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1.
Plant Cell Rep ; 43(7): 168, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864883

RESUMO

KEY MESSAGE: Immunofluorescence staining with frozen sections of plant tissues and a nest tube is convenient and effective, and broadens the applicability of immunofluorescence staining. Immunofluorescence staining is an indispensable and extensively employed technique for determining the subcellular localization of chloroplast division proteins. At present, it is difficult to effectively observe the localization of target proteins in leaves that are hard, or very thin, or have epidermal hair or glands with the current immunofluorescence staining methods. Moreover, signals of target proteins were predominantly detected in mesophyll cells, not the cells of other types. Thus, the method of immunofluorescence staining was further explored for improvement in this study. The plant tissue was embedded with 50% PEG4000 at -60℃, which was then cut into sections by a cryomacrotome. The sections were immediately immersed in fixation solution. Then, the sample was transferred into a special nested plastic tube, which facilitated the fixation and immunofluorescence staining procedures. The use of frozen sections in this method enabled a short processing time and reduced material requirements. By optimizing the thickness of the sections, a large proportion of the cells could be well stained. With this method, we observed the localization of a chloroplast division protein FtsZ1 in the wild-type Arabidopsis and various chloroplast division mutants. Meanwhile, the localization of FtsZ1 was also observed not only in mesophyll cells, but also in guard cells and epidermal cells in a lot of other plant species, including many species with hard leaf tissues. This method is not only easy to use, but also expands the scope of applicability for immunofluorescence staining.


Assuntos
Arabidopsis , Proteínas de Cloroplastos , Cloroplastos , Imunofluorescência , Secções Congeladas , Coloração e Rotulagem , Arabidopsis/metabolismo , Arabidopsis/citologia , Secções Congeladas/métodos , Imunofluorescência/métodos , Cloroplastos/metabolismo , Coloração e Rotulagem/métodos , Proteínas de Cloroplastos/metabolismo , Proteínas de Cloroplastos/genética , Folhas de Planta/metabolismo , Folhas de Planta/citologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Células do Mesofilo/metabolismo , Células do Mesofilo/citologia
2.
Plant Cell Physiol ; 65(7): 1160-1172, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38590036

RESUMO

Endoplasmic reticulum (ER)-derived organelles, ER bodies, participate in the defense against herbivores in Brassicaceae plants. ER bodies accumulate ß-glucosidases, which hydrolyze specialized thioglucosides known as glucosinolates to generate bioactive substances. In Arabidopsis thaliana, the leaf ER (LER) bodies are formed in large pavement cells, which are found in the petioles, margins and blades of rosette leaves. However, the regulatory mechanisms involved in establishing large pavement cells are unknown. Here, we show that the ARABIDOPSIS THALIANA MERISTEM L1 LAYER (ATML1) transcription factor regulates the formation of LER bodies in large pavement cells of rosette leaves. Overexpression of ATML1 enhanced the expression of LER body-related genes and the number of LER body-containing large pavement cells, whereas its knock-out resulted in opposite effects. ATML1 enhances endoreduplication and cell size through LOSS OF GIANT CELLS FROM ORGANS (LGO). Although the overexpression and knock-out of LGO affected the appearance of large pavement cells in Arabidopsis, the effect on LER body-related gene expression and LER body formation was weak. LER body-containing large pavement cells were also found in Eutrema salsugineum, another Brassicaceae species. Our results demonstrate that ATML1 establishes large pavement cells to induce LER body formation in Brassicaceae plants and thereby possibly contribute to the defense against herbivores.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Retículo Endoplasmático , Regulação da Expressão Gênica de Plantas , Folhas de Planta , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/citologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/citologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Retículo Endoplasmático/metabolismo , Diferenciação Celular , Brassicaceae/genética , Brassicaceae/citologia , Brassicaceae/metabolismo , Brassicaceae/fisiologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Plantas Geneticamente Modificadas , Endorreduplicação
3.
Curr Opin Plant Biol ; 79: 102542, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38688201

RESUMO

As the main location of photosynthesis, leaf mesophyll cells are one of the most abundant and essential cell types on earth. Forming the bulk of the internal tissues of the leaf, their size, shape, and patterns of interconnectivity define the internal structure and surface area of the leaf, which in turn determines the efficiency of light capture and carbon fixation. Understanding how these cellular traits are controlled and translated into tissue- and organ-scale traits, and how they influence photosynthetic performance will be key to our ability to improve crop plants in the face of a changing climate. In contrast to the extensive literature on the anatomical and physiological aspects of mesophyll function, our understanding of the cell-level morphogenetic processes underpinning mesophyll cell growth and differentiation is scant. In this review, we focus on how cell division, expansion, and separation are coordinated to create the intricate architecture of the spongy mesophyll.


Assuntos
Divisão Celular , Células do Mesofilo , Células do Mesofilo/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Fotossíntese
4.
Microsc Res Tech ; 87(7): 1640-1646, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38450874

RESUMO

The classification and identification of Aster glehnii F. Schmidt are determined from its foliar epidermal anatomical features. Scanning electronic microscopy has been used to determine the foliar epidermal anatomical characteristics of the species in detail. This study compared the qualitative and quantitative characteristics of the leaf epidermis of A. glehnii for taxonomic identification to be used as a reference for future studies on the species. A. glehnii has smooth, thin cuticles, depressed anomocytic stomata dispersed randomly throughout the leaf surface, polygonal epidermal cells with straight to slightly curved anticlinal walls, and no trichomes. There are obvious veins containing thick-walled bundle sheath cells. The stomatal density is between 100 and 150 stomata per millimeter. The vein density ranges from five to 10 veins per millimeter, and the epidermal cells are 10 to 20 µm long and 5 to 10 µm in width. Understanding the connections between the different A. glehnii species and categorizing and identifying them depend heavily on these foliar epidermal structural features. Taxonomy and conservation are closely intertwined because the former serves as the basis for comprehending and safeguarding biodiversity. RESEARCH HIGHLIGHTS: Optical microscopy of the A. glehnii leaf epidermis for taxonomic identification SEM was used to identify and authenticate endemic species Microscopic identification of endemic species can assist in the conservation.


Assuntos
Microscopia Eletrônica de Varredura , Epiderme Vegetal , Folhas de Planta , Estômatos de Plantas , Folhas de Planta/anatomia & histologia , Folhas de Planta/ultraestrutura , Folhas de Planta/citologia , Epiderme Vegetal/ultraestrutura , Epiderme Vegetal/anatomia & histologia , Epiderme Vegetal/citologia , Estômatos de Plantas/anatomia & histologia , Estômatos de Plantas/ultraestrutura , Asteraceae/anatomia & histologia , Asteraceae/citologia , Asteraceae/classificação , Asteraceae/ultraestrutura
5.
Plant Physiol ; 195(1): 378-394, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38298139

RESUMO

Automated guard cell detection and measurement are vital for understanding plant physiological performance and ecological functioning in global water and carbon cycles. Most current methods for measuring guard cells and stomata are laborious, time-consuming, prone to bias, and limited in scale. We developed StoManager1, a high-throughput tool utilizing geometrical, mathematical algorithms, and convolutional neural networks to automatically detect, count, and measure over 30 guard cell and stomatal metrics, including guard cell and stomatal area, length, width, stomatal aperture area/guard cell area, orientation, stomatal evenness, divergence, and aggregation index. Combined with leaf functional traits, some of these StoManager1-measured guard cell and stomatal metrics explained 90% and 82% of tree biomass and intrinsic water use efficiency (iWUE) variances in hardwoods, making them substantial factors in leaf physiology and tree growth. StoManager1 demonstrated exceptional precision and recall (mAP@0.5 over 0.96), effectively capturing diverse stomatal properties across over 100 species. StoManager1 facilitates the automation of measuring leaf stomatal and guard cells, enabling broader exploration of stomatal control in plant growth and adaptation to environmental stress and climate change. This has implications for global gross primary productivity (GPP) modeling and estimation, as integrating stomatal metrics can enhance predictions of plant growth and resource usage worldwide. Easily accessible open-source code and standalone Windows executable applications are available on a GitHub repository (https://github.com/JiaxinWang123/StoManager1) and Zenodo (https://doi.org/10.5281/zenodo.7686022).


Assuntos
Botânica , Biologia Celular , Células Vegetais , Estômatos de Plantas , Software , Estômatos de Plantas/citologia , Estômatos de Plantas/crescimento & desenvolvimento , Células Vegetais/fisiologia , Botânica/instrumentação , Botânica/métodos , Biologia Celular/instrumentação , Processamento de Imagem Assistida por Computador/normas , Algoritmos , Folhas de Planta/citologia , Redes Neurais de Computação , Ensaios de Triagem em Larga Escala/instrumentação , Ensaios de Triagem em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/normas , Software/normas
6.
Science ; 381(6653): 54-59, 2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37410832

RESUMO

Asymmetric cell divisions specify differential cell fates across kingdoms. In metazoans, preferential inheritance of fate determinants into one daughter cell frequently depends on polarity-cytoskeleton interactions. Despite the prevalence of asymmetric divisions throughout plant development, evidence for analogous mechanisms that segregate fate determinants remains elusive. Here, we describe a mechanism in the Arabidopsis leaf epidermis that ensures unequal inheritance of a fate-enforcing polarity domain. By defining a cortical region depleted of stable microtubules, the polarity domain limits possible division orientations. Accordingly, uncoupling the polarity domain from microtubule organization during mitosis leads to aberrant division planes and accompanying cell identity defects. Our data highlight how a common biological module, coupling polarity to fate segregation through the cytoskeleton, can be reconfigured to accommodate unique features of plant development.


Assuntos
Arabidopsis , Divisão Celular Assimétrica , Epiderme Vegetal , Folhas de Planta , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Linhagem da Célula , Polaridade Celular/genética , Citoesqueleto , Mitose/genética , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Epiderme Vegetal/citologia , Epiderme Vegetal/genética
7.
J Integr Plant Biol ; 64(7): 1325-1338, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35485227

RESUMO

Crop breeding during the Green Revolution resulted in high yields largely due to the creation of plants with semi-dwarf architectures that could tolerate high-density planting. Although semi-dwarf varieties have been developed in rice, wheat and maize, none was reported in soybean (Glycine max), and few genes controlling plant architecture have been characterized in soybean. Here, we demonstrate that the auxin efflux transporter PINFORMED1 (GmPIN1), which determines polar auxin transport, regulates the leaf petiole angle in soybean. CRISPR-Cas9-induced Gmpin1abc and Gmpin1bc multiple mutants displayed a compact architecture with a smaller petiole angle than wild-type plants. GmPIN1 transcripts and auxin were distributed asymmetrically in the petiole base, with high levels of GmPIN1a/c transcript and auxin in the lower cells, which resulted in asymmetric cell expansion. By contrast, the (iso)flavonoid content was greater in the upper petiole cells than in the lower cells. Our results suggest that (iso)flavonoids inhibit GmPIN1a/c expression to regulate the petiole angle. Overall, our study demonstrates that a signal cascade that integrates (iso)flavonoid biosynthesis, GmPIN1a/c expression, auxin accumulation, and cell expansion in an asymmetric manner creates a desirable petiole curvature in soybean. This study provides a genetic resource for improving soybean plant architecture.


Assuntos
Glycine max , Ácidos Indolacéticos , Proteínas de Membrana Transportadoras , Folhas de Planta , Proteínas de Plantas , Flavonoides/biossíntese , Ácidos Indolacéticos/metabolismo , Proteínas de Membrana Transportadoras/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Glycine max/anatomia & histologia , Glycine max/genética , Transcriptoma
8.
Nat Commun ; 13(1): 652, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115512

RESUMO

Stomatal opening requires the provision of energy in the form of ATP for proton pumping across the guard cell (GC) plasma membrane and for associated metabolic rearrangements. The source of ATP for GCs is a matter of ongoing debate that is mainly fuelled by controversies around the ability of GC chloroplasts (GCCs) to perform photosynthesis. By imaging compartment-specific fluorescent ATP and NADPH sensor proteins in Arabidopsis, we show that GC photosynthesis is limited and mitochondria are the main source of ATP. Unlike mature mesophyll cell (MC) chloroplasts, which are impermeable to cytosolic ATP, GCCs import cytosolic ATP through NUCLEOTIDE TRANSPORTER (NTT) proteins. GCs from ntt mutants exhibit impaired abilities for starch biosynthesis and stomatal opening. Our work shows that GCs obtain ATP and carbohydrates via different routes from MCs, likely to compensate for the lower chlorophyll contents and limited photosynthesis of GCCs.


Assuntos
Trifosfato de Adenosina/metabolismo , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Estômatos de Plantas/metabolismo , Amido/metabolismo , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Cloroplastos/efeitos dos fármacos , Cloroplastos/efeitos da radiação , Citosol/metabolismo , Peróxido de Hidrogênio/farmacologia , Luz , Células do Mesofilo/citologia , Células do Mesofilo/metabolismo , Células do Mesofilo/efeitos da radiação , Microscopia Confocal , NADP/metabolismo , Proteínas de Transporte de Nucleotídeos/genética , Proteínas de Transporte de Nucleotídeos/metabolismo , Oxidantes/farmacologia , Epiderme Vegetal/citologia , Epiderme Vegetal/metabolismo , Folhas de Planta/citologia , Folhas de Planta/metabolismo , Estômatos de Plantas/citologia , Estômatos de Plantas/fisiologia , Plantas Geneticamente Modificadas
10.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983847

RESUMO

Symplasmicly connected cells called sieve elements form a network of tubes in the phloem of vascular plants. Sieve elements have essential functions as they provide routes for photoassimilate distribution, the exchange of developmental signals, and the coordination of defense responses. Nonetheless, they are the least understood main type of plant cells. They are extremely sensitive, possess a reduced endomembrane system without Golgi apparatus, and lack nuclei and translation machineries, so that transcriptomics and similar techniques cannot be applied. Moreover, the analysis of phloem exudates as a proxy for sieve element composition is marred by methodological problems. We developed a simple protocol for the isolation of sieve elements from leaves and stems of Nicotiana tabacum at sufficient amounts for large-scale proteome analysis. By quantifying the enrichment of individual proteins in purified sieve element relative to bulk phloem preparations, proteins of increased likelyhood to function specifically in sieve elements were identified. To evaluate the validity of this approach, yellow fluorescent protein constructs of genes encoding three of the candidate proteins were expressed in plants. Tagged proteins occurred exclusively in sieve elements. Two of them, a putative cytochrome b561/ferric reductase and a reticulon-like protein, appeared restricted to segments of the endoplasmic reticulum (ER) that were inaccessible to green fluorescent protein dissolved in the ER lumen, suggesting a previously unknown differentiation of the endomembrane system in sieve elements. Evidently, our list of promising candidate proteins ( SI Appendix, Table S1) provides a valuable exploratory tool for sieve element biology.


Assuntos
Retículo Endoplasmático/metabolismo , Nicotiana/metabolismo , Células Vegetais/metabolismo , Folhas de Planta/metabolismo , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Proteômica , Retículo Endoplasmático/genética , Folhas de Planta/citologia , Folhas de Planta/genética , Caules de Planta/citologia , Caules de Planta/genética , Plantas Geneticamente Modificadas/citologia , Plantas Geneticamente Modificadas/genética , Nicotiana/citologia , Nicotiana/genética
11.
Plant Cell Rep ; 41(2): 319-335, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34837515

RESUMO

KEY MESSAGE: Elevated expression of nucleotide-binding and leucine-rich repeat proteins led to closer vein spacing and higher vein density in rice leaves. To feed the growing global population and mitigate the negative effects of climate change, there is a need to improve the photosynthetic capacity and efficiency of major crops such as rice to enhance grain yield potential. Alterations in internal leaf morphology and cellular architecture are needed to underpin some of these improvements. One of the targets is to generate a "Kranz-like" anatomy in leaves that includes decreased interveinal spacing close to that in C4 plant species. As C4 photosynthesis has evolved from C3 photosynthesis independently in multiple lineages, the genes required to facilitate C4 may already be present in the rice genome. The Taiwan Rice Insertional Mutants (TRIM) population offers the advantage of gain-of-function phenotype trapping, which accelerates the identification of rice gene function. In the present study, we screened the TRIM population to determine the extent to which genetic plasticity can alter vein density (VD) in rice. Close vein spacing mutant 1 (CVS1), identified from a VD screening of approximately 17,000 TRIM lines, conferred heritable high leaf VD. Increased vein number in CVS1 was confirmed to be associated with activated expression of two nucleotide-binding and leucine-rich repeat (NB-LRR) proteins. Overexpression of the two NB-LRR genes individually in rice recapitulates the high VD phenotype, due mainly to reduced interveinal mesophyll cell (M cell) number, length, bulliform cell size and thus interveinal distance. Our studies demonstrate that the trait of high VD in rice can be achieved by elevated expression of NB-LRR proteins limited to no yield penalty.


Assuntos
Proteínas de Repetições Ricas em Leucina/genética , Proteínas NLR/genética , Oryza/genética , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/genética , DNA Bacteriano , Resistência à Doença/genética , Expressão Ectópica do Gene , Regulação da Expressão Gênica de Plantas , Proteínas de Repetições Ricas em Leucina/metabolismo , Células do Mesofilo , Mutação , Proteínas NLR/metabolismo , Oryza/anatomia & histologia , Fotossíntese , Folhas de Planta/citologia , Folhas de Planta/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Plântula/anatomia & histologia , Plântula/genética
12.
Plant J ; 108(6): 1690-1703, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34628678

RESUMO

The riboflavin derivatives flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are essential cofactors for enzymes in multiple cellular processes. Characterizing mutants with impaired riboflavin metabolism can help clarify the role of riboflavin in plant development. Here, we characterized a rice (Oryza sativa) white and lesion-mimic (wll1) mutant, which displays a lesion-mimic phenotype with white leaves, chlorophyll loss, chloroplast defects, excess reactive oxygen species (ROS) accumulation, decreased photosystem protein levels, changes in expression of chloroplast development and photosynthesis genes, and cell death. Map-based cloning and complementation test revealed that WLL1 encodes lumazine synthase, which participates in riboflavin biosynthesis. Indeed, the wll1 mutant showed riboflavin deficiency, and application of FAD rescued the wll1 phenotype. In addition, transcriptome analysis showed that cytokinin metabolism was significantly affected in wll1 mutant, which had increased cytokinin and δ-aminolevulinic acid contents. Furthermore, WLL1 and riboflavin synthase (RS) formed a complex, and the rs mutant had a similar phenotype to the wll1 mutant. Taken together, our findings revealed that WLL1 and RS play pivotal roles in riboflavin biosynthesis, which is necessary for ROS balance and chloroplast development in rice.


Assuntos
Cloroplastos/fisiologia , Complexos Multienzimáticos/metabolismo , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Clorofila/genética , Clorofila/metabolismo , Citocininas/genética , Citocininas/metabolismo , Dano ao DNA , Evolução Molecular , Flavina-Adenina Dinucleotídeo/genética , Flavina-Adenina Dinucleotídeo/metabolismo , Regulação da Expressão Gênica de Plantas , Complexos Multienzimáticos/genética , Mutação , Fenótipo , Filogenia , Folhas de Planta/citologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Riboflavina/genética , Riboflavina/metabolismo , Técnicas do Sistema de Duplo-Híbrido
13.
Plant J ; 108(6): 1597-1608, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34612535

RESUMO

Maize leaf angle (LA) is a complex quantitative trait that is controlled by developmental signals, hormones, and environmental factors. However, the connection between histone methylation and LAs in maize remains unclear. Here, we reported that SET domain protein 128 (SDG128) is involved in leaf inclination in maize. Knockdown of SDG128 using an RNA interference approach resulted in an expanded architecture, less large vascular bundles, more small vascular bundles, and larger spacing of large vascular bundles in the auricles. SDG128 interacts with ZmGID2 both in vitro and in vivo. Knockdown of ZmGID2 also showed a larger LA with less large vascular bundles and larger spacing of vascular bundles. In addition, the transcription level of cell wall expansion family genes ZmEXPA1, ZmEXPB2, and GRMZM2G005887; transcriptional factor genes Lg1, ZmTAC1, and ZmCLA4; and auxin pathway genes ZmYUCCA7, ZmYUCCA8, and ZmARF22 was reduced in SDG128 and ZmGID2 knockdown plants. SDG128 directly targets ZmEXPA1, ZmEXPB2, LG1, and ZmTAC1 and is required for H3K4me3 deposition at these genes. Together, the results of the present study suggest that SDG128 and ZmGID2 are involved in the maize leaf inclination.


Assuntos
Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Zea mays/fisiologia , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Regulação da Expressão Gênica de Plantas , Histonas , Ácidos Indolacéticos/metabolismo , Mutação , Folhas de Planta/citologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Interferência de RNA , Zea mays/citologia
14.
Int J Mol Sci ; 22(20)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34681824

RESUMO

Chloroplasts play an essential role in plant growth and development. Any factors affecting chloroplast development will lead to abnormal plant growth. Here, we characterized a new maize mutant, albino seedling mutant 81647 (as-81647), which exhibits an entirely albino phenotype in leaves and eventually died before the three-leaf stage. Transmission electron microscopy (TEM) demonstrated that the chloroplast thylakoid membrane was impaired and the granum lamellae significantly decreased in as-81647. Map-based cloning and transgenic analysis confirmed that PPR647 encodes a new chloroplast protein consisting of 11 pentratricopeptide repeat domains. Quantitative real-time PCR (qRT-PCR) assays and transcriptome analysis (RNA-seq) showed that the PPR647 mutation significantly disrupted the expression of PEP-dependent plastid genes. In addition, RNA splicing and RNA editing of multiple chloroplast genes showed severe defects in as-81647. These results indicated that PPR647 is crucial for RNA editing, RNA splicing of chloroplast genes, and plays an essential role in chloroplast development.


Assuntos
Cloroplastos/fisiologia , Proteínas de Plantas/genética , Edição de RNA , Splicing de RNA , RNA de Cloroplastos/metabolismo , Zea mays/genética , Zea mays/metabolismo , Cloroplastos/ultraestrutura , Regulação da Expressão Gênica de Plantas , Genes de Cloroplastos , Mutação , Fenótipo , Filogenia , Folhas de Planta/citologia , Proteínas de Plantas/metabolismo , Domínios Proteicos , Plântula/genética , Plântula/metabolismo , Tilacoides/fisiologia , Tilacoides/ultraestrutura
15.
Int J Mol Sci ; 22(20)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34681874

RESUMO

In recent decades, atmospheric pollution led to a progressive reduction of the ozone layer with a consequent increase in UV-B radiation. Despite the high adaptation of olive trees to the Mediterranean environment, the progressive increase of UV-B radiation is a risk factor for olive tree cultivation. It is therefore necessary to understand how high levels of UV-B radiation affect olive plants and to identify olive varieties which are better adapted. In this study we analyzed two Italian olive varieties subjected to chronic UV-B stress. We focused on the effects of UV-B radiation on RubisCO, in terms of quantity, enzymatic activity and isoform composition. In addition, we also analyzed changes in the activity of antioxidant enzymes (SOD, CAT, GPox) to get a comprehensive picture of the antioxidant system. We also evaluated the effects of UV-B on the enzyme sucrose synthase. The overall damage at biochemical level was also assessed by analyzing changes in Hsp70, a protein triggered under stress conditions. The results of this work indicate that the varieties (Giarraffa and Olivastra Seggianese) differ significantly in the use of specific antioxidant defense systems, as well as in the activity and isoform composition of RubisCO. Combined with a different use of sucrose synthase, the overall picture shows that Giarraffa optimized the use of GPox and opted for a targeted choice of RubisCO isoforms, in addition to managing the content of sucrose synthase, thereby saving energy during critical stress points.


Assuntos
Antioxidantes/metabolismo , Olea/metabolismo , Olea/efeitos da radiação , Proteínas de Plantas/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Enzimas/metabolismo , Glucosiltransferases/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Itália , Peroxidação de Lipídeos/efeitos da radiação , Malondialdeído/metabolismo , Microscopia Eletrônica de Transmissão , Olea/citologia , Folhas de Planta/citologia , Folhas de Planta/efeitos da radiação , Raios Ultravioleta
16.
Plant J ; 108(2): 541-554, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34403543

RESUMO

The enucleated vascular elements of the xylem and the phloem offer an excellent system to test the effect of ploidy on plant function because variation in vascular geometry has a direct influence on transport efficiency. However, evaluations of conduit sizes in polyploid plants have remained elusive, most remarkably in woody species. We used a combination of molecular, physiological and microscopy techniques to model the hydraulic resistance between source and sinks in tetraploid and diploid mango trees. Tetraploids exhibited larger chloroplasts, mesophyll cells and stomatal guard cells, resulting in higher leaf elastic modulus and lower dehydration rates, despite the high water potentials of both ploidies in the field. Both the xylem and the phloem displayed a scaling of conduits with ploidy, revealing attenuated hydraulic resistance in tetraploids. Conspicuous wall hygroscopic moieties in the cells involved in transpiration and transport indicate a role in volumetric adjustments as a result of turgor change in both ploidies. In autotetraploids, the enlargement of organelles, cells and tissues, which are critical for water and photoassimilate transport at long distances, point to major physiological novelties associated with whole-genome duplication.


Assuntos
Mangifera/fisiologia , Floema/fisiologia , Folhas de Planta/química , Ploidias , Xilema/fisiologia , Parede Celular/química , Inflorescência/fisiologia , Mangifera/citologia , Mangifera/genética , Células Vegetais/química , Folhas de Planta/anatomia & histologia , Folhas de Planta/citologia , Folhas de Planta/genética , Caules de Planta/fisiologia , Estômatos de Plantas/química , Árvores/citologia , Árvores/genética , Árvores/fisiologia
17.
Nat Commun ; 12(1): 4327, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34267202

RESUMO

Trivalent rare earth elements (REEs) are widely used in agriculture. Aerially applied REEs enter leaf epidermal cells by endocytosis and act systemically to improve the growth of the whole plant. The mechanistic basis of their systemic activity is unclear. Here, we show that treatment of Arabidopsis leaves with trivalent lanthanum [La(III)], a representative of REEs, triggers systemic endocytosis from leaves to roots. La(III)-induced systemic endocytosis requires AtrbohD-mediated reactive oxygen species production and jasmonic acid. Systemic endocytosis impacts the accumulation of mineral elements and the development of roots consistent with the growth promoting effects induced by aerially applied REEs. These findings provide insights into the mechanistic basis of REE activity in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Lantânio/farmacologia , NADPH Oxidases/metabolismo , Arabidopsis/citologia , Proteínas de Arabidopsis/genética , Ciclopentanos/metabolismo , Endocitose/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Minerais/metabolismo , NADPH Oxidases/genética , Oxilipinas/metabolismo , Células Vegetais/efeitos dos fármacos , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais
18.
Nat Plants ; 7(6): 826-841, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34112988

RESUMO

The leaf epidermis is a dynamic biomechanical shell that integrates growth across spatial scales to influence organ morphology. Pavement cells, the fundamental unit of this tissue, morph irreversibly into highly lobed cells that drive planar leaf expansion. Here, we define how tissue-scale cell wall tensile forces and the microtubule-cellulose synthase systems dictate the patterns of interdigitated growth in real time. A morphologically potent subset of cortical microtubules span the periclinal and anticlinal cell faces to pattern cellulose fibres that generate a patch of anisotropic wall. The subsequent local polarized growth is mechanically coupled to the adjacent cell via a pectin-rich middle lamella, and this drives lobe formation. Finite element pavement cell models revealed cell wall tensile stress as an upstream patterning element that links cell- and tissue-scale biomechanical parameters to interdigitated growth. Cell lobing in leaves is evolutionarily conserved, occurs in multiple cell types and is associated with important agronomic traits. Our general mechanistic models of lobe formation provide a foundation to analyse the cellular basis of leaf morphology and function.


Assuntos
Arabidopsis/citologia , Células Vegetais , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Arabidopsis/crescimento & desenvolvimento , Fenômenos Biomecânicos , Forma Celular , Parede Celular/fisiologia , Celulose/metabolismo , Análise de Elementos Finitos , Microscopia Eletrônica de Transmissão , Microtúbulos/metabolismo , Modelos Biológicos , Mutação , Células Vegetais/metabolismo , Plantas Geneticamente Modificadas , Plasmodesmos
19.
BMC Plant Biol ; 21(1): 253, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082706

RESUMO

BACKGROUND: Root hydraulic conductance is primarily determined by the conductance of living tissues to radial water flow. Plasma membrane intrinsic proteins (PIPs) in root cortical cells are important for plants to take up water and are believed to be directly involved in cell growth. RESULTS: In this study, we found that constitutive overexpression of the poplar root-specific gene PtoPIP1;1 in Arabidopsis accelerated bolting and flowering. At the early stage of the developmental process, PtoPIP1;1 OE Arabidopsis exhibited faster cell growth in both leaves and roots. The turgor pressure of plants was correspondingly increased in PtoPIP1;1 OE Arabidopsis, and the water status was changed. At the same time, the expression levels of flowering-related genes (CRY1, CRY2 and FCA) and hub genes in the regulatory networks underlying floral timing (FT and SOC1) were significantly upregulated in OE plants, while the floral repressor FLC gene was significantly downregulated. CONCLUSIONS: Taken together, the results of our study indicate that constitutive overexpression of PtoPIP1;1 in Arabidopsis accelerates bolting and flowering through faster cell growth in both the leaf and root at an early stage of the developmental process. The autonomous pathway of flowering regulation may be executed by monitoring developmental age. The increase in turgor and changes in water status with PtoPIP1;1 overexpression play a role in promoting cell growth.


Assuntos
Aquaporinas/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Proteínas de Plantas/metabolismo , Populus/metabolismo , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Raízes de Plantas/citologia , Raízes de Plantas/crescimento & desenvolvimento , Transpiração Vegetal , Plantas Geneticamente Modificadas , Populus/genética
20.
Int J Mol Sci ; 22(9)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34064353

RESUMO

The lipid bilayer matrix of the thylakoid membrane of cyanobacteria and chloroplasts of plants and algae is mainly composed of uncharged galactolipids, but also contains anionic lipids sulfoquinovosyldiacylglycerol (SQDG) and phosphatidylglycerol (PG) as major constituents. The necessity of PG for photosynthesis is evident in all photosynthetic organisms examined to date, whereas the requirement of SQDG varies with species. In plants, although PG and SQDG are also found in non-photosynthetic plastids, their importance for the growth and functions of non-photosynthetic organs remains unclear. In addition, plants synthesize another anionic lipid glucuronosyldiacylglycerol (GlcADG) during phosphorus starvation, but its role in plant cells is not elucidated yet. To understand the functional relationships among PG, SQDG, and GlcADG, we characterized several Arabidopsis thaliana mutants defective in biosynthesis of these lipids. The mutants completely lacking both PG and SQDG biosynthesis in plastids showed developmental defects of roots, hypocotyls, and embryos in addition to leaves, which suggests that these lipids are pleiotropically required for the development of both photosynthetic and non-photosynthetic organs. Furthermore, our analysis revealed that SQDG, but not GlcADG, is essential for complementing the role of PG, particularly in photosynthesis under PG-deficient conditions such as phosphorus starvation.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/metabolismo , Cloroplastos/metabolismo , Diglicerídeos/metabolismo , Glicolipídeos/metabolismo , Fosfatidilgliceróis/metabolismo , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Cloroplastos/genética , Cianobactérias/genética , Cianobactérias/metabolismo , Galactolipídeos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Hipocótilo/citologia , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Mutação , Células Vegetais/metabolismo , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Sementes/citologia , Sementes/crescimento & desenvolvimento , Sementes/metabolismo
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