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1.
Plant Sci ; 311: 110986, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34482923

RESUMO

In recent years, the plant morphology has been well studied by multiple approaches at cellular and subcellular levels. Two-dimensional (2D) microscopy techniques offer imaging of plant structures on a wide range of magnifications for researchers. However, subcellular imaging is still challenging in plant tissues like roots and seeds. Here we use a three-dimensional (3D) imaging technology based on the X-ray microscope (XRM) and analyze several plant tissues from different plant species. The XRM provides new insights into plant structures using non-destructive imaging at high-resolution and high contrast. We also utilized a workflow aiming to acquire accurate and high-quality images in the context of the whole specimen. Multiple plant samples including rice, tobacco, Arabidopsis and maize were used to display the differences of phenotypes. Our work indicates that the XRM is a powerful tool to investigate plant microstructure in high-resolution scale. Our work also provides evidence that evaluate and quantify tissue specific differences for a range of plant species. We also characterize novel plant tissue phenotypes by the XRM, such as seeds in Arabidopsis, and utilize them for novel observation measurement. Our work represents an evaluated spatial and temporal resolution solution on seed observation and screening.


Assuntos
Arabidopsis/ultraestrutura , Imageamento Tridimensional , Organelas/ultraestrutura , Oryza/ultraestrutura , Sementes/ultraestrutura , Tabaco/ultraestrutura , Zea mays/ultraestrutura , Oryza/anatomia & histologia , Tomografia Computadorizada por Raios X
2.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360554

RESUMO

Leaf angle and grain size are important agronomic traits affecting rice productivity directly and/or indirectly through modulating crop architecture. OsBC1, as a typical bHLH transcription factor, is one of the components comprising a complex formed with LO9-177 and OsBUL1 contributing to modulation of rice leaf inclination and grain size. In the current study, two homologues of OsBC1, OsBCL1 and OsBCL2 were functionally characterized by expressing them under the control of OsBUL1 promoter, which is preferentially expressed in the lamina joint and the spikelet of rice. Increased leaf angle and grain length with elongated cells in the lamina joint and the grain hull were observed in transgenic rice containing much greater gibberellin A3 (GA3) levels than WT, demonstrating that both OsBCL1 and OsBCL2 are positive regulators of cell elongation at least partially through increased GA biosynthesis. Moreover, the cell elongation was likely due to cell expansion rather than cell division based on the related gene expression and, the cell elongation-promoting activities of OsBCL1 and OsBCL2 were functional in a dicot species, Arabidopsis.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/anatomia & histologia , Fenótipo , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
3.
BMC Plant Biol ; 21(1): 398, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433428

RESUMO

BACKGROUND: The root distribution in the soil is one of the elements that comprise the root system architecture (RSA). In monocots, RSA comprises radicle and crown roots, each of which can be basically represented by a single curve with lateral root branches or approximated using a polyline. Moreover, RSA vectorization (polyline conversion) is useful for RSA phenotyping. However, a robust software that can enable RSA vectorization while using noisy three-dimensional (3D) volumes is unavailable. RESULTS: We developed RSAtrace3D, which is a robust 3D RSA vectorization software for monocot RSA phenotyping. It manages the single root (radicle or crown root) as a polyline (a vector), and the set of the polylines represents the entire RSA. RSAtrace3D vectorizes root segments between the two ends of a single root. By utilizing several base points on the root, RSAtrace3D suits noisy images if it is difficult to vectorize it using only two end nodes of the root. Additionally, by employing a simple tracking algorithm that uses the center of gravity (COG) of the root voxels to determine the tracking direction, RSAtrace3D efficiently vectorizes the roots. Thus, RSAtrace3D represents the single root shape more precisely than straight lines or spline curves. As a case study, rice (Oryza sativa) RSA was vectorized from X-ray computed tomography (CT) images, and RSA traits were calculated. In addition, varietal differences in RSA traits were observed. The vector data were 32,000 times more compact than raw X-ray CT images. Therefore, this makes it easier to share data and perform re-analyses. For example, using data from previously conducted studies. For monocot plants, the vectorization and phenotyping algorithm are extendable and suitable for numerous applications. CONCLUSIONS: RSAtrace3D is an RSA vectorization software for 3D RSA phenotyping for monocots. Owing to the high expandability of the RSA vectorization and phenotyping algorithm, RSAtrace3D can be applied not only to rice in X-ray CT images but also to other monocots in various 3D images. Since this software is written in Python language, it can be easily modified and will be extensively applied by researchers in this field.


Assuntos
Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Fenótipo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Software , Algoritmos , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/crescimento & desenvolvimento , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos
4.
BMC Plant Biol ; 21(1): 390, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34418975

RESUMO

BACKGROUND: Panicle is a harvesting organ of rice, and its morphology and development are closely associated with grain yield. The current study was carried on a mutant screened through an EMS (ethyl-methane sulphonate) mutagenized population of a Japonica cultivar Kitaake (WT). RESULTS: A mutant, named as asp-lsl (aberrant spikelet-long sterile lemma), showed a significant decrease in plant height, number of tillers, thousand-grains weight, seed setting rate, spikelet length, kernel length and effective number of grains per panicle as compared to WT. Asp-lsl showed a pleiotropic phenotype coupled with the obvious presence of a long sterile lemma. Cross-sections of lemma showed an increase in the cell volume rather than the number of cells. Genetic segregation analysis revealed its phenotypic trait is controlled by a single recessive nuclear gene. Primary and fine mapping indicated that candidate gene controlling the phenotype of asp-lsl was located in an interval of 212 kb on the short arm of chromosome 8 between RM22445 and RM22453. Further sequencing and indels markers analysis revealed LOC_Os08g06480 harbors a single base substitution (G→A), resulting in a change of 521st amino acid(Gly→Glu. The homology comparison and phylogenetic tree analysis revealed mutation was occurred in a highly conserved domain and had a high degree of similarity in Arabidopsis, corn, and sorghum. The CRISPR/Cas9 mutant line of ASP-LSL produced a similar phenotype as that of asp-lsl. Subcellular localization of ASP-LSL revealed that its protein is localized in the nucleus. Relative expression analysis revealed ASP-LSL was preferentially expressed in panicle, stem, and leaves. The endogenous contents of GA, CTK, and IAA were found significantly decreased in asp-lsl as compared to WT. CONCLUSIONS: Current study presents the novel phenotype of asp-lsl and also validate the previously reported function of OsREL2 (ROMOSA ENHANCER LOCI2), / ASP1(ABERRANT SPIKELET AND PANICLE 1).


Assuntos
Flores/anatomia & histologia , Flores/crescimento & desenvolvimento , Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Oryza/genética , Caules de Planta/anatomia & histologia , Caules de Planta/crescimento & desenvolvimento , China , Grão Comestível/anatomia & histologia , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Fenótipo
5.
J Plant Physiol ; 264: 153482, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34330009

RESUMO

C4 plants are superior to C3 plants in terms of productivity and limited photorespiration. PPDK (pyruvate orthophosphate dikinase) and NADP-ME (NADP-dependent malic enzyme) are two important photosynthetic C4-specific enzymes present in the mesophyll cells of C4 plants. To evaluate the effect of C4 enzymes in rice, we developed transgenic rice lines by separately introducing Setaria italica PPDK [SiPPDK] and S. italica ME [SiME] gene constructs under the control of the green tissue-specific maize PPDK promoter. Rice plant lines for both constructs were screened using the polymerase chain reaction (PCR), Southern hybridization, and expression analysis. The best transgenic plant lines for each case were selected for physiological and biochemical characterization. The results from qRT-PCR and enzyme activity analysis revealed higher expression and activity of both PPDK and NADP-ME genes compared with the nontransformed and empty-vector-transformed plants. The average photosynthetic efficiency of transgenic plant lines carrying the PPDK and NADP-ME genes increased by 18% and 12%, respectively, and was positively correlated with the increased accumulation of photosynthetic pigment. The decrease in Fv/Fm, increased electron transport rate (ETR), and increased photochemical quenching (qP) compared with nontransformed control plants suggest that transgenic rice plants transferred more absorbed light energy to photochemical reactions than wild-type plants. SiME-transgenic plants displayed reduced leaf malate content and superior performance under water deficit conditions. Interestingly, the transgenic plants showed yield enhancement by exhibiting increased plant height, panicle length, panicle weight and thousand grain weight. Overall, the exogenous foxtail millet C4 gene PPDK enhanced photosynthesis and yield to a greater extent than NADP-ME.


Assuntos
Genes de Plantas/genética , Malato Desidrogenase/genética , Oryza/genética , Proteínas de Plantas/genética , Piruvato Ortofosfato Diquinase/genética , Setaria (Planta)/genética , Clorofila/metabolismo , Clonagem Molecular , Malato Desidrogenase/metabolismo , Oryza/anatomia & histologia , Oryza/enzimologia , Oryza/metabolismo , Fotossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/anatomia & histologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Piruvato Ortofosfato Diquinase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Setaria (Planta)/enzimologia , Setaria (Planta)/metabolismo
6.
Nat Plants ; 7(7): 966-978, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34183783

RESUMO

Pollen apertures are an interesting model for the formation of specialized plasma-membrane domains. The plant-specific protein INP1 serves as a key aperture factor in such distantly related species as Arabidopsis, rice and maize. Although INP1 orthologues probably play similar roles throughout flowering plants, they show substantial sequence divergence and often cannot substitute for each other, suggesting that INP1 might require species-specific partners. Here, we present a new aperture factor, INP2, which satisfies the criteria for being a species-specific partner for INP1. Both INP proteins display similar structural features, including the plant-specific DOG1 domain, similar patterns of expression and mutant phenotypes, as well as signs of co-evolution. These proteins interact with each other in a species-specific manner and can restore apertures in a heterologous system when both are expressed but not when expressed individually. Our findings suggest that the INP proteins form a species-specific functional module that underlies formation of pollen apertures.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Pólen/anatomia & histologia , Pólen/crescimento & desenvolvimento , Pólen/genética , Zea mays/crescimento & desenvolvimento , Arabidopsis/anatomia & histologia , Arabidopsis/genética , Parede Celular/genética , Parede Celular/metabolismo , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Oryza/anatomia & histologia , Oryza/genética , Fenótipo , Proteínas de Plantas/genética , Especificidade da Espécie , Zea mays/anatomia & histologia , Zea mays/genética
7.
Plant Sci ; 308: 110878, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34034879

RESUMO

Oryza coarctata is an obligate halophyte of wild species of rice which thrives well under high saline as well as submerged conditions. We report here for the first time that O. coarctata is triploid (2n = 3x = 36), though it was previously known as tetraploid (2n = 4x = 48). The chromosome number of O. coarctata was determined from mitotic plates of root tips and ploidy level was determined by flow cytometer, where it was found to be triploid (2n = 3x = 36). In addition, this species was found to possess several unique anatomical features in leaves such as presence of Kranz-anatomy, increased vein density and higher ratio of bundle sheath to mesophyll cell area as compared to rice variety (IR-29). Ultra-structure of leaf showed the presence of bundle sheath cells with significant number of chloroplasts and mitochondria which were arranged centrifugally. Chloroplasts lack grana in bundle sheath cell whereas, mesophyll cell contain well-developed grana. These anatomical and ultra structural characteristics indicate that this plant is in initial stage of evolving towards C4 photosynthesis due to high selection pressure which might help it to survive in wide range of ecological conditions i.e. from submerged saline to non-saline terrestrial condition.


Assuntos
Evolução Biológica , Ciclo do Carbono , Oryza/anatomia & histologia , Fotossíntese , Triploidia , Oryza/genética , Folhas de Planta/anatomia & histologia
8.
Int J Mol Sci ; 22(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919137

RESUMO

Introduction of C4 photosynthetic traits into C3 crops is an important strategy for improving photosynthetic capacity and productivity. Here, we report the research results of a variant line of sorghum-rice (SR) plant with big panicle and high spikelet density by introducing sorghum genome DNA into rice by spike-stalk injection. The whole-genome resequencing showed that a few sorghum genes could be integrated into the rice genome. Gene expression was confirmed for two C4 photosynthetic enzymes containing pyruvate, orthophosphate dikinase and phosphoenolpyruvate carboxykinase. Exogenous sorghum DNA integration induced a series of key traits associated with the C4 pathway called "proto-Kranz" anatomy, including leaf thickness, bundle sheath number and size, and chloroplast size in bundle sheath cells. Significantly, transgenic plants exhibited enhanced photosynthetic capacity resulting from both photosynthetic CO2-concentrating effect and improved energy balance, which led to an increase in carbohydrate levels and productivity. Furthermore, such rice plant exhibited delayed leaf senescence. In summary, this study provides a proof for the feasibility of inducing the transition from C3 leaf anatomy to proto-Kranz by spike-stalk injection to achieve efficient photosynthesis and increase productivity.


Assuntos
Oryza/fisiologia , Fotossíntese , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Sorghum/fisiologia , Dióxido de Carbono/metabolismo , Genoma de Planta , Oryza/anatomia & histologia , Oryza/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/anatomia & histologia , Plantas Geneticamente Modificadas/genética , Sorghum/anatomia & histologia , Sorghum/genética
9.
Mol Biol Rep ; 48(3): 2209-2221, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33675464

RESUMO

Rice varietal identification is a crucial aspect in breeding, seed production and trade in order to protect the interests of the farmers and consumers. As the number of varieties released is rising every year, the need to identify them unambiguously also increases. Here, we developed a novel barcode system to identify 62 rice genotypes using agro-morphological descriptors and molecular markers. In all, 62 rice genotypes, for 22 agro-morphological traits were recorded. In addition, 19 molecular markers were used for developing genotype-specific DNA fingerprints. The descriptor notes of 10 essential agro-morphological traits and allele codes of the polymorphic markers were used to generate two-dimensional (2-D) barcodes for the rice genotypes. Using agro-morphological traits, 31 rice genotypes were unambiguously distinguished while, with the polymorphic markers we were able to distinguish all rice genotypes except BPT2295 and Jaya. However, using both agro-morphological descriptors and molecular markers in combination, it was possible to distinguish all the rice genotypes used in the present study. These agro-morphological notes and allele codes from the molecular marker data together were used to develop QR (Quick Response) codes for rapid identification of rice genotypes as they facilitate storage of more data. In the present investigation, we have demonstrated the potentiality of agro-morphological traits and molecular markers in distinguishing rice genotypes. The novel QR code system proposed in the present study can also be extended to other crops not only for varietal identification but also for germplasm management and trade.


Assuntos
Agricultura , Código de Barras de DNA Taxonômico , Oryza/anatomia & histologia , Oryza/genética , Impressões Digitais de DNA , Marcadores Genéticos , Genótipo , Melhoramento Vegetal
10.
J Vis Exp ; (168)2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33645568

RESUMO

Roots extensively interact with their soil environment but visualizing such interactions between roots and the surrounding rhizosphere is challenging. The rhizosphere chemistry of wetland plants is particularly challenging to capture because of steep oxygen gradients from the roots to the bulk soil. Here a protocol is described that effectively preserves root structure and rhizosphere chemistry of wetland plants through slam-freezing and freeze drying. Slam-freezing, where the sample is frozen between copper blocks pre-cooled with liquid nitrogen, minimizes root damage and sample distortion that can occur with flash-freezing while still minimizing chemical speciation changes. While sample distortion is still possible, the ability to obtain multiple samples quickly and with minimal cost increases the potential to obtain satisfactory samples and optimizes imaging time. The data show that this method is successful in preserving reduced arsenic species in rice roots and rhizospheres associated with iron plaques. This method can be adopted for studies of plant-soil relationships in a wide variety of wetland environments that span concentration ranges from trace-element cycling to phytoremediation applications.


Assuntos
Elementos Químicos , Imageamento Tridimensional/métodos , Raízes de Plantas/química , Rizosfera , Áreas Alagadas , Liofilização , Oryza/anatomia & histologia , Solo/química
11.
Plant Physiol ; 185(2): 457-468, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721897

RESUMO

Root system architecture (RSA) is a key factor in the efficiency of nutrient capture and water uptake in plants. Understanding the genetic control of RSA will be useful in minimizing fertilizer and water usage in agricultural cropping systems. Using a hydroponic screen and a gel-based imaging system, we identified a rice (Oryza sativa) gene, VAP-RELATED SUPPRESSOR OF TOO MANY MOUTHS1 (OsVST1), which plays a key role in controlling RSA. This gene encodes a homolog of the VAP-RELATED SUPPRESSORS OF TOO MANY MOUTHS (VST) proteins in Arabidopsis (Arabidopsis thaliana), which promote signaling in stomata by mediating plasma membrane-endoplasmic reticulum contacts. OsVST1 mutants have shorter primary roots, decreased root meristem size, and a more compact RSA. We show that the Arabidopsis VST triple mutants have similar phenotypes, with reduced primary root growth and smaller root meristems. Expression of OsVST1 largely complements the short root length and reduced plant height in the Arabidopsis triple mutant, supporting conservation of function between rice and Arabidopsis VST proteins. In a field trial, mutations in OsVST1 did not adversely affect grain yield, suggesting that modulation of this gene could be used as a way to optimize RSA without an inherent yield penalty.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Oryza/genética , Proteínas de Plantas/metabolismo , Transdução de Sinais , Arabidopsis/anatomia & histologia , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Expressão Gênica , Hidroponia , Meristema/anatomia & histologia , Meristema/genética , Meristema/crescimento & desenvolvimento , Mutação , Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Fenótipo , Proteínas de Plantas/genética , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento
12.
Plant Cell ; 33(5): 1417-1429, 2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-33647940

RESUMO

Both genetic and epigenetic information must be transferred from mother to daughter cells during cell division. The mechanisms through which information about chromatin states and epigenetic marks like histone 3 lysine 27 trimethylation (H3K27me3) are transferred have been characterized in animals; these processes are less well understood in plants. Here, based on characterization of a dwarf rice (Oryza sativa) mutant (dwarf-related wd40 protein 1, drw1) deficient for yeast CTF4 (CHROMOSOME TRANSMISSION FIDELITY PROTEIN 4), we discovered that CTF4 orthologs in plants use common cellular machinery yet accomplish divergent functional outcomes. Specifically, drw1 exhibited no flowering-related phenotypes (as in the putatively orthologous Arabidopsis thaliana eol1 mutant), but displayed cell cycle arrest and DNA damage responses. Mechanistically, we demonstrate that DRW1 sustains normal cell cycle progression by modulating the expression of cell cycle inhibitors KIP-RELATED PROTEIN 1 (KRP1) and KRP5, and show that these effects are mediated by DRW1 binding their promoters and increasing H3K27me3 levels. Thus, although CTF4 orthologs ENHANCER OF LHP1 1 (EOL1) in Arabidopsis and DRW1 in rice are both expressed uniquely in dividing cells, commonly interact with several Polycomb complex subunits, and promote H3K27me3 deposition, we now know that their regulatory functions diverged substantially during plant evolution. Moreover, our work experimentally illustrates specific targets of CTF4/EOL1/DRW1, their protein-proteininteraction partners, and their chromatin/epigenetic effects in plants.


Assuntos
Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Núcleo Celular/metabolismo , Dano ao DNA , DNA Polimerase I/metabolismo , Flores/fisiologia , Histonas/metabolismo , Lisina/metabolismo , Metilação , Mutação/genética , Oryza/anatomia & histologia , Oryza/citologia , Fenótipo , Proteínas de Plantas/genética , Ligação Proteica , Fase S
13.
Plant Sci ; 304: 110734, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33568286

RESUMO

OVATE family proteins (OFPs) are plant-specific transcription factors that regulate plant growth and development. OFPs interact with 3-aa loop extension (TALE) homeodomain proteins and brassinosteroid (BR) signaling components to modulate gibberellic acid (GA) biosynthesis and BR responses. Bioactive GAs are essential in regulating plant organogenesis and organ growth by promoting cell differentiation and elongation. DELLA proteins act as the central repressors of GA-regulated processes and are targeted to be degraded by the 26S proteasome in the presence of GA. We discovered that the rice OFP22 negatively regulates GA and BR signal transduction. OsOFP22 expression was rapidly up-regulated by exogenous GA and BR application, detected predominantly in the calli and spikelets. Overexpression of OsOFP22 conferred multiple morphological phenotypes, including reduced plant height, dark green leaves, and shortened and widened leaves, floral organs and grains. The GA-induced elongation of the second leaf sheath in the seedlings, and α-amylase activity in the endosperms were attenuated in transgenic lines overexpressing OsOFP22, while GA-biosynthesis gene transcripts and bioactive GA3 and GA4 contents were increased in the transgenic plants. OsOFP22 promotes the protein accumulation of SLR1, the single DELLA in rice protein. Furthermore, Overexpression of OsOFP22 suppresses BR response and the expression of BR-related genes. OsOFP22 is thus involved in the repression of GA and BR signal transduction and integrates GA with BR to regulate plant growth and development.


Assuntos
Brassinosteroides/metabolismo , Giberelinas/metabolismo , Oryza/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Transdução de Sinais , Western Blotting , Regulação da Expressão Gênica de Plantas , Oryza/anatomia & histologia , Oryza/genética , Reguladores de Crescimento de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia
14.
Mol Plant ; 14(1): 9-26, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33316465

RESUMO

Crop domestication has fundamentally altered the course of human history, causing a shift from hunter-gatherer to agricultural societies and stimulating the rise of modern civilization. A greater understanding of crop domestication would provide a theoretical basis for how we could improve current crops and develop new crops to deal with environmental challenges in a sustainable manner. Here, we provide a comprehensive summary of the similarities and differences in the domestication processes of maize and rice, two major staple food crops that feed the world. We propose that maize and rice might have evolved distinct genetic solutions toward domestication. Maize and rice domestication appears to be associated with distinct regulatory and evolutionary mechanisms. Rice domestication tended to select de novo, loss-of-function, coding variation, while maize domestication more frequently favored standing, gain-of-function, regulatory variation. At the gene network level, distinct genetic paths were used to acquire convergent phenotypes in maize and rice domestication, during which different central genes were utilized, orthologous genes played different evolutionary roles, and unique genes or regulatory modules were acquired for establishing new traits. Finally, we discuss how the knowledge gained from past domestication processes, together with emerging technologies, could be exploited to improve modern crop breeding and domesticate new crops to meet increasing human demands.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Domesticação , Oryza/crescimento & desenvolvimento , Melhoramento Vegetal , Zea mays/crescimento & desenvolvimento , Evolução Biológica , Oryza/anatomia & histologia , Oryza/genética , Zea mays/anatomia & histologia , Zea mays/genética
15.
Plant Sci ; 302: 110715, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288021

RESUMO

The vascular bundles play important roles in transportation of photoassimilate, and the number, size, and capacity of vascular bundles influence the transportation efficiency. Dissecting the genetic basis may help to make better use of naturally occurring vascular bundle variations. Here, we conducted a genome-wide association study (GWAS) of the vascular bundle variations in a worldwide collection of 529 Oryza sativa accessions. A total of 42 and 93 significant association loci were identified in the neck panicle and flag leaf, respectively. The introgression lines showing extreme values of the target traits harbored at least one GWAS signal, indicating the reliability of the GWAS loci. Based on the data of near-isogenic lines and transgenic plants, Grain number, plant height, and heading date7 (Ghd7) was identified as a major locus for the natural variation of vascular bundles in the neck panicle at the heading stage. In addition, Narrow leaf1 (NAL1) was found to influence the vascular bundles in both the neck panicle and flag leaf, and the effects of the major haplotypes of NAL1 were characterized. The loci or candidate genes identified would help to improve vascular bundle system in rice breeding.


Assuntos
Oryza/genética , Feixe Vascular de Plantas/genética , Genes de Plantas/genética , Genes de Plantas/fisiologia , Introgressão Genética/genética , Estudo de Associação Genômica Ampla , Haplótipos/genética , Desequilíbrio de Ligação/genética , Oryza/anatomia & histologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Feixe Vascular de Plantas/anatomia & histologia , Locos de Características Quantitativas/genética , Característica Quantitativa Herdável
16.
Int J Mol Sci ; 21(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143090

RESUMO

Plant architecture is critical for enhancing the adaptability and productivity of crop plants. Mutants with an altered plant architecture allow researchers to elucidate the genetic network and the underlying mechanisms. In this study, we characterized a novel nal1 rice mutant with short height, small panicle, and narrow and thick deep green leaves that was identified from a cross between a rice cultivar and a weedy rice accession. Bulked segregant analysis coupled with genome re-sequencing and cosegregation analysis revealed that the overall mutant phenotype was caused by a 1395-bp deletion spanning over the last two exons including the transcriptional end site of the nal1 gene. This deletion resulted in chimeric transcripts involving nal1 and the adjacent gene, which were validated by a reference-guided assembly of transcripts followed by PCR amplification. A comparative transcriptome analysis of the mutant and the wild-type rice revealed 263 differentially expressed genes involved in cell division, cell expansion, photosynthesis, reproduction, and gibberellin (GA) and brassinosteroids (BR) signaling pathways, suggesting the important regulatory role of nal1. Our study indicated that nal1 controls plant architecture through the regulation of genes involved in the photosynthetic apparatus, cell cycle, and GA and BR signaling pathways.


Assuntos
Regulação da Expressão Gênica de Plantas , Mutação , Oryza/anatomia & histologia , Fotossíntese , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/genética , Mapeamento Cromossômico , Redes Reguladoras de Genes , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Transcriptoma
17.
BMC Plant Biol ; 20(1): 527, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33208102

RESUMO

BACKGROUND: The ratio of CO2 mesophyll conductance (gm) to Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) content has been suggested to positively affect photosynthetic nitrogen use efficiency (PNUE). The anatomical basis of gm has been quantified, but information on the relationship between cell-level anatomies and PNUE is less advanced. Here, hydroponic experiments were conducted in rice plants supplied with ammonium (NH4+) and nitrate (NO3-) under three N levels (low, 0.71 mM; intermediate, 2.86 mM; high, 7.14 mM) to investigate the gas exchange parameters, leaf anatomical structure and PNUE. RESULTS: The results showed a lower PNUE in plants supplied with high nitrogen and NH4+, which was positively correlated with the gm/Rubisco ratio. A one-dimensional within-leaf model revealed that the resistance to CO2 diffusion in the liquid phase (rliq) dominated the overall mesophyll resistance (rm), in which CO2 transfer resistance in the cell wall, cytoplasm and stroma were significantly affected by nitrogen supply. The chloroplast surface area exposed to intercellular space (Sc) per Rubisco rather than the gm/Sc ratio was positively correlated with PNUE and was thus considered a key component influencing PNUE. CONCLUSION: In conclusion, our study emphasized that Sc was the most important anatomical trait in coordinating gm and PNUE with contrasting N supply.


Assuntos
Nitrogênio/metabolismo , Oryza/anatomia & histologia , Fotossíntese , Folhas de Planta/anatomia & histologia , Dióxido de Carbono/metabolismo , Parede Celular/metabolismo , Cloroplastos/metabolismo , Células do Mesofilo/fisiologia , Oryza/enzimologia , Oryza/fisiologia , Folhas de Planta/enzimologia , Folhas de Planta/fisiologia , Ribulose-Bifosfato Carboxilase/metabolismo
18.
Development ; 147(20)2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33028608

RESUMO

The phytohormone cytokinin regulates diverse aspects of plant growth and development. Our understanding of the metabolism and perception of cytokinin has made great strides in recent years, mostly from studies of the model dicot Arabidopsis Here, we employed a CRISPR/Cas9-based approach to disrupt a subset of cytokinin histidine kinase (HK) receptors in rice (Oryza sativa) in order to explore the role of cytokinin in a monocot species. In hk5 and hk6 single mutants, the root growth, leaf width, inflorescence architecture and/or floral development were affected. The double hk5 hk6 mutant showed more substantial defects, including severely reduced root and shoot growth, a smaller shoot apical meristem, and an enlarged root cap. Flowering was delayed in the hk5 hk6 mutant and the panicle was significantly reduced in size and infertile due to multiple defects in floral development. The hk5 hk6 mutant also exhibited a severely reduced cytokinin response, consistent with the developmental phenotypes arising from a defect in cytokinin signaling. These results indicate that HK5 and HK6 act as cytokinin receptors, with overlapping functions to regulate diverse aspects of rice growth and development.


Assuntos
Citocininas/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Receptores de Superfície Celular/metabolismo , Citocininas/farmacologia , Flores/efeitos dos fármacos , Flores/crescimento & desenvolvimento , Meristema/efeitos dos fármacos , Meristema/crescimento & desenvolvimento , Mutação/genética , Oryza/anatomia & histologia , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento
19.
Plant J ; 104(6): 1603-1616, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33058400

RESUMO

Panicle number (PN) is one of the three yield components in rice. As one of the most unstable traits, the dynamic change in tiller number (DCTN) may determine the final PN. However, the genetic basis of DCTN and its relationship with PN remain unclear. Here, 377 deeply re-sequenced rice accessions were used to perform genome-wide association studies (GWAS) for tiller/PN. It was found that the DCTN pattern rather than maximum tiller number or effective tiller ratio is the determinant factor of high PN. The DCTN pattern that affords more panicles exhibits a period of stable tillering peak between 30 and 45 days after transplant (called DT30 and DT45, respectively), which was believed as an ideal pattern contributing to the steady transition from tiller development to panicle development (ST-TtP). Consistently, quantitative trait loci (QTL) expressed near DT30-DT45 were especially critical to the rice DCTN and in supporting the ST-TtP. The spatio-temporal expression analysis showed that the expression pattern of keeping relatively high expression in root at 24:00 (R24-P2) from about DT30 to DT45 is a typical expression pattern of cloned tiller genes, and the candidate genes with R24-P2 can facilitate the prediction of PN. Moreover, gene OsSAUR27 was identified by an integrated approach combining GWAS, bi-parental QTL mapping and transcription. These findings related to the genetic basis underlying the DCTN will provide the genetic theory in making appropriate decisions on field management, and in developing new varieties with high PN and ideal dynamic plant architecture.


Assuntos
Flores/crescimento & desenvolvimento , Oryza/genética , Caules de Planta/crescimento & desenvolvimento , Transcriptoma/genética , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Genes de Plantas/fisiologia , Estudo de Associação Genômica Ampla , Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Locos de Características Quantitativas/genética , Característica Quantitativa Herdável , Transcriptoma/fisiologia
20.
Plant Physiol ; 184(3): 1424-1437, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32913047

RESUMO

Tiller angle largely determines plant architecture, which in turn substantially influences crop production by affecting planting density. A recent study revealed that HEAT STRESS TRANSCRIPTION FACTOR2D (HSFA2D) acts upstream of LAZY1 (LA1) to regulate tiller angle establishment in rice (Oryza sativa). However, the mechanisms underlying transcriptional regulation of HSFA2D remain unknown. In this study, two class II homeodomain-Leu zipper genes, OsHOX1 and OsHOX28, were identified as positive regulators of tiller angle by affecting shoot gravitropism. OsHOX1 and OsHOX28 showed strong transcriptional suppressive activity in rice protoplasts and formed intricate self- and mutual-transcriptional negative feedback loops. Moreover, OsHOX1 and OsHOX28 bound to the pseudopalindromic sequence CAAT(C/G)ATTG within the promoter of HSFA2D, thus suppressing its expression. In contrast to HSFA2D and LA1, OsHOX1 and OsHOX28 attenuated lateral auxin transport, thus repressing the expression of WUSCHEL-RELATED HOMEOBOX 6 (WOX6) and WOX11 in the lower side of the shoot base of plants subjected to gravistimulation. Genetic analysis further confirmed that OsHOX1 and OsHOX28 act upstream of HSFA2D Additionally, both OsHOX1 and OsHOX28 inhibit the expression of multiple OsYUCCA genes and decrease auxin biosynthesis. Taken together, these results demonstrated that OsHOX1 and OsHOX28 regulate the local distribution of auxin, and thus tiller angle establishment, through suppression of the HSFA2D-LA1 pathway and reduction of endogenous auxin content. Our finding increases the knowledge concerning fine tuning of tiller angles to optimize plant architecture in rice.


Assuntos
Gravitropismo/genética , Fatores de Transcrição de Choque Térmico/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/anatomia & histologia , Oryza/crescimento & desenvolvimento , Oryza/genética , Brotos de Planta/crescimento & desenvolvimento , China , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Fatores de Transcrição de Choque Térmico/genética , Brotos de Planta/anatomia & histologia , Brotos de Planta/genética
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