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1.
Biomolecules ; 12(12)2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-36551200

RESUMO

The need to produce crops with higher yields is critical due to a growing global population, depletion of agricultural land, and severe climate change. Compared with the "source" and "sink" transport systems that have been studied a lot, the development and utilization of vascular bundles (conducting vessels in plants) are increasingly important. Due to the complexity of the vascular system, its structure, and its delicate and deep position in the plant body, the current research on model plants remains basic knowledge and has not been repeated for crops and applied to field production. In this review, we aim to summarize the current knowledge regarding biomolecular strategies of vascular bundles in transport systems (source-flow-sink), allocation, helping crop architecture establishment, and influence of the external environment. It is expected to help understand how to use sophisticated and advancing genetic engineering technology to improve the vascular system of crops to increase yield.


Assuntos
Produtos Agrícolas , Feixe Vascular de Plantas , Produtos Agrícolas/genética , Agricultura , Mudança Climática
2.
Physiol Plant ; 174(3): e13695, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35491933

RESUMO

Phloem unloading and loading are associated with stem non-structural carbohydrates (NSCs) accumulation and remobilization in rice (Oryza sativa L.). Four rice recombinant inbred lines (R032, R191, R046, and R146) derived from a cross between Zhenshan 97 and Minghui 63 were used to investigate the contributions of stem large and small vascular bundles (SVBs) to NSCs accumulation and translocation. Before heading, the parenchyma cells in stem cortex tissues (PCs) surrounding SVBs had higher starch density than those surrounding large vascular bundles (LVBs). Moreover, the protein levels of sucrose transporters (SUTs), cell wall invertase, sucrose synthase, and adenosine diphosphate glucose pyrophosphorylase, as well as the phloem plasmodesma densities were higher in SVBs than those in LVBs. After heading, starch density decreased more in PCs surrounding SVBs than in LVBs. Also, the protein levels of SUTs, α-amylase, sucrose phosphate synthase and sucrose synthase, the phloem plasmodesma densities in SVBs were higher than those in LVBs. The correlations of the number and total cross-sectional area of SVBs with mass and contribution to yield of transferred NSCs were higher than those of LVBs. Our results suggest that SVBs may have higher contributions to pre-anthesis stem NSCs accumulation and post-anthesis translocation than LVBs, which is potentially attributed to the high level of protein and enzyme involved in stem unloading and loading via apoplastic and symplastic pathways.


Assuntos
Oryza , Transporte Biológico , Carboidratos , Proteínas de Membrana Transportadoras/metabolismo , Oryza/metabolismo , Floema/metabolismo , Feixe Vascular de Plantas/metabolismo , Amido/metabolismo , Sacarose/metabolismo
3.
Plant Cell ; 34(6): 2328-2342, 2022 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-35285491

RESUMO

The Arabidopsis (Arabidopsis thaliana) leaf veins bundle-sheath cells (BSCs)-a selective barrier to water and solutes entering the mesophyll-increase the leaf radial hydraulic conductance (Kleaf) by acidifying the xylem sap by their plasma membrane H+-ATPase,  AHA2. Based on this and on the BSCs' expression of phototropins PHOT1 and PHOT2, and the known blue light (BL)-induced Kleaf increase, we hypothesized that, resembling the guard cells, BL perception by the BSCs' phots activates its H+-ATPase, which, consequently, upregulates Kleaf. Indeed, under BL, the Kleaf of the knockout mutant lines phot1-5, phot2-1, phot1-5 phot2-1, and aha2-4 was lower than that of the wild-type (WT). BSC-only-directed complementation of phot1-5 or aha2-4 by PHOT1 or AHA2, respectively, restored the BL-induced Kleaf increase. BSC-specific silencing of PHOT1 or PHOT2 prevented such Kleaf increase. A xylem-fed kinase inhibitor (tyrphostin 9) replicated this also in WT plants. White light-ineffective in the phot1-5 mutant-acidified the xylem sap (relative to darkness) in WT and in the PHOT1-complemented phot1-5. These results, supported by BL increase of BSC protoplasts' water permeability and cytosolic pH and their hyperpolarization by BL, identify the BSCs as a second phot-controlled water conductance element in leaves, in series with stomatal conductance. Through both, BL regulates the leaf water balance.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Luz , Fototropinas/genética , Fototropinas/metabolismo , Folhas de Planta/metabolismo , Feixe Vascular de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Água/metabolismo
4.
Plant Biotechnol J ; 20(6): 1042-1053, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35080335

RESUMO

The peduncle vascular system of maize is critical for the transport of photosynthetic products, nutrients, and water from the roots and leaves to the ear. Accordingly, it positively affects the grain yield. However, the genetic basis of peduncle vascular bundle (PVB)-related traits in maize remains unknown. Thus, 15 PVB-related traits of 386 maize inbred lines were investigated at three locations (Yongcheng, 17YC; Kaifeng, 20KF; and Yuanyang, 20YY). The repeatability for the 15 traits ranged from 35.53% to 92.13%. A genome-wide association study was performed and 69 non-redundant quantitative trait loci (QTL) were detected, including 9, 41, and 27 QTL identified at 17YC, 20KF, and 20YY, respectively. These QTL jointly explained 4.72% (SLL) to 37.30% (NSVB) of the phenotypic variation. Eight QTL were associated with the same trait at two locations. Furthermore, four pleiotropic QTL were identified. Moreover, one QTL (qPVB44), associated with NSVB_20KF, was co-localized with a previously reported locus related to kernel width, implying qPVB44 may affect the kernel width by modulating the number of small vascular bundles. Examinations of the 69 QTL identified 348 candidate genes that were classified in five groups. Additionally, 26 known VB-related homologous genes (e.g. VLN2, KNOX1, and UGT72B3) were detected in 20 of the 69 QTL. A comparison of the NSVB between a Zmvln2 EMS mutant and its wild type elucidated the function of the candidate gene ZmVLN2. These results are important for clarifying the genetic basis of PVB-related traits and may be useful for breeding new high-yielding maize cultivars.


Assuntos
Estudo de Associação Genômica Ampla , Zea mays , Mapeamento Cromossômico/métodos , Fenótipo , Melhoramento Vegetal , Feixe Vascular de Plantas , Zea mays/genética
5.
Biomolecules ; 11(11)2021 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-34827716

RESUMO

Fingerprint analysis is a common technique in forensic and criminal investigations. Similar techniques exist in the field of infrared spectroscopy to identify biomolecules according to their characteristic spectral fingerprint features. These unique markers are located in a wavenumber range from 1800 to 600 cm-1 in the mid infrared region. Here, a novel bioanalytical concept of correlating these spectral features with corresponding mass spectrometry datasets to unravel metabolic clusters within complex plant tissues was applied. As proof of concept, vascular bundles of oilseed rape (Brassica napus) were investigated, one of the most important and widely cultivated temperate zone oilseed crops. The link between mass spectrometry data and spectral data identified features that co-aligned within both datasets. Regions of origin were then detected by searching for these features in hyperspectral images of plant tissues. This approach, based on co-alignment and co-localization, finally enabled the detection of eight distinct metabolic clusters, reflecting functional and structural arrangements within the vascular bundle. The proposed analytical concept may assist future synergistic research approaches and may lead to biotechnological innovations with regard to crop yield and sustainability.


Assuntos
Brassica napus , Feixe Vascular de Plantas , Produtos Agrícolas , Traqueófitas
6.
Sci Rep ; 11(1): 21754, 2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34741092

RESUMO

The wound inflicted during grafting of watermelon seedlings requires rapid and sufficient vascular development which is affected by light quality. Our objective was to investigate the effect of light spectra emitted by light-emitting diodes (LEDs) during healing of grafted watermelon (Citrullus lanatus) seedlings on their vascular development, physiological and phytohormonal profile, and root architecture. Three LEDs emitting red (R), blue (B), and RB with 12% blue (12B) were tested in a healing chamber. During the first three days, the photosynthetic apparatus portrayed by PIABS, φP0, ψE0, and ΔVIP was less damaged and faster repaired in B-treated seedlings. B and 12B promoted vascular reconnection and root development (length, surface area and volume). This was the result of signaling cascade between phytohormones such as indole-3-acetic acid and others. After vascular reconnection the seedlings switched lights for 3 more days and the picture was reversed. Seedlings treated with B for the first 3 days and R for days 4 to 6 had better photosynthetic characteristics, root system development, morphological, shoot and root biomass, and quality (i.e. Dickson's quality index) characteristics. We concluded that blue light is important during the first 3 days of healing, while the presence of red is necessary after vascular reconnection.


Assuntos
Citrullus/efeitos da radiação , Produção Agrícola/métodos , Feixe Vascular de Plantas/crescimento & desenvolvimento , Plântula/efeitos da radiação , Citrullus/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento
7.
Cells ; 10(7)2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34359895

RESUMO

The combined response of exclusion of solar ultraviolet radiation (UV-A+B and UV-B) and static magnetic field (SMF) pre-treatment of 200 mT for 1 h were studied on soybean (Glycine max) leaves using synchrotron imaging. The seeds of soybean with and without SMF pre-treatment were sown in nursery bags kept in iron meshes where UV-A+B (280-400 nm) and UV-B (280-315 nm) from solar radiation were filtered through a polyester filters. Two controls were planned, one with polythene filter controls (FC)- which allows all the UV (280-400 nm); the other control had no filter used (open control-OC). Midrib regions of the intact third trifoliate leaves were imaged using the phase-contrast imaging technique at BL-4, Indus-2 synchrotron radiation source. The solar UV exclusion results suggest that ambient UV caused a reduction in leaf growth which ultimately reduced the photosynthesis in soybean seedlings, while SMF treatment caused enhancement of leaf growth along with photosynthesis even under the presence of ambient UV-B stress. The width of midrib and second-order veins, length of the second-order veins, leaf vein density, and the density of third-order veins obtained from the quantitative image analysis showed an enhancement in the leaves of plants that emerged from SMF pre-treated seeds as compared to untreated ones grown in open control and filter control conditions (in the presence of ambient UV stress). SMF pre-treated seeds along with UV-A+B and UV-B exclusion also showed significant enhancements in leaf parameters as compared to the UV excluded untreated leaves. Our results suggested that SMF-pretreatment of seeds diminishes the ambient UV-induced adverse effects on soybean.


Assuntos
Campos Magnéticos , Folhas de Planta/efeitos da radiação , Soja/efeitos da radiação , Síncrotrons , Raios Ultravioleta , Folhas de Planta/anatomia & histologia , Estômatos de Plantas/anatomia & histologia , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Feixe Vascular de Plantas/anatomia & histologia , Feixe Vascular de Plantas/efeitos da radiação , Espectrofotometria Ultravioleta
8.
Int J Biol Macromol ; 188: 983-992, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34403677

RESUMO

Plant laccases have been proposed to participate in lignin biosynthesis. However, there is no direct evidence that individual laccases in Populus can polymerize lignin monomers and alter cell wall structure. Here, a Populus laccase, PtrLAC16, was expressed and purified in a eukaryotic system. Enzymatic analysis of PtrLAC16 showed that it could polymerize lignin monomers in vitro. PtrLAC16 preferred sinapyl alcohol, and this preference is associated with an altered S/G ratio in transgenic Populus lines. PtrLAC16 was localized exclusively in the cell walls of stem vascular tissue, and a reduction in PtrLAC16 expression led to a significant decrease in lignin content and altered cell wall structure. There was a direct correlation between the inhibition of PtrLAC16 expression and structural changes in the stem cell wall of Populus. This study provides direct evidence that PtrLAC16 plays a key role in the polymerization of lignin monomers, especially for sinapyl lignin, and affects the formation of xylem cell walls in Populus.


Assuntos
Biocatálise , Parede Celular/enzimologia , Lacase/metabolismo , Lignina/metabolismo , Proteínas de Plantas/metabolismo , Polimerização , Populus/enzimologia , Xilema/enzimologia , Regulação da Expressão Gênica de Plantas , Cinética , Lacase/isolamento & purificação , Especificidade de Órgãos , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Feixe Vascular de Plantas/metabolismo , Plantas Geneticamente Modificadas , Populus/genética , Transporte Proteico , Análise Espectral Raman , Frações Subcelulares/metabolismo , Tabaco , Xilema/ultraestrutura
9.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34155141

RESUMO

When exposed to high light, plants produce reactive oxygen species (ROS). In Arabidopsis thaliana, local stress such as excess heat or light initiates a systemic ROS wave in phloem and xylem cells dependent on NADPH oxidase/respiratory burst oxidase homolog (RBOH) proteins. In the case of excess light, although the initial local accumulation of ROS preferentially takes place in bundle-sheath strands, little is known about how this response takes place. Using rice and the ROS probes diaminobenzidine and 2',7'-dichlorodihydrofluorescein diacetate, we found that, after exposure to high light, ROS were produced more rapidly in bundle-sheath strands than mesophyll cells. This response was not affected either by CO2 supply or photorespiration. Consistent with these findings, deep sequencing of messenger RNA (mRNA) isolated from mesophyll or bundle-sheath strands indicated balanced accumulation of transcripts encoding all major components of the photosynthetic apparatus. However, transcripts encoding several isoforms of the superoxide/H2O2-producing enzyme NADPH oxidase were more abundant in bundle-sheath strands than mesophyll cells. ROS production in bundle-sheath strands was decreased in mutant alleles of the bundle-sheath strand preferential isoform of OsRBOHA and increased when it was overexpressed. Despite the plethora of pathways able to generate ROS in response to excess light, NADPH oxidase-mediated accumulation of ROS in the rice bundle-sheath strand was detected in etiolated leaves lacking chlorophyll. We conclude that photosynthesis is not necessary for the local ROS response to high light but is in part mediated by NADPH oxidase activity.


Assuntos
Luz , NADPH Oxidases/metabolismo , Oryza/enzimologia , Oryza/efeitos da radiação , Fotossíntese/efeitos da radiação , Feixe Vascular de Plantas/enzimologia , Feixe Vascular de Plantas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Benzidinas/metabolismo , Dióxido de Carbono/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/fisiologia , Oxigênio/metabolismo , Fotossíntese/genética , Folhas de Planta/genética , Folhas de Planta/efeitos da radiação , Feixe Vascular de Plantas/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma/genética
10.
Plant J ; 107(3): 938-955, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33974297

RESUMO

Acclimation of plants to adverse conditions requires the coordination of gene expression and signalling pathways between tissues and cell types. As the energy and carbon capturing organs, leaves are significantly affected by abiotic and biotic stresses. However, tissue- or cell type-specific analyses of stress responses have focussed on the Arabidopsis root. Here, we comparatively explore the transcriptomes of three leaf tissues (epidermis, mesophyll, vasculature) after induction of diverse stress pathways by chemical stimuli (antimycin A, 3-amino-1,2,4-triazole, methyl viologen, salicylic acid) and ultraviolet light in Arabidopsis using laser capture microdissection followed by RNA sequencing. Stimulation of stress pathways caused an overall reduction in the number of genes expressed in a tissue-specific manner, though a small subset gained or changed their tissue specificity. We find no evidence of a common stress response, with only a few genes consistently responsive to two or more treatments in the analysed tissues. However, differentially expressed genes overlap between tissues for individual treatments. A focussed analysis provided evidence for an interaction of auxin and ethylene that mediates retrograde signalling during mitochondrial dysfunction specifically in the epidermis, and a gene regulatory network defined the hierarchy of interactions. Taken together, we have generated an extensive reference dataset that will be valuable for future experiments analysing transcriptional responses on a tissue or single-cell level. Our results will enable the tailoring of the tissue-specific engineering of stress-tolerant plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/metabolismo , Células do Mesofilo/metabolismo , Epiderme Vegetal/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Microdissecção e Captura a Laser , Epiderme Vegetal/citologia , Feixe Vascular de Plantas , Estresse Fisiológico , Transcrição Genética
11.
J Plant Res ; 134(4): 765-778, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33837510

RESUMO

In various monocotyledons, there are basally blindly ended stem vascular bundles, which never connect to the vascular bundles of roots. These blindly ended vascular bundles seem to be unsuitable for transferring water in terrestrial plants. In the present study, we aim to clarify the trace of the blindly ended stem vascular bundles in whole plants, and consider the evolutional process for holding such vascular bundles in the stem. We examined a whole stem vasculature of Eriocaulon taquetii (Eriocaulaceae, monocotyledons) by observation of serial transverse sections, cut by a manual rotary microtome, and viewed under an epifluorescence microscope. Our investigation revealed a threedimensional reconfiguration of the scape vasculature and detected basipetally developing and basally blindly ended vascular bundles, originated from involucral bracts and arranged with acropetally developing vascular bundles alternately in the scape internode. The basipetally developing and basally blindly ended vascular bundles, which originate from the primodia of foliar organs, have been reported in various commelinids. The characteristic vascular bundles would be homologous and presumed to be a synapomorphy of commelinids. These vascular bundles are considered to be a relic characteristic from ancestral semiaquatic plants of monocotyledons.


Assuntos
Eriocaulaceae , Evolução Biológica , Feixe Vascular de Plantas , Sementes
12.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920962

RESUMO

The plant hormone auxin acts as a mediator providing positional instructions in a range of developmental processes. Studies in Arabidopsis thaliana L. show that auxin acts in large part via activation of Auxin Response Factors (ARFs) that in turn regulate the expression of downstream genes. The rice (Oryza sativa L.) gene OsARF11 is of interest because of its expression in developing rice organs and its high sequence similarity with MONOPTEROS/ARF5, a gene with prominent roles in A. thaliana development. We have assessed the phenotype of homozygous insertion mutants in the OsARF11 gene and found that in relation to wildtype, osarf11 seedlings produced fewer and shorter roots as well as shorter and less wide leaves. Leaves developed fewer veins and larger areoles. Mature osarf11 plants had a reduced root system, fewer branches per panicle, fewer grains per panicle and fewer filled seeds. Mutants had a reduced sensitivity to auxin-mediated callus formation and inhibition of root elongation, and phenylboronic acid (PBA)-mediated inhibition of vein formation. Taken together, our results implicate OsARF11 in auxin-mediated growth of multiple organs and leaf veins. OsARF11 also appears to play a central role in the formation of lateral root, panicle branch, and grain meristems.


Assuntos
Meristema/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/metabolismo , Feixe Vascular de Plantas/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Ácidos Borônicos/farmacologia , Gravitropismo/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Mutação/genética , Tamanho do Órgão , Oryza/genética , Fenótipo , Feixe Vascular de Plantas/metabolismo , Plântula/metabolismo
13.
Plant J ; 107(2): 629-648, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33914380

RESUMO

Beyond facilitating transport and providing mechanical support to the leaf, veins have important roles in the performance and productivity of plants and the ecosystem. In recent decades, computational image analysis has accelerated the extraction and quantification of vein traits, benefiting fields of research from agriculture to climatology. However, most of the existing leaf vein image analysis programs have been developed for the reticulate venation found in dicots. Despite the agroeconomic importance of cereal grass crops, like Oryza sativa (rice) and Zea mays (maize), a dedicated image analysis program for the parallel venation found in monocots has yet to be developed. To address the need for an image-based vein phenotyping tool for model and agronomic grass species, we developed the grass vein image quantification (grasviq) framework. Designed specifically for parallel venation, this framework automatically segments and quantifies vein patterns from images of cleared leaf pieces using classical computer vision techniques. Using image data sets from maize inbred lines and auxin biosynthesis and transport mutants in maize, we demonstrate the utility of grasviq for quantifying important vein traits, including vein density, vein width and interveinal distance. Furthermore, we show that the framework can resolve quantitative differences and identify vein patterning defects, which is advantageous for genetic experiments and mutant screens. We report that grasviq can perform high-throughput vein quantification, with precision on a par with that of manual quantification. Therefore, we envision that grasviq will be adopted for vein phenomics in maize and other grass species.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Folhas de Planta/anatomia & histologia , Feixe Vascular de Plantas/anatomia & histologia , Zea mays/anatomia & histologia , Automação/métodos , Conjuntos de Dados como Assunto , Melhoramento Vegetal , Poaceae/anatomia & histologia , Característica Quantitativa Herdável
14.
PLoS Pathog ; 17(3): e1009459, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33765095

RESUMO

The host-pathogen combinations-Malus domestica (apple)/`Candidatus Phytoplasma mali´, Prunus persica (peach)/`Ca. P. prunorum´ and Pyrus communis (pear)/`Ca. P. pyri´ show different courses of diseases although the phytoplasma strains belong to the same 16SrX group. While infected apple trees can survive for decades, peach and pear trees die within weeks to few years. To this date, neither morphological nor physiological differences caused by phytoplasmas have been studied in these host plants. In this study, phytoplasma-induced morphological changes of the vascular system as well as physiological changes of the phloem sap and leaf phytohormones were analysed and compared with non-infected plants. Unlike peach and pear, infected apple trees showed substantial reductions in leaf and vascular area, affecting phloem mass flow. In contrast, in infected pear mass flow and physicochemical characteristics of phloem sap increased. Additionally, an increased callose deposition was detected in pear and peach leaves but not in apple trees in response to phytoplasma infection. The phytohormone levels in pear were not affected by an infection, while in apple and peach trees concentrations of defence- and stress-related phytohormones were increased. Compared with peach and pear trees, data from apple suggest that the long-lasting morphological adaptations in the vascular system, which likely cause reduced sap flow, triggers the ability of apple trees to survive phytoplasma infection. Some phytohormone-mediated defences might support the tolerance.


Assuntos
Produtos Agrícolas/microbiologia , Malus/imunologia , Doenças por Fitoplasmas/imunologia , Imunidade Vegetal/fisiologia , Prunus persica/imunologia , Produtos Agrícolas/imunologia , Malus/microbiologia , Phytoplasma/imunologia , Folhas de Planta/microbiologia , Feixe Vascular de Plantas/microbiologia , Prunus persica/microbiologia , RNA Ribossômico 16S
15.
Biochem Biophys Res Commun ; 549: 21-26, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33652206

RESUMO

Polarity is a feature of life. In higher plants, non-autonomous polarity is largely directed by auxin, the morphogen that drives its own polarized flow, Polar Auxin Transport (PAT), to guide patterning events such as phyllotaxis and tropism. The plasma membrane-localized PIN-FORMED (PIN) auxin efflux carriers are rate-limiting factors in PAT. In yeasts and metazoans, the STE20 kinases are key players in cell polarity. We had previously characterized SIK1 as a STE20/Hippo orthologue in Arabidopsis and confirmed its function in mitotic exit and organ growth. Here we explore the possible link between SIK1, auxin, PIN, and polarity. Abnormal phyllotaxis and gravitropism were observed in sik1. sik1 was more sensitive to exogenous auxin in primary root elongation and lateral root emergence. RNA-Seq revealed reduced expression in auxin biosynthesis genes and induced expression of auxin flux carriers in sik1. However, normal tissue- and sub-cellular localization patterns of PIN1 and PIN2 were observed in sik1. The dark-induced vacuolar degradation of PIN2 also appeared normal in sik1. An additive phenotype was observed in the sik1 pin1 double mutant, indicating that SIK1 does not directly regulate PIN1. The polarity defects of sik1 are hence unlikely mediated by PINs and await future exploration.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/citologia , Arabidopsis/enzimologia , Polaridade Celular , Proteínas de Membrana Transportadoras/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Cotilédone/crescimento & desenvolvimento , Escuridão , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Gravitropismo/fisiologia , Ácidos Indolacéticos/farmacologia , Mutação/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Feixe Vascular de Plantas/efeitos dos fármacos , Feixe Vascular de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética
16.
Commun Biol ; 4(1): 254, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33637850

RESUMO

C4 photosynthesis provides an effective solution for overcoming the catalytic inefficiency of Rubisco. The pathway is characterised by a biochemical CO2 concentrating mechanism that operates across mesophyll and bundle sheath (BS) cells and relies on a gas tight BS compartment. A screen of a mutant population of Setaria viridis, an NADP-malic enzyme type C4 monocot, generated using N-nitroso-N-methylurea identified a mutant with an amino acid change in the gene coding region of the ABCG transporter, a step in the suberin synthesis pathway. Here, Nile red staining, TEM, and GC/MS confirmed the alteration in suberin deposition in the BS cell wall of the mutant. We show that this has disrupted the suberin lamellae of BS cell wall and increased BS conductance to CO2 diffusion more than two-fold in the mutant. Consequently, BS CO2 partial pressure is reduced and CO2 assimilation was impaired in the mutant. Our findings provide experimental evidence that a functional suberin lamellae is an essential anatomical feature for efficient C4 photosynthesis in NADP-ME plants like S. viridis and have implications for engineering strategies to ensure future food security.


Assuntos
Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Dióxido de Carbono/metabolismo , Lipídeos/biossíntese , Mutação , Fotossíntese , Feixe Vascular de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Setaria (Planta)/metabolismo , Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Difusão , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica de Plantas , Microscopia Eletrônica de Transmissão , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/ultraestrutura , Feixe Vascular de Plantas/genética , Feixe Vascular de Plantas/crescimento & desenvolvimento , Feixe Vascular de Plantas/ultraestrutura , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/ultraestrutura , Setaria (Planta)/genética , Setaria (Planta)/crescimento & desenvolvimento , Setaria (Planta)/ultraestrutura
17.
Artigo em Inglês | MEDLINE | ID: mdl-33431582

RESUMO

Throughout plant development, vascular cells continually form from within a population of seemingly equivalent cells. Vascular cells connect end to end to form continuous strands, and vascular strands connect at both or either end to form networks of exquisite complexity and mesmerizing beauty. Here we argue that experimental evidence gained over the past few decades implicates the plant hormone auxin-its production, transport, perception, and response-in all the steps that lead to the patterned formation of the plant vascular system, from the formation of vascular cells to their connection into vascular networks. We emphasize the organizing principles of the cell- and tissue-patterning process, rather than its molecular subtleties. In the picture that emerges, cells compete for an auxin-dependent, cell-polarizing signal; positive feedback between cell polarization and cell-to-cell movement of the polarizing signal leads to gradual selection of cell files; and selected cell files differentiate into vascular strands that drain the polarizing signal from the neighboring cells. Although the logic of the patterning process has become increasingly clear, the molecular details remain blurry; the future challenge will be to bring them into razor-sharp focus.


Assuntos
Ácidos Indolacéticos/metabolismo , Desenvolvimento Vegetal , Feixe Vascular de Plantas/crescimento & desenvolvimento , Plantas/metabolismo , Padronização Corporal , Feixe Vascular de Plantas/metabolismo
18.
Plant Biotechnol J ; 19(1): 35-50, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32569428

RESUMO

High-throughput phenotyping is increasingly becoming an important tool for rapid advancement of genetic gain in breeding programmes. Manual phenotyping of vascular bundles is tedious and time-consuming, which lags behind the rapid development of functional genomics in maize. More robust and automated techniques of phenotyping vascular bundles traits at high-throughput are urgently needed for large crop populations. In this study, we developed a standard process for stem micro-CT data acquisition and an automatic CT image process pipeline to obtain vascular bundle traits of stems including geometry-related, morphology-related and distribution-related traits. Next, we analysed the phenotypic variation of stem vascular bundles between natural population subgroup (480 inbred lines) based on 48 comprehensively phenotypic information. Also, the first database for stem micro-phenotypes, MaizeSPD, was established, storing 554 pieces of basic information of maize inbred lines, 523 pieces of experimental information, 1008 pieces of CT scanning images and processed images, and 24 192 pieces of phenotypic data. Combined with genome-wide association studies (GWASs), a total of 1562 significant single nucleotide polymorphism (SNPs) were identified for 30 stem micro-phenotypic traits, and 84 unique genes of 20 traits such as VBNum, VBAvArea and PZVBDensity were detected. Candidate genes identified by GWAS mainly encode enzymes involved in cell wall metabolism, transcription factors, protein kinase and protein related to plant signal transduction and stress response. The results presented here will advance our knowledge about phenotypic trait components of stem vascular bundles and provide useful information for understanding the genetic controls of vascular bundle formation and development.


Assuntos
Feixe Vascular de Plantas , Zea mays , Estudos de Associação Genética , Fenótipo , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Zea mays/genética
19.
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
20.
Plant J ; 105(4): 1053-1071, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33211340

RESUMO

Stems of bioenergy sorghum (Sorghum bicolor L. Moench.), a drought-tolerant C4 grass, contain up to 50 nodes and internodes of varying length that span 4-5 m and account for approximately 84% of harvested biomass. Stem internode growth impacts plant height and biomass accumulation and is regulated by brassinosteroid signaling, auxin transport, and gibberellin biosynthesis. In addition, an AGCVIII kinase (Dw2) regulates sorghum stem internode growth, but the underlying mechanism and signaling network are unknown. Here we provide evidence that mutation of Dw2 reduces cell proliferation in internode intercalary meristems, inhibits endocytosis, and alters the distribution of heteroxylan and mixed linkage glucan in cell walls. Phosphoproteomic analysis showed that Dw2 signaling influences the phosphorylation of proteins involved in lipid signaling (PLDδ), endomembrane trafficking, hormone, light, and receptor signaling, and photosynthesis. Together, our results show that Dw2 modulates endomembrane function and cell division during sorghum internode growth, providing insight into the regulation of monocot stem development.


Assuntos
Proliferação de Células/fisiologia , Parede Celular/metabolismo , Proteínas de Plantas/metabolismo , Caules de Planta/metabolismo , Sorghum/fisiologia , Xilanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hibridização In Situ , Microscopia Confocal , Fosforilação , Proteínas de Plantas/fisiologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/fisiologia , Feixe Vascular de Plantas/metabolismo , Feixe Vascular de Plantas/fisiologia , Feixe Vascular de Plantas/ultraestrutura , Proteômica , Sorghum/enzimologia , Sorghum/crescimento & desenvolvimento , Sorghum/metabolismo
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