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1.
PLoS One ; 16(10): e0258253, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34634063

RESUMO

Current knowledge on responses of aquatic clonal plants to resource availability is largely based on studies manipulating limited resource levels, which may have failed to capture the "big picture" for aquatic clonal plants in response to resource availability. In a greenhouse experiment, we grew the floating clonal plant Spirodela polyrhiza under ten nutrient levels (i.e., 1/64×, 1/32×, 1/16×, 1/8×, 1/4×, 1/2×, 1×, 2×, 4× and 8×full-strength Hoagland solution) and examined their responses in terms of clonal growth, morphology and biomass allocations. The responses of total biomass and number of ramets to nutrient availability were unimodal. A similar pattern was found for frond mass, frond length and frond width, even though area per frond and specific frond area fluctuated greatly in response to nutrient availability. In contrast, the responses of root mass and root length to nutrient availability were U-shaped. Moreover, S. polyrhiza invested more to roots under lower nutrient concentrations. These results suggest that nutrient availability may have distinct influences on roots and fronds of the aquatic clonal plant S. polyrhiza, resulting in a great influence on the whole S. polyrhiza population.


Assuntos
Araceae/fisiologia , Nutrientes/farmacologia , Folhas de Planta/fisiologia , Raízes de Plantas/fisiologia , Araceae/anatomia & histologia , Araceae/efeitos dos fármacos , Araceae/crescimento & desenvolvimento , Biomassa , Células Clonais , Folhas de Planta/anatomia & histologia , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/anatomia & histologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia
2.
BMC Plant Biol ; 21(1): 477, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34670492

RESUMO

BACKGROUND: Both underground rhizomes/buds and above-ground Moso bamboo (Phyllostachys heterocycla) shoots/culms/branches are connected together into a close inter-connecting system in which nutrients are transported and shared among each organ. However, the starch storage and utilization mechanisms during bamboo shoot growth remain unclear. This study aimed to reveal in which organs starch was stored, how carbohydrates were transformed among each organ, and how the expression of key genes was regulated during bamboo shoot growth and developmental stages which should lay a foundation for developing new theoretical techniques for bamboo cultivation. RESULTS: Based on changes of the NSC content, starch metabolism-related enzyme activity and gene expression from S0 to S3, we observed that starch grains were mainly elliptical in shape and proliferated through budding and constriction. Content of both soluble sugar and starch in bamboo shoot peaked at S0, in which the former decreased gradually, and the latter initially decreased and then increased as shoots grew. Starch synthesis-related enzymes (AGPase, GBSS and SBE) and starch hydrolase (α-amylase and ß-amylase) activities exhibited the same dynamic change patterns as those of the starch content. From S0 to S3, the activity of starch synthesis-related enzyme and starch amylase in bamboo rhizome was significantly higher than that in bamboo shoot, while the NSC content in rhizomes was obviously lower than that in bamboo shoots. It was revealed by the comparative transcriptome analysis that the expression of starch synthesis-related enzyme-encoding genes were increased at S0, but reduced thereafter, with almost the same dynamic change tendency as the starch content and metabolism-related enzymes, especially during S0 and S1. It was revealed by the gene interaction analysis that AGPase and SBE were core genes for the starch and sucrose metabolism pathway. CONCLUSIONS: Bamboo shoots were the main organ in which starch was stored, while bamboo rhizome should be mainly functioned as a carbohydrate transportation channel and the second carbohydrate sink. Starch metabolism-related genes were expressed at the transcriptional level during underground growth, but at the post-transcriptional level during above-ground growth. It may be possible to enhance edible bamboo shoot quality for an alternative starch source through genetic engineering.


Assuntos
Metabolismo dos Carboidratos/genética , Proteínas de Plantas/metabolismo , Poaceae/genética , Amido/metabolismo , Transcriptoma , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Amilases/genética , Amilases/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Brotos de Planta/ultraestrutura , Poaceae/crescimento & desenvolvimento , Poaceae/fisiologia , Poaceae/ultraestrutura , Rizoma/genética , Rizoma/crescimento & desenvolvimento , Rizoma/fisiologia , Rizoma/ultraestrutura
4.
Plant Mol Biol ; 107(1-2): 63-84, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34460049

RESUMO

KEY MESSAGE: Overexpressing Nicotinamidase 3 gene, and the exogenous application of its metabolite nicotinic acid (NA), enhance drought stress tolerance and increase biomass in Arabidopsis thaliana. With progressive global climatic changes, plant productivity is threatened severely by drought stress. Deciphering the molecular mechanisms regarding genes responsible for balancing plant growth and stress amelioration could imply multiple possibilities for future sustainable goals. Nicotinamide adenine dinucleotide (NAD) biosynthesis and recycling/ distribution is a crucial feature for plant growth. The current study focuses on the functional characterization of nicotinamidase 3 (NIC3) gene, which is involved in the biochemical conversion of nicotinamide (NAM) to nicotinic acid (NA) in the salvage pathway of NAD biosynthesis. Our data show that overexpression of NIC3 gene enhances drought stress tolerance and increases plant growth. NIC3-OX plants accumulated more NA as compared to WT plants. Moreover, the upregulation of several genes related to plant growth/stress tolerance indicates that regulating the NAD salvage pathway could significantly enhance plant growth and drought stress tolerance. The exogenous application of nicotinic acid (NA) showed a similar phenotype as the effect of overexpressing NIC3 gene. In short, we contemplated the role of NIC3 gene and NA application in drought stress tolerance and plant growth. Our results would be helpful in engineering plants with enhanced drought stress tolerance and increased growth potential.


Assuntos
Adaptação Fisiológica/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Biomassa , Secas , Genes de Plantas , Niacina/farmacologia , Nicotinamidase/genética , Adaptação Fisiológica/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Modelos Biológicos , NAD/metabolismo , NADP/metabolismo , Nicotinamidase/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Plantas Geneticamente Modificadas , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Transcriptoma/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
5.
Methods Mol Biol ; 2288: 73-88, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270005

RESUMO

In the context of plant regeneration, in vitro systems to produce embryos are frequently used. In many of these protocols, nonzygotic embryos are initiated that will produce shoot-like structures but may lack a primary root. By increasing the auxin-to-cytokinin ratio in the growth medium, roots are then regenerated in a second step. Therefore, in vitro systems might not or only partially execute a similar developmental program as employed during zygotic embryogenesis. There are, however, in vitro systems that can remarkably mimic zygotic embryogenesis such as Brassica microspore-derived embryos. In this case, the patterning process of these haploid embryos closely follows zygotic embryogenesis and all fundamental tissue types are generated in a rather similar manner. In this review, we discuss the most fundamental molecular events during early zygotic embryogenesis and hope that this brief summary can serve as a reference for studying and developing in vitro embryogenesis systems in the context of doubled haploid production.


Assuntos
Magnoliopsida/embriologia , Padronização Corporal/genética , Padronização Corporal/fisiologia , Brassicaceae/embriologia , Brassicaceae/genética , Brassicaceae/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Ácidos Indolacéticos/metabolismo , Sistema de Sinalização das MAP Quinases , Magnoliopsida/genética , Magnoliopsida/fisiologia , Modelos Biológicos , Biologia Molecular/métodos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Regeneração/genética , Regeneração/fisiologia , Nicho de Células-Tronco/genética , Nicho de Células-Tronco/fisiologia , Zigoto
6.
Cells ; 10(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209882

RESUMO

GABA (gamma-aminobutyric acid) and melatonin are endogenous compounds that enhance plant responses to abiotic stresses. The response of Vicia faba to different stressors (salinity (NaCl), poly ethylene glycol (PEG), and sulfur dioxide (SO2)) was studied after priming with sole application of GABA and melatonin or their co-application (GABA + melatonin). Both melatonin and GABA and their co-application increased leaf area, number of flowers, shoot dry and fresh weight, and total biomass. Plants treated with GABA, melatonin, and GABA + melatonin developed larger stomata with wider aperture compared to the stomata of control plants. The functionality of the photosynthetic system was improved in primed plants. To investigate the photosynthetic functionality in details, the leaf samples of primed plants were exposed to different stressors, including SO2, PEG, and NaCl. The maximum quantum yield of photosystem II (PS II) was higher in the leaf samples of primed plants, while the non-photochemical quenching (NPQ) of primed plants was decreased when leaf samples were exposed to the stressors. Correlation analysis showed the association of initial PIabs with post-stress FV/FM and NPQ. Stressors attenuated the association of initial PIabs with both FV/FM and NPQ, while priming plants with GABA, melatonin, or GABA + melatonin minimized the effect of stressors by attenuating these correlations. In conclusion, priming plants with both GABA and melatonin improved growth and photosynthetic performance of Vicia faba and mitigated the effects of abiotic stressors on the photosynthetic performance.


Assuntos
Melatonina/farmacologia , Fotossíntese/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia , Biomassa , Clorofila/metabolismo , Flores/efeitos dos fármacos , Flores/fisiologia , Pressão Osmótica/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Cloreto de Sódio/farmacologia , Dióxido de Enxofre/toxicidade , Vicia faba/efeitos dos fármacos , Vicia faba/crescimento & desenvolvimento , Vicia faba/fisiologia
7.
PLoS One ; 16(7): e0254318, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34314420

RESUMO

Screening for drought tolerance requires precise techniques like phonemics, which is an emerging science aimed at non-destructive methods allowing large-scale screening of genotypes. Large-scale screening complements genomic efforts to identify genes relevant for crop improvement. Thirty maize inbred lines from various sources (exotic and indigenous) maintained at Dryland Agriculture Research Station were used in the current study. In the automated plant transport and imaging systems (LemnaTec Scanalyzer system for large plants), top and side view images were taken of the VIS (visible) and NIR (near infrared) range of the light spectrum to capture phenes. All images were obtained with a thermal imager. All sensors were used to collect images one day after shifting the pots from the greenhouse for 11 days. Image processing was done using pre-processing, segmentation and flowered by features' extraction. Different surrogate traits such as pixel area, plant aspect ratio, convex hull ratio and calliper length were estimated. A strong association was found between canopy temperature and above ground biomass under stress conditions. Promising lines in different surrogates will be utilized in breeding programmes to develop mapping populations for traits of interest related to drought resilience, in terms of improved tissue water status and mapping of genes/QTLs for drought traits.


Assuntos
Secas , Zea mays/fisiologia , Biomassa , Produtos Agrícolas , Genótipo , Processamento de Imagem Assistida por Computador , Fenótipo , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Locos de Características Quantitativas , Água/fisiologia , Zea mays/genética , Zea mays/crescimento & desenvolvimento
8.
BMC Plant Biol ; 21(1): 236, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044782

RESUMO

BACKGROUND: Lateral branches vigorously proliferate in tobacco after the topping of the inflorescence portions of stems for the maturation of the leaves to be harvested. Therefore, tobacco varieties with inhibited lateral shoot formation are highly desired by tobacco farmers. RESULTS: Genetic inhibition of lateral shoot formation was attempted in tobacco. Two groups of genes were examined by RNA interference. The first group comprised homologs of the genes mediating lateral shoot formation in other plants, whereas the second group included genes highly expressed in axillary bud primordial stages. Although "primary" lateral shoots that grew after the plants were topped off when flower buds emerged were unaffected, the growth of "secondary" lateral shoots, which were detected on the abaxial side of the primary lateral shoot base, was significantly suppressed in the knock-down lines of NtLs, NtBl1, NtREV, VE7, and VE12. Chemically induced mutations to NtLs, NtBl1, and NtREV similarly inhibited the development of secondary and "tertiary" lateral shoots, but not primary lateral shoots. The mutations to NtLs and NtBl1 were incorporated into an elite variety by backcrossing. The agronomic characteristics of the backcross lines were examined in field trials conducted in commercial tobacco production regions. The lines were generally suitable for tobacco leaf production and may be useful as new tobacco varieties. CONCLUSION: The suppressed expression of NtLs, NtBl1, NtREV, VE7, or VE12 inhibited the development of only the secondary and tertiary lateral shoots in tobacco. The mutant lines may benefit tobacco farmers by minimizing the work required to remove secondary and tertiary lateral shoots that emerge when farmers are harvesting leaves, which is a labor-intensive process.


Assuntos
Tabaco/genética , Inflorescência/enzimologia , Inflorescência/genética , Meristema/genética , Meristema/crescimento & desenvolvimento , Mutação , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/fisiologia , Interferência de RNA , Tabaco/crescimento & desenvolvimento , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
BMC Plant Biol ; 21(1): 243, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34049485

RESUMO

BACKGROUND: Branch angle is a pivotal component of tea plant architecture. Tea plant architecture not only affects tea quality and yield but also influences the efficiency of automatic tea plant pruning. However, the molecular mechanism controlling the branch angle, which is an important aspect of plant architecture, is poorly understood in tea plants. RESULTS: In the present study, three CsLAZY genes were identified from tea plant genome data through sequence homology analysis. Phylogenetic tree displayed that the CsLAZY genes had high sequence similarity with LAZY genes from other plant species, especially those in woody plants. The expression patterns of the three CsLAZYs were surveyed in eight tissues. We further verified the expression levels of the key CsLAZY1 transcript in different tissues among eight tea cultivars and found that CsLAZY1 was highly expressed in stem. Subcellular localization analysis showed that the CsLAZY1 protein was localized in the plasma membrane. CsLAZY1 was transferred into Arabidopsis thaliana to investigate its potential role in regulating shoot development. Remarkably, the CsLAZY1 overexpressed plants responded more effectively than the wild-type plants to a gravity inversion treatment under light and dark conditions. The results indicate that CsLAZY1 plays an important role in regulating shoot gravitropism in tea plants. CONCLUSIONS: The results provide important evidence for understanding the functions of CsLAZY1 in regulating shoot gravitropism and influencing the stem branch angle in tea plants. This report identifies CsLAZY1 as a promising gene resource for the improvement of tea plant architecture.


Assuntos
Camellia sinensis/genética , Genoma de Planta/genética , Gravitropismo/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Camellia sinensis/fisiologia , Filogenia , Brotos de Planta/genética , Brotos de Planta/fisiologia , Caules de Planta/genética , Caules de Planta/fisiologia , Chá
10.
Plant Cell Rep ; 40(9): 1665-1678, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34052885

RESUMO

KEY MESSAGE: Improved compact shoot architecture of Osteospermum fruticosum Ri lines obtained through Rhizobium rhizogenes transformation reduces the need for chemical growth retardants. Compactness is for many ornamental crops an important commercial trait that is usually obtained through the application of growth retardants. Here, we have adopted a genetic strategy to introduce compactness in the perennial shrub Cape daisy (Osteospermum fruticosum Norl.). To this end, O. fruticosum was transformed using six different wild type Rhizobium rhizogenes strains. The most effective R. rhizogenes strains Arqua1 and ATCC15834 were used to create hairy root cultures from six Cape daisy genotypes. These root cultures were regenerated to produce transgenic Ri lines, which were analyzed for compactness. Ri lines displayed the characteristic Ri phenotype, i.e., reduced plant height, increased branching, shortened internodes, shortened peduncles, and smaller flowers. Evaluation of the Ri lines under commercial production conditions showed that similar compactness was obtained as the original Cape daisy genotypes treated with growth retardant. The results suggest that the use of chemical growth retardants may be omitted or reduced in commercial production systems of Cape daisy through implementation of Ri lines in future breeding programs.


Assuntos
Agrobacterium/fisiologia , Asteraceae/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Asteraceae/efeitos dos fármacos , Asteraceae/genética , Asteraceae/microbiologia , Clormequat/farmacologia , Técnicas de Cocultura , Fenótipo , Melhoramento Vegetal/métodos , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/citologia , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Técnicas de Cultura de Tecidos/métodos , Transformação Genética/fisiologia
11.
Biomolecules ; 11(3)2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33809550

RESUMO

3,3'-diindolylmethane (DIM) belongs to a family of indole glucosinolate compounds that have been shown to improve Brassica napus growth through the modulation of reactive oxygen species when applied exogenously. The B. napus cultivar AV Garnet was previously identified as a vanadium-sensitive cultivar. Therefore, in this study we investigated whether exogenous DIM could improve the vanadium tolerance of AV Garnet. We performed the following experiments: seed germination assessment, dry weight assessment, cell viability assay, chlorophyll content assay, malondialdehyde (MDA) assay, conjugated diene (CD) content assay, hydrogen peroxide (H2O2) content assay, superoxide (O2-) content determination, methylglyoxal (MG) content determination, hydroxyl radical (·OH) concentration determination, ascorbate peroxidase (APX) activity assay, superoxide dismutase (SOD) activity assay, glyoxalase I (Gly I) activity assay, glutathione S-transferase (GST) activity assay and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis for vanadium content determination. Under vanadium stress, exogenous DIM increased the seed germination percentage, shoot dry weight, cell viability and chlorophyll content. Exogenous DIM also led to a decrease in MDA, CD, H2O2, O2-, MG and ·OH, under vanadium stress in the shoots. Furthermore, DIM application led to an increase in the enzymatic activities of APX, SOD, Gly I and GST under vanadium stress. Interestingly, under vanadium stress, DIM treatment did not alter vanadium content in B. napus shoots. Our results indicate that exogenous application of DIM can improve B. napus seedling shoot growth and biomass under vanadium stress by priming the antioxidant enzymes via reactive oxygen species (ROS) signaling.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/metabolismo , Brassica napus/enzimologia , Brassica napus/fisiologia , Indóis/farmacologia , Brotos de Planta/fisiologia , Plântula/fisiologia , Vanádio/toxicidade , Brassica napus/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Clorofila/metabolismo , Germinação/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Radical Hidroxila/metabolismo , Malondialdeído , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Aldeído Pirúvico/metabolismo , Plântula/efeitos dos fármacos , Superóxidos/metabolismo
12.
J Plant Physiol ; 260: 153405, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33743435

RESUMO

In vitro organogenesis is a multistep process which is largely controlled by the balance between auxin and cytokinin. Previous studies revealed a complex network regulating in vitro organogenesis in Arabidopsis thaliana; however, our knowledge of the molecular mechanisms underlying de novo shoot formation in papaya (Carica papaya) remains limited. Here, we optimized multiple factors to achieve an efficient and reproducible protocol for the induction of papaya callus formation and shoot regeneration. Subsequently, we analyzed the dynamic transcriptome profiles of samples undergoing this process, identified 5381, 642, 4047, and 2386 differentially expressed genes (DEGs), including 447, 66, 350, and 263 encoding transcription factors (TFs), in four stage comparisons. The DEGs were mainly involved in phytohormone modulation and transduction processes, particularly for auxin and cytokinin. Of these, 21 and 7 candidate genes involved in the auxin and cytokinin pathways, respectively, had distinct expression patterns throughout in vitro organogenesis. Furthermore, we found two genes encoding key TFs, CpLBD19 and CpESR1, were sharply induced on callus induction medium and shoot induction medium, indicating these two TFs may serve as proxies for callus induction and shoot formation in papaya. We therefore report a regulatory network of auxin and cytokinin signaling in papaya according to the one previously modeled for Arabidopsis. Our comprehensive analyses provide insight into the early molecular regulation of callus initiation and shoot formation in papaya, and are useful for the further identification of the regulators governing in vitro organogenesis.


Assuntos
Carica/fisiologia , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Organogênese Vegetal/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Brotos de Planta/fisiologia , Regeneração , Estresse Fisiológico
13.
PLoS One ; 16(2): e0245487, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606701

RESUMO

Many apple cultivars are subject to biennial fluctuations in flowering and fruiting. It is believed that this phenomenon is caused by a repressive effect of developing fruit on the initiation of flowers in the apex of proximal bourse shoots. However, the genetic pathways of floral initiation are incompletely described in apple, and the biological nature of floral repression by fruit is currently unknown. In this study, we characterized the transcriptional landscape of bourse shoot apices in the biennial cultivar, 'Honeycrisp', during the period of floral initiation, in trees bearing a high fruit load and in trees without fruit. Trees with high fruit load produced almost exclusively vegetative growth in the subsequent year, whereas the trees without fruit produced flowers on the majority of the potential flowering nodes. Using RNA-based sequence data, we documented gene expression at high resolution, identifying >11,000 transcripts that had not been previously annotated, and characterized expression profiles associated with vegetative growth and flowering. We also conducted a census of genes related to known flowering genes, organized the phylogenetic and syntenic relationships of these genes, and compared expression among homeologs. Several genes closely related to AP1, FT, FUL, LFY, and SPLs were more strongly expressed in apices from non-bearing, floral-determined trees, consistent with their presumed floral-promotive roles. In contrast, a homolog of TFL1 exhibited strong and persistent up-regulation only in apices from bearing, vegetative-determined trees, suggesting a role in floral repression. Additionally, we identified four GIBBERELLIC ACID (GA) 2 OXIDASE genes that were expressed to relatively high levels in apices from bearing trees. These results define the flowering-related transcriptional landscape in apple, and strongly support previous studies implicating both gibberellins and TFL1 as key components in repression of flowering by fruit.


Assuntos
Flores , Frutas , Regulação da Expressão Gênica de Plantas , Malus , Brotos de Planta/fisiologia , Flores/genética , Flores/fisiologia , Frutas/genética , Frutas/fisiologia , Malus/genética , Malus/fisiologia , Proteínas de Plantas/genética
14.
Plant Cell Physiol ; 62(4): 678-692, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-33570567

RESUMO

The force of gravity is a constant environmental factor. Plant shoots respond to gravity through negative gravitropism and gravity resistance. These responses are essential for plants to direct the growth of aerial organs away from the soil surface after germination and to keep an upright posture above ground. We took advantage of the effect of brassinosteroids (BRs) on the two types of graviresponses in Arabidopsis thaliana hypocotyls to disentangle functions of cell wall polymers during etiolated shoot growth. The ability of etiolated Arabidopsis seedlings to grow upward was suppressed in the presence of 24-epibrassinolide (EBL) but enhanced in the presence of brassinazole (BRZ), an inhibitor of BR biosynthesis. These effects were accompanied by changes in cell wall mechanics and composition. Cell wall biochemical analyses, confocal microscopy of the cellulose-specific pontamine S4B dye and cellular growth analyses revealed that the EBL and BRZ treatments correlated with changes in cellulose fibre organization, cell expansion at the hypocotyl base and mannan content. Indeed, a longitudinal reorientation of cellulose fibres and growth inhibition at the base of hypocotyls supported their upright posture whereas the presence of mannans reduced gravitropic bending. The negative effect of mannans on gravitropism is a new function for this class of hemicelluloses. We also found that EBL interferes with upright growth of hypocotyls through their uneven thickening at the base.


Assuntos
Arabidopsis/fisiologia , Brassinosteroides/metabolismo , Celulose/metabolismo , Hipocótilo/fisiologia , Mananas/metabolismo , Arabidopsis/citologia , Arabidopsis/efeitos dos fármacos , Brassinosteroides/farmacologia , Parede Celular/química , Parede Celular/efeitos dos fármacos , Celulose/química , Gravitropismo/fisiologia , Hipocótilo/química , Mananas/química , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/fisiologia , Polissacarídeos/química , Esteroides Heterocíclicos/metabolismo , Esteroides Heterocíclicos/farmacologia , Imagem com Lapso de Tempo
15.
Int J Mol Sci ; 22(4)2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557073

RESUMO

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.


Assuntos
Adaptação Fisiológica , Arabidopsis/fisiologia , Temperatura Baixa , Desidratação/metabolismo , Brotos de Planta/fisiologia , Estresse Fisiológico , Ceras/metabolismo , Aclimatação , Alelos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Desidratação/genética , Cromatografia Gasosa-Espectrometria de Massas , Interações Hidrofóbicas e Hidrofílicas , Metabolismo dos Lipídeos , Lipídeos/química , Mutação , Desenvolvimento Vegetal , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Fisiológico/genética , Ceras/química
16.
Plant Cell Physiol ; 62(2): 366-377, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33399871

RESUMO

Tea (Camellia sinensis [L.] O. Kuntze) tree is a perennial plant in which winter dormancy is an important biological adaptation to environmental changes. We discovered and reported a novel tea tree cultivar that can generate tender shoots in winter several years ago, but the molecular mechanism for this unique phenotype remains unknown . Here, we conducted comparative transcriptomics, proteomics and metabolomics along with phytohormone quantitation between the winter and spring tender shoots to investigate the physiological basis and putative regulatory mechanisms of its evergrowing character during winter. Our multi-omics study has led to the following findings. Gibberellin (GA) levels and key enzymes for GA biosynthesis and the signal transduction pathway were increased in the winter shoots, causing the ABA/GA content ratio to decrease, which might play a key regulatory role in maintaining normal growth during winter. The abundance of proteins, genes and metabolites involved in energy metabolism was all increased in winter shoots, indicating that energy is critical for continuous growth under the relatively weak-light and low-temperature environment. Abiotic resistance-related proteins and free amino acids were also increased in abundance in the winter shoots, which possibly represents an adaptation response to winter conditions. These results allowed us to hypothesize a novel molecular mechanism of adaptation for this unique tender shoot evergrowing in winter.


Assuntos
Camellia sinensis/fisiologia , Brotos de Planta/fisiologia , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Camellia sinensis/genética , Camellia sinensis/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Metabolômica , Dormência de Plantas/genética , Dormência de Plantas/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/fisiologia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Proteômica , Estações do Ano , Transdução de Sinais/fisiologia
17.
Plant Cell Rep ; 40(3): 437-459, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33389046

RESUMO

KEY MESSAGE: Cell wall plasticity plays a very crucial role in vegetative and reproductive development of rice under drought and is a highly potential trait for improving rice yield under drought. Drought is a major constraint in rice (Oryza sativa L.) cultivation severely affecting all developmental stages, with the reproductive stage being the most sensitive. Rice plants employ multiple strategies to cope with drought, in which modification in cell wall dynamics plays a crucial role. Over the years, significant progress has been made in discovering the cell wall-specific genomic resources related to drought tolerance at vegetative and reproductive stages of rice. However, questions remain about how the drought-induced changes in cell wall made by these genomic resources potentially influence the vegetative and reproductive development of rice. The possibly major candidate genes underlying the function of quantitative trait loci directly or indirectly associated with the cell wall plasticization-mediated drought tolerance of rice might have a huge promise in dissecting the putative genomic regions associated with cell wall plasticity under drought. Furthermore, engineering the drought tolerance of rice using cell wall-related genes from resurrection plants may have huge prospects for rice yield improvement. Here, we review the comprehensive multidisciplinary analyses to unravel different components and mechanisms involved in drought-induced cell wall plasticity at vegetative and reproductive stages that could be targeted for improving rice yield under drought.


Assuntos
Parede Celular/química , Secas , Oryza/citologia , Oryza/genética , Proteínas de Plantas/genética , Parede Celular/genética , Parede Celular/ultraestrutura , Regulação da Expressão Gênica de Plantas , Genômica/métodos , Oryza/crescimento & desenvolvimento , Raízes de Plantas/citologia , Raízes de Plantas/fisiologia , Brotos de Planta/citologia , Brotos de Planta/fisiologia , Locos de Características Quantitativas
18.
Int J Mol Sci ; 22(3)2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33513755

RESUMO

High bicarbonate concentrations of calcareous soils with high pH can affect crop performance due to different constraints. Among these, Fe deficiency has mostly been studied. The ability to mobilize sparingly soluble Fe is a key factor for tolerance. Here, a comparative transcriptomic analysis was performed with two naturally selected Arabidopsis thaliana demes, the carbonate-tolerant A1(c+) and the sensitive T6(c-). Analyses of plants exposed to either pH stress alone (pH 5.9 vs. pH 8.3) or to alkalinity caused by 10 mM NaHCO3 (pH 8.3) confirmed better growth and nutrient homeostasis of A1(c+) under alkaline conditions. RNA-sequencing (RNA-seq) revealed that bicarbonate quickly (3 h) induced Fe deficiency-related genes in T6(c-) leaves. Contrastingly, in A1(c+), initial changes concerned receptor-like proteins (RLP), jasmonate (JA) and salicylate (SA) pathways, methionine-derived glucosinolates (GS), sulfur starvation, starch degradation, and cell cycle. Our results suggest that leaves of carbonate-tolerant plants do not sense iron deficiency as fast as sensitive ones. This is in line with a more efficient Fe translocation to aerial parts. In A1(c+) leaves, the activation of other genes related to stress perception, signal transduction, GS, sulfur acquisition, and cell cycle precedes the induction of iron homeostasis mechanisms yielding an efficient response to bicarbonate stress.


Assuntos
Arabidopsis/metabolismo , Bicarbonatos/toxicidade , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Brotos de Planta/efeitos dos fármacos , Salicilatos/metabolismo , Estresse Fisiológico/genética , Transcriptoma/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Bicarbonatos/farmacologia , Calmodulina/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Ontologia Genética , Glucosinolatos/metabolismo , Glutationa/metabolismo , Homeostase , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Peroxidases/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Brotos de Planta/fisiologia , Mapas de Interação de Proteínas , RNA-Seq , Transdução de Sinais/efeitos dos fármacos , Amido/metabolismo , Enxofre/metabolismo , Fatores de Transcrição
19.
BMC Plant Biol ; 21(1): 63, 2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33494700

RESUMO

BACKGROUND: Shoot architecture is fundamentally crucial to crop growth and productivity. As a key component of shoot architecture, plant height is known to be controlled by both genetic and environmental factors, though specific details remain scarce. RESULTS: In this study, 308 representative soybean lines from a core collection and 168 F9 soybean progeny were planted at distinct field sites. The results demonstrated the presence of significant genotype × environment interaction (G × E) effects on traits associated with plant height in a natural soybean population. In total, 19 loci containing 51 QTLs (quantitative trait locus) for plant height were identified across four environments, with 23, 13 and 15 being QTLs for SH (shoot height), SNN (stem node number) and AIL (average internode length), respectively. Significant LOD ranging from 2.50 to 16.46 explained 2.80-26.10% of phenotypic variation. Intriguingly, only two loci, Loc11 and Loc19-1, containing 20 QTLs, were simultaneously detected across all environments. Results from Pearson correlation analysis and PCA (principal component analysis) revealed that each of the five agro-meteorological factors and four soil properties significantly affected soybean plant height traits, and that the corresponding QTLs had additive effects. Among significant environmental factors, AD (average day-length), AMaT (average maximum temperature), pH, and AN (available nitrogen) had the largest impacts on soybean plant height. Therefore, in spite of uncontrollable agro-meteorological factors, soybean shoot architecture might be remolded through combined efforts to produce superior soybean genetic materials while also optimizing soil properties. CONCLUSIONS: Overall, the comprehensive set of relationships outlined herein among environment factors, soybean genotypes and QTLs in effects on plant height opens new avenues to explore in work aiming to increase soybean yield through improvements in shoot architecture.


Assuntos
Regulação da Expressão Gênica de Plantas , Locos de Características Quantitativas/genética , Soja/genética , Meio Ambiente , Genótipo , Fenótipo , Brotos de Planta/anatomia & histologia , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Soja/anatomia & histologia , Soja/crescimento & desenvolvimento , Soja/fisiologia
20.
Plant Cell Environ ; 44(5): 1642-1662, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33464573

RESUMO

Adventitious roots (ARs) are produced from non-root tissues in response to different environmental signals, such as abiotic stresses, or after wounding, in a complex developmental process that requires hormonal crosstalk. Here, we characterized AR formation in young seedlings of Solanum lycopersicum cv. 'Micro-Tom' after whole root excision by means of physiological, genetic and molecular approaches. We found that a regulated basipetal auxin transport from the shoot and local auxin biosynthesis triggered by wounding are both required for the re-establishment of internal auxin gradients within the vasculature. This promotes cell proliferation at the distal cambium near the wound in well-defined positions of the basal hypocotyl and during a narrow developmental window. In addition, a pre-established pattern of differential auxin responses along the apical-basal axis of the hypocotyl and an as of yet unknown cell-autonomous inhibitory pathway contribute to the temporal and spatial patterning of the newly formed ARs on isolated hypocotyl explants. Our work provides an experimental outline for the dissection of wound-induced AR formation in tomato, a species that is suitable for molecular identification of gene regulatory networks via forward and reverse genetics approaches.


Assuntos
Ácidos Indolacéticos/metabolismo , Lycopersicon esculentum/fisiologia , Raízes de Plantas/fisiologia , Brotos de Planta/fisiologia , Transporte Biológico , Meio Ambiente , Gravitropismo/fisiologia , Hipocótilo/fisiologia
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