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1.
Int J Mol Sci ; 25(13)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39000433

RESUMO

Drought presents a significant abiotic stress that threatens crop productivity worldwide. Rhizosphere bacteria play pivotal roles in modulating plant growth and resilience to environmental stresses. Despite this, the extent to which rhizosphere bacteria are instrumental in plant responses to drought, and whether distinct cassava (Manihot esculenta Crantz) varieties harbor specific rhizosphere bacterial assemblages, remains unclear. In this study, we measured the growth and physiological characteristics, as well as the physical and chemical properties of the rhizosphere soil of drought-tolerant (SC124) and drought-sensitive (SC8) cassava varieties under conditions of both well-watered and drought stress. Employing 16S rDNA high-throughput sequencing, we analyzed the composition and dynamics of the rhizosphere bacterial community. Under drought stress, biomass, plant height, stem diameter, quantum efficiency of photosystem II (Fv/Fm), and soluble sugar of cassava decreased for both SC8 and SC124. The two varieties' rhizosphere bacterial communities' overall taxonomic structure was highly similar, but there were slight differences in relative abundance. SC124 mainly relied on Gamma-proteobacteria and Acidobacteriae in response to drought stress, and the abundance of this class was positively correlated with soil acid phosphatase. SC8 mainly relied on Actinobacteria in response to drought stress, and the abundance of this class was positively correlated with soil urease and soil saccharase. Overall, this study confirmed the key role of drought-induced rhizosphere bacteria in improving the adaptation of cassava to drought stress and clarified that this process is significantly related to variety.


Assuntos
Secas , Manihot , Rizosfera , Microbiologia do Solo , Estresse Fisiológico , Manihot/microbiologia , Bactérias/classificação , Bactérias/genética , RNA Ribossômico 16S/genética , Microbiota , Raízes de Plantas/microbiologia , Solo/química
2.
Commun Biol ; 7(1): 835, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982288

RESUMO

Significant progress has been made in the field of plant genomics, as demonstrated by the increased use of high-throughput methodologies that enable the characterization of multiple genome-wide molecular phenotypes. These findings have provided valuable insights into plant traits and their underlying genetic mechanisms, particularly in model plant species. Nonetheless, effectively leveraging them to make accurate predictions represents a critical step in crop genomic improvement. We present AgroNT, a foundational large language model trained on genomes from 48 plant species with a predominant focus on crop species. We show that AgroNT can obtain state-of-the-art predictions for regulatory annotations, promoter/terminator strength, tissue-specific gene expression, and prioritize functional variants. We conduct a large-scale in silico saturation mutagenesis analysis on cassava to evaluate the regulatory impact of over 10 million mutations and provide their predicted effects as a resource for variant characterization. Finally, we propose the use of the diverse datasets compiled here as the Plants Genomic Benchmark (PGB), providing a comprehensive benchmark for deep learning-based methods in plant genomic research. The pre-trained AgroNT model is publicly available on HuggingFace at https://huggingface.co/InstaDeepAI/agro-nucleotide-transformer-1b  for future research purposes.


Assuntos
Genoma de Planta , Plantas Comestíveis/genética , Genômica/métodos , Aprendizado Profundo , Manihot/genética
3.
BMC Genomics ; 25(1): 699, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39020298

RESUMO

BACKGROUND: Cassava is one of three major potato crops and the sixth most important food crop globally. Improving yield remains a primary aim in cassava breeding. Notably, plant height significantly impacts the yield and quality of crops; however, the mechanisms underlying cassava plant height development are yet to be elucidated. RESULTS: In this study, we investigated the mechanisms responsible for cassava plant height development using phenotypic, anatomical, and transcriptomic analyses. Phenotypic and anatomical analysis revealed that compared to the high-stem cassava cultivar, the dwarf-stem cassava cultivar exhibited a significant reduction in plant height and a notable increase in internode tissue xylem area. Meanwhile, physiological analysis demonstrated that the lignin content of dwarf cassava was significantly higher than that of high cassava. Notably, transcriptome analysis of internode tissues identified several differentially expressed genes involved in cell wall synthesis and expansion, plant hormone signal transduction, phenylpropanoid biosynthesis, and flavonoid biosynthesis between the two cassava cultivars. CONCLUSIONS: Our findings suggest that internode tissue cell division, secondary wall lignification, and hormone-related gene expression play important roles in cassava plant height development. Ultimately, this study provides new insights into the mechanisms of plant height morphogenesis in cassava and identifies candidate regulatory genes associated with plant height that can serve as valuable genetic resources for future crop dwarfing breeding.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Manihot , Manihot/genética , Manihot/crescimento & desenvolvimento , Manihot/metabolismo , Fenótipo , Transcriptoma , Lignina/metabolismo , Lignina/biossíntese
5.
Viruses ; 16(6)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38932233

RESUMO

Disease resistance gene (R gene)-encoded nucleotide-binding leucine-rich repeat proteins (NLRs) are critical players in plant host defence mechanisms because of their role as receptors that recognise pathogen effectors and trigger plant effector-triggered immunity (ETI). This study aimed to determine the putative role of a cassava coiled-coil (CC)-NLR (CNL) gene MeRPPL1 (Manes.12G091600) (single allele) located on chromosome 12 in the tolerance or susceptibility to South African cassava mosaic virus (SACMV), one of the causal agents of cassava mosaic disease (CMD). A transient protoplast system was used to knock down the expression of MeRPPL1 by clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9). The MeRPPL1-targeting CRISPR vectors and/or SACMV DNA A and DNA B infectious clones were used to transfect protoplasts isolated from leaf mesophyll cells from the SACMV-tolerant cassava (Manihot esculenta) cultivar TME3. The CRISPR/Cas9 silencing vector significantly reduced MeRPPL1 expression in protoplasts whether with or without SACMV co-infection. Notably, SACMV DNA A replication was higher in protoplasts with lower MeRPPL1 expression levels than in non-silenced protoplasts. Mutagenesis studies revealed that protoplast co-transfection with CRISPR-MeRPPL1 silencing vector + SACMV and transfection with only SACMV induced nucleotide substitution mutations that led to altered amino acids in the highly conserved MHD motif of the MeRPPL1-translated polypeptide. This may abolish or alter the regulatory role of the MHD motif in controlling R protein activity and could contribute to the increase in SACMV-DNA A accumulation observed in MeRPPL1-silenced protoplasts. The results herein demonstrate for the first time a role for a CNL gene in tolerance to a geminivirus in TME3.


Assuntos
Begomovirus , Manihot , Doenças das Plantas , Proteínas de Plantas , Replicação Viral , Manihot/virologia , Manihot/genética , Doenças das Plantas/virologia , Doenças das Plantas/genética , Begomovirus/genética , Begomovirus/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Geminiviridae/genética , Geminiviridae/fisiologia , Sistemas CRISPR-Cas , Resistência à Doença/genética , Protoplastos/virologia , Protoplastos/metabolismo , Proteínas de Repetições Ricas em Leucina
6.
Int J Biol Macromol ; 273(Pt 1): 132803, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38848836

RESUMO

Bionanocomposites offer a promising solution to the plastic waste crisis. Although tapioca starch shows potential as a bioplastic material, it is characterized by low mechanical properties, poor thermal stability, and high water absorption owing to its hydrophilic nature. To increase the flexibility of the material and reduce the transmission rate of oxygen and water vapor, additives such as fructose and titanium dioxide (TiO2) can be incorporated into the material. TiO2 nanoparticles are commonly utilized in agriculture to enhance nutrient release and promote plant growth. In this study, X-ray diffraction analysis revealed that TiO2 reduced crystal size while increasing the crystallinity of bionanocomposites. Fourier-transform infrared spectroscopy analysis revealed an absorption peak at 3397 cm-1, indicating hydrogen bonding between TiO2 and starch-OH groups, and a peak at 773 cm-1, indicating an increase in the intensity of Ti-O-Ti stretching vibrations with the incorporation of TiO2. Water absorption rate results confirmed that TiO2 addition enhanced bionanocomposite resistance to water vapor and moisture, evidenced by increased tensile strength from 0.11 to 0.49 MPa and Young's modulus from 2.48 to 5.26 MPa, as well as decreased elongation at break from 21.46 % to 2.36 % in bionanocomposites with TiO2. Furthermore, with TiO2 addition, the biodegradation rate of the bionanocomposites decreased, which is beneficial for enhancing plant nutrient content.


Assuntos
Embalagem de Alimentos , Frutose , Manihot , Nanocompostos , Amido , Titânio , Nanocompostos/química , Titânio/química , Amido/química , Embalagem de Alimentos/métodos , Frutose/química , Manihot/química , Fertilizantes , Resistência à Tração , Água/química , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Plant Genome ; 17(2): e20469, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38880944

RESUMO

The starchy storage roots of cassava are commonly processed into a variety of products, including cassava granulated processed products (gari). The commercial value of cassava roots depends on the yield and quality of processed products, directly influencing the acceptance of new varieties by farmers, processors, and consumers. This study aims to estimate genetic advance through phenotypic selection and identify genomic regions associated and candidate genes linked with gari yield and quality. Higher single nucleotide polymorphism (SNP)-based heritability estimates compared to broad-sense heritability estimates were observed for most traits highlighting the influence of genetic factors on observed variation. Using genome-wide association analysis of 188 clones, genotyped using 53,150 genome-wide SNPs, nine SNPs located on seven chromosomes were significantly associated with peel loss, gari yield, color parameters for gari and eba, bulk density, swelling index, and textural properties of eba. Future research will focus on validating and understanding the functions of identified genes and their influence on gari yield and quality traits.


Assuntos
Estudo de Associação Genômica Ampla , Manihot , Polimorfismo de Nucleotídeo Único , Manihot/genética , Fenótipo , Raízes de Plantas/genética
8.
Plant Genome ; 17(2): e20471, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38923724

RESUMO

Regular measurement of realized genetic gain allows plant breeders to assess and review the effectiveness of their strategies, allocate resources efficiently, and make informed decisions throughout the breeding process. Realized genetic gain estimation requires separating genetic trends from nongenetic trends using the linear mixed model (LMM) on historical multi-environment trial data. The LMM, accounting for the year effect, experimental designs, and heterogeneous residual variances, estimates best linear unbiased estimators of genotypes and regresses them on their years of origin. An illustrative example of estimating realized genetic gain was provided by analyzing historical data on fresh cassava (Manihot esculenta Crantz) yield in West Africa (https://github.com/Biometrics-IITA/Estimating-Realized-Genetic-Gain). This approach can serve as a model applicable to other crops and regions. Modernization of breeding programs is necessary to maximize the rate of genetic gain. This can be achieved by adopting genomics to enable faster breeding, accurate selection, and improved traits through genomic selection and gene editing. Tracking operational costs, establishing robust, digitalized data management and analytics systems, and developing effective varietal selection processes based on customer insights are also crucial for success. Capacity building and collaboration of breeding programs and institutions also play a significant role in accelerating genetic gains.


Assuntos
Manihot , Melhoramento Vegetal , Melhoramento Vegetal/métodos , Manihot/genética , África Subsaariana , Produtos Agrícolas/genética , Genótipo , Modelos Genéticos
9.
Bioprocess Biosyst Eng ; 47(7): 1057-1070, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38842769

RESUMO

The treatment of agroindustrial wastewater using microbial fuel cells (MFCs) is a technological strategy to harness its chemical energy while simultaneously purifying the water. This manuscript investigates the organic load effect as chemical oxygen demand (COD) on the production of electricity during the treatment of cassava wastewater by means of a dual-chamber microbial fuel cell in batch mode. Additionally, specific conditions were selected to evaluate the semi-continuous operational mode. The dynamics of microbial communities on the graphite anode were also investigated. The maximum power density delivered by the batch MFC (656.4 µW m - 2 ) was achieved at the highest evaluated organic load (6.8 g COD L - 1 ). Similarly, the largest COD removal efficiency (61.9%) was reached at the lowest organic load (1.17 g COD L - 1 ). Cyanide degradation percentages (50-70%) were achieved across treatments. The semi-continuous operation of the MFC for 2 months revealed that the voltage across the cell is dependent on the supply or suspension of the organic load feed. The electrode polarization resistance was observed to decreases over time, possibly due to the enrichment of the anode with electrogenic microbial communities. A metataxonomic analysis revealed a significant increase in bacteria from the phylum Firmicutes, primarily of the genus Enterococcus.


Assuntos
Fontes de Energia Bioelétrica , Manihot , Águas Residuárias , Fontes de Energia Bioelétrica/microbiologia , Manihot/química , Águas Residuárias/microbiologia , Águas Residuárias/química , Análise da Demanda Biológica de Oxigênio , Eletrodos , Purificação da Água/métodos
10.
Bioresour Technol ; 404: 130915, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823561

RESUMO

This work proposes the pyrolysis of the cassava plant shoot system biomass and a comprehensive chemical characterization of the resulting bio-oil. The highest yields of liquid products were obtained at 600 °C, with 12.6 % bio-oil (organic fraction), which presented the lowest total acid number of 65.7 mg KOH g-1. The bio-oil produced at 500 °C exhibited the highest total phenolic content of approximately 41 % GAE, confirmed by GC/MS analysis (33.8 % of the total area). FT-Orbitrap MS analysis found hundreds of oxygenated constituents in the bio-oils, belonging to the O2-7 classes, as well as nitrogen compounds from the Ny and OxNy classes. Higher pyrolysis temperatures resulted in more oxygenated phenolics (O4-7) undergoing secondary degradation and deoxygenation reactions, generating O2-3 compounds. Additional classes affected were O3-5N2-3, while O1-2N1 presented more stable compounds. These findings show that cassava bio-oils are promising sources of renewable chemicals.


Assuntos
Manihot , Oxigênio , Brotos de Planta , Pirólise , Manihot/química , Brotos de Planta/química , Oxigênio/metabolismo , Nitrogênio , Biocombustíveis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas/métodos , Compostos de Nitrogênio/química , Óleos de Plantas , Polifenóis
11.
Int J Biol Macromol ; 272(Pt 2): 132865, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38844286

RESUMO

The presence of salt can impact the fluid phase and gelatinization process of starch granules. The variation in viscosity and rheology models including the Herschel-Bulkley, the Casson model, and the power law, were determined by adding salts before and after starch ultrasonication. Non-isothermal kinetics can be utilized for the mathematical modeling of the gelatinization process and the evolution of the reaction. Unlike Na+ ions, Ca+2 ions notably elevate viscosity. The Casson model accurately predicts viscosity data. Results indicate that the addition of Na+ ions decreases yield stress by up to 60.4 %, while Ca+2 ions increase by up to 100.8 %. Adding Na+ ions decreases the required thermal energy by as much as 49.6 %, while the presence of Ca+2 ions can lead to a substantial increase of up to 337.1 % compared to control samples. The positive ∆G indicates a non-spontaneous gelatinization process. The addition of NaCl promotes a spontaneous reaction, while the addition of CaCl2 increases the Gibbs energy. The changes in entropy are minimal, implying minimal changes in starches' disorder structure.


Assuntos
Cloreto de Cálcio , Manihot , Reologia , Cloreto de Sódio , Amido , Termodinâmica , Amido/química , Cinética , Cloreto de Sódio/química , Cloreto de Cálcio/química , Manihot/química , Viscosidade , Gelatina/química
12.
Plant Sci ; 346: 112163, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38880339

RESUMO

A20/AN1 zinc-finger domain-containing genes are very promising candidates in improving plant tolerance to abiotic stresses, but considerably less is known about functions and mechanisms for many of them. In this study, Metip3 (5, and 7), cassava (Manihot esculenta) A20/AN1 genes carrying one A20 domain and one AN1 domain, were functionally characterized at different layers. Metip3 (5, and 7) proteins were all located in the nucleus. No interactions were found between these three proteins. Metip3 (5, and 7)-expressing Arabidopsis was more tolerant to multiple abiotic stresses by Na, Cd, Mn, Al, drought, high temperature, and low temperature. Metip3- and Metip5-expressing Arabidopsis was sensitive to Cu stress, while Metip7-expressing Arabidopsis was insensitive. The H2O2 production significantly decreased in all transgenic Arabidopsis, however, O2·- production significantly decreased in Metip3- and Metip5-expressing Arabidopsis but did not significantly changed in Metip7-expressing Arabidopsis under drought. Metip3 (5, and 7) expression-silenced cassava showed the decreased tolerance to drought and NaCl, presented significant decreases in superoxide dismutase and catalase activities and proline content, and displayed a significant increase in malondialdehyde content under drought. Taken together with transcriptome sequencing analysis, it is suggested that Metip5 gene can not only affect signal transduction related to plant hormone, mitogen activated protein kinases, and starch and sucrose metabolism, DRE-binding transcription factors, and antioxidants, conferring the drought tolerance, but also might deliver the signals from DREB2A INTERACTING PROTEIN1, E3 ubiquitin-protein ligases to proteasome, leading to the drought intolerance. The results are informative not only for further study on evolution of A20/AN1 genes but also for development of climate resilient crops.


Assuntos
Arabidopsis , Manihot , Proteínas de Plantas , Plantas Geneticamente Modificadas , Estresse Fisiológico , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Manihot/genética , Manihot/fisiologia , Estresse Fisiológico/genética , Plantas Geneticamente Modificadas/genética , Regulação da Expressão Gênica de Plantas , Secas , Genes de Plantas , Família Multigênica
13.
Food Chem ; 456: 139872, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-38865818

RESUMO

The release of hydrogen cyanide (HCN) after food ingestion can pose a serious health risk to consumers. This study aimed to simultaneously quantify four cyanogenic glycosides (lotaustralin, prunasin, taxiphyllin, and dhurrin) using liquid chromatography-tandem mass spectrometry. The analysis scope extended beyond agricultural products to various consumer foods to estimate dietary exposure to cyanogenic glycosides and assess its risk levels. The major exposure sources are cassava chips (lotaustralin), apples (seeds) (prunasin and dhurrin), and Prunus mume axis (taxiphyllin). In addition to quantifying specific cyanogenic glycosides, this study proposed the development of a preliminary risk assessment framework based on the dietary exposure assessment and the calculation of theoretical levels of HCN derived from cyanogenic glycoside concentrations. In the absence of established guidelines for the permissible intake of foods containing cyanogenic glycosides, this study provides initial guidance for assessing the risks associated with a range of commonly consumed foods.


Assuntos
Contaminação de Alimentos , Glicosídeos , Cianeto de Hidrogênio , Manihot , Glicosídeos/química , Glicosídeos/análise , Cianeto de Hidrogênio/análise , Cianeto de Hidrogênio/química , Humanos , Contaminação de Alimentos/análise , Manihot/química , República da Coreia , Espectrometria de Massas em Tandem , Malus/química , Adulto , Prunus/química , Exposição Dietética/análise , Medição de Risco , Adulto Jovem
14.
Environ Res ; 257: 119287, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38823610

RESUMO

Heavy metal pollution in soil has emerged as a major environmental concern. This can be attributed to human activities such as mining, modern agriculture, and industrialization. This study was conducted to determine how heavy metals spread from mine tailings to surrounding farmland. Metal absorption and accumulation were also investigated in the root and shoot biomass of tapioca crops grown in those farmlands. Metal concentrations in MTAS1 were 85.3 ± 1.2, 45.8 ± 1.5, 134.8 ± 1.7, 92.4 ± 2.2, and 78.95 ± 1.4 mg kg-1, respectively. Heavy metal concentrations in MTAS2 and MTAS3 were found to be 79.62 ± 1.6, 75.4 ± 1.5, 41.31 ± 1.1, 47.8 ± 1.6, 142.5 ± 2.1, 128.4 ± 1.4, 86.2 ± 1.9, 79.5 ± 1.3, and 83.4 ± 1.2 mg kg-1, respectively. Tapioca crop shoot and root biomass grown at these metal polluted sites absorbed and accumulated significant amounts of Cd, Cu, Zn, Pb, Ni, and Mn. Notably, the metal content of the tapioca crop's root and shoot biomass exceeded national standards.


Assuntos
Biomassa , Metais Pesados , Mineração , Raízes de Plantas , Brotos de Planta , Poluentes do Solo , Metais Pesados/análise , Metais Pesados/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Brotos de Planta/crescimento & desenvolvimento , Manihot/crescimento & desenvolvimento , Manihot/metabolismo , Manihot/química , Agricultura/métodos , Monitoramento Ambiental
15.
PeerJ ; 12: e17386, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38832032

RESUMO

Cassava (Manihot esculenta) is among the most important staple crops globally, with an imperative role in supporting the Sustainable Development Goal of 'Zero hunger'. In sub-Saharan Africa, it is cultivated mainly by millions of subsistence farmers who depend directly on it for their socio-economic welfare. However, its yield in some regions has been threatened by several diseases, especially the cassava brown streak disease (CBSD). Changes in climatic conditions enhance the risk of the disease spreading to other planting regions. Here, we characterise the current and future distribution of cassava, CBSD and whitefly Bemisia tabaci species complex in Africa, using an ensemble of four species distribution models (SDMs): boosted regression trees, maximum entropy, generalised additive model, and multivariate adaptive regression splines, together with 28 environmental covariates. We collected 1,422 and 1,169 occurrence records for cassava and Bemisia tabaci species complex from the Global Biodiversity Information Facility and 750 CBSD occurrence records from published literature and systematic surveys in East Africa. Our results identified isothermality as having the highest contribution to the current distribution of cassava, while elevation was the top predictor of the current distribution of Bemisia tabaci species complex. Cassava harvested area and precipitation of the driest month contributed the most to explain the current distribution of CBSD outbreaks. The geographic distributions of these target species are also expected to shift under climate projection scenarios for two mid-century periods (2041-2060 and 2061-2080). Our results indicate that major cassava producers, like Cameron, Ivory Coast, Ghana, and Nigeria, are at greater risk of invasion of CBSD. These results highlight the need for firmer agricultural management and climate-change mitigation actions in Africa to combat new outbreaks and to contain the spread of CBSD.


Assuntos
Hemípteros , Manihot , Doenças das Plantas , Manihot/parasitologia , Animais , Hemípteros/fisiologia , Doenças das Plantas/parasitologia , Doenças das Plantas/estatística & dados numéricos , África/epidemiologia , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/parasitologia
16.
Sci Rep ; 14(1): 10587, 2024 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719851

RESUMO

Cassava root-rot incited by soil-borne pathogens is one of the major diseases that reduces root yield. Although the use of resistant cultivars is the most effective method of management, the genetic basis for root-rot resistance remains poorly understood. Therefore, our work analyzed the transcriptome of two contrasting genotypes (BRS Kiriris/resistant and BGM-1345/susceptible) using RNA-Seq to understand the molecular response and identify candidate genes for resistance. Cassava seedlings (resistant and susceptible to root-rot) were both planted in infested and sterilized soil and samples from Initial-time and Final-time periods, pooled. Two controls were used: (i) seedlings collected before planting in infested soil (absolute control) and, (ii) plants grown in sterilized soil (mock treatments). For the differentially expressed genes (DEGs) analysis 23.912 were expressed in the resistant genotype, where 10.307 were differentially expressed in the control treatment, 15 DEGs in the Initial Time-period and 366 DEGs in the Final Time-period. Eighteen candidate genes from the resistant genotype were related to plant defense, such as the MLP-like protein 31 and the peroxidase A2-like gene. This is the first model of resistance at the transcriptional level proposed for the cassava × root-rot pathosystem. Gene validation will contribute to screening for resistance of germplasm, segregating populations and/or use in gene editing in the pursuit to develop most promising cassava clones with resistance to root-rot.


Assuntos
Resistência à Doença , Regulação da Expressão Gênica de Plantas , Manihot , Doenças das Plantas , Raízes de Plantas , Transcriptoma , Manihot/genética , Manihot/microbiologia , Resistência à Doença/genética , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Perfilação da Expressão Gênica , Genótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Genes de Plantas
17.
Virus Res ; 346: 199397, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38750679

RESUMO

The ipomoviruses (family Potyviridae) that cause cassava brown streak disease (cassava brown streak virus [CBSV] and Uganda cassava brown streak virus [UCBSV]) are damaging plant pathogens that affect the sustainability of cassava production in East and Central Africa. However, little is known about the rate at which the viruses evolve and when they emerged in Africa - which inform how easily these viruses can host shift and resist RNAi approaches for control. We present here the rates of evolution determined from the coat protein gene (CP) of CBSV (Temporal signal in a UCBSV dataset was not sufficient for comparable analysis). Our BEAST analysis estimated the CBSV CP evolves at a mean rate of 1.43 × 10-3 nucleotide substitutions per site per year, with the most recent common ancestor of sampled CBSV isolates existing in 1944 (95% HPD, between years 1922 - 1963). We compared the published measured and estimated rates of evolution of CPs from ten families of plant viruses and showed that CBSV is an average-evolving potyvirid, but that members of Potyviridae evolve more quickly than members of Virgaviridae and the single representatives of Betaflexiviridae, Bunyaviridae, Caulimoviridae and Closteroviridae.


Assuntos
Proteínas do Capsídeo , Evolução Molecular , Manihot , Filogenia , Doenças das Plantas , Potyviridae , Potyviridae/genética , Doenças das Plantas/virologia , Manihot/virologia , Proteínas do Capsídeo/genética
18.
Phytochemistry ; 224: 114143, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38762153

RESUMO

Cassava (Manihot esculenta Crantz), a crucial global tuber crop, encounters significant economic losses attributed to postharvest physiological deterioration (PPD). The PPD phenomenon in cassava is closely related to the accumulation of reactive oxygen species (ROS), and amino acids play a pivotal role in regulating signaling pathways and eliminating ROS. In this study, the storage performance of eight cassava varieties were conducted. Cassava cultivar SC5 showed the best storage performance among the eight cassava varieties, but the edible cassava cultivar SC9 performed much worse. Comparative analysis of free amino acids was conducted in eight cassava varieties, revealing changes in proline, aspartic acid, histidine, glutamic acid, threonine, and serine. Exogenous supplementation of these six amino acids was performed to inhibit PPD of SC9. Proline was confirmed as the key amino acid for inhibiting PPD. Treatment with optimal exogenous proline of 5 g/L resulted in a 17.9% decrease in the deterioration rate compared to untreated cassava. Accompanied by a decrease in H2O2 content and an increase in catalase, superoxide dismutase and ascorbate peroxidase activity. Proline treatment proved to be an effective approach to alleviate cell oxidative damage, inhibit PPD in cassava, and prolong shelf life.


Assuntos
Antioxidantes , Manihot , Prolina , Manihot/química , Prolina/farmacologia , Prolina/metabolismo , Prolina/química , Antioxidantes/farmacologia , Antioxidantes/química , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia
19.
J Food Sci ; 89(6): 3687-3699, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38767926

RESUMO

The vibrating superfine mill (VSM) is a machine that belongs to the micronization technique. In this study, VSM was employed to produce micronized tapioca starch by varying micronization times (15, 30, 45, and 60 min). The structural and physicochemical properties of the micronized starch were then examined. Scanning electron microscopy studies revealed that micronized starch was partially gelatinized, and the granule size dramatically increased when micronization time increased. X-ray diffraction patterns showed that the relative crystallinity was decreased from 24.67% (native) to 4.13% after micronization treatment for 15 min and slightly decreased after that. The solubility of micronized starch significantly increased as the micronization time increased, which was associated with the destruction of the starch crystalline structure. Differential scanning calorimetry investigations confirmed that micronized starch was "partly gelatinized," and the degree of gelatinization increased to 81.27% when the micronization time was 60 min. The weight-average molar mass was reduced by 15.0% (15 min), 30.9% (30 min), 55.7% (45 min), and 70.5% (60 min), respectively, indicating that the molecular structure was seriously degraded. The results demonstrated that the physicochemical changes of micronized starch granules were related to the destruction of the starch structure. These observations would provide details on micronized starch and its potential applications. PRACTICAL APPLICATION: These observations would provide details on micronized starch and its potential applications. Moreover, we believe that when the structures of starches were known, it is probable that the effect of VSM on the structural and physicochemical properties change of other starches might be predicted by adjusting the processing time.


Assuntos
Varredura Diferencial de Calorimetria , Manihot , Microscopia Eletrônica de Varredura , Solubilidade , Amido , Difração de Raios X , Amido/química , Manihot/química , Microscopia Eletrônica de Varredura/métodos , Gelatina/química , Tamanho da Partícula , Manipulação de Alimentos/métodos , Fenômenos Químicos
20.
Plant Cell Rep ; 43(6): 153, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806727

RESUMO

KEY MESSAGE: MePMTR1 is involved in plant development and production as well as photosynthesis in plant. Melatonin is widely involved in plant growth and development as well as stress responses. Compared with the extending studies of melatonin in stress responses, the direct link between melatonin and plant development in the whole stages remains unclear. With the identification of phytomelatonin receptor PMTR1 in plants, melatonin signalling is becoming much clearer. However, the function of MePMTR1 in tropical crop cassava remains elusive. In this study, we found that overexpression of MePMTR1 showed larger biomass than wild type (WT), including higher number and area of leaves, weight, and accompanying with higher photosynthetic efficiency. Consistently, exogenous melatonin accelerated photosynthetic rate in Arabidopsis. In addition, MePMTR1-overexpressed plants exhibited more resistance to dark-induced senescence compared with WT, demonstrated by higher chlorophyll, lower hydrogen peroxide and superoxide content. In summary, this study illustrated that melatonin and its receptor regulate growth, development and senescence in plants, highlighting the potential application of melatonin and its receptor in improving crop yield and photosynthesis.


Assuntos
Arabidopsis , Regulação da Expressão Gênica de Plantas , Manihot , Melatonina , Fotossíntese , Plantas Geneticamente Modificadas , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Melatonina/metabolismo , Manihot/genética , Manihot/crescimento & desenvolvimento , Manihot/metabolismo , Receptores de Melatonina/metabolismo , Receptores de Melatonina/genética , Luz , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Clorofila/metabolismo , Escuridão , Peróxido de Hidrogênio/metabolismo
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