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1.
Ecotoxicol Environ Saf ; 208: 111597, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396118

RESUMO

Tribolium castaneum (Herbst) is an important pest of stored grain, and benzoquinones secreted by this pest are harmful to humans. T. castaneum has developed strong resistance to fumigants, and an ecofriendly alternative for managing T. castaneum is urgently needed. 1-Octen-3-ol is a major volatile compound present in many mushrooms and fungi. In the current study, the direct toxicity and sublethal and transgenerational effects of 1-octen-3-ol on T. castaneum were investigated. Our results showed that 1-octen-3-ol had strong insecticidal activity against all developmental stages of T. castaneum and repelled T. castaneum adults. 1-Octen-3-ol showed negative effects on the development and reproduction of parental T. castaneum and the subsequent generation: LC30 and LC50 treatments significantly decreased the pupa and adult weights, pupation and emergence rates and fecundity of the parental generation. In addition, LC50 treatment shortened the larval and pupal periods. In the unexposed progeny (F1) of 1-octen-3-ol-exposed parents, decreased survival and pupation rates as well as reduced pupa and adult weights were observed under LC30 and LC50 treatments. In addition, a model food-system experiment showed that 1-octen-3-ol at 98 µL/L exhibited an efficacy of 100% after 7 days of fumigation and completely eliminated T. castaneum offspring. Although a higher concentration of 1-octen-3-ol was needed to achieve an efficacy equal to that of the positive control, dichlorvos (DDVP), 1-octen-3-ol promoted the seedling growth of wheat seeds, suggesting that the concentration used was not only acceptable but also beneficial for wheat seeds. Overall, 1-octen-3-ol seems to be a promising candidate for use as a fumigant and repellent against T. castaneum as well as a seed protectant.


Assuntos
Besouros/fisiologia , Repelentes de Insetos/toxicidade , Inseticidas/toxicidade , Octanóis/toxicidade , Tribolium/efeitos dos fármacos , Animais , Besouros/efeitos dos fármacos , Grão Comestível/efeitos dos fármacos , Fungos/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Pupa/efeitos dos fármacos , Triticum/efeitos dos fármacos
2.
Ecotoxicol Environ Saf ; 208: 111605, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396125

RESUMO

This is a novel study about responses of leaf photosynthetic traits and plant mercury (Hg) accumulation of rice grown in Hg polluted soils to elevated CO2 (ECO2). The aim of this study was to provide basic information on the acclimation capacity of photosynthesis and Hg accumulation in rice grown in Hg polluted soil under ECO2 at day, night, and full day. For this purpose, we analyzed leaf photosynthetic traits of rice at flowering and grain filling. In addition, chlorophyll content, soluble sugar and Malondialdehyde (MDA) of rice leaves were measured at flowering. Seed yield, ear number, grain number per ear, 1000-grain weight, total mercury (THg) and methylmercury (MeHg) contents were determined after harvest. Our results showed that Hg polluted soil and ECO2 had no significant effect on leaf chlorophyll content and leaf mass per area (LMA) in rice. The contents of soluble sugar and MDA in leaves increased significantly under ECO2. Mercury polluted soil treatment significantly reduced the light saturated CO2 assimilation rate (Asat) of rice leaves only at flowering, but not at grain filling. Night ECO2 greatly improved rice leaf water use efficiency (WUE). ECO2 greatly increased seed yield and ear number. In addition, ECO2 did not affect THg accumulation in rice organs, but ECO2 and Hg treatment had a significant interaction on MeHg in seeds, husks and roots.


Assuntos
Dióxido de Carbono/análise , Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Oryza/metabolismo , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/toxicidade , Bioacumulação , Clorofila/metabolismo , Grão Comestível/química , Grão Comestível/efeitos dos fármacos , Monitoramento Ambiental/métodos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Oryza/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Solo/química , Poluentes do Solo/análise
3.
Plant Physiol Biochem ; 160: 184-192, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33513465

RESUMO

An appropriate selenium intake can be beneficial for human health. Se-biofortified food in Se-deficient regions is becoming an increasingly common practice but there are still issues to be addressed regarding the observed Se-induced toxicity to the plant. In this respect, plant biostimulants are used to enhance nutrition efficiency, abiotic stress tolerance and crop quality. In this work, the efficacy of a plant biostimulant to counteract the Se-induced stress in wheat plants is experimentally assessed. The co-application of different Se-biofortification treatments and the biostimulant at different growth stages (tillering or heading stage) was investigated. The use of micro focused X-ray spectroscopy allows us to confirm organic Se species to be the main Se species found in wheat grain and that the proportion of organic Se species is only slightly affected by the Se application stage. Our study proves that the biostimulant had a key role in the enhancement of both the amount of grains produced per spike and their dry biomass without hindering Se enrichment process, neither diminishing the Se concentration nor massively disrupting the Se species present. This information will be useful to minimize both plant toxicity and economic cost towards a more effective and plant healthy selenium supplementation.


Assuntos
Grão Comestível/crescimento & desenvolvimento , Selênio , Triticum/efeitos dos fármacos , Biofortificação , Grão Comestível/efeitos dos fármacos , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Selênio/farmacologia , Triticum/crescimento & desenvolvimento
4.
Ecotoxicol Environ Saf ; 205: 111167, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827967

RESUMO

Contamination of agricultural fields with Cadmium (Cd) due to several agricultural practices is increasing worldwide. The rice plants can easily take up Cd and accumulate it into different parts, including the grains, posing a threat to human health even at low concentration exposure. Several phytohormones, including Salicylic acid (SA) have been investigated since long for its alleviating properties under various biotic and abiotic stress conditions. In the present study, 100 µM SA application to ameliorate 25 µM Cd stress was studied for 72 h in hydroponics in Oryza sativa cv. Bandana seedlings. Pot experiments were done with same treatment condition and plants were grown till maturity. SA application to Cd exposed rice seedlings alleviated the stress condition, which was established by several physiological, biochemical, histochemical and gene expression analysis. SA treatment to Cd stressed seedlings showed elevated photosynthetic pigment content, on-protein thiol content and relieved the Cd induced growth inhibition considerably. It lowered the accumulation of ROS like, O2- and H2O2 with a regulated antioxidative enzymatic activity. SA application in Cd exposed rice seedlings had upregulated expression of OsHMA3 and OsPCS1 whereasOsNRAMP2 gene was downregulated. Co-application of SA and Cd led to higher yield and improved agronomic traits in comparison to only Cd exposed plants under pot experimentation. Daily intake of Cd and Carcinogenic risk were also reduced by 99.75% and 99.99% respectively in the SA treated Cd stressed plants. SA positively affected the growth and tolerance of rice seedlings to Cd stress. Hence, SA addition to Cd contaminated soil can ensure rice cultivation without posing health risk to consumers.


Assuntos
Bioacumulação/efeitos dos fármacos , Cádmio/toxicidade , Grão Comestível/efeitos dos fármacos , Oryza/efeitos dos fármacos , Ácido Salicílico/farmacologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Cádmio/metabolismo , Grão Comestível/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroponia , Oryza/metabolismo , Fotossíntese/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/metabolismo , Poluentes do Solo/metabolismo , Estresse Fisiológico/efeitos dos fármacos
5.
Bull Environ Contam Toxicol ; 105(2): 237-243, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32651610

RESUMO

We assessed the effects of carbon dioxide (CO2) and decabromodiphenyl ether (BDE-209, 0, 3 and 30 mg/kg) on rice (Oryza sativa L. cv. Wuyunjing) in field free-air CO2 enrichment system. Rice at elevated (580 ppm) CO2 had increased net photosynthetic rate, intercellular CO2 concentration, shoot biomass, yield and phosphorus content in grains. However, there were no significant changes in such parameters observed on rice at elevated CO2 combined with BDE-209 (3 and 30 mg/kg). Elevated CO2 alone had no significant effects on sugar or starch content in rice grains, whereas its combination with BDE-209 (3 mg/kg) significantly decreased grain sugar and starch content. In conclusion, rice reared in soil polluted by BDE-209 under elevated CO2 modulates the effects in grain feature.


Assuntos
Dióxido de Carbono/toxicidade , Éteres Difenil Halogenados/toxicidade , Oryza/efeitos dos fármacos , Poluentes do Solo/toxicidade , Biomassa , Dióxido de Carbono/análise , China , Mudança Climática , Grão Comestível/química , Grão Comestível/efeitos dos fármacos , Éteres Difenil Halogenados/análise , Oryza/química , Fotossíntese/efeitos dos fármacos , Solo/química , Poluentes do Solo/análise
6.
Ecotoxicol Environ Saf ; 203: 110964, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32678754

RESUMO

Soil salinization is the most common abiotic stress limiting agricultural productivity worldwide. Recent research has suggested that the application of silicon (Si) has beneficial effects against salt stress in sorghum (Sorghum bicolor L. Moench) and sunflower (Helianthus annuus L.) by regulating the antioxidant system, mineral nutrients, and other important mechanisms. However, whether these effects can be achieved through foliar application of Si, or whether Si application affects Si-accumulating (e.g., sorghum), and intermediate-Si-accumulating (e.g., sunflower) plant species differently, remains unclear. This study investigated different methods of Si application in attenuating the detrimental effects of salt stress, based on the biological responses of two distinct species of Si accumulators, under greenhouse conditions. Two pot experiments were designed as a factorial (2 × 4), randomized complete blocks design (RCBD) with control and salt-stress groups (0 and 100 mmol.L-1 NaCl), and four Si-treatment groups: control (no Si), foliar application (28.6 mmol.L-1), root application (2 mmol.L-1), and combined foliar and root applications. Our results showed that the harmful effects of salt stress were attenuated by Si treatments in both plant species, which decreased Na+ uptake and lipid peroxidation, and increased Si and K+ uptake, relative leaf water content, antioxidant enzyme activities, leaf area, and shoot dry matter. These results were more prominent when Si was applied via nutrient solution in the sorghum plants, and the combined foliar and root applications of Si in sunflower plants. In addition, foliar application of Si alone is an efficient alternative in attenuating the effects of salinity in both plant species when Si is not available in the growth medium. These results suggest that the Si application method plays an important role in Na+ detoxification by modifying the antioxidative defense mechanism, which could actively mediate some important physiological and biochemical processes and helps to increase the shoot dry matter production in sorghum and sunflower plants under salt stress.


Assuntos
Antioxidantes/metabolismo , Helianthus/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Salino , Silício/farmacologia , Sorghum/efeitos dos fármacos , Grão Comestível/efeitos dos fármacos , Grão Comestível/metabolismo , Helianthus/metabolismo , Componentes Aéreos da Planta/efeitos dos fármacos , Componentes Aéreos da Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Distribuição Aleatória , Salinidade , Solo/química , Sorghum/metabolismo
7.
PLoS One ; 15(6): e0234029, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484836

RESUMO

The aim of this study was to determine the effects and underlying molecular mechanisms of humic acid (HA) on foxtail millet (Setaria italica Beauv.) under drought conditions. The rainless climate of the Shanxi Province (37°42'N, 112°58'E) in China provides a natural simulation of drought conditions. Two foxtail millet cultivars, Jingu21 and Zhangza10, were cultivated in Shanxi for two consecutive years (2017-2018) based on a split-plot design. Plant growth, grain quality, and mineral elements were analyzed in foxtail millet treated with HA (50, 100, 200, 300, and 400 mg L-1) and those treated with clear water. Transcriptome sequencing followed by bioinformatics analysis was performed on plants in the normal control (CK), drought treatment (D), and drought + HA treatment (DHA) groups. Results were verified using real-time quantitative PCR (RT-qPCR). HA at a concentration of 100-200 mg L-1 caused a significant increase in the yield of foxtail millet and had a positive effect on dry weight and root-shoot ratio. HA also significantly increased P, Fe, Cu, Zn, and Mg content in grains. Moreover, a total of 1098 and 409 differentially expressed genes (DEGs) were identified in group D vs. CK and D vs. DHA, respectively. A protein-protein interaction network and two modules were constructed based on DEGs (such as SETIT_016654mg) between groups D and DHA. These DEGs were mainly enriched in the metabolic pathway. In conclusion, HA (100 mg L-1) was found to promote the growth of foxtail millet under drought conditions. Furthermore, SETIT_016654mg may play a role in the effect of HA on foxtail millet via control of the metabolic pathway. This study lays the foundation for research into the molecular mechanisms that underlie the alleviating effects of HA on foxtail millet under drought conditions.


Assuntos
Substâncias Húmicas , Proteínas de Plantas/genética , Setaria (Planta)/crescimento & desenvolvimento , Transcriptoma/genética , China , Secas , Grão Comestível/efeitos dos fármacos , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Setaria (Planta)/efeitos dos fármacos , Setaria (Planta)/genética , Estresse Fisiológico/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
8.
Ecotoxicol Environ Saf ; 196: 110525, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32224370

RESUMO

Fragrant rice is a high-valued quality rice type which is gaining much popularity over the globe due to its better cooking qualities and special aromatic characteristics. Selenium (Se) and silicon (Si) could improve the growth and yield of rice; however, the combine effects of Se and Si (Se-Si treatments) on rice grain quality, aroma and lodging in fragrant rice were rarely investigated. The pot and field experiments were conducted with two fragrant rice cultivars i.e., Xiangyaxiangzhan and Yuxiangyouzhan, grown under three Se levels i.e., 0, 120, and 240 mg kg-1 of soil (for pot experiment) and 0, 300, and 600 kg ha-1 (for field experiment) regarded as LSe, MSe and HSe, respectively and two Si levels i.e., 0 and 60 mg kg-1 of soil (for pot experiment) and 0 and 150 kg ha-1 (for field experiment) regarded as -Si and +Si, respectively. Results depicted that the Se-Si treatments regulated head rice yield, grain yield and yield related traits and the HSe+Si treatment sustainably improved the grain yield and head rice yield by regulating plant growth, antioxidant response and malondialdehyde (MDA) contents in fragrant rice. The Se-Si treatments also improved the grain 2AP contents owing to regulation in the proline, pyrroline-5-carboxylate (P5C) and γ-aminobutyric acid (GABA) contents. Besides, Se-Si treatments also regulated the grain quality attributes and influenced the plant Se contents. Moreover, the Si mitigated Se-induced lodging resulted from changes in the lodging parameters i.e., lodging index, fresh weight per tiller, pushing resistance force, plant height and bending moment. Overall, the Se and Si application improved the grain yield and regulated the dry weight accumulation, antioxidant attributes and quality attributes. Meanwhile, the Si application mitigated the negative effect of Se-induced lodging in fragrant rice.


Assuntos
Grão Comestível/efeitos dos fármacos , Odorantes/análise , Oryza/efeitos dos fármacos , Selênio/farmacologia , Silício/farmacologia , Antioxidantes/análise , Relação Dose-Resposta a Droga , Grão Comestível/química , Grão Comestível/crescimento & desenvolvimento , Malondialdeído/análise , Oryza/química , Oryza/crescimento & desenvolvimento , Prolina/análise , Pirróis/análise , Solo/química
9.
BMC Genomics ; 21(1): 127, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32028884

RESUMO

BACKGROUND: Node is the central organ of transferring nutrients and ions in plants. Cadmium (Cd) induced crop pollution threatens the food safety. Breeding of low Cd accumulation cultivar is a chance to resolve this universal problem. This study was performed to identify tissue specific genes involved in Cd accumulation in different rice stem nodes. Panicle node and the first node under panicle (node I) were sampled in two rice cultivars: Xiangwanxian No. 12 (low Cd accumulation cultivar) and Yuzhenxiang (high Cd accumulation cultivar). RNA-seq analysis was performed to identify differentially expressed genes (DEGs) and microRNAs. RESULTS: Xiangwanxian No. 12 had lower Cd concentration in panicle node, node I and grain compared with Yuzhenxiang, and node I had the highest Cd concentration in the two cultivars. RNA seq analysis identified 4535 DEGs and 70 miRNAs between the two cultivars. Most genesrelated to the "transporter activity", such as OsIRT1, OsNramp5, OsVIT2, OsNRT1.5A, and OsABCC1, play roles in blocking the upward transport of Cd. Among the genes related to "response to stimulus", we identified OsHSP70 and OsHSFA2d/B2c in Xiangwanxian No. 12, but not in Yuzhenxiang, were all down-regulated by Cd stimulus. The up-regulation of miRNAs (osa-miR528 and osa-miR408) in Xiangwanxian No. 12 played a potent role in lowering Cd accumulation via down regulating the expression of candidate genes, such as bZIP, ERF, MYB, SnRK1 and HSPs. CONCLUSIONS: Both panicle node and node I of Xiangwanxian No. 12 played a key role in blocking the upward transportation of Cd, while node I played a critical role in Yuzhenxiang. Distinct expression patterns of various transporter genes such as OsNRT1.5A, OsNramp5, OsIRT1, OsVIT2 and OsABCC1 resulted in differential Cd accumulation in different nodes. Likewise, distinct expression patterns of these transporter genes are likely responsible for the low Cd accumulation in Xiangwanxian No. 12 cultivar. MiRNAs drove multiple transcription factors, such as OsbZIPs, OsERFs, OsMYBs, to play a role in Cd stress response.


Assuntos
Cádmio/farmacocinética , Grão Comestível/metabolismo , Oryza/metabolismo , Poluentes do Solo/farmacocinética , Transporte Biológico , Cádmio/toxicidade , Grão Comestível/efeitos dos fármacos , Grão Comestível/genética , MicroRNAs/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Caules de Planta/efeitos dos fármacos , Caules de Planta/genética , Caules de Planta/metabolismo , RNA-Seq , Poluentes do Solo/toxicidade , Transcriptoma/efeitos dos fármacos
10.
Molecules ; 25(3)2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32019268

RESUMO

Exopolymeric substances (EPS) can determine plant-microorganism interactions and have great potential as bioactive compounds. The different amounts of EPS obtained from cultures of three endophytic Fusarium culmorum strains with different aggressiveness-growth promoting (PGPF), deleterious (DRMO), and pathogenic towards cereal plants-depended on growth conditions. The EPS concentrations (under optimized culture conditions) were the lowest (0.2 g/L) in the PGPF, about three times higher in the DRMO, and five times higher in the pathogen culture. The EPS of these strains differed in the content of proteins, phenolic components, total sugars, glycosidic linkages, and sugar composition (glucose, mannose, galactose, and smaller quantities of arabinose, galactosamine, and glucosamine). The pathogen EPS exhibited the highest total sugar and mannose concentration. FTIR analysis confirmed the ß configuration of the sugars. The EPS differed in the number and weight of polysaccharidic subfractions. The EPS of PGPF and DRMO had two subfractions and the pathogen EPS exhibited a subfraction with the lowest weight (5 kDa). The three EPS preparations (ethanol-precipitated EP, crude C, and proteolysed P) had antioxidant activity (particularly high for the EP-EPS soluble in high concentrations). The EP-EPS of the PGPF strain had the highest antioxidant activity, most likely associated with the highest content of phenolic compounds in this EPS.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Grão Comestível/efeitos dos fármacos , Matriz Extracelular de Substâncias Poliméricas/química , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Fusarium/fisiologia , Antioxidantes/isolamento & purificação , Grão Comestível/microbiologia , Interações Hospedeiro-Patógeno
11.
Ecotoxicol Environ Saf ; 191: 110218, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31962215

RESUMO

Heavy metals contamination of soil especially with cadmium (Cd) is a serious environmental concern in the current industrial era. Biochar serves as an excellent ameliorating agent depending upon its properties and application rates. In the pot scale study, effect of acid treated (AWSB) and untreated wheat straw biochar (WSB) was studied on physiology, grain yield, Cd accumulation, and tolerance of quinoa with possible health risks. Different levels of Cd (0, 25, 50 and 75 mg kg-1), AWSB and WSB (1% and 2% (w/w)) were applied in soil. Accumulation of Cd in control plant tissues led to oxidative stress which was shown in terms of increased lipid peroxidation. While biochar application relieved the oxidative damage as confirmed by the low production of H2O2 and TBARS contents. Application of AWSB improved plant growth, pigment contents and gas exchange attributes by limiting the accumulation of Cd in root, shoot and grain of quinoa. Results revealed a significant improvement in the activity of superoxide (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) with biochar at elevated levels of Cd in soil. Target Hazard Quotient (THQ) remained < 1 in the quinoa grains with WSB and AWSB under Cd stress. These results revealed that AWSB most effectively alleviated Cd toxicity in quinoa thereby decreasing Cd accumulation and regulation of Cd induced oxidative stress triggered by the antioxidant enzymatic system.


Assuntos
Ácidos/química , Cádmio/metabolismo , Carvão Vegetal/farmacologia , Chenopodium quinoa/efeitos dos fármacos , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Cádmio/análise , Carvão Vegetal/química , Chenopodium quinoa/crescimento & desenvolvimento , Chenopodium quinoa/metabolismo , Grão Comestível/efeitos dos fármacos , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Solo/química , Poluentes do Solo/análise , Triticum/química
12.
PLoS One ; 15(1): e0223086, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31899771

RESUMO

Rice wild relatives (RWR) constitute an extended gene pool that can be tapped for the breeding of novel rice varieties adapted to abiotic stresses such as iron (Fe) toxicity. Therefore, we screened 75 Oryza genotypes including 16 domesticated O. sativa genotypes, one O. glaberrima, and 58 RWR representing 21 species, for tolerance to Fe toxicity. Plants were grown in a semi-artificial greenhouse setup, in which they were exposed either to control conditions, an Fe shock during the vegetative growth stage (acute treatment), or to a continuous moderately high Fe level (chronic treatment). In both stress treatments, foliar Fe concentrations were characteristic of Fe toxicity, and plants developed foliar stress symptoms, which were more pronounced in the chronic Fe stress especially toward the end of the growing season. Among the genotypes that produced seeds, only the chronic stress treatment significantly reduced yields due to increases in spikelet sterility. Moreover, a moderate but non-significant increase in grain Fe concentrations, and a significant increase in grain Zn concentrations were seen in chronic stress. Both domesticated rice and RWR exhibited substantial genotypic variation in their responses to Fe toxicity. Although no RWR strikingly outperformed domesticated rice in Fe toxic conditions, some genotypes scored highly in individual traits. Two O. meridionalis accessions were best in avoiding foliar symptom formation in acute Fe stress, while an O. rufipogon accession produced the highest grain yields in both chronic and acute Fe stress. In conclusion, this study provides the basis for using interspecific crosses for adapting rice to Fe toxicity.


Assuntos
Resistência à Doença/genética , Ferro/toxicidade , Oryza/genética , Doenças das Plantas/genética , Animais , Grão Comestível/efeitos dos fármacos , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Etanol , Genótipo , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
13.
Ecotoxicol Environ Saf ; 189: 110008, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31796254

RESUMO

Excess iron (Fe) is commonly observed in wetland rice (Oryza sativa L.) plants, impairing crop growth and productivity. Some information suggests that silicon (Si) can reduce Fe content in leaves and roots of rice (vegetative phase), but nothing is known if Si could mitigate the effects of Fe toxicity on rice production and photosynthesis. Here, we assessed the role of Si in alleviating the well-known effects of Fe toxicity on nutritional imbalances, biomass accumulation, photosynthesis and grain yield using two rice cultivars having differential abilities to tolerate excess Fe. Plants were hydroponically grown under two Fe levels (25 µM or 5 mM) and the nutrient solutions were amended with Si (0 or 2 mM). Under excess Fe were detected (i) nutritional deficiencies, especially of calcium and magnesium in leaves; (ii) negligible changes in grain nutritional composition, independently of Si application; (iii) decreases in net photosynthetic rates, stomatal conductance and electron transport rate, in parallel to decreased grain yield components (total grain biomass, 1000-grain mass, percentage of filled grains, number of grains per plant and harvest index), especially in the Fe-sensitive cultivar. These impairments were partially reversed by the application of Si. Results also suggest that Si alleviated the negative impacts of Fe on spikelet sterility. In summary, we conclude that the use of Si can be recommended as an effective management strategy to reduce the negative impacts of Fe toxicity on rice photosynthetic performance and crop yield.


Assuntos
Grão Comestível/efeitos dos fármacos , Ferro/toxicidade , Oryza/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Silício/farmacologia , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Hidroponia , Ferro/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
14.
BMC Plant Biol ; 19(1): 502, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31730480

RESUMO

BACKGROUND: Selenium (Se) is a beneficial element for higher plants and essential for mammals. To study the effect of the foliar application of sodium selenate on fragrant rice performance, a pot experiment was conducted in Guangdong, China. At the initial heading stage, one-time foliar application of sodium selenate with concentrations of 0, 10, 20, 30, 40 and 50 µmol·L- 1 (named CK, Se1, Se2, Se3, Se4 and Se5, respectively) were foliar applied on two fragrant rice varieties, 'Meixiangzhan-2' and 'Xiangyaxiangzhan'. RESULTS: Selenate application at the initial heading stage not only improved the grain yield of fragrant rice by increasing the seed-setting rate and grain weight, but also promoted the grain quality by increasing crude protein contents and lowering the chalky rice rate. Furthermore, Se applications enhanced the biosynthesis of 2-acetyl-1- pyrroline (2-AP), the main aromatic compound, by increasing the contents of precursors (△1- pyrroline, proline and pyrroline-5-carboxylic acid (P5C)) and the activities of enzymes (proline dehydrogenase (PRODH), △1-pyrroline-5-carboxylic acid synthetase (P5CS), and ornithine aminotransferase (OAT)) in fragrant rice. The results also showed that foliar application of sodium selenate enhanced the antioxidant system of both varieties by promoting the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and reducing the contents of malondialdehyde (MDA). Furthermore, the real-time PCR analyses depicted that foliar application of selenate up-regulated the GPX1, GPX4 and CATC transcripts. The higher antioxidative enzymatic activities might strength the stress resistant to ensure the stability of yield in fragrant rice form abiotic stress. CONCLUSIONS: Foliar applications of sodium selenate at the initial heading stage increased the grain 2-AP content by enhancing the biosynthesis-related enzymes and precursors. The grain yield and quality of fragrant rice also increased due to selenate application. Furthermore, foliar application of selenate promoted the activities of enzymes such as POD, SOD and CAT and up-regulated the expression of gene GPX4, GPX1 and CATC.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/efeitos dos fármacos , Pirróis/metabolismo , Ácido Selênico/administração & dosagem , Antioxidantes/metabolismo , Biomassa , Catalase/metabolismo , Grão Comestível/efeitos dos fármacos , Grão Comestível/enzimologia , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Malondialdeído/metabolismo , Oryza/enzimologia , Oryza/genética , Oryza/crescimento & desenvolvimento , Peroxidases/metabolismo , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Superóxido Dismutase/metabolismo
15.
Int J Mol Sci ; 20(21)2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31661847

RESUMO

Grain number per panicle is an important component of grain yield in sorghum (Sorghum bicolor (L.)) and other cereal crops. Previously, we reported that mutations in multi-seeded 1 (MSD1) and MSD2 genes result in a two-fold increase in grain number per panicle due to the restoration of the fertility of the pedicellate spikelets, which invariably abort in natural sorghum accessions. Here, we report the identification of another gene, MSD3, which is also involved in the regulation of grain numbers in sorghum. Four bulked F2 populations from crosses between BTx623 and each of the independent msd mutants p6, p14, p21, and p24 were sequenced to 20× coverage of the whole genome on a HiSeq 2000 system. Bioinformatic analyses of the sequence data showed that one gene, Sorbi_3001G407600, harbored homozygous mutations in all four populations. This gene encodes a plastidial ω-3 fatty acid desaturase that catalyzes the conversion of linoleic acid (18:2) to linolenic acid (18:3), a substrate for jasmonic acid (JA) biosynthesis. The msd3 mutants had reduced levels of linolenic acid in both leaves and developing panicles that in turn decreased the levels of JA. Furthermore, the msd3 panicle phenotype was reversed by treatment with methyl-JA (MeJA). Our characterization of MSD1, MSD2, and now MSD3 demonstrates that JA-regulated processes are critical to the msd phenotype. The identification of the MSD3 gene reveals a new target that could be manipulated to increase grain number per panicle in sorghum, and potentially other cereal crops, through the genomic editing of MSD3 functional orthologs.


Assuntos
Produtos Agrícolas/enzimologia , Ciclopentanos/metabolismo , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Oxilipinas/metabolismo , Sorghum/enzimologia , Alelos , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Ciclopentanos/farmacologia , Grão Comestível/efeitos dos fármacos , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Sequenciamento de Nucleotídeos em Larga Escala , Ácido Linoleico/química , Ácido Linoleico/metabolismo , Mutação , Oxilipinas/farmacologia , Fenótipo , Sementes/efeitos dos fármacos , Sementes/genética , Sementes/crescimento & desenvolvimento , Sorghum/genética , Sorghum/metabolismo , Ácido alfa-Linoleico/biossíntese , Ácido alfa-Linoleico/química
16.
Ecotoxicol Environ Saf ; 184: 109640, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31499448

RESUMO

Altering Cd chemical form is one of the mechanisms to alleviate Cd toxicity in rice plant. Field experiments were carried out in this study to investigate the potential of rice vegetative organs in altering Cd into insoluble chemical forms in the natural environment. Experimental results showed that more than 80% of Cd in rice roots existed in the insoluble forms. Uppermost nodes altered Cd into insoluble form preferentially and generally had higher content of insoluble Cd than other organs. Rachises displayed a slow increasing trend in soluble Cd when total Cd in roots was less than 1.8 mg kg-1. However, when Cd content in roots exceeded 2.8 mg kg-1, the ratio of insoluble to soluble Cd remained stable at 85:15 in rachises and roots, and at 75:25 in uppermost nodes and flag leaves. Cd concentration in grains was greatly lower than that in vegetative organs, and closely correlated with the content of soluble Cd in rachises (r = 0.991**) as well as in uppermost nodes. Soluble Cd in the uppermost nodes displayed a much lower mobility than that in other organs. Accumulation of soluble Cd was always companied by decrease of Ca and increase of Mn in roots, uppermost nodes and rachises. A small increase of soluble Cd from 0.05 to 0.1 mg kg-1 caused a sharp decline of Ca:Mn ratio in roots and rachises. Roots and nodes had much higher Ca:Mn ratio than rachises when soluble Cd was less than 0.5 mg kg-1 in them. These results indicate that vegetative organs have a great potential to alter more than 75% Cd into insoluble forms and increasing Ca:Mn ratio may be another way to alleviate Cd toxicity by establishing new ionic homeostasis in rice plants.


Assuntos
Cádmio/toxicidade , Cálcio/análise , Manganês/análise , Oryza/efeitos dos fármacos , Cádmio/química , Grão Comestível/química , Grão Comestível/efeitos dos fármacos , Modelos Teóricos , Oryza/química , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Solubilidade
17.
J Exp Bot ; 70(21): 6447-6459, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31504692

RESUMO

Hot days are becoming hotter and more frequent, threatening wheat yields worldwide. Developing wheat varieties ready for future climates calls for improved understanding of how elevated CO2 (eCO2) and heat stress (HS) interactively impact wheat yields. We grew a modern, high-yielding wheat cultivar (Scout) at ambient CO2 (aCO2, 419 µl l -1) or eCO2 (654 µl l-1) in a glasshouse maintained at 22/15 °C (day/night). Half of the plants were exposed to HS (40/24 °C) for 5 d at anthesis. In non-HS plants, eCO2 enhanced (+36%) CO2 assimilation rates (Asat) measured at growth CO2 despite down-regulation of photosynthetic capacity. HS reduced Asat (-42%) in aCO2- but not in eCO2-grown plants because eCO2 protected photosynthesis by increasing ribulose bisphosphate regeneration capacity and reducing photochemical damage under HS. eCO2 stimulated biomass (+35%) of all plants and grain yield (+30%) of non-HS plants only. Plant biomass initially decreased following HS but recovered at maturity due to late tillering. HS equally reduced grain yield (-40%) in aCO2- and eCO2-grown plants due to grain abortion and reduced grain filling. While eCO2 mitigated the negative impacts of HS at anthesis on wheat photosynthesis and biomass, grain yield was reduced by HS in both CO2 treatments.


Assuntos
Dióxido de Carbono/farmacologia , Grão Comestível/crescimento & desenvolvimento , Resposta ao Choque Térmico/efeitos dos fármacos , Triticum/fisiologia , Aclimatação/efeitos dos fármacos , Biomassa , Clorofila/metabolismo , Grão Comestível/efeitos dos fármacos , Fluorescência , Modelos Biológicos , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Temperatura , Triticum/efeitos dos fármacos
18.
Environ Int ; 132: 105092, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31442740

RESUMO

Mulching can effectively maintain and improve soil health and functionality. The mechanisms, however, have not been fully elucidated. Therefore, the effects of temperature on the biogeochemical properties of soil were investigated in the present study in relation to nitrogen management and soil functionality. The results of the 3-year field experiments showed that integrated straw mulch (S) and nitrogen fertilizer (N) treatments enhanced the activities of soil urease, invertase, alkaline phosphatase, and catalase by >1.8, 2.1, 2.0 and 1.4 fold, respectively, compared with the control treatment. Furthermore, these treatments increased soil available N by 28%, phosphorus by 45%, and potassium by 55%. In general, the soil organic carbon, dissolved carbon and labile organic carbon content in the treated plot were approximately 1.2-2.9 folds greater than in the control plot. These improvements in soil fertility and carbon indices increased the biomass and grain yield of soybean (67 and 75%, respectively) during the three-year study period. During 2015-2017, the straw mulch and nitrogen fertilizer treatment increased the soil moisture (23%) and decreased the soil temperature (8%) in comparison to the control in the 0-0.2 m soil depth and, therefore, improved soil enzyme activities, nutrient availability, and carbon stocks, and ultimately, soil functionality and sustainability, in the semiarid region.


Assuntos
Agricultura/métodos , Fertilizantes , Solo/química , Soja/efeitos dos fármacos , Triticum , Biomassa , Carbono/análise , Grão Comestível/efeitos dos fármacos , Grão Comestível/crescimento & desenvolvimento , Nitrogênio/química , Nitrogênio/farmacologia , Fósforo/análise , Potássio/análise , Soja/crescimento & desenvolvimento , Temperatura
19.
BMC Plant Biol ; 19(1): 327, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324148

RESUMO

BACKGROUND: Diethyl aminoethyl hexanoate (DA-6), a plant growth regulator, has many beneficial effects on agricultural production. DA-6 has been applied to many plant species, but the molecular mechanism by which spraying DA-6 after anthesis regulates wheat grain filling is still unknown. RESULTS: In this study, we used four DA-6 concentrations: C0 (0 g/L), C2 (2 g/L), C4 (4 g/L), and C6 (6 g/L). The results showed that C4 and C6 led to a significantly higher 1000-grain weight and seed protein content than C0 during two wheat growing seasons. We then subjected samples at 24 days after anthesis (at which point the grain weight increased rapidly) to transcriptome analysis. Flag leaf (L), seed (S), and stem (T) samples under C6 and C0 were used for RNA-seq. The seed samples under C6 compared with C0 (S6vsS0) presented the most differentially expressed genes (DEGs; 2164). Plant hormone signal transduction (p = 1.97 × 10- 4), protein processing in the endoplasmic reticulum (ER; p = 9.04 × 10- 11) and starch and sucrose metabolism (p = 1.90 × 10- 10) pathways were the most markedly enriched pathways in the flag leaves, stems, and seeds, respectively. DEGs involved in sucrose synthesis in the flag leaves, protein processing in ER in the stems, and starch synthesis and protein processing in ER in the seeds were significantly upregulated under C6 compared with C0. CONCLUSIONS: Overall, we propose a model for spraying DA-6 after anthesis to regulate metabolic pathways in wheat, which provides new insights into wheat in response to DA-6.


Assuntos
Caproatos/farmacologia , Grão Comestível/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Triticum/efeitos dos fármacos , Relação Dose-Resposta a Droga , Grão Comestível/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Proteínas de Armazenamento de Sementes/metabolismo , Triticum/crescimento & desenvolvimento
20.
Sci Rep ; 9(1): 8164, 2019 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-31160657

RESUMO

Research has shown that chitosan induces plant stress tolerance and protection, but few studies have explored chemical modifications of chitosan and their effects on plants under water stress. Chitosan and its derivatives were applied (isolated or in mixture) to maize hybrids sensitive to water deficit under greenhouse conditions through foliar spraying at the pre-flowering stage. After the application, water deficit was induced for 15 days. Analyses of leaves and biochemical gas exchange in the ear leaf were performed on the first and fifteenth days of the stress period. Production attributes were also analysed at the end of the experiment. In general, the application of the two chitosan derivatives or their mixture potentiated the activities of the antioxidant enzymes superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and guaiacol peroxidase at the beginning of the stress period, in addition to reducing lipid peroxidation (malonaldehyde content) and increasing gas exchange and proline contents at the end of the stress period. The derivatives also increased the content of phenolic compounds and the activity of enzymes involved in their production (phenylalanine ammonia lyase and tyrosine ammonia lyase). Dehydroascorbate reductase and compounds such as total soluble sugars, total amino acids, starch, grain yield and harvest index increased for both the derivatives and chitosan. However, the mixture of derivatives was the treatment that led to the higher increase in grain yield and harvest index compared to the other treatments. The application of semisynthetic molecules derived from chitosan yielded greater leaf gas exchange and a higher incidence of the biochemical conditions that relieve plant stress.


Assuntos
Antioxidantes/metabolismo , Quitosana/farmacologia , Fotossíntese/efeitos dos fármacos , Zea mays/crescimento & desenvolvimento , Antioxidantes/química , Ascorbato Peroxidases/metabolismo , Catalase/genética , Catalase/metabolismo , Quitosana/síntese química , Grão Comestível/efeitos dos fármacos , Grão Comestível/crescimento & desenvolvimento , Glutationa Redutase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Peroxidase/metabolismo , Folhas de Planta/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Água/química , Zea mays/efeitos dos fármacos
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