficiency and seed yield and its components under drought. The wheat-alien chromosome lines T5DS·5S#3L (TA5088) with a chromosome segment from Aegilops speltoides (5S) and T5DL.5 V#3S (TA5638) with a chromosome segment from Dasypyrum villosum (5 V) were identified as drought tolerant, and the drought tolerance mechanism was associated with a deep, thin and profuse root system. CONCLUSIONS: The two germplasm lines (TA5088 and TA5638) could be used in wheat breeding programs to improve drought tolerance in wheat and understand the underlying molecular genetic mechanisms of root architecture and drought tolerance.


Assuntos
Cromossomos de Plantas/genética , Secas , Genes de Plantas/genética , Melhoramento Vegetal , Triticum/genética , Aegilops/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Poaceae/genética , Triticum/anatomia & histologia , Triticum/crescimento & desenvolvimento
10.
PLoS One ; 14(5): e0215126, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31042717

RESUMO

Fine roots of plants play an important role in terrestrial ecosystems. There is a close association between the anatomical characteristics and physiological and ecological functions of plants, but we still have a very limited knowledge of anatomical traits. For example, (1) we do not know if herbs and grasses have anatomical patterns similar to those of woody plants, and (2) the variation among different woody plants in the same ecosystem is unclear. In the present study, we analysed the anatomical structures of the fine root systems of various groups of vascular plants (ferns, eudicot herbs, monocots and woody plants) from the same ecosystem (a natural secondary forest on Mao'er Mountain, Heilongjiang, China) to answer the following questions: (1) How does the anatomy of the fine roots change with root order in various plant groups in the same ecosystem? (2) What is the pattern of variation within group? The results show that anatomical traits can be divided into 3 categories: traits that indicate the root capacity to transport resource along the root (stele diameter, xylem cell diameter and xylem cell area); traits that indicate absorptive capacity cortical thickness, (the number of cortical cell layers and the diameter of cortical cells); and traits that are integrated indicators (diameter and the stele to root diameter ratio). The traits indicate the root capacity to transport resource along the root order is generally similar among groups, but absorptive capacity is very different. The shift in function is the main factor influencing the fine root anatomy. Some traits show large variation within groups, but the variations in other traits are small. The traits indicate that the lower-order roots (absorbing roots) in distinct groups are of the first one or two root order in ferns, the first two or three orders in eudicot herbs, the first (only two root orders) or first two orders (more than three root orders) in monocots and the first four or five root orders in woody plants and the other roots are higher-order roots (transport roots). The result will helpful to understand the similarities and differences among groups and the physiological and ecological functions of plant roots.


Assuntos
Raízes de Plantas/anatomia & histologia , Traqueófitas/anatomia & histologia , Evolução Biológica , China , Temperatura , Traqueófitas/classificação
11.
Plant Sci ; 284: 135-142, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31084866

RESUMO

Bacteria rely on chemical communication to sense the environment and to retrieve information on their population densities. Accordingly, a vast repertoire of molecules is released, which synchronizes expression of genes, coordinates behavior through a process termed quorum-sensing (QS), and determines the relationships with eukaryotic species. Already identified QS molecules from Gram negative bacteria can be grouped into two main classes, N-acyl-L-homoserine lactones (AHLs) and cyclodipeptides (CDPs), with roles in biofilm formation, bacterial virulence or symbiotic interactions. Noteworthy, plants detect each of these molecules, change their own gene expression programs, re-configurate root architecture, and activate defense responses, improving in this manner their adaptation to natural and agricultural ecosystems. AHLs may act as alarm signals, pathogen and/or microbe-associated molecular patterns, whereas CDPs function as hormonal mimics for plants via their putative interactions with the auxin receptor Transport Inhibitor Response1 (TIR1). A major challenge is to identify the molecular pathways of QS-mediated crosstalk and the plant receptors and interacting proteins for AHLs, CDPs and related signals.


Assuntos
Raízes de Plantas/microbiologia , Percepção de Quorum/fisiologia , Rhizobiaceae/metabolismo , Interações Hospedeiro-Patógeno , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/fisiologia
12.
Plant Sci ; 283: 177-188, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128687

RESUMO

Phytohormone signaling is involved in the low-phosphate (LP) response and causes root system changes. To understand the roles of auxin and gibberellic acid (GA) in the maize response to LP stress, inbred line Q319 was used to identify the changes in root morphology and the gene expression response to LP stress with or without exogenous auxin, GA or their inhibitors. The root morphology, IAA and GAs concentration and genes related to the LP response, cell elongation and division, auxin transport and signaling, and GA synthesis and signaling were analyzed. The LP-induced maize root morphological adaption was dependent on changes in the expression of related genes, like IPS1, pht1;1 LPR1b, KRPs, and EXPB1-4. The altered local auxin concentration and signaling were involved in promoting axial root elongation and reducing lateral root density and length under LP conditions, which were regulated by PID and PP2A activity and the auxin signaling pathway. The upregulation of the GA synthesis genes AN1, GA20ox1, and GA20ox2 and the downregulation of the GA inactive genes GA2ox1 and GA2ox2 were observed in maize roots subjected to LP stress, and the increased GA biosynthesis and signaling were involved in root growth. Both hormones participate in LP stress response and jointly regulated root modification and LP acclimation in maize.


Assuntos
Giberelinas/fisiologia , Ácidos Indolacéticos/metabolismo , Fosfatos/deficiência , Reguladores de Crescimento de Planta/fisiologia , Zea mays/metabolismo , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estresse Fisiológico , Zea mays/anatomia & histologia , Zea mays/fisiologia
13.
Plant Sci ; 283: 211-223, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128691

RESUMO

Drought resistance is a crucial attribute of plants and to properly decipher its mechanisms, a valuable plant model is required. Lolium multiflorum is a forage grass characterized by a low level of abiotic stress resistance, whereas Festuca arundinacea is recognized as a species with drought resistance, including both stress avoidance and tolerance strategies. These two species can be crossed with each other. Two closely related L. multiflorum/F. arundinacea introgression forms with distinct levels of field drought resistance were involved, thus enabling the dissection of this complex trait into its crucial components. The processes occurring in roots were shown to be the most significant for the expression of drought resistance. Thus, the analysis was focused on the root architecture and the accumulation of selected hormones, primary metabolites and glycerolipids in roots. The introgression form, with a higher resistance to field water deficit was characterized by a deeper soil penetration by its roots, and it had a higher accumulation level of primary metabolites, including well recognized osmoprotectants, such as proline, sucrose or maltose, and an increase in phosphatidylcholine to phosphatidylethanolamine ratio compared to the low resistant form. A comprehensive model of root performance under water deficit conditions is presented here for the first time for the grass species of the Lolium-Festuca complex.


Assuntos
Festuca/anatomia & histologia , Lolium/anatomia & histologia , Raízes de Plantas/anatomia & histologia , Desidratação , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Metabolismo dos Lipídeos , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Folhas de Planta/anatomia & histologia , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Água/metabolismo
14.
PLoS One ; 14(5): e0217454, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31125376

RESUMO

The Russian dandelion (Taraxacum koksaghyz) is a promising source of inulin and natural rubber because large amounts of both feedstocks can be extracted from its roots. However, the domestication of T. koksaghyz requires the development of stable agronomic traits such as higher yields of inulin and natural rubber, a higher root biomass, and an agronomically preferable root morphology which is more suitable for cultivation and harvesting. Arabidopsis thaliana Rapid Alkalinisation Factor 1 (RALF1) has been shown to suppress root growth. We identified the T. koksaghyz orthologue TkRALF-like 1 and knocked out the corresponding gene (TkRALFL1) using the CRISPR/Cas9 system to determine its impact on root morphology, biomass, and inulin and natural rubber yields. The TkRALFL1 knockout lines more frequently developed a taproot phenotype which is easier to cultivate and harvest, as well as a higher root biomass and greater yields of both inulin and natural rubber. The TkRALFL1 gene could therefore be suitable as a genetic marker to support the breeding of profitable new dandelion varieties with improved agronomic traits. To our knowledge, this is the first study addressing the root system of T. koksaghyz to enhance the agronomic performance.


Assuntos
Mutação com Perda de Função , Hormônios Peptídicos/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Taraxacum/genética , Biomassa , Sistemas CRISPR-Cas , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Taraxacum/anatomia & histologia , Taraxacum/crescimento & desenvolvimento
15.
Nat Commun ; 10(1): 2203, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101818

RESUMO

The root economics spectrum (RES), a common hypothesis postulating a tradeoff between resource acquisition and conservation traits, is being challenged by conflicting relationships between root diameter, tissue density (RTD) and root nitrogen concentration (RN). Here, we analyze a global trait dataset of absorptive roots for over 800 plant species. For woody species (but not for non-woody species), we find nonlinear relationships between root diameter and RTD and RN, which stem from the allometric relationship between stele and cortical tissues. These nonlinear relationships explain how sampling bias from different ends of the nonlinear curves can result in conflicting trait relationships. Further, the shape of the relationships varies depending on evolutionary context and mycorrhizal affiliation. Importantly, the observed nonlinear trait relationships do not support the RES predictions. Allometry-based nonlinearity of root trait relationships improves our understanding of the ecology, physiology and evolution of absorptive roots.


Assuntos
Evolução Biológica , Raízes de Plantas/genética , Plantas/genética , Característica Quantitativa Herdável , Conjuntos de Dados como Assunto , Dinâmica não Linear , Fenótipo , Filogenia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/metabolismo , Plantas/anatomia & histologia , Plantas/metabolismo
16.
Theor Appl Genet ; 132(8): 2309-2323, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31101925

RESUMO

KEY MESSAGE: Application of a low-cost and high-efficiency hydroponic system in a rapeseed population verified two types of genetic factors ("persistent" and "stage-specific") that control root development. The root system is a vital plant component for nutrient and water acquisition and is targeted to enhance plant productivity. Genetic dissection of the root system generally focuses on a single stage, but roots grow continuously during plant development. To reveal the temporal genetic patterns of root development, we measured nine root-related traits in a rapeseed recombinant inbred line population at six continuous stages during vegetative growth, using a modified hydroponic system with low-cost and high-efficiency features that could synchronize plant growth under controlled conditions. Phenotypic correlation and growth dynamic analysis suggested the existence of two types of genetic factors ("persistent" and "stage-specific") that control root development. Dynamic (unconditional and conditional) quantitative trait loci (QTL) mapping detected 28 stage-specific and 23 persistent QTLs related to root growth. Among them, 13 early stage-specific, 19 persistent and 8 later stage-specific QTLs were detected at 7 DAS (days after sowing), 16 DAS and 5 EL (expanding leaf stage), respectively, providing efficient and adaptable stages for QTL identification. The effective prediction of biomass accumulation using root morphological traits (up to 96.6% or 92.64% at a specific stage or the final stage, respectively) verified that root growth allocation with maximum root uptake area facilitated biomass accumulation. Furthermore, marker-assistant selection, which combined the "persistent" and "stage-specific" QTLs, proved their effectiveness for root improvement with an excellent uptake area. Our results highlight the potential of high-throughput and precise phenotyping to assess the dynamic genetics of root growth and provide new insights into ideotype root system-based biomass breeding.


Assuntos
Brassica napus/crescimento & desenvolvimento , Brassica napus/genética , Custos e Análise de Custo , Hidroponia/economia , Hidroponia/métodos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/genética , Biomassa , Marcadores Genéticos , Genótipo , Endogamia , Fenótipo , Raízes de Plantas/anatomia & histologia , Locos de Características Quantitativas/genética , Fatores de Tempo
17.
Appl Microbiol Biotechnol ; 103(11): 4405-4415, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31004206

RESUMO

Panax notoginseng is a commonly used Traditional Chinese Medicine (TCM) and has diverse pharmacological activities with triterpenoid saponins as its main active ingredient. In the cultivation of P. notoginseng, continuous cropping is a serious problem, which could induce reduced productivity, low tuber quality, and plant mortality. With unique advantages of easy control, relative stability, high yields, tissue culture is widely used in the protection of TCM resources. In this study, we screened one adventitious root line, multi-branched (MB) root induced from wild-type roots of P. notoginseng, with a high yield of total triterpenoid saponins (17.92 mg/g). The morphology analysis showed that MB root had structure similar to that of wild-type roots, except for the highly branched phenotype. MB root also showed close gene expression levels and metabolite profiles, which were also similar to those of wild-type roots of Demonstration Park (S3Y). Pearson's correlation coefficient analysis confirmed the importance of key gene, 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), and transcription factor, PnERF1, in regulating triterpenoid saponin biosynthesis in P. notoginseng. These results suggested that MB root possesses potential value in the large-scale cultivation of P. notoginseng.


Assuntos
Perfilação da Expressão Gênica , Metabolômica , Panax notoginseng/anatomia & histologia , Panax notoginseng/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Saponinas/metabolismo , Testes Genéticos , Panax notoginseng/química , Panax notoginseng/metabolismo , Raízes de Plantas/metabolismo
18.
PLoS One ; 14(4): e0214145, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947257

RESUMO

Root growth angle (RGA) in response to gravity controlled by auxin is a pertinent target trait for obtainment of higher yield in cereals. But molecular basis of this root architecture trait remain obscure in wheat and barley. We selected four cultivars two each for wheat and barley to unveil the molecular genetic mechanism of Deeper Rooting 1-like gene which controls RGA in rice leading to higher yield under drought imposition. Morphological analyses revealed a deeper and vertically oriented root growth in "NARC 2009" variety of wheat than "Galaxy" and two other barley cultivars "Scarlet" and "ISR42-8". Three new homoeologs designated as TaANDRO1-like, TaBNDRO1-like and TaDNDRO1-like corresponding to A, B and D genomes of wheat could be isolated from "NARC 2009". Due to frameshift and intronization/exonization events the gene structures of these paralogs exhibit variations in size. DRO1-like genes with five distinct domains prevail in diverse plant phyla from mosses to angiosperms but in lower plants their differentiation from LAZY, NGR and TAC1 (root and shoot angle genes) is enigmatic. Instead of IGT as denominator motif of this family, a new C-terminus motif WxxTD in the V-domain is proposed as family specific motif. The EAR-like motif IVLEM at the C-terminus of the TaADRO1-like and TaDDRO1-like that diverged to KLHTLIPNK in TaBDRO1-like and HvDRO1-like is the hallmark of these proteins. Split-YFP and yeast two hybrid assays complemented the interaction of TaDRO1-like with TOPLESS-a repressor of auxin regulated root promoting genes in plants-through IVLEM/KLHTLIPNK motif. Quantitative RT-PCR revealed abundance of DRO1-like RNA in root tips and spikelets while transcript signals were barely detectable in shoot and leaf tissues. Interestingly, wheat exhibited stronger expression of TaBDRO1-like than barley (HvDRO1-like), but TaBDRO1-like was the least expressing among three paralogs. The underlying cause of this expression divergence seems to be the presence of AuxRE motif TGTCTC and core TGTC with a coupling AuxRE-like motif ATTTTCTT proximal to the transcriptional start site in TaBDRO1-like and HvDRO1-like promoters. This is evident from binding of ARF1 to TGTCTC and TGTC motifs of TaBDRO1-like as revealed by yeast one-hybrid assay. Thus, evolution of DRO1-like wheat homoeologs might incorporate the C-terminus mutations as well as gain and loss of AuxREs and other cis-regulatory elements during expression divergence. Since root architecture is an important target trait for wheat crop improvement, therefore DRO1-like genes have potential applications in plant breeding for enhancement of plant productivity by the use of modern genome editing approaches.


Assuntos
Evolução Molecular , Ácidos Indolacéticos/farmacologia , Mutação/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Elementos de Resposta/genética , Homologia de Sequência de Aminoácidos , Triticum/genética , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hordeum/anatomia & histologia , Hordeum/efeitos dos fármacos , Íntrons/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Triticum/anatomia & histologia , Triticum/efeitos dos fármacos
19.
Cell Mol Biol (Noisy-le-grand) ; 65(3): 1-10, 2019 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30942150

RESUMO

In this study the effects of zinc sulfate and gibberellin on agro physiological of white bean under water deficiency were studied. Therefore, an experiment was conducted in a split-split plot design based on a randomized complete block with three replications in two places. The experimental factors included three irrigation levels, spraying of zinc sulfate in four levels and two levels of non-spraying and spraying of gibberellin. Analysis of measured data indicated that the water stress had a significant effect on all traits, except proline amount and 100 seeds weight. Spraying of zinc sulfate showed a significant effect on all traits except carotenoid value. Application of gibberellin had a significant effect on all traits except ion leakage, carotenoids, number of seeds per pod and grain yield. The interaction effect of stress×zincsulfate×gibberellin was significant on all traits except number of seeds per pod. In addition, comparison of means at 5% level, showed that application of 1.5 ml L-1of zinc sulfate plus gibberellin improved bean biochemical properties. Under optimum water level, using of 4.5 ml L-1of zinc sulfate and under severe water stress conditions, using of 4.5 ml L-1 of zinc sulfate plus gibberellin are recommended for obtaining the maximum crop performance.


Assuntos
Secas , Fabaceae/fisiologia , Giberelinas/farmacologia , Sulfato de Zinco/farmacologia , Análise de Variância , Desidratação , Eletrólitos/metabolismo , Fabaceae/efeitos dos fármacos , Geografia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Prolina/metabolismo , Água/metabolismo
20.
Planta ; 250(1): 333-345, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31030327

RESUMO

MAIN CONCLUSION: Selenium modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings. Selenium (Se) at low concentrations can control root growth through interaction with hormone biosynthesis. Auxin and ethylene have been shown to control the root architecture, with most of the information obtained from the eudicots such Arabidopsis and Nicotiana tabacum. Here, we presented the effects of Se on auxin and ethylene pathways and examined their impact on primary metabolism and root system architecture in rice (Oryza sativa L.) seedlings. Se treatment increased elongation of primary root, but decreased the number and length of lateral roots. Se led to decreased expression of genes associated with the biosynthesis of auxin and ethylene, concomitantly with reduced production of these hormones by the roots. Moreover, Se decreased the abundance of transcripts encoding auxin transport proteins. Indole-3-acetic acid (IAA) treatment overrode the repressive effect of Se on lateral root growth. The ethylene synthesis inhibitor L-α-(2-aminoethoxyvinyl)-glycine (AVG) increased elongation of primary root, whereas the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) resulted in the opposite effect. Soluble sugars accumulate in roots of rice seedlings under Se treatment. Thus, Se modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings.


Assuntos
Ácidos Indolacéticos/farmacologia , Oryza/efeitos dos fármacos , Reguladores de Crescimento de Planta/metabolismo , Selênio/farmacologia , Transporte Biológico , Regulação para Baixo/efeitos dos fármacos , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Oryza/anatomia & histologia , Oryza/metabolismo , Reguladores de Crescimento de Planta/farmacologia , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/anatomia & histologia , Plântula/genética , Plântula/metabolismo
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