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1.
Plant J ; 118(2): 373-387, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38159103

RESUMO

Petals in rapeseed (Brassica napus) serve multiple functions, including protection of reproductive organs, nutrient acquisition, and attraction of pollinators. However, they also cluster densely at the top, forming a thick layer that absorbs and reflects a considerable amount of photosynthetically active radiation. Breeding genotypes with large, small, or even petal-less varieties, requires knowledge of primary genes for allelic selection and manipulation. However, our current understanding of petal-size regulation is limited, and the lack of markers and pre-breeding materials hinders targeted petal-size breeding. Here, we conducted a genome-wide association study on petal size using 295 diverse accessions. We identified 20 significant single nucleotide polymorphisms and 236 genes associated with petal-size variation. Through a cross-analysis of genomic and transcriptomic data, we focused on 14 specific genes, from which molecular markers for diverging petal-size features can be developed. Leveraging CRISPR-Cas9 technology, we successfully generated a quadruple mutant of Far-Red Elongated Hypocotyl 3 (q-bnfhy3), which exhibited smaller petals compared to the wild type. Our study provides insights into the genetic basis of petal-size regulation in rapeseed and offers abundant potential molecular markers for breeding. The q-bnfhy3 mutant unveiled a novel role of FHY3 orthologues in regulating petal size in addition to previously reported functions.


Assuntos
Brassica napus , Brassica rapa , Brassica napus/genética , Estudo de Associação Genômica Ampla , Sistemas CRISPR-Cas , Melhoramento Vegetal , Brassica rapa/genética , Mutagênese
2.
Nat Food ; 4(9): 788-796, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37696964

RESUMO

Rice is a staple food for half of the human population, but the effects of diversification on yields, economy, biodiversity and ecosystem services have not been synthesized. Here we quantify diversification effects on environmental and socio-economic aspects of global rice production. We performed a second-order meta-analysis based on 25 first-order meta-analyses covering four decades of research, showing that diversification can maintain soil fertility, nutrient cycling, carbon sequestration and yield. We used three individual first-order meta-analyses based on 39 articles to close major research gaps on the effects of diversification on economy, biodiversity and pest control, showing that agricultural diversification can increase biodiversity by 40%, improve economy by 26% and reduce crop damage by 31%. Trade-off analysis showed that agricultural diversification in rice production promotes win-win scenarios between yield and other ecosystem services in 81% of all cases. Knowledge gaps remain in understanding the spatial and temporal effects of specific diversification practices and trade-offs.


Assuntos
Oryza , Humanos , Oryza/genética , Ecossistema , Agricultura , Solo , Ciclismo
3.
Plant Phenomics ; 5: 0040, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37022332

RESUMO

Accurate and high-throughput plant phenotyping is important for accelerating crop breeding. Spectral imaging that can acquire both spectral and spatial information of plants related to structural, biochemical, and physiological traits becomes one of the popular phenotyping techniques. However, close-range spectral imaging of plants could be highly affected by the complex plant structure and illumination conditions, which becomes one of the main challenges for close-range plant phenotyping. In this study, we proposed a new method for generating high-quality plant 3-dimensional multispectral point clouds. Speeded-Up Robust Features and Demons was used for fusing depth and snapshot spectral images acquired at close range. A reflectance correction method for plant spectral images based on hemisphere references combined with artificial neural network was developed for eliminating the illumination effects. The proposed Speeded-Up Robust Features and Demons achieved an average structural similarity index measure of 0.931, outperforming the classic approaches with an average structural similarity index measure of 0.889 in RGB and snapshot spectral image registration. The distribution of digital number values of the references at different positions and orientations was simulated using artificial neural network with the determination coefficient (R 2) of 0.962 and root mean squared error of 0.036. Compared with the ground truth measured by ASD spectrometer, the average root mean squared error of the reflectance spectra before and after reflectance correction at different leaf positions decreased by 78.0%. For the same leaf position, the average Euclidean distances between the multiview reflectance spectra decreased by 60.7%. Our results indicate that the proposed method achieves a good performance in generating plant 3-dimensional multispectral point clouds, which is promising for close-range plant phenotyping.

4.
Theor Appl Genet ; 136(3): 42, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36897406

RESUMO

KEY MESSAGE: We found that the flowering time order of accessions in a genetic population considerably varied across environments, and homolog copies of essential flowering time genes played different roles in different locations. Flowering time plays a critical role in determining the life cycle length, yield, and quality of a crop. However, the allelic polymorphism of flowering time-related genes (FTRGs) in Brassica napus, an important oil crop, remains unclear. Here, we provide high-resolution graphics of FTRGs in B. napus on a pangenome-wide scale based on single nucleotide polymorphism (SNP) and structural variation (SV) analyses. A total of 1337 FTRGs in B. napus were identified by aligning their coding sequences with Arabidopsis orthologs. Overall, 46.07% of FTRGs were core genes and 53.93% were variable genes. Moreover, 1.94%, 0.74%, and 4.49% FTRGs had significant presence-frequency differences (PFDs) between the spring and semi-winter, spring and winter, and winter and semi-winter ecotypes, respectively. SNPs and SVs across 1626 accessions of 39 FTRGs underlying numerous published qualitative trait loci were analyzed. Additionally, to identify FTRGs specific to an eco-condition, genome-wide association studies (GWASs) based on SNP, presence/absence variation (PAV), and SV were performed after growing and observing the flowering time order (FTO) of plants in a collection of 292 accessions at three locations in two successive years. It was discovered that the FTO of plants in a genetic population changed a lot across various environments, and homolog copies of some key FTRGs played different roles in different locations. This study revealed the molecular basis of the genotype-by-environment (G × E) effect on flowering and recommended a pool of candidate genes specific to locations for breeding selection.


Assuntos
Arabidopsis , Brassica napus , Brassica napus/genética , Locos de Características Quantitativas , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Genótipo , Arabidopsis/genética
5.
Plant Phenomics ; 5: 0027, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36939450

RESUMO

Silique morphology is an important trait that determines the yield output of oilseed rape (Brassica napus L.). Segmenting siliques and quantifying traits are challenging because of the complicated structure of an oilseed rape plant at the reproductive stage. This study aims to develop an accurate method in which a skeletonization algorithm was combined with the hierarchical segmentation (SHS) algorithm to separate siliques from the whole plant using 3-dimensional (3D) point clouds. We combined the L1-median skeleton with the random sample consensus for iteratively extracting skeleton points and optimized the skeleton based on information such as distance, angle, and direction from neighborhood points. Density-based spatial clustering of applications with noise and weighted unidirectional graph were used to achieve hierarchical segmentation of siliques. Using the SHS, we quantified the silique number (SN), silique length (SL), and silique volume (SV) automatically based on the geometric rules. The proposed method was tested with the oilseed rape plants at the mature stage grown in a greenhouse and field. We found that our method showed good performance in silique segmentation and phenotypic extraction with R 2 values of 0.922 and 0.934 for SN and total SL, respectively. Additionally, SN, total SL, and total SV had the statistical significance of correlations with the yield of a plant, with R values of 0.935, 0.916, and 0.897, respectively. Overall, the SHS algorithm is accurate, efficient, and robust for the segmentation of siliques and extraction of silique morphological parameters, which is promising for high-throughput silique phenotyping in oilseed rape breeding.

6.
Transl Cancer Res ; 11(11): 4137-4147, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36523306

RESUMO

Background: To evaluate the clinical research related to the level and integrity of circulating free DNA (cfDNA) in the plasma of patients with multiple myeloma (MM). Methods: The plasma samples of 56 patients with newly diagnosed MM and 60 healthy volunteers were collected. ALU247 fragment and ALU115 fragment were used as target genes, and quantitative polymerase chain reaction (qPCR) was used to assess the plasma of the patient and healthy control groups. The cfDNA level in MM was analyzed, and the ALU247/ALU115 ratio was used to calculate the integrity of cfDNA. The correlation between the cfDNA level and integrity and the clinical characteristics of patients with primary MM was analyzed, and their value in efficacy monitoring and prognostic evaluation was evaluated. Results: The plasma concentrations of ALU247 and ALU115 and the integrity of cfDNA in patients with primary MM were significantly higher than those in the healthy controls (P<0.05). The ALU247 fragment concentration was markedly correlated with the Durie-Salmon (D-S), International Staging System (ISS), and Revised-International Staging System (R-ISS) stages (P<0.05). After three courses of induction chemotherapy, the levels of ALU247, ALU115, and cfDNA integrity in both groups were lower than those before chemotherapy (P<0.05). Patients with curative effects of CR, sCR, and VGPR were classified into the ≥ very good partial response (VGPR) group (n=38), while those with curative effects of PR and SD were allocated into the

7.
Trends Plant Sci ; 27(2): 191-208, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34417079

RESUMO

Optical sensors and sensing-based phenotyping techniques have become mainstream approaches in high-throughput phenotyping for improving trait selection and genetic gains in crops. We review recent progress and contemporary applications of optical sensing-based phenotyping (OSP) techniques in cereal crops and highlight optical sensing principles for spectral response and sensor specifications. Further, we group phenotypic traits determined by OSP into four categories - morphological, biochemical, physiological, and performance traits - and illustrate appropriate sensors for each extraction. In addition to the current status, we discuss the challenges of OSP and provide possible solutions. We propose that optical sensing-based traits need to be explored further, and that standardization of the language of phenotyping and worldwide collaboration between phenotyping researchers and other fields need to be established.


Assuntos
Produtos Agrícolas , Grão Comestível , Produtos Agrícolas/genética , Fenótipo
9.
J Exp Bot ; 72(13): 4691-4707, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-33963382

RESUMO

Fractional vegetation cover (FVC) is the key trait of interest for characterizing crop growth status in crop breeding and precision management. Accurate quantification of FVC among different breeding lines, cultivars, and growth environments is challenging, especially because of the large spatiotemporal variability in complex field conditions. This study presents an ensemble modeling strategy for phenotyping crop FVC from unmanned aerial vehicle (UAV)-based multispectral images by coupling the PROSAIL model with a gap probability model (PROSAIL-GP). Seven field experiments for four main crops were conducted, and canopy images were acquired using a UAV platform equipped with RGB and multispectral cameras. The PROSAIL-GP model successfully retrieved FVC in oilseed rape (Brassica napus L.) with coefficient of determination, root mean square error (RMSE), and relative RMSE (rRMSE) of 0.79, 0.09, and 18%, respectively. The robustness of the proposed method was further examined in rice (Oryza sativa L.), wheat (Triticum aestivum L.), and cotton (Gossypium hirsutum L.), and a high accuracy of FVC retrieval was obtained, with rRMSEs of 12%, 6%, and 6%, respectively. Our findings suggest that the proposed method can efficiently retrieve crop FVC from UAV images at a high spatiotemporal domain, which should be a promising tool for precision crop breeding.


Assuntos
Oryza , Tecnologia de Sensoriamento Remoto , Produtos Agrícolas , Melhoramento Vegetal , Triticum
10.
Front Plant Sci ; 12: 645977, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841474

RESUMO

Accurate acquisition of plant phenotypic information has raised long-standing concerns in support of crop breeding programs. Different methods have been developed for high throughput plant phenotyping, while they mainly focused on the canopy level without considering the spatiotemporal heterogeneity at different canopy layers and growth stages. This study aims to phenotype spatiotemporal heterogeneity of chlorophyll (Chl) content and fluorescence response within rice leaves and canopies. Multipoint Chl content and high time-resolved Chl a fluorescence (ChlF) transient (OJIP transient) of rice plants were measured at different nitrogen levels and growth stages. Results showed that the Chl content within the upper leaves exhibited an increasing trend from the basal to the top portions but a decreasing pattern within the lower leaves at the most growth stages. Leaf Chl content within the rice canopy was higher in the lower leaves in the vegetative phase, while from the initial heading stage the pattern gradually reversed with the highest Chl content appearing in the upper leaves. Nitrogen supply mainly affects the occurrence time of the reverse vertical pattern. This could be the result of different nutritional demands of leaves transforming from sinks to sources, and it was further confirmed by the fall of the JI phase of OJIP transient in the vegetative phase and the rise in the reproductive phase. We further deduced that the vertical distribution of Chl content could have a defined pattern at a specific growth stage. Furthermore, the reduction of end acceptors at photosystem I (PSI) electron acceptor side per cross section (RE0/CS) was found to be a potential sensitive predictor for identifying the vertical heterogeneity of leaf Chl content. These findings provide prior knowledge on the vertical profiles of crop physiological traits, which explore the opportunity to develop more efficient plant phenotyping tools for crop breeding.

11.
Sensors (Basel) ; 21(2)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33477933

RESUMO

Three-dimensional (3D) structure is an important morphological trait of plants for describing their growth and biotic/abiotic stress responses. Various methods have been developed for obtaining 3D plant data, but the data quality and equipment costs are the main factors limiting their development. Here, we propose a method to improve the quality of 3D plant data using the time-of-flight (TOF) camera Kinect V2. A K-dimension (k-d) tree was applied to spatial topological relationships for searching points. Background noise points were then removed with a minimum oriented bounding box (MOBB) with a pass-through filter, while outliers and flying pixel points were removed based on viewpoints and surface normals. After being smoothed with the bilateral filter, the 3D plant data were registered and meshed. We adjusted the mesh patches to eliminate layered points. The results showed that the patches were closer. The average distance between the patches was 1.88 × 10-3 m, and the average angle was 17.64°, which were 54.97% and 48.33% of those values before optimization. The proposed method performed better in reducing noise and the local layered-points phenomenon, and it could help to more accurately determine 3D structure parameters from point clouds and mesh models.


Assuntos
Brassica napus , Imageamento Tridimensional
12.
J Exp Bot ; 71(20): 6429-6443, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-32777073

RESUMO

Nitrogen (N) fertilizer maximizes the growth of oilseed rape (Brassica napus L.) by improving photosynthetic performance. Elucidating the dynamic relationship between fluorescence and plant N status could provide a non-destructive diagnosis of N status and the breeding of N-efficient cultivars. The aim of this study was to explore the impacts of different N treatments on photosynthesis at a spatial-temporal scale and to evaluate the performance of three fluorescence techniques for the diagnosis of N status. One-way ANOVA and linear discriminant analysis were applied to analyze fluorescence data acquired by a continuous excitation chlorophyll fluorimeter (OJIP transient analysis), pulse amplitude-modulated chlorophyll fluorescence (PAM-ChlF), and multicolor fluorescence (MCF) imaging. The results showed that the maximum quantum efficiency of PSII photochemistry (Fv/Fm) and performance index for photosynthesis (PIABS) of bottom leaves were sensitive to N status at the bolting stage, whereas the red fluorescence/far-red fluorescence ratio of top leaves was sensitive at the early seedling stage. Although the classification of N treatments by the three techniques achieved comparable accuracies, MCF imaging showed the best potential for early diagnosis of N status in field phenotyping because it had the highest sensitivity in the top leaves, at the early seedling stage. The findings of this study could facilitate research on N management and the breeding of N-efficient cultivars.


Assuntos
Brassica napus , Clorofila , Fluorescência , Nitrogênio , Fotossíntese , Melhoramento Vegetal , Folhas de Planta
13.
Food Chem ; 299: 125121, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31310915

RESUMO

White shrimp (Litopenaeus vannamei) raised in low-salinity farm are considered inferior to those in seawater. In order to develop a rapid discrimination method for the food industry, we investigated the potential of using near-infrared hyperspectral imaging to discriminate shrimp muscle samples from freshwater and seawater farms. We constructed 3 different discrimination models with 4 optimal wavelength selection methods and compared the performance of each model. The results showed that sequential forward selection combined with partial least squares discriminant analysis (SFS-PLS-DA) generated the best discrimination performance with an overall accuracy of 99.2%. The elemental and isotopic analysis indicated a high correlation between 918 and 925 nm region (which was selected by SFS) and 13C concentration. This agrees with the fact that there is more 13C in shrimp of salty water compared to those of freshwater. The results demonstrated (hyperspectral imaging) HSI is promising to discriminate L. vannamei raised in fresh and seawater environments.


Assuntos
Penaeidae/fisiologia , Animais , Isótopos de Carbono/análise , Fazendas , Estudos de Viabilidade , Salinidade , Água do Mar
14.
Sensors (Basel) ; 19(12)2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31212744

RESUMO

Resistance to drought stress is one of the most favorable traits in breeding programs yet drought stress is one of the most poorly addressed biological processes for both phenomics and genetics. In this study, we investigated the potential of using a time-series chlorophyll fluorescence (ChlF) analysis to dissect the ChlF fingerprints of salt overly sensitive (SOS) mutants under drought stress. Principle component analysis (PCA) was used to identify a shifting pattern of different genotypes including sos mutants and wild type (WT) Col-0. A time-series deep-learning algorithm, sparse auto encoders (SAEs) neural network, was applied to extract time-series ChlF features which were used in four classification models including linear discriminant analysis (LDA), k-nearest neighbor classifier (KNN), Gaussian naive Bayes (NB) and support vector machine (SVM). The results showed that the discrimination accuracy of sos mutants SOS1-1, SOS2-3, and wild type Col-0 reached 95% with LDA classification model. Sequential forward selection (SFS) algorithm was used to obtain ChlF fingerprints of the shifting pattern, which could address the response of sos mutants and Col-0 to drought stress over time. Parameters including QY, NPQ and Fm, etc. were significantly different between sos mutants and WT. This research proved the potential of ChlF imaging for gene function analysis and the study of drought stress using ChlF in a time-series manner.


Assuntos
Clorofila/química , Imagem Óptica , Fotossíntese/genética , Proteína Son Of Sevenless de Drosófila/química , Algoritmos , Arabidopsis/genética , Arabidopsis/ultraestrutura , Teorema de Bayes , Clorofila/isolamento & purificação , Secas , Redes Neurais de Computação , Análise de Componente Principal , Cloreto de Sódio/toxicidade , Proteína Son Of Sevenless de Drosófila/genética , Estresse Fisiológico/genética , Máquina de Vetores de Suporte
15.
Plant Methods ; 15: 54, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31139243

RESUMO

BACKGROUND: The advances of hyperspectral technology provide a new analytic means to decrease the gap of phenomics and genomics caused by the fast development of plant genomics with the next generation sequencing technology. Through hyperspectral technology, it is possible to phenotype the biochemical attributes of rice seeds and use the data for GWAS. RESULTS: The results of correlation analysis indicated that Normalized Difference Spectral Index (NDSI) had high correlation with protein content (PC) with RNDSI 2 = 0.68. Based on GWAS analysis using all the traits, NDSI was able to identify the same SNP loci as rice protein content that was measured by traditional methods. In total, hyperspectral trait NDSI identified all the 43 genes that were identified by biochemical trait PC. NDSI identified 1 extra SNP marker on chromosome 1, which annotated extra 22 genes that were not identified by PC. Kegg annotation results showed that traits NDSI annotated 3 pathways that are exactly the same as PC. The cysteine and methionine metabolic pathway identified by both NDSI and PC was reported important for biosynthesis and metabolism of some of amino acids/protein in rice seeds. CONCLUSION: This study combined hyperspectral technology and GWAS analysis to dissect PC of rice seeds, which was high throughput and proven to be able to apply to GWAS as a new phenotyping tool. It provided a new means to phenotype one of the important biochemical traits for the determination of rice quality that could be used for genetic studies.

16.
Plant Methods ; 15: 32, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30972143

RESUMO

BACKGROUND: Unmanned aerial vehicle (UAV)-based remote sensing provides a flexible, low-cost, and efficient approach to monitor crop growth status at fine spatial and temporal resolutions, and has a high potential to accelerate breeding process and improve precision field management. METHOD: In this study, we discussed the use of lightweight UAV with dual image-frame snapshot cameras to estimate aboveground biomass (AGB) and panicle biomass (PB) of rice at different growth stages with different nitrogen (N) treatments. The spatial-temporal variations in the typical vegetation indices (VIs) and AGB were first investigated, and the accuracy of crop surface model (CSM) extracted from the Red Green Blue (RGB) images at two different stages were also evaluated. Random forest (RF) model for AGB estimation as well as the PB was then developed. Furthermore, variable importance and sensitivity analysis of UAV variables were performed to study the potential of improving model robustness and prediction accuracies. RESULTS: It was found that the canopy height extracted from the CSM (Hcsm) exhibited a high correlation with the ground-measured canopy height, while it was unsuitable to be independently used for biomass assessment of rice during the entire growth stages. We also observed that several VIs were highly correlated with AGB, and the modified normalized difference spectral index extracted from the multispectral image achieved the highest correlation. RF model with fusing RGB and multispectral image data substantially improved the prediction results of AGB and PB with the prediction of root mean square error (RMSEP) reduced by 8.33-16.00%. The best prediction results for AGB and PB were achieved with the coefficient of determination (r2), the RMSEP and relative RMSE (RRMSE) of 0.90, 0.21 kg/m2 and 14.05%, and 0.68, 0.10 kg/m2 and 12.11%, respectively. In addition, the result confirmed that the sensitivity analysis could simplify the prediction model without reducing the prediction accuracy. CONCLUSION: These findings demonstrate the feasibility of applying lightweight UAV with dual image-frame snapshot cameras for rice biomass estimation, and its potential for high throughput analysis of plant growth-related traits in precision agriculture as well as the advanced breeding program.

17.
Front Plant Sci ; 9: 603, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29868063

RESUMO

Plant responses to drought stress are complex due to various mechanisms of drought avoidance and tolerance to maintain growth. Traditional plant phenotyping methods are labor-intensive, time-consuming, and subjective. Plant phenotyping by integrating kinetic chlorophyll fluorescence with multicolor fluorescence imaging can acquire plant morphological, physiological, and pathological traits related to photosynthesis as well as its secondary metabolites, which will provide a new means to promote the progress of breeding for drought tolerant accessions and gain economic benefit for global agriculture production. Combination of kinetic chlorophyll fluorescence and multicolor fluorescence imaging proved to be efficient for the early detection of drought stress responses in the Arabidopsis ecotype Col-0 and one of its most affected mutants called reduced hyperosmolality-induced [Ca2+]i increase 1. Kinetic chlorophyll fluorescence curves were useful for understanding the drought tolerance mechanism of Arabidopsis. Conventional fluorescence parameters provided qualitative information related to drought stress responses in different genotypes, and the corresponding images showed spatial heterogeneities of drought stress responses within the leaf and the canopy levels. Fluorescence parameters selected by sequential forward selection presented high correlations with physiological traits but not morphological traits. The optimal fluorescence traits combined with the support vector machine resulted in good classification accuracies of 93.3 and 99.1% for classifying the control plants from the drought-stressed ones with 3 and 7 days treatments, respectively. The results demonstrated that the combination of kinetic chlorophyll fluorescence and multicolor fluorescence imaging with the machine learning technique was capable of providing comprehensive information of drought stress effects on the photosynthesis and the secondary metabolisms. It is a promising phenotyping technique that allows early detection of plant drought stress.

18.
Plant Physiol ; 176(3): 2543-2556, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29431629

RESUMO

Lipopolysaccharides (LPS) are major components of the outer membrane of gram-negative bacteria and are an important microbe-associated molecular pattern (MAMP) that triggers immune responses in plants and animals. A previous genetic screen in Arabidopsis (Arabidopsis thaliana) identified LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION (LORE), a B-type lectin S-domain receptor kinase, as a sensor of LPS. However, the LPS-activated LORE signaling pathway and associated immune responses remain largely unknown. In this study, we found that LPS trigger biphasic production of reactive oxygen species (ROS) in Arabidopsis. The first transient ROS burst was similar to that induced by another MAMP, flagellin, whereas the second long-lasting burst was induced only by LPS. The LPS-triggered second ROS burst was found to be conserved in a variety of plant species. Microscopic observation of the generation of ROS revealed that the LPS-triggered second ROS burst was largely associated with chloroplasts, and functional chloroplasts were indispensable for this response. The lipid A moiety, the most conserved portion of LPS, appears to be responsible for the second ROS burst. Surprisingly, the LPS- and lipid A-triggered second ROS burst was only partially dependent on LORE. Together, our findings provide insight on the LPS-triggered ROS production and the associated signaling pathway.


Assuntos
Arabidopsis/metabolismo , Cloroplastos/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Cloroplastos/metabolismo , Flagelina/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lipídeo A/farmacologia , Mutação , Moléculas com Motivos Associados a Patógenos/imunologia , Moléculas com Motivos Associados a Patógenos/metabolismo , Plantas Geneticamente Modificadas , Proteínas Quinases/genética , Pseudomonas syringae/patogenicidade , Fatores de Transcrição/genética
19.
Front Plant Sci ; 8: 1509, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28900440

RESUMO

Huanglongbing (HLB) is one of the most destructive diseases of citrus, which has posed a serious threat to the global citrus production. This research was aimed to explore the use of chlorophyll fluorescence imaging combined with feature selection to characterize and detect the HLB disease. Chlorophyll fluorescence images of citrus leaf samples were measured by an in-house chlorophyll fluorescence imaging system. The commonly used chlorophyll fluorescence parameters provided the first screening of HLB disease. To further explore the photosynthetic fingerprint of HLB infected leaves, three feature selection methods combined with the supervised classifiers were employed to identify the unique fluorescence signature of HLB and perform the three-class classification (i.e., healthy, HLB infected, and nutrient deficient leaves). Unlike the commonly used fluorescence parameters, this novel data-driven approach by using the combination of the mean fluorescence parameters and image features gave the best classification performance with the accuracy of 97%, and presented a better interpretation for the spatial heterogeneity of photochemical and non-photochemical components in HLB infected citrus leaves. These results imply the potential of the proposed approach for the citrus HLB disease diagnosis, and also provide a valuable insight for the photosynthetic response to the HLB disease.

20.
Opt Express ; 18(16): 17412-32, 2010 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-20721128

RESUMO

This paper reports on the optimization and assessment of a hyperspectral imaging-based spatially-resolved system for determination of the optical properties of biological materials over the wavelengths of 500-1,000 nm. Twelve model samples covering a wide range of absorption and reduced scattering coefficients were created to validate the hyperspectral imaging system, and their true values of absorption and reduced scattering coefficients were determined and then cross-validated using three commonly used methods (i.e., transmittance, integrating sphere, and empirical equation). Light beam and source-detector distance were optimized through Monte Carlo simulations and experiments for the model samples. The optimal light beam should be of Gaussian type with the diameter of less than 1 mm, and the optimal minimum and maximum source-detector distance should be 1.5 mm and 10-20 mean free paths, respectively. The optimized hyperspectral imaging-based spatially-resolved system achieved good estimation of the optical parameters.


Assuntos
Algoritmos , Luz , Modelos Biológicos , Nefelometria e Turbidimetria/métodos , Espalhamento de Radiação , Absorção , Humanos
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