Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.542
Filtrar
1.
Plant Sci ; 313: 111088, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34763873

RESUMO

Abiotic stress greatly affects plant growth and developmental processes, resulting in poor productivity. A variety of basic helix-loop-helix (bHLH) transcription factors (TFs) that play important roles in plant abiotic stress response pathways have been identified. However, bHLH proteins of Zoysia japonica, one of the warm-season turfgrasses, have not been widely studied. In this study, 141 bHLH genes (ZjbHLHs) were identified and classified into 22 subfamilies. The ZjbHLHs were mapped on 19 chromosomes except for Chr17 and one pair of the tandemly arrayed genes was identified on Chr06. Also, the co-linearity of ZjbHLHs was found to have been driven mostly by segmental duplication events. The subfamily IIIb genes of our present interest, possessed various stress responsive cis-elements in their promoters. ZjbHLH076/ZjICE1, a MYC-type bHLH TF in subfamily IIIb was analyzed by overexpression and its loss-of-function via overexpressing a short ZjbHLH076/ZjICE1 fragment in the antisense direction. The overexpression of ZjbHLH076/ZjICE1 enhanced the tolerance to cold and salinity stress in the transgenic Z. japonica plants. However, the anti-sense expression of ZjbHLH076/ZjICE1 showed sensitive to these abiotic stresses. These results suggest that ZjbHLH076/ZjICE1 would be a promising candidate for the molecular breeding program to improve the abiotic stress tolerance of Z. japonica.


Assuntos
Temperatura Baixa , Poaceae/genética , Poaceae/fisiologia , Estresse Salino , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Estudo de Associação Genômica Ampla
2.
BMC Plant Biol ; 21(1): 477, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34670492

RESUMO

BACKGROUND: Both underground rhizomes/buds and above-ground Moso bamboo (Phyllostachys heterocycla) shoots/culms/branches are connected together into a close inter-connecting system in which nutrients are transported and shared among each organ. However, the starch storage and utilization mechanisms during bamboo shoot growth remain unclear. This study aimed to reveal in which organs starch was stored, how carbohydrates were transformed among each organ, and how the expression of key genes was regulated during bamboo shoot growth and developmental stages which should lay a foundation for developing new theoretical techniques for bamboo cultivation. RESULTS: Based on changes of the NSC content, starch metabolism-related enzyme activity and gene expression from S0 to S3, we observed that starch grains were mainly elliptical in shape and proliferated through budding and constriction. Content of both soluble sugar and starch in bamboo shoot peaked at S0, in which the former decreased gradually, and the latter initially decreased and then increased as shoots grew. Starch synthesis-related enzymes (AGPase, GBSS and SBE) and starch hydrolase (α-amylase and ß-amylase) activities exhibited the same dynamic change patterns as those of the starch content. From S0 to S3, the activity of starch synthesis-related enzyme and starch amylase in bamboo rhizome was significantly higher than that in bamboo shoot, while the NSC content in rhizomes was obviously lower than that in bamboo shoots. It was revealed by the comparative transcriptome analysis that the expression of starch synthesis-related enzyme-encoding genes were increased at S0, but reduced thereafter, with almost the same dynamic change tendency as the starch content and metabolism-related enzymes, especially during S0 and S1. It was revealed by the gene interaction analysis that AGPase and SBE were core genes for the starch and sucrose metabolism pathway. CONCLUSIONS: Bamboo shoots were the main organ in which starch was stored, while bamboo rhizome should be mainly functioned as a carbohydrate transportation channel and the second carbohydrate sink. Starch metabolism-related genes were expressed at the transcriptional level during underground growth, but at the post-transcriptional level during above-ground growth. It may be possible to enhance edible bamboo shoot quality for an alternative starch source through genetic engineering.


Assuntos
Metabolismo dos Carboidratos/genética , Proteínas de Plantas/metabolismo , Poaceae/genética , Amido/metabolismo , Transcriptoma , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Amilases/genética , Amilases/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Brotos de Planta/ultraestrutura , Poaceae/crescimento & desenvolvimento , Poaceae/fisiologia , Poaceae/ultraestrutura , Rizoma/genética , Rizoma/crescimento & desenvolvimento , Rizoma/fisiologia , Rizoma/ultraestrutura
3.
Sci Rep ; 11(1): 14581, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272406

RESUMO

Plants can interact with different individuals in their lifetime which may lead to plastic response that affect performance. If conspecific interactions are altered through previous plastic responses that could affect stabilizing niche mechanisms, in which conspecifics compete more intensely to promote diversity and coexistence. Here, I show interactions between Pascopyrum smithii and conspecifics resulted in largely canalized traits, whereas P. smithii with an invasive grass, Bromus tectorum resulted in plastic responses for root mass (p = 0.02), shoot mass (p < 0.0001), root mass fraction (p = 0.003) and plant height (p < 0.0001). A subset of individuals transplanted from these two interaction treatments which were moved with new, same aged conspecifics showed that previous interactions led to differing trait relationships: increases in the number of leaves for the interspecific-induced plants were related to increases in non-focal leaf production, whereas increases in the number of leaves for the intraspecific-induced plants were related to decreases in the non-focal plants (R2 = 0.52, p = 0.006). These results suggest that previous intraspecific interactions intensify conspecific competition and stabilize subsequent interactions with conspecifics by imposing greater competition, and that invasive-interspecific interactions can weaken stabilizing niche mechanisms, thus negatively influencing species coexistence.


Assuntos
Adaptação Fisiológica , Fenômenos Fisiológicos Vegetais , Poaceae/fisiologia , Plântula/fisiologia , Ecossistema , Fenótipo , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/fisiologia
4.
PLoS One ; 16(6): e0253346, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34138963

RESUMO

Thorough knowledge of the germination behavior of weed species could aid in the development of effective weed control practices, especially when glyphosate resistance is involved. A study was conducted using two glyphosate-resistant (GR) (SGW2 and CP2) and two glyphosate-susceptible (GS) (Ch and SGM2) populations of Chloris virgata, an emerging and troublesome weed species of Australian farming systems, to evaluate their germination response to different alternating temperature (15/5, 25/15 and 35/25°C with 12 h/12 h light/dark photoperiod) and moisture stress regimes (0, -0.1, -0.2, -0.4, -0.8 and -1.6 MPa). These temperature regimes represent temperatures occurring throughout the year in the eastern grain region of Australia. Seeds germinated in all the temperature regimes with no clear indication of optimum thermal conditions for the GR and GS populations. All populations exhibited considerable germination at the lowest alternating temperature regime 15/5°C (61%, 87%, 49%, and 47% for Ch, SGM2, SGW2, and CP2, respectively), demonstrating the ability of C. virgata to germinate in winter months despite being a summer annual. Seed germination of all populations was inhibited at -0.8 and -1.6 MPa osmotic potential at two alternating temperature regimes (15/5 and 35/25°C); however, some seeds germinated at 25/15°C at -0.8 MPa osmotic potential, indicating the ability of C. virgata to germinate in arid regions and drought conditions. Three biological parameters (T10: incubation period required to reach 10% germination; T50: incubation period required to reach 50% germination; and T90: incubation period required to reach 90% germination) suggested late water imbibition with increasing moisture stress levels. The GR population SGW2 exhibited a distinctive pattern in T10, T50, and T90, possessing delayed germination behaviour and thus demonstrating an escape mechanism against pre-plating weed management practices. Knowledge gained from this study will help in developing site-specific and multi-tactic weed control protocols.


Assuntos
Germinação/fisiologia , Glicina/análogos & derivados , Herbicidas/farmacologia , Poaceae/fisiologia , Estresse Fisiológico/fisiologia , Controle de Plantas Daninhas/métodos , Austrália , Secas , Germinação/efeitos dos fármacos , Glicina/farmacologia , Fotoperíodo , Poaceae/efeitos dos fármacos , Temperatura
5.
Plant Cell Rep ; 40(7): 1181-1197, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33945005

RESUMO

KEY MESSAGE: Puccinellia tenuiflora was domesticated for two years by growing it under non-saline conditions, providing epigenetic and biochemical insights into the initial domestication of extreme halophytes. Some halophytes have economic value as crop species. The domestication of halophytes may offer hope in solving the problem of soil salinization. We domesticated a wild halophyte, Puccinellia tenuiflora, for two years by growing it under non-saline conditions in a greenhouse and used re-sequencing, genome-wide DNA methylation, biochemical, and transcriptome analyses to uncover the mechanisms underlying alterations in the halophyte's tolerance to saline following domestication. Our results showed that non-saline domestication altered the methylation status for a number of genes and transposable elements, resulting in a much higher frequency of hypomethylation than hypermethylation. These modifications to DNA methylation were observed in many critical salinity-tolerance genes, particularly their promoter regions or transcriptional start sites. Twenty-nine potassium channel genes were hypomethylated and three were hypermethylated, suggesting that the DNA methylation status of potassium channel genes was influenced by domestication. The accelerated uptake of potassium is a major salinity tolerance characteristic of P. tenuiflora. We propose that modifications to the DNA methylation of potassium channel genes may be associated with the development of salinity tolerance in this species. By assessing whether non-saline domestication could change the salinity tolerance of P. tenuiflora, we demonstrated that non-saline domesticated plants are less tolerant to saline, which may be attributable to altered sucrose metabolism. DNA methylation and transposable elements may, therefore, be integrated into an environment-sensitive molecular engine that promotes the rapid domestication of P. tenuiflora to enable its use as a crop plant.


Assuntos
Metilação de DNA , Poaceae/genética , Tolerância ao Sal/genética , Plantas Tolerantes a Sal/genética , China , Elementos de DNA Transponíveis , Domesticação , Epigênese Genética , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Poaceae/fisiologia , Polimorfismo de Nucleotídeo Único , Potássio/metabolismo
6.
Molecules ; 26(5)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33800104

RESUMO

Imperata cylindrica is a medicinal plant native to southwestern Asia and the tropical and subtropical zones. To date, 72 chemical constituents have been isolated and identified from I. cylindrica Among these compounds, saponins, flavonoids, phenols, and glycosides are the major constituents. Investigations of pharmacological activities of I. cylindrica revealed that this edible medicinal herb exhibits a wide range of therapeutic potential including immunomodulatory, antibacterial, antitumor, anti-inflammatory, and liver protection activities both in vivo and in vitro. The purpose of this review is to provide an overview of I. cylindrica studies until 2019. This article also intends to review advances in the botanical, phytochemical, and pharmacological studies and industrial applications of I. cylindrica, which will provide a useful bibliography for further investigations and applications of I. cylindrica in medicines and foods.


Assuntos
Extratos Vegetais/farmacologia , Poaceae/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Diuréticos/química , Diuréticos/farmacologia , Humanos , Patentes como Assunto , Extratos Vegetais/química , Plantas Medicinais/química , Poaceae/fisiologia
7.
PLoS One ; 16(4): e0249488, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33852572

RESUMO

The world's most severe thunderstorm asthma event occurred in Melbourne, Australia on 21 November 2016, coinciding with the peak of the grass pollen season. The aetiological role of thunderstorms in these events is thought to cause pollen to rupture in high humidity conditions, releasing large numbers of sub-pollen particles (SPPs) with sizes very easily inhaled deep into the lungs. The humidity hypothesis was implemented into a three-dimensional atmospheric model and driven by inputs from three meteorological models. However, the mechanism could not explain how the Melbourne event occurred as relative humidity was very low throughout the atmosphere, and most available grass pollen remained within 40 m of the surface. Our tests showed humidity induced rupturing occurred frequently at other times and would likely lead to recurrent false alarms if used in a predictive capacity. We used the model to investigate a range of other possible pollen rupturing mechanisms which could have produced high concentrations of SPPs in the atmosphere during the storm. The mechanisms studied involve mechanical friction from wind gusts, electrical build up and discharge incurred during conditions of low relative humidity, and lightning strikes. Our results suggest that these mechanisms likely operated in tandem with one another, but the lightning method was the only mechanism to generate a pattern in SPPs following the path of the storm. If humidity induced rupturing cannot explain the 2016 Melbourne event, then new targeted laboratory studies of alternative pollen rupture mechanisms would be of considerable value to help constrain the parameterisation of the pollen rupturing process.


Assuntos
Asma/epidemiologia , Atmosfera , Poaceae/fisiologia , Rinite Alérgica Sazonal/epidemiologia , Austrália , Processos Climáticos , Humanos , Modelos Estatísticos , Pólen/fisiologia
8.
Appl Environ Microbiol ; 87(11)2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33741614

RESUMO

Coastal wetlands are experiencing frequent flooding because of global climate changes, such as the rising sea level. Despite the key role of archaea in soil biogeochemical cycles, the assembly processes and co-occurrence patterns of archaeal communities in coastal wetlands in response to increasing inundation frequencies remain elusive. In this study, we established an in situ mesocosm with an inundation frequency gradient to investigate the response of soil archaeal community toward increasing inundation frequencies in monocultures of Spartina alterniflora and a mangrove species, Kandelia obovata Both neutral community model and null model analyses suggested that stochastic processes are dominant in governing the archaeal community assembly and that the stochastic processes are enhanced with increasing inundation frequencies. Increasing inundation frequencies significantly increased the community niche width. Moreover, archaeal community in S. alterniflora soil displayed lower niche overlap and higher stochasticity than in K. obovata soil. Co-occurrence network analysis revealed that the network complexity increases with increase in the inundation frequencies. Soil water content is the most decisive factor influencing the archaeal communities. Overall, we found that increasing inundation frequencies enhance the stochastic processes and network complexity of the soil archaeal community in coastal wetlands. This study could enhance our understanding on the response of soil archaeal communities in coastal wetlands toward global change.IMPORTANCE Coastal wetlands, subjected to regular disturbances by periodic tides, are highly productive and important in the regulation of climate change. However, the assembly mechanisms and co-occurrence patterns of soil archaeal communities in coastal areas remain poorly known, especially for their responses to increasing inundation frequencies. In this study, we aimed at unraveling these uncertainties by studying typical estuarine ecosystems in southern China. We show that increasing inundation frequencies enhance the stochastic processes and network complexity of the soil archaeal community. This study offers a new path for an improved understanding of archaeal community assembly and species coexistence in coastal environments, with a special focus on the role of inundation frequency.


Assuntos
Archaea/fisiologia , Inundações , Microbiota , Elevação do Nível do Mar , Microbiologia do Solo , Áreas Alagadas , China , Poaceae/fisiologia , Rhizophoraceae/fisiologia , Processos Estocásticos
9.
PLoS One ; 16(3): e0248318, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33724993

RESUMO

Dirigent-jacalin (D-J) genes belong to the plant chimeric lectin family, and play vital roles in plant growth and resistance to abiotic and biotic stresses. To explore the functions of the D-J family in the growth and development of Moso bamboo (Phyllostachys edulis), their physicochemical properties, phylogenetic relationships, gene and protein structures, and expression patterns were analyzed in detail. Four putative PeD-J genes were identified in the Moso bamboo genome, and microsynteny and phylogenetic analyses indicated that they represent a new branch in the evolution of plant lectins. PeD-J proteins were found to be composed of a dirigent domain and a jacalin-related lectin domain, each of which contained two different motifs. Multiple sequence alignment and homologous modeling analysis indicated that the three-dimensional structure of the PeD-J proteins was significantly different compared to other plant lectins, primarily due to the tandem dirigent and jacalin domains. We surveyed the upstream putative promoter regions of the PeD-Js and found that they mainly contained cis-acting elements related to hormone and abiotic stress response. An analysis of the expression patterns of root, leaf, rhizome and panicle revealed that four PeD-J genes were highly expressed in the panicle, indicating that they may be required during the formation and development of several different tissue types in Moso bamboo. Moreover, PeD-J genes were shown to be involved in the rapid growth and development of bamboo shoots. Quantitative Real-time PCR (qRT PCR) assays further verified that D-J family genes were responsive to hormones and stresses. The results of this study will help to elucidate the biological functions of PeD-Js during bamboo growth, development and stress response.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Lectinas de Plantas/genética , Poaceae/fisiologia , Adaptação Biológica/genética , Sequência Conservada , Perfilação da Expressão Gênica , Genoma de Planta/genética , Estudo de Associação Genômica Ampla , Filogenia , Regiões Promotoras Genéticas , Estrutura Terciária de Proteína/genética , Estresse Fisiológico
10.
PLoS One ; 16(3): e0248320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735182

RESUMO

Sediment retention is a key ecosystem function provided by floodplains to filter sediments and nutrients from the river water during floods. Floodplain vegetation is an important driver of fine sediment retention. We aim to understand which structural properties of the vegetation are most important for capturing sediments. In a hydraulic flume experiment, we investigated this by disentangling sedimentation on and underneath 96 vegetation patches (40 cm x 60 cm). We planted two grass and two herb species in each patch and conducted a full-factorial manipulation of 1) vegetation density, 2) vegetation height, 3) structural diversity (small-tall vs tall-tall species combinations) and 4) leaf pubescence (based on trait information). We inundated the vegetation patches for 21 h in a flume with silt- and clay-rich water and subsequently measured the amount of accumulated sediment on the vegetation and on a fleece as ground underneath it. We quantified the sediment by washing it off the biomass and off the fleece, drying the sediment and weighting it. Our results showed that all manipulated vegetation properties combined (vegetation density and height, and the interaction of structural diversity and leaf pubescence) explained sedimentation on the vegetation (total R2 = 0.34). The sedimentation underneath the vegetation was explained by the structural diversity and the leaf pubescence (total R2 = 0.11). We further found that vegetation biomass positively affected the sedimentation on and underneath the vegetation. These findings are crucial for floodplain management strategies with the aim to increase sediment retention. Based on our findings, we can identify management strategies and target plant communities that are able to maximize a floodplain's ability to capture sediments.


Assuntos
Biodiversidade , Sedimentos Geológicos , Poaceae/fisiologia , Rios , Erosão do Solo/prevenção & controle , Biomassa , Inundações
11.
Ecotoxicol Environ Saf ; 213: 112023, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33578096

RESUMO

Arbuscular mycorrhizal fungi (AMF) play an important role in improving plant tolerance and accumulation of zinc (Zn) and cadmium (Cd). The growth, physiology and absorption of elements and transport in Phragmites australis (P. australis) were investigated under Zn and Cd stress to identify the transport mechanisms of toxic trace elements (TE) under the influence of AMF. Thus, AMF were observed to alleviate the toxic effects of Zn and Cd on P. australis by increasing plant biomass and through different regulatory patterns under different TE concentrations. The activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) increased under Zn stress, and the activities of SOD, catalase (CAT), peroxidase (POD), and APX significantly increased under high concentrations of Cd. AMF differ in their strategies of regulating the transport of different metals under TE stress. Under Zn stress, the concentration of Zn in P. australis decreased by 10-57%, and the effect on Zn translocation factor (TFZn) was concentration-dependent. AMF increased the TFZn under low concentration stress, but decreased under high concentration stress. Under Cd stress, the concentration of Cd increased by as much as 17-40%, and the TFCd decreased. AMF were also found to change the interaction of Zn×Cd. In the absence of AMF, Cd exposure decreased the Zn concentrations in P. australis at Zn100 mg/L and Zn300 mg/L, while it increased the contents of Zn at Zn700 mg/L. The opposite trend was observed following treatment with AMF. However, regardless of the concentration of Cd, the addition of Zn decreased the concentration of Cd in both treatments in both the presence and absence of AMF. Under different TE stress conditions, the regulation of metal elements by AMF in host plants does not follow a single strategy but a trade-off between different trends of transportations. The findings of our study are important for applying AMF-P. australis systems in the phytoremediation of Zn-Cd co-contaminated ecosystems.


Assuntos
Micorrizas/fisiologia , Poaceae/fisiologia , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Cádmio/toxicidade , Ecossistema , Raízes de Plantas/efeitos dos fármacos , Plantas/efeitos dos fármacos , Poaceae/efeitos dos fármacos , Poaceae/microbiologia , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Oligoelementos/metabolismo , Oligoelementos/toxicidade , Zinco/farmacologia
12.
PLoS One ; 16(2): e0247159, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33596591

RESUMO

Restoring fire regimes is a major goal of biodiversity conservation efforts in fire-prone ecosystems from which fire has been excluded. In the southeastern U.S.A., nearly a century of fire exclusion in pine savannas has led to significant biodiversity declines in one of the most species-rich ecosystems of North America. In these savannas, frequent fires that support biodiversity are driven by vegetation-fire feedbacks. Understory grasses are key components of these feedbacks, fueling the spread of fires that keep tree density low and maintain a high-light environment. When fire is reintroduced to long-unburned sites, however, remnant populations of bunchgrasses might experience high mortality from fuel accumulation during periods of fire exclusion. Our objective was to quantify fire effects on wiregrass (Aristida beyrichiana), a key component of vegetation-fire feedbacks, following 16 years without fire in a dry pine savanna typically considered to burn every 1-3 years. We examined how wiregrass size and fuel (duff depth and presence of pinecones) affected post-fire survival, inflorescence and seed production, and seed germination. Wiregrass exhibited high survival regardless of size or fuels. Probability of flowering and inflorescence number per plant were unaffected by fuel treatments but increased significantly with plant size (p = 0.016). Germination of filled seeds was consistent (29-43%) regardless of fuels, although plants in low duff produced the greatest proportion of filled seeds. The ability of bunchgrasses to persist and reproduce following fire exclusion could jumpstart efforts to reinstate frequent-fire regimes and facilitate biodiversity restoration where remnant bunchgrass populations remain.


Assuntos
Poaceae/fisiologia , Biodiversidade , Ecossistema , Germinação/fisiologia , Pradaria , Sementes/fisiologia
13.
BMC Plant Biol ; 21(1): 71, 2021 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33530948

RESUMO

BACKGROUND: Carpet grass [Axonopus compressus (L.)] is an important warm-season perennial grass around the world and is known for its adaptability to varied environmental conditions. However, Carpet grass lacks enough data in public data banks, which confined our comprehension of the mechanisms of environmental adaptations, gene discovery, and development of molecular markers. In current study, the DEGs (differentially expressed genes) in Axonopus compressus under drought stress (DS) were identified and compared with CK (control) by RNA-Seq. RESULTS: A total of 263,835 unigenes were identified in Axonopus compressus, and 201,303 (also added to the numbers of the remaining 2 databases) a sequence of unigenes significantly matched in at least one of the seven databases. A total of 153,697 (58.25%) unigenes classified to 144 KEGG pathways, and 7444 unigenes were expressed differentially between DS and CK, of which 4249 were up-regulated and 3195 were down-regulated unigenes. Of the 50 significantly enriched GO terms, 18, 6, and 14 items were related to BP, CC, and MF respectively. Analysis of KEGG enrichment revealed 2569 DEGs involved in 143 different pathways, under drought stress. 2747 DEGs were up-regulated and 2502 DEGs were down-regulated. Moreover, we identified 352 transcription factors (TFs) in Axonopus compressus, of which 270 were differentially expressed between CK and DS. The qRT-PCR validation experiment also supports the transcriptional response of Axonopus compressus against drought. Accuracy of transcriptome unigenes of Axonopus compressus was assessed with BLAST, which showed 3300 sequences of Axonopus compressus in the NCBI. CONCLUSION: The 7444 unigenes were found to be between DS and CK treatments, which indicate the existence of a strong mechanism of drought tolerance in Axonopus compressus. The current findings provide the first framework for further investigations for the particular roles of these unigenes in Axonopus compressus in response to drought.


Assuntos
Adaptação Fisiológica/genética , Secas , Poaceae/genética , Poaceae/fisiologia , Transcrição Genética , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Redes e Vias Metabólicas , Anotação de Sequência Molecular , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo
14.
Photosynth Res ; 147(2): 161-175, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33387194

RESUMO

The semi-arid ecosystems of the African Sahel play an important role in the global carbon cycle and are among the most sensitive ecosystems to future environmental pressures. Still, basic data of photosynthetic characteristics of Sahelian vegetation are very limited, preventing us to properly understand these ecosystems and to project their response to future global changes. Here, we aim to study and quantify key leaf traits, including photosynthetic parameters and leaf nutrients (Nleaf and Pleaf), of common C3 and C4 Sahelian plants (trees, lianas, and grasses) at the Dahra field site (Senegal). Dahra is a reference site for grazed semi-arid Sahelian savannah ecosystems in carbon cycle studies. Within the studied species, we found that photosynthetic parameters varied considerably between functional types. We also found significant relationships between and within photosynthetic parameters and leaf traits which mostly differed in their slopes from C3 to C4 plants. In agreement with the leaf economic spectrum, strong relationships (R2 = 0.71) were found between SLA and Nleaf whereby C3 and C4 plants showed very similar relationships. By comparing our data to a global dataset of plant traits, we show that measured Sahelian plants exhibit higher photosynthetic capacity (Asat) compared to the non-Sahelian vegetation, with values that are on average a fourfold of the global average. Moreover, Sahelian C3 plants showed photosynthetic nutrient use efficiencies that were on average roughly twice as high as global averages. We interpreted these results as the potential adaptation of Sahelian plants to short growing season lengths via an efficient nutrient allocation to optimize photosynthesis during this period. Our study provides robust estimates of key functional traits, but also traits relationships that will help to calibrate and validate vegetation models over this data-poor region.


Assuntos
Ciclo do Carbono , Nitrogênio/metabolismo , Fosfatos/metabolismo , Fotossíntese , Fenômenos Fisiológicos Vegetais , Plantas , Adaptação Fisiológica , África do Norte , Ecossistema , Fenótipo , Folhas de Planta/fisiologia , Poaceae/fisiologia , Senegal , Árvores/fisiologia
15.
Photosynth Res ; 147(2): 211-227, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33393063

RESUMO

C4-like plants represent the penultimate stage of evolution from C3 to C4 plants. Although Coleataenia prionitis (formerly Panicum prionitis) has been described as a C4 plant, its leaf anatomy and gas exchange traits suggest that it may be a C4-like plant. Here, we reexamined the leaf structure and biochemical and physiological traits of photosynthesis in this grass. The large vascular bundles were surrounded by two layers of bundle sheath (BS): a colorless outer BS and a chloroplast-rich inner BS. Small vascular bundles, which generally had a single BS layer with various vascular structures, also occurred throughout the mesophyll together with BS cells not associated with vascular tissue. The mesophyll cells did not show a radial arrangement typical of Kranz anatomy. These features suggest that the leaf anatomy of C. prionitis is on the evolutionary pathway to a complete C4 Kranz type. Phosphoenolpyruvate carboxylase (PEPC) and pyruvate, Pi dikinase occurred in the mesophyll and outer BS. Glycine decarboxylase was confined to the inner BS. Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) accumulated in the mesophyll and both BSs. C. prionitis had biochemical traits of NADP-malic enzyme type, whereas its gas exchange traits were close to those of C4-like intermediate plants rather than C4 plants. A gas exchange study with a PEPC inhibitor suggested that Rubisco in the mesophyll could fix atmospheric CO2. These data demonstrate that C. prionitis is not a true C4 plant but should be considered as a C4-like plant.


Assuntos
Dióxido de Carbono/metabolismo , Fotossíntese , Poaceae/fisiologia , Cloroplastos/enzimologia , Cloroplastos/fisiologia , Cloroplastos/ultraestrutura , Glicina Desidrogenase (Descarboxilante)/metabolismo , Malato Desidrogenase/metabolismo , Células do Mesofilo/enzimologia , Células do Mesofilo/fisiologia , Células do Mesofilo/ultraestrutura , Fenótipo , Fosfoenolpiruvato Carboxilase/antagonistas & inibidores , Fosfoenolpiruvato Carboxilase/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/fisiologia , Folhas de Planta/ultraestrutura , Proteínas de Plantas/metabolismo , Poaceae/enzimologia , Poaceae/ultraestrutura , Ribulose-Bifosfato Carboxilase/metabolismo
16.
BMC Plant Biol ; 21(1): 2, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33390157

RESUMO

BACKGROUND: Giant Juncao is often used as feed for livestock because of its huge biomass. However, drought stress reduces forage production by affecting the normal growth and development of plants. Therefore, investigating the molecular mechanisms of drought tolerance will provide important information for the improvement of drought tolerance in this grass. RESULTS: A total of 144.96 Gb of clean data was generated and assembled into 144,806 transcripts and 93,907 unigenes. After 7 and 14 days of drought stress, a total of 16,726 and 46,492 differentially expressed genes (DEGs) were observed, respectively. Compared with normal irrigation, 16,247, 23,503, and 11,598 DEGs were observed in 1, 5, and 9 days following rehydration, respectively. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed abiotic stress-responsive genes and pathways related to catalytic activity, methyltransferase activity, transferase activity, and superoxide metabolic process. We also identified transcription factors belonging to several families, including basic helix-loop-helix (bHLH), WRKY, NAM (no apical meristem), ATAF1/2 and CUC2 (cup-shaped cotyledon) (NAC), fatty acyl-CoA reductase (FAR1), B3, myeloblastosis (MYB)-related, and basic leucine zipper (bZIP) families, which are important drought-rehydration-responsive proteins. Weighted gene co-expression network analysis was also used to analyze the RNA-seq data to predict the interrelationship between genes. Twenty modules were obtained, and four of these modules may be involved in photosynthesis and plant hormone signal transduction that respond to drought and rehydration conditions. CONCLUSIONS: Our research is the first to provide a more comprehensive understanding of DEGs involved in drought stress at the transcriptome level in Giant Juncao with different drought and recovery conditions. These results may reveal insights into the molecular mechanisms of drought tolerance in Giant Juncao and provide diverse genetic resources involved in drought tolerance research.


Assuntos
Ração Animal , Secas , Poaceae/genética , Poaceae/fisiologia , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Transcriptoma
17.
Plant Signal Behav ; 16(4): 1875646, 2021 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-33465000

RESUMO

Non-negligible nighttime transpiration rates (TRN) have been identified in grasses such as wheat and barley. Evidence from the last 30 years indicate that in drought-prone environments with high evaporative demand, TRN could amount to 8-55% of daytime TR, leading several investigators to hypothesize that reducing TRN might represent a viable water-saving strategy that minimizes seemingly 'wasteful' water loss that is not traded for CO2 fixation. More recently however, evidence suggests that actual increases in TRN during pre-dawn hours, which are presumably controlled by the circadian clock, mediate drought tolerance - not through water conservation - but by enabling maximized gas exchange early in the morning before midday depression sets in. Finally, new findings point to a previously undocumented role for leaf sheaths as substantial contributors (up to 45%) of canopy TRN, although the extent of their involvement in these two strategies remains unknown. In this paper, we synthesize and reconcile key results from experimental and simulation-based modeling efforts conducted at scales ranging from the leaf tissue to the field plot on wheat and barley to show that both strategies could in fact concomitantly enable yield gains under limited water supply. We propose a simple framework highlighting the role played by TRN dynamics in drought tolerance and provide a synthesis of potential research directions, with an emphasis on the need for further examining the role played by the circadian clock and leaf sheath gas exchange.


Assuntos
Adaptação Fisiológica , Secas , Transpiração Vegetal/fisiologia , Poaceae/fisiologia , Fatores de Tempo , Pressão de Vapor
18.
Plant Biol (Stuttg) ; 23(1): 44-56, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33030790

RESUMO

Miscanthus sinensis Anderss. is a good candidate for C4 bioenergy crop development for marginal lands. As one of the characteristics of marginal lands, salinization is a major limitation to agricultural production. The present work aimed to investigate the possible factors involved in the tolerance of M. sinensis C4 photosynthesis to salinity stress. Seedlings of two accessions (salt-tolerant 'JM0119' and salt-sensitive 'JM0099') were subjected to 0 mm NaCl (control) or 250 mm NaCl (salt stress treatment) for 2 weeks. The chlorophyll content, parameters of photosynthesis and chlorophyll a fluorescence, activity of C4 enzymes and expression of C4 genes were measured. The results showed that photosynthesis rate, transpiration rate, chlorophyll content, PSII operating efficiency, coefficient of photochemical quenching, activity of phosphoenolpyruvate carboxylase (PEPC) and pyruvate, orthophosphate dikinase (PPDK) and gene expression of PEPC and PPDK under salinity were higher after long-term salinity exposure in 'JM0119' than in 'JM0099', while activity of NADP-malate dehydrogenase (NADP-MDH) and NADP-malic enzyme (NADP-ME), together with expression of NADP-MDH and NADP-ME, were much higher in 'JM0099' than in 'JM0119'. In conclusion, the increased photosynthetic capacity under long-term salt stress in the salt-tolerant relative to the salt-sensitive M. sinensis accession was mainly associated with non-stomatal factors, such as reduced chlorophyll loss, higher PSII operating efficiency, enhanced activity of PEPC and PPDK and relatively lower activity of NADP-ME.


Assuntos
Fotossíntese , Poaceae/fisiologia , Estresse Salino , Clorofila A , Regulação da Expressão Gênica de Plantas
19.
Environ Geochem Health ; 43(4): 1427-1439, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31522310

RESUMO

In recent decades, the problem of the constantly increasin level of anthropogenic load on the environment is becoming more and more acute. Some of the most dangerous pollutants entering the environment from industrial emissions are heavy metals. These pollutants are not susceptible to biodegradation over time, which leads to their accumulation in the environment in dangerous concentrations. The purpose of this work is to study the sustainability of cultivated and wild plants of the Poaceae family to aerotechnogenic pollution in the soil. The content of heavy metals in couch grass (Elytrigia repens (L.) Nevski), meadow bluegrass (Poa pratensis L.) and soft wheat (Triticum aestivum) plants grown in the impact zone of Novocherkassk Power Station has been analyzed. Contamination of cultivated and wild cereals with Pb, Zn, Ni and Cd has been established. It has been shown that the accumulation of heavy metals is individual for each plant species. An average and close correlation have been established between the total HM content and the content of their mobile forms in the soil and their content in plants. For the plants studied, the translocation factor (TF) and the distribution coefficient (DC) of HM have been calculated. The TF is formed by the ratio of the concentration of an element in the root plant dry weight to the content of its mobile compounds in the soil. The DC value makes it possible to estimate the capacity of the aboveground parts of plants to absorb and accumulate elements under soil pollution conditions and is determined as the ratio of the metal content in the aboveground biomass to its concentration in the roots. TF and DC values have shown a significant accumulation of elements by plants from the soil, as well as their translocation from the root system to the aboveground part. It has been revealed that even within the same Poaceae family, cultural species are more sensitive to man-made pollution than wild-growing ones.


Assuntos
Produtos Agrícolas/efeitos dos fármacos , Metais Pesados/toxicidade , Poaceae/fisiologia , Poluentes do Solo/toxicidade , Agricultura , Biodegradação Ambiental , Produtos Agrícolas/metabolismo , Produtos Agrícolas/fisiologia , Grão Comestível/efeitos dos fármacos , Grão Comestível/metabolismo , Grão Comestível/fisiologia , Metais Pesados/análise , Poaceae/efeitos dos fármacos , Poaceae/metabolismo , Federação Russa , Poluentes do Solo/análise , Especificidade da Espécie , Triticum/efeitos dos fármacos , Triticum/metabolismo
20.
Nat Prod Res ; 35(3): 499-502, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31282217

RESUMO

Suaeda glauca and Puccinellia tenuiflora are two important saline-alkali tolerant plants that can improve the soil properties. For exploring the different tolerance mechanisms between them, GC-MS-based metabolomics was used to comprehensively evaluate the primary metabolites differences, a total of 51 different metabolites were present in different quantities. The identified compounds were mainly 11 sugars, 7 amino acids, 5 alcohols and 18 organic acids; they play an important role in responding to the saline-alkali stress and distinguish between S. glauca and P. tenuiflora. All identified metabolites classes showed similar trend to largely accumulate in P. tenuiflora roots and S. glauca shoots, this reveals that the two plants used different physiological strategies to cope with saline-alkali stress.


Assuntos
Chenopodiaceae/metabolismo , Poaceae/metabolismo , Plantas Tolerantes a Sal/metabolismo , Solo/química , Álcoois/metabolismo , Aminoácidos/metabolismo , Chenopodiaceae/fisiologia , Cromatografia Gasosa-Espectrometria de Massas , Metabolômica , Raízes de Plantas/metabolismo , Poaceae/fisiologia , Plantas Tolerantes a Sal/fisiologia , Estresse Fisiológico , Açúcares/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...