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1.
Plant Sci ; 311: 111013, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34482916

RESUMO

Salinity is an important environmental factor that reduces plant productivity in many world regions. It affects negatively photosynthesis causing a growth reduction. Likewise, calcium (Ca2+) is crucial in plant stress response. Therefore, the modification of Ca2+ cation exchangers (CAX) transporters could be a potential strategy to increase plant tolerance to salinity. Using Targeting Induced Local Lesions in Genomes (TILLING), researchers generated three mutants of Brassica rapa CAX1a transporter: BraA.cax1a-7, BraA.cax1a-4, and BraA.cax1a-12. The aim of this study was to test the effect of those mutations on salt tolerance focusing on the response to the photosynthesis process. Thus, the three BraA.cax1a mutants and the parental line (R-o-18) were grown under salinity conditions, and parameters related to biomass, photosynthesis performance, glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49), and soluble carbohydrates were measured. BraA.cax1a-4 provided higher biomass and a better photosynthetic performance manifested by higher water use efficiency (WUE), Fv/Fm, electron fluxes, and Rubisco (EC 4.1.1.39) values. In addition, BraA.cax1a-4 presented increased osmotic protection through myo-inositol accumulation. On the other hand, BraA.cax1a-7 produced some negative effects on photosynthesis performance and lower G6PDH and Rubisco accumulations. Therefore, this study points out BraA.cax1a-4 as a useful mutation to improve photosynthetic performance in plants grown under saline conditions.


Assuntos
Brassica rapa/genética , Brassica rapa/fisiologia , Fotossíntese/genética , Fotossíntese/fisiologia , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Mutação , Folhas de Planta/genética , Folhas de Planta/fisiologia
2.
Plant Sci ; 311: 111015, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34482918

RESUMO

In the current climate change scenario, understanding crops' physiological performance under water shortage is crucial to overcome drought periods. Although the implication of leaf water relations maintaining leaf turgor and stomatal functioning under water deprivation has been suggested, the relationships between photosynthesis and osmotic and elastic adjustments remain misunderstood. Similarly, only few studies in dicotyledonous analysed how changes in cell wall composition affected photosynthesis and leaf water relations under drought. To induce modifications in photosynthesis, leaf water relations and cell wall composition, Hordeum vulgare and Triticum aestivum were subjected to different water regimes: control (CL, full irrigation), moderate and severe water deficit stress (Mod WS and Sev WS, respectively). Water shortage decreased photosynthesis mainly due to stomatal conductance (gs) declines, being accompanied by reduced osmotic potential at full turgor (πo) and increased bulk modulus of elasticity (ε). Whereas both species enhanced pectins when intensifying water deprivation, species-dependent adjustments occurred for cellulose and hemicelluloses. From these results, we showed that πo and ε influenced photosynthesis, particularly, gs. Furthermore, the (Cellulose+Hemicelluloses)/Pectins ratio determined ε and mesophyll conductance (gm) in grasses, presenting the lowest pectins content within angiosperms. Thus, we highlight the relevance of cell wall composition regulating grasses physiology during drought acclimation.


Assuntos
Parede Celular/química , Desidratação/fisiopatologia , Secas , Hordeum/fisiologia , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Triticum/fisiologia , Água/metabolismo , Mudança Climática , Produtos Agrícolas/fisiologia
3.
BMC Plant Biol ; 21(1): 430, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34551719

RESUMO

BACKGROUND: Functional trait-based ecological research has been instrumental in advancing our understanding of environmental changes. It is still, however, unclear how the functional traits of urban plants respond to atmospheric particulate matter, and which trade-off strategies are shown. In order to explore the variation of plant functional traits with the gradient of urban atmospheric particulate matter, we divided atmospheric particulate matter into three levels according to road distance, and measured the variation of six essential leaf functional traits and their trade-off strategies. RESULTS: Here, we show that the functional traits of plants can be used as predictors of plant response to urban atmospheric particulate matter. Within the study, leaf thickness, leaf dry matter content, leaf tissue density, stomatal density were positively correlated with atmospheric particulate matter. On the contrary, chlorophyll content index and specific leaf area were negatively correlated with atmospheric particulate matter. Plants can improve the efficiency of gas exchange by optimizing the spatial distribution of leaf stomata. Under the atmospheric particulate matter environment, urban plants show a trade-off relationship of economics spectrum traits at the intraspecific level. CONCLUSION: Under the influence of urban atmospheric particulate matter, urban plant shows a "slow investment-return" type in the leaf economics spectrum at the intraspecific level, with lower specific leaf area, lower chlorophyll content index, ticker leaves, higher leaf dry matter content, higher leaf tissue density and higher stomatal density. This finding provides a new perspective for understanding the resource trades-off strategy of plants adapting to atmospheric particulate matter.


Assuntos
Exposição Ambiental/efeitos adversos , Euonymus/anatomia & histologia , Euonymus/fisiologia , Material Particulado/efeitos adversos , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , China , Cidades
4.
J Plant Physiol ; 264: 153485, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34358945

RESUMO

Soil salinity is a global concern and often the primary factor contributing to land degradation, limiting crop growth and production. Alfalfa (Medicago sativa L.) is a low input high value forage legume with a wide adaptation. Examining the tissue-specific responses to salt stress will be important to understanding physiological changes of alfalfa. The responses of two alfalfa cultivars (salt tolerant 'Halo', salt intolerant 'Vernal') were studied for 12 weeks in five gradients of salt stress in a sand based hydroponic system in the greenhouse. The accumulation and localization of elements and organic compounds in different tissues of alfalfa under salt stress were evaluated using synchrotron beamlines. The pattern of chlorine accumulation for 'Halo' was: root > stem ~ leaf at 8 dSm-1, and root ~ leaf > stem at 12 dSm-1, potentially preventing toxic ion accumulation in leaf tissues. In contrast, for 'Vernal', it was leaf > stem ~ root at 8 dSm-1 and leaf > root ~ stem at 12 dSm-1. The distribution of chlorine in 'Halo' was relatively uniform in the leaf surface and vascular bundles of the stem. Amide concentration in the leaf and stem tissues was greater for 'Halo' than 'Vernal' at all salt gradients. This study determined that low ion accumulation in the shoot was a common strategy in salt tolerant alfalfa up to 8 dSm-1 of salt stress, which was then replaced by shoot tissue tolerance at 12 dSm-1.


Assuntos
Medicago sativa/metabolismo , Cálcio/análise , Cálcio/metabolismo , Cloro/análise , Cloro/metabolismo , Medicago sativa/química , Medicago sativa/fisiologia , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Caules de Planta/química , Caules de Planta/metabolismo , Caules de Planta/fisiologia , Potássio/análise , Potássio/metabolismo , Estresse Salino , Tolerância ao Sal , Sódio/análise , Sódio/metabolismo
5.
BMC Plant Biol ; 21(1): 375, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34388962

RESUMO

BACKGROUND: The lace plant (Aponogeton madagascariensis) is an aquatic monocot that develops leaves with uniquely formed perforations through the use of a developmentally regulated process called programmed cell death (PCD). The process of perforation formation in lace plant leaves is subdivided into several developmental stages: pre-perforation, window, perforation formation, perforation expansion and mature. The first three emerging "imperforate leaves" do not form perforations, while all subsequent leaves form perforations via developmentally regulated PCD. PCD is active in cells called "PCD cells" that do not retain the antioxidant anthocyanin in spaces called areoles framed by the leaf veins of window stage leaves. Cells near the veins called "NPCD cells" retain a red pigmentation from anthocyanin and do not undergo PCD. While the cellular changes that occur during PCD are well studied, the gene expression patterns underlying these changes and driving PCD during leaf morphogenesis are mostly unknown. We sought to characterize differentially expressed genes (DEGs) that mediate lace plant leaf remodelling and PCD. This was achieved performing gene expression analysis using transcriptomics and comparing DEGs among different stages of leaf development, and between NPCD and PCD cells isolated by laser capture microdissection. RESULTS: Transcriptomes were sequenced from imperforate, pre-perforation, window, and mature leaf stages, as well as PCD and NPCD cells isolated from window stage leaves. Differential expression analysis of the data revealed distinct gene expression profiles: pre-perforation and window stage leaves were characterized by higher expression of genes involved in anthocyanin biosynthesis, plant proteases, expansins, and autophagy-related genes. Mature and imperforate leaves upregulated genes associated with chlorophyll development, photosynthesis, and negative regulators of PCD. PCD cells were found to have a higher expression of genes involved with ethylene biosynthesis, brassinosteroid biosynthesis, and hydrolase activity whereas NPCD cells possessed higher expression of auxin transport, auxin signalling, aspartyl proteases, cysteine protease, Bag5, and anthocyanin biosynthesis enzymes. CONCLUSIONS: RNA sequencing was used to generate a de novo transcriptome for A. madagascariensis leaves and revealed numerous DEGs potentially involved in PCD and leaf remodelling. The data generated from this investigation will be useful for future experiments on lace plant leaf development and PCD in planta.


Assuntos
Alismatales/genética , Alismatales/fisiologia , Apoptose , Folhas de Planta/fisiologia , Alismatales/crescimento & desenvolvimento , Antocianinas/biossíntese , Apoptose/genética , Parede Celular/enzimologia , Regulação da Expressão Gênica de Plantas , Células Vegetais , Reguladores de Crescimento de Plantas/fisiologia , Folhas de Planta/genética , Proteínas de Plantas/metabolismo , RNA de Plantas , RNA-Seq , Fatores de Transcrição/fisiologia , Transcriptoma
6.
Nat Plants ; 7(8): 998-1009, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34373605

RESUMO

For decades, the dynamic nature of chlorophyll a fluorescence (ChlaF) has provided insight into the biophysics and ecophysiology of the light reactions of photosynthesis from the subcellular to leaf scales. Recent advances in remote sensing methods enable detection of ChlaF induced by sunlight across a range of larger scales, from using instruments mounted on towers above plant canopies to Earth-orbiting satellites. This signal is referred to as solar-induced fluorescence (SIF) and its application promises to overcome spatial constraints on studies of photosynthesis, opening new research directions and opportunities in ecology, ecophysiology, biogeochemistry, agriculture and forestry. However, to unleash the full potential of SIF, intensive cross-disciplinary work is required to harmonize these new advances with the rich history of biophysical and ecophysiological studies of ChlaF, fostering the development of next-generation plant physiological and Earth-system models. Here, we introduce the scale-dependent link between SIF and photosynthesis, with an emphasis on seven remaining scientific challenges, and present a roadmap to facilitate future collaborative research towards new applications of SIF.


Assuntos
Clorofila A/fisiologia , Ciências da Terra , Fluorescência , Biologia Molecular , Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Tecnologia de Sensoriamento Remoto/métodos
7.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445687

RESUMO

Leaf coloration changes evoke different photosynthetic responses among different poplar cultivars. The aim of this study is to investigate the photosynthetic difference between a red leaf cultivar (ZHP) and a green leaf (L2025) cultivar of Populus deltoides. In this study, 'ZHP' exhibited wide ranges and huge potential for absorption and utilization of light energy and CO2 concentration which were similar to those in 'L2025' and even showed a stronger absorption for weak light. However, with the increasing light intensity and CO2 concentration, the photosynthetic capacity in both 'L2025' and 'ZHP' was gradually restricted, and the net photosynthetic rate (Pn) in 'ZHP' was significantly lower than that in 'L2025'under high light or high CO2 conditions, which was mainly attributed to stomatal regulation and different photosynthetic efficiency (including the light energy utilization efficiency and photosynthetic CO2 assimilation efficiency) in these two poplars. Moreover, the higher anthocyanin content in 'ZHP' than that in 'L2025' was considered to be closely related to the decreased photosynthetic efficiency in 'ZHP'. According to the results from the JIP-test, the capture efficiency of the reaction center for light energy in 'L2025' was significantly higher than that in 'ZHP'. Interestingly, the higher levels of light quantum caused relatively higher accumulation of QA- in 'L2025', which blocked the electron transport and weakened the photosystem II (PSII) performance as compared with 'ZHP'; however, the decreased capture of light quantum also could not promote the utilization of light energy, which was the key to the low photosynthetic efficiency in 'ZHP'. The differential expressions of a series of photosynthesis-related genes further promoted these specific photosynthetic processes between 'L2025' and 'ZHP'.


Assuntos
Fotossíntese/fisiologia , Folhas de Planta/fisiologia , Populus/fisiologia , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Cor , Transporte de Elétrons/fisiologia , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Populus/genética , Populus/metabolismo
8.
Int J Mol Sci ; 22(15)2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34361053

RESUMO

Leaf senescence is a genetically regulated developmental process that can be triggered by a variety of internal and external signals, including hormones and environmental stimuli. Among the senescence-associated genes controlling leaf senescence, the transcriptional factors (TFs) comprise a functional class that is highly active at the onset and during the progression of leaf senescence. The plant-specific NAC (NAM, ATAF, and CUC) TFs are essential for controlling leaf senescence. Several members of Arabidopsis AtNAC-SAGs are well characterized as players in elucidated regulatory networks. However, only a few soybean members of this class display well-known functions; knowledge about their regulatory circuits is still rudimentary. Here, we describe the expression profile of soybean GmNAC-SAGs upregulated by natural senescence and their functional correlation with putative AtNAC-SAGs orthologs. The mechanisms and the regulatory gene networks underlying GmNAC081- and GmNAC030-positive regulation in leaf senescence are discussed. Furthermore, new insights into the role of GmNAC065 as a negative senescence regulator are presented, demonstrating extraordinary functional conservation with the Arabidopsis counterpart. Finally, we describe a regulatory circuit which integrates a stress-induced cell death program with developmental leaf senescence via the NRP-NAC-VPE signaling module.


Assuntos
Senescência Celular , Redes Reguladoras de Genes , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Soja/fisiologia , Estresse Fisiológico , Transativadores/metabolismo , Proteínas de Plantas/genética , Transativadores/genética
9.
J Plant Physiol ; 263: 153465, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225176

RESUMO

Tea is one of the most consumed beverages worldwide, and trichome formation in tea plant leaves impairs their commercial value. In Arabidopsis thaliana leaves, trichome formation is negatively regulated by the CPC family genes, which encode R3-type MYB transcription factors. Here, we identified six CPC-like genes in a tea plant (Camellia sinensis var. sinensis) for the first time. Simulated three-dimensional structure of the MYB domains of all the six CPC-like proteins exhibited negative charge on the surface, as observed on that of the Arabidopsis CPC protein that does not bind to DNA, indicating their similarity with regard to molecular interaction. We further found that the six CPC-like genes were differentially expressed in different developmental stages of tea leaves, and four out of the six genes were upregulated in the youngest 1st leaves, which formed more trichomes than other older leaves. Although it does not establish a causal link, the correlation between differential expression of CPC-like genes and variable trichome formation suggests that the R3-type MYB transcription factors are potential precipitating factors in affecting the value of tea leaf.


Assuntos
Camellia sinensis/genética , Camellia sinensis/fisiologia , Genes de Plantas , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas Proto-Oncogênicas c-myb/genética , Tricomas/genética , Tricomas/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/fisiologia , Regulação da Expressão Gênica de Plantas , Variação Genética , Japão , Proteínas Proto-Oncogênicas c-myb/fisiologia
10.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201710

RESUMO

High temperature stress leads to complex changes to plant functionality, which affects, i.a., the cell wall structure and the cell wall protein composition. In this study, the qualitative and quantitative changes in the cell wall proteome of Brachypodium distachyon leaves in response to high (40 °C) temperature stress were characterised. Using a proteomic analysis, 1533 non-redundant proteins were identified from which 338 cell wall proteins were distinguished. At a high temperature, we identified 46 differentially abundant proteins, and of these, 4 were over-accumulated and 42 were under-accumulated. The most significant changes were observed in the proteins acting on the cell wall polysaccharides, specifically, 2 over- and 12 under-accumulated proteins. Based on the qualitative analysis, one cell wall protein was identified that was uniquely present at 40 °C but was absent in the control and 24 proteins that were present in the control but were absent at 40 °C. Overall, the changes in the cell wall proteome at 40 °C suggest a lower protease activity, lignification and an expansion of the cell wall. These results offer a new insight into the changes in the cell wall proteome in response to high temperature.


Assuntos
Brachypodium/metabolismo , Parede Celular/metabolismo , Temperatura Alta , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Estresse Fisiológico , Brachypodium/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Proteoma/análise , Proteômica
11.
Biochemistry (Mosc) ; 86(7): 878-886, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34284711

RESUMO

The effects of superoxide dismutase (SOD) inhibitors, diethyldithiocarbamate (DDC), triethylenetetramine (trien), and their combination with glucose on cells of the epidermis from pea leaves of different age (rapidly growing young leaves and slowly growing old leaves) was investigated. DDC and trien caused death of the guard cells as determined by destruction of their nuclei. Glucose did not affect destruction of the nuclei induced by SOD inhibitors in the cells from old leaves, but intensified it in the cells from young leaves. 2-Deoxyglucose, an inhibitor of glycolysis, and propyl gallate, SOD-mimic and antioxidant, suppressed destruction of the nuclei that was caused by SOD inhibitors and glucose in cells of the epidermis from the young, but not from the old leaves. Glucose and trien stimulated, and propyl gallate reduced generation of reactive oxygen species (ROS) in the pea epidermis as determined by the fluorescence of 2',7'-dichlorofluorescein (DCF). Carbonyl cyanide m-chlorophenylhydrazone (CCCP), a protonophoric uncoupler of oxidative and photosynthetic phosphorylation, suppressed the DCF fluorescence in the guard cells. Treatment of the cells with CCCP followed by its removal with washing increased destruction of the nuclei caused by SOD inhibitors and glucose. In young leaves, CCCP was less effective than in old ones. The findings demonstrate the effects of SOD inhibitors and glucose on the cell death and generation of ROS and could indicate glycolysis-dependent ROS production.


Assuntos
Ditiocarb/farmacologia , Glucose/metabolismo , Ervilhas/efeitos dos fármacos , Epiderme Vegetal/efeitos dos fármacos , Espécies Reativas de Oxigênio , Superóxido Dismutase/antagonistas & inibidores , Trientina/farmacologia , Morte Celular , Quelantes/farmacologia , Inibidores Enzimáticos/farmacologia , Glucose/farmacologia , Ervilhas/enzimologia , Ervilhas/metabolismo , Ervilhas/fisiologia , Epiderme Vegetal/enzimologia , Epiderme Vegetal/metabolismo , Epiderme Vegetal/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia
12.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34299004

RESUMO

Plant production technologies based solely on the improvement of plants themselves face obstacles resulting from the natural limitations of the biological potential of varieties. Therefore, new substances are sought that positively influence the growth and development of plants and increase resistance to various biotic and abiotic stresses, which also translates into an increase in obtained yields. The exogenous application of various phytoprotectants shows great promise in terms of cost effectiveness compared to traditional breeding methods or transgenic approaches in relation to increasing plant tolerance to abiotic stresses. Quercetin is a strong antioxidant among phenolic compounds, and it plays a physiological and biochemical role in plants. As such, the aim of this research was to assess the effect of an aqueous solution of a quercetin derivative with potassium, applied in various concentrations (0.5%, 1.0%, 3.0% and 5.0%), on the efficiency of the photosynthetic apparatus and biochemical properties of maize. Among the tested variants, compared to the control, the most stimulating effect on the course of physiological processes (PN, gs, ci, CCI, Fv/Fm, Fv/F0, PI) in maize leaves was found in 3.0 and 5.0% aqueous solutions of the quercetin derivative. The highest total antioxidant capacity and total content of polyphenolic compounds were found for plants sprayed with 5.0% quercetin derivative solution; therefore, in this study, the optimal concentration could not be clearly selected.


Assuntos
Antioxidantes/farmacologia , Melhoramento Vegetal/métodos , Potássio/química , Quercetina/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Antioxidantes/administração & dosagem , Antioxidantes/química , Clorofila/análise , Clorofila/química , Fluorescência , Fenóis/análise , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Quercetina/administração & dosagem , Quercetina/análogos & derivados , Quercetina/química , Zea mays/crescimento & desenvolvimento , Zea mays/fisiologia
13.
Plant Sci ; 309: 110934, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34134841

RESUMO

With the discovery of essential genes regulating tillering, such as MONOCULM 1 (MOC1) in rice and LATERAL SUPPRESSOR (LAS in Arabidopsis, LS in tomato), research on tillering mechanisms has made great progress; however, the study of tillering in non-heading Chinese cabbage (NHCC) is rare. Here, we report that BcLAS, as a member of the GRAS family, plays an important role in the tillering of NHCC during its vegetative growth. BcLAS was almost not expressed in other examed parts except leaf axils throughout life. When the expression of BcLAS was silenced utilizing virus-induced gene silencing (VIGS) technology, we found that the tiller number of 'Maertou' decreased sharply. In 'Suzhouqing', overexpression of BcLAS significantly promoted tillering. BcCCS52, the orthologue to CELL CYCLE SEITCH 52 (CCS52), interacts with BcLAS. Downregulation of the expression of BcCCS52 promoted tillering of 'Suzhouqing'; therefore, we conclude that BcCCS52 plays a negative role in tillering regulation. Our findings reveal the tillering regulation mechanism of NHCCs at the vegetative stage and report an orthologue of CCS52 regulating tillering in NHCC.


Assuntos
Brassica rapa/genética , Proteínas de Ciclo Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Motivos de Aminoácidos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica rapa/crescimento & desenvolvimento , Brassica rapa/fisiologia , Ciclo Celular , Proteínas de Ciclo Celular/genética , Expressão Gênica , Inativação Gênica , Filogenia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Domínios Proteicos
14.
Methods Mol Biol ; 2326: 225-239, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097272

RESUMO

As increasing application of nanoparticles, nanoparticles have been becoming a new emerging environmental pollution that attracts a lot of attention from the scientific community and also regulatory agents. In the past decade, studying the toxicity and environmental impacts of nanoparticles is becoming a hot research field and more and more researches have been published using both plant and animal system. In this chapter, using oxidized metal nanoparticles as an example, we introduce a detailed protocol for performing research on biochemical and physiological toxicity of nanoparticles in plant. We employ a hydroponics system to study phytotoxicity of nanoparticles, which makes it easier to study the impact of nanoparticles. In this chapter, we majorly focus on plant respiration and photosynthesis, root vigor as well as oxidative stress. Oxidative stress is one major physiological response to different environmental pollution, in which we present a detailed method for detecting free radical oxygen species as well as the major molecules and enzymes associating with oxidative stress, including SOD and POD. Although we introduce the methods using cotton as an example, the protocols presented in this chapter can be used almost any plant species to test the biochemical and physiological toxicity of an environmental pollution.


Assuntos
Gossypium/fisiologia , Nanopartículas/toxicidade , Fotossíntese , Folhas de Planta/fisiologia , Raízes de Plantas/fisiologia , Gossypium/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Testes de Toxicidade/métodos
15.
Biomolecules ; 11(5)2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063498

RESUMO

Dendrobium officinale Kimura et Migo is a precious traditional Chinese medicine. Despite D. officinale displaying a good salt-tolerance level, the yield and growth of D. officinale were impaired drastically by the increasing soil secondary salinization. The molecular mechanisms of D. officinale plants' adaptation to salt stress are not well documented. Therefore, in the present study, D. officinale plants were treated with 250 mM NaCl. Transcriptome analysis showed that salt stress significantly altered various metabolic pathways, including phenylalanine metabolism, flavonoid biosynthesis, and α-linolenic acid metabolism, and significantly upregulated the mRNA expression levels of DoAOC, DoAOS, DoLOX2S, DoMFP, and DoOPR involved in the jasmonic acid (JA) biosynthesis pathway, as well as rutin synthesis genes involved in the flavonoid synthesis pathway. In addition, metabolomics analysis showed that salt stress induced the accumulation of some compounds in D. officinale leaves, especially flavonoids, sugars, and alkaloids, which may play an important role in salt-stress responses of leaf tissues from D. officinale. Moreover, salt stress could trigger JA biosynthesis, and JA may act as a signal molecule that promotes flavonoid biosynthesis in D. officinale leaves. To sum up, D. officinale plants adapted to salt stress by enhancing the biosynthesis of secondary metabolites.


Assuntos
Ciclopentanos/metabolismo , Dendrobium/fisiologia , Flavonoides/metabolismo , Oxilipinas/metabolismo , Vias Biossintéticas , Dendrobium/genética , Dendrobium/crescimento & desenvolvimento , Dendrobium/metabolismo , Metaboloma , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Estresse Salino , Transcriptoma
16.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072403

RESUMO

Gradually increasing temperatures at global and local scales are causing heat stress for cool and summer-season food legumes, such as lentil (Lens culinaris Medik.), which is highly susceptible to heat stress, especially during its reproductive stages of development. Hence, suitable strategies are needed to develop heat tolerance in this legume. In the present study, we tested the effectiveness of heat priming (HPr; 6 h at 35 °C) the lentil seeds and a foliar treatment of γ-aminobutyric acid (GABA; 1 mM; applied twice at different times), singly or in combination (HPr+GABA), under heat stress (32/20 °C) in two heat-tolerant (HT; IG2507, IG3263) and two heat-sensitive (HS; IG2821, IG2849) genotypes to mitigate heat stress. The three treatments significantly reduced heat injury to leaves and flowers, particularly when applied in combination, including leaf damage assessed as membrane injury, cellular oxidizing ability, leaf water status, and stomatal conductance. The combined HPr+GABA treatment significantly improved the photosynthetic function, measured as photosynthetic efficiency, chlorophyll concentration, and sucrose synthesis; and significantly reduced the oxidative damage, which was associated with a marked up-regulation in the activities of enzymatic antioxidants. The combined treatment also facilitated the synthesis of osmolytes, such as proline and glycine betaine, by upregulating the expression of their biosynthesizing enzymes (pyrroline-5-carboxylate synthase; betaine aldehyde dehydrogenase) under heat stress. The HPr+GABA treatment caused a considerable enhancement in endogenous levels of GABA in leaves, more so in the two heat-sensitive genotypes. The reproductive function, measured as germination and viability of pollen grains, receptivity of stigma, and viability of ovules, was significantly improved with combined treatment, resulting in enhanced pod number (21-23% in HT and 35-38% in HS genotypes, compared to heat stress alone) and seed yield per plant (22-24% in HT and 37-40% in HS genotypes, in comparison to heat stress alone). The combined treatment (HPr+GABA) was more effective and pronounced in heat-sensitive than heat-tolerant genotypes for all the traits tested. This study offers a potential solution for tackling and protecting heat stress injury in lentil plants.


Assuntos
Aclimatação , Resposta ao Choque Térmico , Temperatura Alta , Lens (Planta)/fisiologia , Característica Quantitativa Herdável , Sementes/fisiologia , Ácido gama-Aminobutírico/metabolismo , Lens (Planta)/efeitos dos fármacos , Oxirredução , Estresse Oxidativo , Fotossíntese , Folhas de Planta/fisiologia , Fenômenos Fisiológicos Vegetais , Reprodução , Sementes/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia
17.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068250

RESUMO

Chinese galls are the result of hyperplasia in host plants induced by aphids. The metabolism and gene expression of these galls are modified to accommodate the aphids. Here, we highlight the molecular and histologic features of horned galls according to transcriptome and anatomical structures. In primary pathways, genes were found to be unevenly shifted and selectively expressed in the galls and leaves near the galls (LNG). Pathways for amino acid synthesis and degradation were also unevenly shifted, favoring enhanced accumulation of essential amino acids in galls for aphids. Although galls enhanced the biosynthesis of glucose, which is directly available to aphids, glucose content in the gall tissues was lower due to the feeding of aphids. Pathways of gall growth were up-regulated to provide enough space for aphids. In addition, the horned gall has specialized branched schizogenous ducts and expanded xylem in the stalk, which provide a broader feeding surface for aphids and improve the efficiency of transportation and nutrient exchange. Notably, the gene expression in the LNG showed a similar pattern to that of the galls, but on a smaller scale. We suppose the aphids manipulate galls to their advantage, and galls lessen competition by functioning as a medium between the aphids and their host plants.


Assuntos
Afídeos/fisiologia , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Parasita , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Tumores de Planta/genética , Animais , Perfilação da Expressão Gênica , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Tumores de Planta/parasitologia
18.
Int J Mol Sci ; 22(9)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34067069

RESUMO

Banana (Musa spp.), one of the most important fruits worldwide, is generally cold sensitive. In this study, by using the cold-sensitive banana variety Tianbaojiao (Musa acuminate) as the study material, we investigated the effects of Piriformospora indica on banana cold resistance. Seedlings with and without fungus colonization were subjected to 4 °C cold treatment. The changes in plant phenotypes, some physiological and biochemical parameters, chlorophyll fluorescence parameters, and the expression of eight cold-responsive genes in banana leaves before and after cold treatment were measured. Results demonstrated that P. indica colonization reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2) but increased the activities of superoxide dismutase (SOD) and catalase (CAT) and the contents of soluble sugar (SS) and proline. Noteworthily, the CAT activity and SS content in the leaves of P. indica-colonized banana were significant (p < 0.05). After 24 h cold treatment, the decline in maximum photochemistry efficiency of photosystem II (Fv/Fm), photochemical quenching coefficient (qP), efficient quantum yield [Y(II)], and photosynthetic electron transport rate (ETR) in the leaves of P. indica-colonized banana was found to be lower than in the non-inoculated controls (p < 0.05). Moreover, although the difference was not significant, P. indica colonization increased the photochemical conversion efficiency and electron transport rate and alleviated the damage to the photosynthetic reaction center of banana leaves under cold treatment to some extent. Additionally, the expression of the most cold-responsive genes in banana leaves was significantly induced by P. indica during cold stress (p < 0.05). It was concluded that P. indica confers banana with enhanced cold resistance by stimulating antioxidant capacity, SS accumulation, and the expression of cold-responsive genes in leaves. The results obtained from this study are helpful for understanding the P. indica-induced cold resistance in banana.


Assuntos
Basidiomycota/fisiologia , Temperatura Baixa , Resistência à Doença , Endófitos/fisiologia , Musa/enzimologia , Basidiomycota/crescimento & desenvolvimento , Catalase/metabolismo , Clorofila/metabolismo , Contagem de Colônia Microbiana , Eletrólitos/metabolismo , Fluorescência , Regulação da Expressão Gênica de Plantas , Musa/genética , Musa/microbiologia , Peroxidase/metabolismo , Fenótipo , Folhas de Planta/enzimologia , Folhas de Planta/microbiologia , Folhas de Planta/fisiologia , Superóxido Dismutase/metabolismo
19.
J Plant Physiol ; 262: 153438, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34034043

RESUMO

Rhamphicarpa fistulosa is a facultative root parasitic annual forb, of the family Orobanchaceae that is native to sub-Saharan Africa. Parasitism results in yield reductions by the host plants but it is not known how exactly R. fistulosa affects its host or how the host responds physiologically. In three pot experiments, we investigated whether and when the parasite affects photosynthesis of rice, whether the level of impact was parasite density dependent and explored mechanisms underlying the response of rice photosynthesis to parasitism. Photosynthesis and related parameters were measured at a range of light use intensities. Host photosynthesis was negatively affected while light use efficiency was negatively affected only later on in the growth process. Except for dark respiration rates, which were never affected by parasite infection, suppression of host photosynthesis at light saturation, the initial light-use efficiency, chlorophyll content, specific leaf area and shoot weight were parasite density dependent with a stronger effect for higher parasite densities. Only at 56 days after sowing, the slope of the linear relationship between light adapted quantum efficiency of PSII electron transport (ΦPSII) and the quantum yield of CO2 assimilation (ΦCO2) of infected plants was less than those of un-infected plants. There was a considerable time lag between the parasite's acquisition of benefits from the association, in terms of growth (previously observed around 42 DAS), and the reduction of host photosynthesis (around 56 DAS). Expression of relative reductions in host growth rates started at the same time as the relative suppression of host photosynthesis. This indicated that R. fistulosa affects host growth by first extracting assimilates and making considerable gains in growth, before impacting host photosynthesis and growth.


Assuntos
Orobanchaceae/metabolismo , Oryza/parasitologia , Fotossíntese , Clorofila/metabolismo , Oryza/metabolismo , Oryza/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia
20.
BMC Plant Biol ; 21(1): 237, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044761

RESUMO

BACKGROUND: Water supply limits agricultural productivity of many crops including lettuce. Identifying cultivars within crop species that can maintain productivity with reduced water supply is a significant challenge, but central to developing resilient crops for future water-limited climates. We investigated traits known to be related to water-use efficiency (WUE) and yield in lettuce, a globally important leafy salad crop, in a recombinant inbred line (RIL) lettuce mapping population, produced from a cross between the cultivated Lactuca sativa L. cv. Salinas and its wild progenitor L. serriola L. RESULTS: Wild and cultivated lettuce differed in their WUE and we observed transgressive segregation in yield and water-use traits in the RILs. Quantitative trait loci (QTL) analysis identified genomic regions controlling these traits under well-watered and droughted conditions. QTL were detected for carbon isotope discrimination, transpiration, stomatal conductance, leaf temperature and yield, controlling 4-23 % of the phenotypic variation. A QTL hotspot was identified on chromosome 8 that controlled carbon isotope discrimination, stomatal conductance and yield under drought. Several promising candidate genes in this region were associated with WUE, including aquaporins, late embryogenesis abundant proteins, an abscisic acid-responsive element binding protein and glutathione S-transferases involved in redox homeostasis following drought stress were also identified. CONCLUSIONS: For the first time, we have characterised the genetic basis of WUE of lettuce, a commercially important and water demanding crop. We have identified promising candidate genomic regions determining WUE and yield under well-watered and water-limiting conditions, providing important pre-breeding data for future lettuce selection and breeding where water productivity will be a key target.


Assuntos
Alface/genética , Locos de Características Quantitativas/genética , Água/metabolismo , Agricultura , Isótopos de Carbono/análise , Produtos Agrícolas , Secas , Alface/fisiologia , Fenótipo , Folhas de Planta/genética , Folhas de Planta/fisiologia
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