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1.
Int J Mol Sci ; 23(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36012245

RESUMO

The distribution and content of auxin within plant tissues affect a variety of important growth and developmental processes. Polar auxin transport (PAT), mainly mediated by auxin influx and efflux transporters, plays a vital role in determining auxin maxima and gradients in plants. The auxin efflux carrier PIN-FORMED (PIN) family is one of the major protein families involved in PAT. Rice (Oryza sativa L.) genome possesses 12 OsPIN genes. However, the detailed functions of OsPIN genes involved in regulating the rice architecture and gravity response are less well understood. In the present study, OsPIN1b was disrupted by CRISPR/Cas9 technology, and its roles in modulating rice architecture and root gravitropism were investigated. Tissue-specific analysis showed that OsPIN1b was mainly expressed in roots, stems and sheaths at the seedling stage, and the transcript abundance was progressively decreased during the seedling stages. Expression of OsPIN1b could be quickly and greatly induced by NAA, indicating that OsPIN1b played a vital role in PAT. IAA homeostasis was disturbed in ospin1b mutants, as evidenced by the changed sensitivity of shoot and root to NAA and NPA treatment, respectively. Mutation of OsPIN1b resulted in pleiotropic phenotypes, including decreased growth of shoots and primary roots, reduced adventitious root number in rice seedlings, as well as shorter and narrower leaves, increased leaf angle, more tiller number and decreased plant height and panicle length at the late developmental stage. Moreover, ospin1b mutants displayed a curly root phenotype cultured with tap water regardless of lighting conditions, while nutrient solution culture could partially rescue the curly root phenotype in light and almost completely abolish this phenotype in darkness, indicating the involvement of the integration of light and nutrient signals in root gravitropism regulation. Additionally, amyloplast sedimentation was impaired in the peripheral tiers of the ospin1b root cap columella cell, while it was not the main contributor to the abnormal root gravitropism. These data suggest that OsPIN1b not only plays a vital role in regulating rice architecture but also functions in regulating root gravitropism by the integration of light and nutrient signals.


Assuntos
Gravitropismo , Oryza , Sistemas CRISPR-Cas , Regulação da Expressão Gênica de Plantas , Gravitropismo/genética , Ácidos Indolacéticos/metabolismo , Mutação , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Plântula/genética , Plântula/metabolismo
2.
Int J Mol Sci ; 23(16)2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36012641

RESUMO

The phytohormone salicylic acid (SA) plays a crucial role in plant growth and development. However, the mechanism of high-concentration SA-affected gravitropic response in plant root growth and root hair development is still largely unclear. In this study, wild-type, pin2 mutant and various transgenic fluorescence marker lines of Arabidopsis thaliana were investigated to understand how root growth is affected by high SA treatment under gravitropic stress conditions. We found that exogenous SA application inhibited gravitropic root growth and root hair development in a dose-dependent manner. Further analyses using DIRECT REPEAT5 (DR5)-GFP, auxin sensor DII-VENUS, auxin efflux transporter PIN2-GFP, trans-Golgi network/early endosome (TGN/EE) clathrin-light-chain 2 (CLC2)-mCherry and prevacuolar compartment (PVC) (Rha1)-mCherry transgenic marker lines demonstrated that high SA treatment severely affected auxin accumulation, root-specific PIN2 distribution and PIN2 gene transcription and promoted the vacuolar degradation of PIN2, possibly independent of clathrin-mediated endocytic protein trafficking. Our findings proposed a new underlying mechanism of SA-affected gravitropic root growth and root hair development via the regulation of PIN2 gene transcription and PIN2 protein endocytosis in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Clatrina/metabolismo , Gravitropismo/fisiologia , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Raízes de Plantas/metabolismo , Ácido Salicílico/metabolismo , Ácido Salicílico/farmacologia
3.
Int J Mol Sci ; 23(16)2022 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-36012716

RESUMO

Tiller angle is an important trait that determines plant architecture and yield in cereal crops. Tiller angle is partially controlled during gravistimulation by the dynamic re-allocation of LAZY1 (LA1) protein between the nucleus and plasma membrane, but the underlying mechanism remains unclear. In this study, we identified and characterized a new allele of LA1 based on analysis of a rice (Oryza sativa L.) spreading-tiller mutant la1G74V, which harbors a non-synonymous mutation in the predicted transmembrane (TM) domain-encoding region of this gene. The mutation causes complete loss of shoot gravitropism, leading to prostrate growth of plants. Our results showed that LA1 localizes not only to the nucleus and plasma membrane but also to the endoplasmic reticulum. Removal of the TM domain in LA1 showed spreading-tiller phenotype of plants similar to la1G74V but did not affect the plasma membrane localization; thus, making it distinct from its ortholog ZmLA1 in Zea mays. Therefore, we propose that the TM domain is indispensable for the biological function of LA1, but this domain does not determine the localization of the protein to the plasma membrane. Our study provides new insights into the LA1-mediated regulation of shoot gravitropism.


Assuntos
Gravitropismo , Oryza , Aminoácidos/metabolismo , Regulação da Expressão Gênica de Plantas , Gravitropismo/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(31): e2201350119, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35881796

RESUMO

Root angle in crops represents a key trait for efficient capture of soil resources. Root angle is determined by competing gravitropic versus antigravitropic offset (AGO) mechanisms. Here we report a root angle regulatory gene termed ENHANCED GRAVITROPISM1 (EGT1) that encodes a putative AGO component, whose loss-of-function enhances root gravitropism. Mutations in barley and wheat EGT1 genes confer a striking root phenotype, where every root class adopts a steeper growth angle. EGT1 encodes an F-box and Tubby domain-containing protein that is highly conserved across plant species. Haplotype analysis found that natural allelic variation at the barley EGT1 locus impacts root angle. Gravitropic assays indicated that Hvegt1 roots bend more rapidly than wild-type. Transcript profiling revealed Hvegt1 roots deregulate reactive oxygen species (ROS) homeostasis and cell wall-loosening enzymes and cofactors. ROS imaging shows that Hvegt1 root basal meristem and elongation zone tissues have reduced levels. Atomic force microscopy measurements detected elongating Hvegt1 root cortical cell walls are significantly less stiff than wild-type. In situ analysis identified HvEGT1 is expressed in elongating cortical and stele tissues, which are distinct from known root gravitropic perception and response tissues in the columella and epidermis, respectively. We propose that EGT1 controls root angle by regulating cell wall stiffness in elongating root cortical tissue, counteracting the gravitropic machinery's known ability to bend the root via its outermost tissues. We conclude that root angle is controlled by EGT1 in cereal crops employing an antigravitropic mechanism.


Assuntos
Produtos Agrícolas , Gravitropismo , Hordeum , Proteínas de Plantas , Raízes de Plantas , Parede Celular/química , Produtos Agrícolas/química , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Gravitropismo/genética , Hordeum/química , Hordeum/genética , Hordeum/crescimento & desenvolvimento , Microscopia de Força Atômica , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Raízes de Plantas/química , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Transcrição Genética
5.
Plant Signal Behav ; 17(1): 2098646, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-35819101

RESUMO

Root gravitropism is important for anchorage and exploration of soil for water and nutrients. It affects root architecture, which is one of the elements that influence crop yield. The mechanism of primary root gravitropism has been widely studied, but it is still not clear how lateral root gravitropism is regulated. Here, in this study, we found that Topoisomerase I α (TOP1α) repressed lateral root gravitropic growth, which was opposite to the previous report that TOP1α maintains primary root gravitropism, revealing a dual function of TOP1α in root gravitropism regulation. Further investigation showed that Target of Rapamycin (TOR) was suppressed in columella cells of lateral root to inhibit columella cell development, especially amyloplast biosynthesis. Our findings uncovered a new mechanism about lateral root gravitropism regulation, which might provide a theoretical support for improving agricultural production.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , DNA Topoisomerases Tipo I , Gravitropismo/genética , Raízes de Plantas/metabolismo
6.
Sci Rep ; 12(1): 9635, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688922

RESUMO

Arabidopsis roots grown on inclined agar surfaces exhibit unusual sinusoidal patterns known as root-waving. The origin of these patterns has been ascribed to both genetic and environmental factors. Here we propose a mechano-sensing model for root-waving, based on a combination of friction induced by gravitropism, the elasticity of the root and the anchoring of the root to the agar by thin hairs, and demonstrate its relevance to previously obtained experimental results. We further test the applicability of this model by performing experiments in which we measure the effect of gradually changing the inclination angles of the agar surfaces on the wavelength and other properties of the growing roots. We find that the observed dynamics is different than the dynamics reported in previous works, but that it can still be explained using the same mechano-sensing considerations. This is supported by the fact that a scaling relation derived from the model describes the observed dependence of the wavelength on the tilt angle for a large range of angles. We also compare the prevalence of waving in different plant species and show that it depends on root thickness as predicted by the model. The results indicate that waving can be explained using mechanics and gravitropism alone and that mechanics may play a greater role in root growth and form than was previously considered.


Assuntos
Arabidopsis , Raízes de Plantas , Ágar , Arabidopsis/genética , Gravitropismo
8.
J Integr Plant Biol ; 64(7): 1339-1351, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35475598

RESUMO

Gravitropism is an essential adaptive response of land plants. Asymmetric auxin gradients across plant organs, interpreted by multiple auxin signaling components including AUXIN RESPONSE FACTOR7 (ARF7), trigger differential growth and bending response. However, how this fundamental process is strictly maintained in nature remains unclear. Here, we report that gravity stimulates the transcription of METHYL ESTERASE17 (MES17) along the lower side of the hypocotyl via ARF7-dependent auxin signaling. The asymmetric distribution of MES17, a methyltransferase that converts auxin from its inactive form methyl indole-3-acetic acid ester (MeIAA) to its biologically active form free-IAA, enhanced the gradient of active auxin across the hypocotyl, which in turn reversely amplified the asymmetric auxin responses and differential growth that shape gravitropic bending. Taken together, our findings reveal the novel role of MES17-mediated auxin homeostasis in gravitropic responses and identify an ARF7-triggered feedback mechanism that reinforces the asymmetric distribution of active auxin and strictly controls gravitropism in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Retroalimentação , Gravitropismo/fisiologia , Homeostase , Ácidos Indolacéticos , Raízes de Plantas , Fatores de Transcrição
9.
Methods Mol Biol ; 2494: 3-16, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35467196

RESUMO

Gravity is a powerful element in shaping plant development, with gravitropism, the oriented growth response of plant organs to the direction of gravity, leading to each plant's characteristic form both above and below ground. Despite being conceptually simple to follow, monitoring a plant's directional growth responses can become complex as variation arises from both internal developmental cues as well as effects of the environment. In this protocol, we discuss approaches to gravitropism assays, focusing on automated analyses of root responses. For Arabidopsis, we recommend a simple 90° rotation using seedlings that are 5-8 days old. If images are taken at regular intervals and the environmental metadata is recorded during both seedling development and gravitropic assay, these data can be used to reveal quantitative kinetic patterns at distinct stages of the assay. The use of software that analyzes root system parameters and stores this data in the RSML format opens up the possibility for a host of root parameters to be extracted to characterize growth of the primary root and a range of lateral root phenotypes.


Assuntos
Arabidopsis , Gravitropismo , Arabidopsis/genética , Gravitropismo/fisiologia , Desenvolvimento Vegetal , Raízes de Plantas/genética , Plantas
10.
BMC Plant Biol ; 22(1): 156, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35354405

RESUMO

BACKGROUND: The tomato psyllid, Bactericera cockerelli Sulc (Hemiptera: Triozidae), is a pest of solanaceous crops such as tomato (Solanum lycopersicum L.) in the U.S. and vectors the disease-causing pathogen 'Candidatus Liberibacter solanacearum' (or Lso). Disease symptom severity is dependent on Lso haplotype: tomato plants infected with Lso haplotype B experience more severe symptoms and higher mortality compared to plants infected with Lso haplotype A. By characterizing the molecular differences in the tomato plant's responses to Lso haplotypes, the key components of LsoB virulence can be identified and, thus, targeted for disease mitigation strategies. RESULTS: To characterize the tomato plant genes putatively involved in the differential immune responses to Lso haplotypes A and B, RNA was extracted from tomato 'Moneymaker' leaves 3 weeks after psyllid infestation. Gene expression levels were compared between uninfected tomato plants (i.e., controls and plants infested with Lso-free psyllids) and infected plants (i.e., plants infested with psyllids infected with either Lso haplotype A or Lso haplotype B). Furthermore, expression levels were compared between plants infected with Lso haplotype A and plants infected with Lso haplotype B. A whole transcriptome analysis identified 578 differentially expressed genes (DEGs) between uninfected and infected plants as well as 451 DEGs between LsoA- and LsoB-infected plants. These DEGs were primarily associated with plant defense against abiotic and biotic stressors, growth/development, plant primary metabolism, transport and signaling, and transcription/translation. These gene expression changes suggested that tomato plants traded off plant growth and homeostasis for improved defense against pathogens, especially when infected with LsoB. Consistent with these results, tomato plant growth experiments determined that LsoB-infected plants were significantly stunted and had impaired negative geotropism. However, it appeared that the defense responses mounted by tomatoes were insufficient for overcoming the disease symptoms and mortality caused by LsoB infection, while these defenses could compensate for LsoA infection. CONCLUSION: The transcriptomic analysis and growth experiments demonstrated that Lso-infected tomato plants underwent gene expression changes related to abiotic and biotic stressors, impaired growth/development, impaired plant primary metabolism, impaired transport and signaling transduction, and impaired transcription/translation. Furthermore, the transcriptomic analysis also showed that LsoB-infected plants, relative to LsoA-infected, experienced more severe stunting, had improved responses to some stressors and impaired responses to others, had poorer transport and signaling transduction, and had impaired carbohydrate synthesis and photosynthesis.


Assuntos
Lycopersicon esculentum , Rhizobiaceae , Expressão Gênica , Gravitropismo , Haplótipos , Liberibacter , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Rhizobiaceae/genética
11.
Plant Physiol Biochem ; 171: 191-200, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35007950

RESUMO

We performed a series of experiments to study the interaction between phototropism and gravitropism in Arabidopsis thaliana as part of the Seedling Growth Project on the International Space Station. Red-light-based and blue-light-based phototropism were examined in microgravity and at 1g, a control that was produced by an on-board centrifuge. At the end of the experiments, seedlings were frozen and brought back to Earth for gene profiling studies via RNASeq methods. In this paper, we focus on five genes identified in these space studies by their differential expression in space: one involved in auxin transport and four others encoding genes for: a methyltransferase subunit, a transmembrane protein, a transcription factor for endodermis formation, and a cytoskeletal element (an intermediate filament protein). Time course studies using mutant strains of these five genes were performed for blue-light and red-light phototropism studies as well as for gravitropism assays on ground. Interestingly, all five of the genes had some effects on all the tropisms under the conditions studied. In addition, RT-PCR analyses examined expression of the five genes in wild-type seedlings during blue-light-based phototropism. Previous studies have supported a role of both microfilaments and microtubules in tropism pathways. However, the most interesting finding of the present space studies is that NFL, a gene encoding an intermediate filament protein, plays a role in phototropism and gravitropism, which opens the possibility that this cytoskeletal element modulates signal transduction in plants.


Assuntos
Voo Espacial , Ausência de Peso , Gravitropismo/genética , Filamentos Intermediários , Luz , Fototropismo
12.
Life Sci Space Res (Amst) ; 32: 8-16, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35065766

RESUMO

Long-duration space missions will need to rely on the use of plants in bio-regenerative life support systems (BLSSs) because these systems can produce fresh food and oxygen, reduce carbon dioxide levels, recycle metabolic waste, and purify water. In this scenario, the need for new experiments on the effects of altered gravity conditions on plant biological processes is increasing, and significant efforts should be devoted to new ideas aimed at increasing the scientific output and lowering the experimental costs. Here, we report the design of an easy-to-produce and inexpensive device conceived to analyze the effect of interaction between gravity and light on root tropisms. Each unit consisted of a polystyrene multi-slot rack with light-emitting diodes (LEDs), capable of holding Petri dishes and assembled with a particular filter-paper folding. The device was successfully used for the ROOTROPS (for root tropisms) experiment performed in the Large Diameter Centrifuge (LDC) and Random Positioning Machine (RPM) at ESA's European Space Research and Technology centre (ESTEC). During the experiments, four light treatments and six gravity conditions were factorially combined to study their effects on root orientation of Brassica oleracea seedlings. Light treatments (red, blue, and white) and a dark condition were tested under four hypergravity levels (20 g, 15 g, 10 g, 5 g), a 1 g control, and a simulated microgravity (RPM) condition. Results of validation tests showed that after 24 h, the assembled system remained unaltered, no slipping or displacement of seedlings occurred at any hypergravity treatment or on the RPM, and seedlings exhibited robust growth. Overall, the device was effective and reliable in achieving scientific goals, suggesting that it can be used for ground-based research on phototropism-gravitropism interactions. Moreover, the concepts developed can be further expanded for use in future spaceflight experiments with plants.


Assuntos
Voo Espacial , Ausência de Peso , Gravitropismo , Fototropismo , Plântula , Tropismo
13.
Plant Signal Behav ; 17(1): 2025325, 2022 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-35023420

RESUMO

Gravitropism is an important strategy for the adaptation of plants to the changing environment. Previous reports indicated that Ca2+ participated in plant gravity response. However, present information on the functions of Ca2+ in plant gravitropism was obtained mainly on coleoptiles, hypocotyls, and petioles, little is known about the dynamic changes of Ca2+ during root gravitropism. In the present study, the transgenic Arabidopsis thaliana R-GECO1 was placed horizontally and subsequently vertically on a refitted Leica SP8 laser scanning confocal microscopy with a vertical stage. Real-time observations indicated that gravistimulation induced not only an increase in the Ca2+ concentration, but also an accelerated occurrence of Ca2+ sparks in the root cap, especially in the lower side of the lateral root cap, indicating a strong tie between Ca2+ dynamics and gravistimulation during the early stage of root gravity response.


Assuntos
Arabidopsis , Gravitropismo , Arabidopsis/genética , Gravitação , Gravitropismo/fisiologia , Sensação Gravitacional , Hipocótilo , Raízes de Plantas/fisiologia
14.
Trends Plant Sci ; 27(5): 440-449, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34848141

RESUMO

The phytohormone auxin is the major growth regulator governing tropic responses including gravitropism. Auxin build-up at the lower side of stimulated shoots promotes cell expansion, whereas in roots it inhibits growth, leading to upward shoot bending and downward root bending, respectively. Yet it remains an enigma how the same signal can trigger such opposite cellular responses. In this review, we discuss several recent unexpected insights into the mechanisms underlying auxin regulation of growth, challenging several existing models. We focus on the divergent mechanisms of apoplastic pH regulation in shoots and roots revisiting the classical Acid Growth Theory and discuss coordinated involvement of multiple auxin signaling pathways. From this emerges a more comprehensive, updated picture how auxin regulates growth.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Gravitropismo , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo
16.
Plant Mol Biol ; 108(1-2): 31-49, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34601701

RESUMO

KEY MESSAGE: Arabidopsis PLDζ1 and PLDζ2 localize to the trans-Golgi network and to compartments including the trans-Golgi network, multi-vesicular bodies, and the tonoplast, respectively, depending on their N-terminal regions containing PX-PH domains. Phospholipase D (PLD) is involved in dynamic cellular processes, including membrane trafficking, cytoskeletal reorganization, and signal transduction for gene expression, through the production of phosphatidic acid in membrane compartments specific to each process. Although PLD plays crucial roles in various plant phenomena, the underlying processes involving PLD for each phenomenon remain largely elusive, partly because the subcellular localization of PLD remains obscure. In this study, we performed comparative subcellular localization analyses of the Arabidopsis thaliana PX-PH-PLDs PLDζ1 and PLDζ2. In mature lateral root cap cells, own promoter-driven fluorescence protein fusions of PLDζ1 localized to the entire trans-Golgi network (TGN) while that of PLDζ2 localized to punctate structures including part of the TGN and multi-vesicular bodies as well as the tonoplast. These localization patterns were reproduced using N-terminal partial proteins, which contain PX-PH domains. An inducibly overexpressed fluorescence protein fusion of the PLDζ2 partial protein first localized to punctate structures, and then accumulated predominantly on the tonoplast. Further domain dissection analysis revealed that the N-terminal moiety preceding the PX-PH domain of PLDζ2 was required for the tonoplast-predominant accumulation. These findings suggest that PLDζ1 and PLDζ2 play partially overlapping but nonetheless distinctive roles in post-Golgi compartments along the membrane trafficking pathway from the TGN to the tonoplast.


Assuntos
Proteínas de Arabidopsis/metabolismo , Complexo de Golgi/metabolismo , Fosfolipase D/metabolismo , Arabidopsis/metabolismo , Gravitropismo , Microscopia Confocal , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real
17.
Protoplasma ; 259(4): 917-935, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34595603

RESUMO

The growing zone (GZ) of the unicellular coenocytic sporangiophore of Phycomyces blakesleeanus represents the site of stimulus reception (light, gravity, gas) and stimulus response, i.e., local modulations of the elongation growth, which may result, in dependence of the stimulus direction, in tropic bending. Until now, evidence for a possible participation of the columella in sensory reception is absent. We confirm with light microscopy earlier studies that show that the GZ and the columella are not separated by a membrane or cell wall, but rather form a spatial continuum that allows free exchange of cytoplasm and organelle transport. Evidence is presented that the columella is responsive to external stimuli. Columellae, from which spores and sporangial cell wall had been removed, respond to exogenous auxin with a local depolarization of the membrane potential and an increased growth rate of the GZ. In contrast, auxin applied to the GZ causes a decrease of the growth rate irrespective of the presence or absence of sporangia. The response pattern is specific and relevant for the sensory reception of Phycomyces, because the light-insensitive mutant C148carAmadC, which lacks the RAS-GAP protein MADC, displays abnormal IAA sensitivity and membrane depolarization. We argue that the traditional concept of the GZ as the only stimulus-sensitive zone should be abandoned in favor of a model in which GZ and columella operate as a single entity capable to orchestrate a multitude of stimulus inputs, including auxin, to modulate the membrane potential and elongation growth of the GZ.


Assuntos
Phycomyces , Gravitropismo/fisiologia , Ácidos Indolacéticos , Luz , Potenciais da Membrana , Organelas , Transdução de Sinais
18.
Mol Plant ; 15(1): 125-137, 2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34896639

RESUMO

Crop plant architecture is an important agronomic trait that contributes greatly to crop yield. Tiller angle is one of the most critical components that determine crop plant architecture, which in turn substantially affects grain yield mainly owing to its large influence on plant density. Gravity is a fundamental physical force that acts on all organisms on earth. Plant organs sense gravity to control their growth orientation, including tiller angle in rice (Oryza sativa). This review summarizes recent research advances made using rice tiller angle as a research model, providing insights into domestication of rice tiller angle, genetic regulation of rice tiller angle, and shoot gravitropism. Finally, we propose that current discoveries in rice can shed light on shoot gravitropism and improvement of plant tiller/branch angle in other species, thereby contributing to agricultural production in the future.


Assuntos
Gravitropismo/genética , Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Oryza/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/genética , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas
19.
Methods Mol Biol ; 2368: 43-51, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34647246

RESUMO

Tropisms are among the most important growth responses for plant adaptation to the surrounding environment. One of the most common tropisms is root gravitropism. Root gravitropism enables the plant to anchor securely to the soil enabling the absorption of water and nutrients. Most of the knowledge related to the plant gravitropism has been acquired from the flowering plants, due to limited research in non-seed plants. Limited research on non-seed plants is due in large part to the lack of standard research methods. Here, we describe the experimental methods to evaluate gravitropism in representative non-seed plant species, including the non-vascular plant moss Physcomitrium patens, the early diverging extant vascular plant lycophyte Selaginella moellendorffii and fern Ceratopteris richardii. In addition, we introduce the methods used for statistical analysis of the root gravitropism in non-seed plant species.


Assuntos
Gravitropismo , Bryopsida , Plantas , Pteridaceae
20.
Methods Mol Biol ; 2368: 61-70, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34647248

RESUMO

The ability of roots to orient their growth relative to the vector of gravity, root gravitropism (positive gravitropism), is observed in root systems of higher plants and is an essential part of plant growth and development. While there are various methods for quantifying root gravitropism, many methods that can efficiently measure gravitropism at a reasonable throughput do not yield temporal resolution of the process, while methods that allow for high-temporal resolution are often not suitable for an efficient measurement of multiple roots. Here, we describe a method to analyze the root gravitropism activity at an increased throughput with a fine time-resolution using Arabidopsis thaliana plants.


Assuntos
Ágar , Arabidopsis , Proteínas de Arabidopsis , Gravitropismo , Raízes de Plantas
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