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1.
PLoS One ; 15(7): e0235444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614863

RESUMO

Commercial storage of potatoes often relies on the use of sprout inhibitors to prolong storage and reduce spoilage. The compound 1,4-dimethylnaphthalene (DMN) has seen increase application as a sprout inhibitor in the potato industry as older chemistries are being phased out. The mode of action of DMN is poorly understood as is the sensitivity of potato tissues to this new class of inhibitor. During storage potato tubers transition from a state of endo-dormant to eco-dormant and it is not known if the DMN response is consistent across this developmental transition. RNA-seq gene expression profiling was used to establish if stored potato tubers (Solanum tuberosum cv La Chipper) have differential sensitivity to DMN as tubers age. DMN was applied at three different times during storage; just after harvest when tubers are in endo-dormancy, midwinter at early eco-dormancy, and in spring during late eco-dormancy when sprouting was prevented via exposure to cold storage temperatures. Changes in gene expression were lowest during endo-dormancy while midwinter and spring treatments exhibited a greater and more diverse expression response. Functional analysis of differential gene expression demonstrated gene sets associated with DNA replication, cell division, and DNA methylation are suppressed after DMN treatment. However, gene sets associated with salicylic acid, jasmonic acid, abiotic and biotic stress responses are elevated by DMN only after endodormancy terminates. Gene clusters associated with pathogenesis related proteins PR-4 and PR-5 are also upregulated in response to DMN. These results indicate that DMN sensitivity changes as potato tubers age and transition from endo-dormant to eco-dormant in storage and the overall response is a shift in gene classes that regulate growth and response to stress.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Meristema , Dormência de Plantas , Tubérculos , Solanum tuberosum , Armazenamento de Alimentos , Perfilação da Expressão Gênica/métodos , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Naftalenos/química , Tubérculos/genética , Tubérculos/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo
2.
PLoS Pathog ; 16(6): e1008608, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32574227

RESUMO

Transmission is a crucial part of a viral life cycle and transmission mode can have an important impact on virus biology. It was demonstrated that transmission mode can influence the virulence and evolution of a virus; however, few empirical data are available to describe the direct underlying changes in virus population structure dynamics within the host. Potato virus Y (PVY) is an RNA virus and one of the most damaging pathogens of potato. It comprises several genetically variable strains that are transmitted between plants via different transmission modes. To investigate how transmission modes affect the within-plant viral population structure, we have used a deep sequencing approach to examine the changes in the genetic structure of populations (in leaves and tubers) of three PVY strains after successive passages by horizontal (aphid and mechanical) and vertical (via tubers) transmission modes. Nucleotide diversities of viral populations were significantly influenced by transmission modes; lineages transmitted by aphids were the least diverse, whereas lineages transmitted by tubers were the most diverse. Differences in nucleotide diversities of viral populations between leaves and tubers were transmission mode-dependent, with higher diversities in tubers than in leaves for aphid and mechanically transmitted lineages. Furthermore, aphid and tuber transmissions were shown to impose stronger genetic bottlenecks than mechanical transmission. To better understand the structure of virus populations within the host, transmission mode, movement of the virus within the host, and the number of replication cycles after transmission event need to be considered. Collectively, our results suggest a significant impact of virus transmission modes on the within-plant diversity of virus populations and provide quantitative fundamental data for understanding how transmission can shape virus diversity in the natural ecosystems, where different transmission modes are expected to affect virus population structure and consequently its evolution.


Assuntos
Modelos Biológicos , Doenças das Plantas/virologia , Folhas de Planta , Tubérculos , Potyvirus , Solanum tuberosum , Folhas de Planta/metabolismo , Folhas de Planta/virologia , Tubérculos/metabolismo , Tubérculos/virologia , Potyvirus/metabolismo , Potyvirus/patogenicidade , Solanum tuberosum/metabolismo , Solanum tuberosum/virologia
4.
Chemosphere ; 258: 127254, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32559492

RESUMO

Glyphosate is the most used herbicide worldwide, targeting physiological pathways in plants. Recent studies have shown that glyphosate can also cause toxic effects in animals. We investigated the glyphosate-based herbicide (GBH)-induced changes in potato (Solanum tuberosum) plant chemistry and the effects of a GBH on the survival rate and oxidative status of the Colorado potato beetle (Leptinotarsa decemlineata). The beetles were reared on potato plants grown in pots containing soil treated with a GBH (Roundup Gold, 450 g/l) or untreated soil (water control). The 2nd instar larvae were introduced to the potato plants and then collected in 2 phases: as 4th instar larvae and as adults. The main glycoalkaloids of the potato plants, α-solanine and α-chaconine, were measured twice during the experiment. The α-solanine was reduced in potato plants grown in GBH-treated soil, which can be detrimental to plant defenses against herbivores. GBH treatment had no effect on the survival rate or body mass of the larvae or the adult beetles. In the larvae, total glutathione (tGSH) concentration and the enzyme activity of catalase (CAT), superoxide dismutase, and glutathione-S-transferase were increased in the GBH treatment group. In the adult beetles, CAT activity and tGSH levels were affected by the interactive effect of GBH treatment and the body mass. To conclude, environmentally relevant concentrations of a GBH can affect the potato plant's glycoalkaloid concentrations, but are not likely to directly affect the survival rate of the Colorado potato beetle, but instead, modify the antioxidant defense of the beetles via diet.


Assuntos
Besouros/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Solo/química , Solanum tuberosum/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Besouros/metabolismo , Glutationa Transferase/metabolismo , Glicina/toxicidade , Larva/efeitos dos fármacos , Larva/metabolismo , Oxirredução , Solanina/análogos & derivados , Solanina/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/metabolismo
5.
Food Chem ; 326: 126966, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32416419

RESUMO

Phenolic compounds and ascorbic acid were analyzed in one yellow and four purple-flesh potato cultivars grown at 13 °C and 18 °C and harvested at different stages of tuber development, using HPLC-DAD and UHPLC-MS. The expression of genes in the phenylpropanoid pathway was studied at transcription level using qPCR. Petunidin-3-p-coumaroylrutinoside-5-glucoside was the most abundant anthocyanin in 'Blue Congo', 'Blaue Schweden', and 'Synkeä Sakari', whereas malvidin-3-p-coumaroylrutinoside-5-glucoside dominated in 'Blaue Veltlin'. In mature tubers, the purple cultivar 'Synkeä Sakari' showed the highest content of anthocyanins (2.4 mg/g freeze-dried sample), and 'Blaue Veltlin' had the highest content of phenolic acids (5.5 mg/g). Cultivar was the main variable affecting the biosynthesis of the studied metabolites, whereas the temperatures studied did not show different impact. The content of the main phenolic acids and anthocyanins in the potato cultivars correlated positively with the expression levels of the genes involved in the phenylpropanoid pathway.


Assuntos
Ácido Ascórbico/metabolismo , Fenóis/metabolismo , Tubérculos/química , Solanum tuberosum/química , Solanum tuberosum/crescimento & desenvolvimento , Antocianinas/metabolismo , Ácido Ascórbico/análise , Cromatografia Líquida de Alta Pressão , Glucosídeos/metabolismo , Espectrometria de Massas , Fenóis/análise , Pigmentação , Tubérculos/crescimento & desenvolvimento , Tubérculos/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Temperatura
6.
PLoS One ; 15(5): e0233076, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428011

RESUMO

Nitrogen is an important nutrient for plant growth and tuber quality of potato. Since potato crop requires high dose of N, improving nitrogen use efficiency (NUE) of plant is an inevitable approach to minimize N fertilization. The aim of this study was to identify and characterize microRNAs (miRNAs) by small RNA sequencing in potato plants grown in aeroponic under two contrasting N (high and low) regimes. A total of 119 conserved miRNAs belonging to 41 miRNAs families, and 1002 putative novel miRNAs were identified. From total, 52 and 54 conserved miRNAs, and 404 and 628 putative novel miRNAs were differentially expressed in roots and shoots, respectively under low N stress. Of total 34,135 predicted targets, the gene ontology (GO) analysis indicated that maximum targets belong to biological process followed by molecular function and cellular component. Eexpression levels of the selected miRNAs and targets were validated by real time-quantitative polymerase chain reaction (RT-qPCR) analysis. Two predicted targets of potential miRNAs (miR397 and miR398) were validated by 5' RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends). In general, predicted targets are associated with stress-related, kinase, transporters and transcription factors such as universal stress protein, heat shock protein, salt-tolerance protein, calmodulin binding protein, serine-threonine protein kinsae, Cdk10/11- cyclin dependent kinase, amino acid transporter, nitrate transporter, sugar transporter, transcription factor, F-box family protein, and zinc finger protein etc. Our study highlights that miR397 and miR398 play crucial role in potato during low N stress management. Moreover, study provides insights to modulate miRNAs and their predicted targets to develop N-use efficient potato using transgenic/genome-editing tools in future.


Assuntos
Perfilação da Expressão Gênica/métodos , MicroRNAs/genética , Solanum tuberosum/crescimento & desenvolvimento , Sequenciamento Completo do Genoma/métodos , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Nitrogênio/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , RNA de Plantas/genética , Análise de Sequência de RNA , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Estresse Fisiológico
7.
Proc Natl Acad Sci U S A ; 117(17): 9613-9620, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32284406

RESUMO

In plants and animals, nucleotide-binding leucine-rich repeat (NLR) proteins are intracellular immune sensors that recognize and eliminate a wide range of invading pathogens. NLR-mediated immunity is known to be modulated by environmental factors. However, how pathogen recognition by NLRs is influenced by environmental factors such as light remains unclear. Here, we show that the agronomically important NLR Rpi-vnt1.1 requires light to confer disease resistance against races of the Irish potato famine pathogen Phytophthora infestans that secrete the effector protein AVRvnt1. The activation of Rpi-vnt1.1 requires a nuclear-encoded chloroplast protein, glycerate 3-kinase (GLYK), implicated in energy production. The pathogen effector AVRvnt1 binds the full-length chloroplast-targeted GLYK isoform leading to activation of Rpi-vnt1.1. In the dark, Rpi-vnt1.1-mediated resistance is compromised because plants produce a shorter GLYK-lacking the intact chloroplast transit peptide-that is not bound by AVRvnt1. The transition between full-length and shorter plant GLYK transcripts is controlled by a light-dependent alternative promoter selection mechanism. In plants that lack Rpi-vnt1.1, the presence of AVRvnt1 reduces GLYK accumulation in chloroplasts counteracting GLYK contribution to basal immunity. Our findings revealed that pathogen manipulation of chloroplast functions has resulted in a light-dependent immune response.


Assuntos
Cloroplastos/microbiologia , Regulação da Expressão Gênica de Plantas/imunologia , Luz , Proteínas NLR/metabolismo , Phytophthora infestans/metabolismo , Proteínas de Plantas/metabolismo , Agrobacterium/metabolismo , Animais , Cloroplastos/metabolismo , Escherichia coli/metabolismo , Proteínas Fúngicas , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Inativação Gênica , Microscopia Confocal , Proteínas NLR/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas de Plantas/genética , Plântula , Solanum tuberosum/metabolismo , Solanum tuberosum/microbiologia , Tabaco/metabolismo , Tabaco/microbiologia , Técnicas do Sistema de Duplo-Híbrido
8.
PLoS One ; 15(3): e0230458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32168339

RESUMO

Gradients in the elemental composition of a potato leaf tissue (i.e. its ionome) can be linked to crop potential. Because the ionome is a function of genetics and environmental conditions, practitioners aim at fine-tuning fertilization to obtain an optimal ionome based on the needs of potato cultivars. Our objective was to assess the validity of cultivar grouping and predict potato tuber yields using foliar ionomes. The dataset comprised 3382 observations in Québec (Canada) from 1970 to 2017. The first mature leaves from top were sampled at the beginning of flowering for total N, P, K, Ca, and Mg analysis. We preprocessed nutrient concentrations (ionomes) by centering each nutrient to the geometric mean of all nutrients and to a filling value, a transformation known as row-centered log ratios (clr). A density-based clustering algorithm (dbscan) on these preprocessed ionomes failed to delineate groups of high-yield cultivars. We also used the preprocessed ionomes to assess their effects on tuber yield classes (high- and low-yields) on a cultivar basis using k-nearest neighbors, random forest and support vector machines classification algorithms. Our machine learning models returned an average accuracy of 70%, a fair diagnostic potential to detect in-season nutrient imbalance of potato cultivars using clr variables considering potential confounding factors. Optimal ionomic regions of new cultivars could be assigned to the one of the closest documented cultivar.


Assuntos
Produtos Agrícolas/química , Estado Nutricional , Folhas de Planta/química , Solanum tuberosum/química , Algoritmos , Canadá , Produtos Agrícolas/metabolismo , Humanos , Aprendizado de Máquina , Folhas de Planta/metabolismo , Quebeque , Solanum tuberosum/metabolismo
9.
J Biosci Bioeng ; 129(6): 672-678, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32088137

RESUMO

l-Asparaginases have the potential to inhibit the formation of acrylamide, a harmful toxin formed during high temperature processing of food. A novel bacterium which produces l-asparaginase was screened. Type I l-asparaginase gene from Acinetobacter soli was cloned and expressed in Escherichia coli. The recombinant l-asparaginase had an activity of 42.0 IU mL-1 and showed no activity toward l-glutamine and d-asparagine. The recombinant l-asparaginase exhibited maximum catalytic activity at pH 8.0 and 40°C. The enzyme was stable in the pH ranging from 6.0 to 9.0. The activity of the recombinant enzyme was substantially enhanced by Ba2+, dithiothreitol, and ß-mercaptoethanol. The Km and Vmax values of the l-asparaginase for the l-asparagine were 3.22 mmol L-1 and 1.55 IU µg-1, respectively. Moreover, the recombinant l-asparaginase had the ability to mitigate acrylamide formation in potato chips. Compared with the untreated group, the content of acrylamide in samples treated with the enzyme was effectively decreased by 55.9%. These results indicate that the novel type I l-asparaginase has the potential for application in the food processing industry.


Assuntos
Acinetobacter/enzimologia , Acrilamida/metabolismo , Asparaginase/metabolismo , Solanum tuberosum/metabolismo , Acinetobacter/genética , Asparaginase/genética , Asparagina/metabolismo , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Glutamina/metabolismo , Lanches
10.
Food Chem ; 317: 126416, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32087519

RESUMO

T-2 toxin at low concentrations can induce ROS accumulation and modulate host resistance in plants. NOX plays crucial roles in ROS production and is regulated by Ca2+via direct binding to EF-hand motifs. In this study, the effect of EGTA (Ca2+ chelating agent) on the expression and enzymatic activity of NOX, as well as the activities and corresponding gene expressions involved in ROS metabolism and cell membrane integrity, were investigated in treated slices. Results indicated that EGTA treatment significantly affected gene expression and activity of NOX, and reduced ROS accumulation and cell membrane integrity and the enzymatic activities and gene expression involved in ROS metabolism when exposed to treatment. The addition of exogenous Ca2+ restored the initial relative transcript abundance, ROS accumulation and their activities. Results suggest that Ca2+ affected by EGTA plays a crucial role in NOX activity regulation, ultimately affecting ROS metabolism in slices induced by T-2 toxin.


Assuntos
Cálcio/metabolismo , NADPH Oxidases/metabolismo , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Solanum tuberosum/metabolismo , Toxina T-2/metabolismo , Animais , Cálcio/química , Membrana Celular/metabolismo , Ácido Egtázico/química , Malondialdeído/metabolismo , NADPH Oxidases/genética , Proteínas de Plantas/genética , Tubérculos/metabolismo
11.
J Agric Food Chem ; 68(8): 2467-2476, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32031791

RESUMO

Enzymatic browning is a major issue affecting the quality of processed potato (Solanum tuberosum L.). To understand the molecular mechanism of browning, transcriptional analyses were performed by employing potatoes that differed in browning. Coexpression analysis indicated that 9 out of 15 upregulated genes in browning-less groups encoded for potato protease inhibitors (StPIs). In addition, gene otology analysis showed that the enriched terms were mainly involved in protease inhibitors. Overexpression of cysteine StPI 143 and StPI 146 individually reduced browning and lowered protease activities and tyrosine and total free amino acid (FAA) contents, but they could not decrease polyphenol oxidase activity. Moreover, supplementing exogenous tyrosine or total FAAs into transgenic potato mash to wild-type amounts promoted mash browning, browning with total FAAs, more than with tyrosine, resembling wild-type levels. These results implied that cysteine StPIs reduced browning via lowering the accumulation of FAAs in addition to tyrosine. Our findings have enriched the knowledge about the roles and mechanisms of protease inhibitors in regulating enzymatic browning of potato, which provide new ways for controlling potato browning.


Assuntos
Aminoácidos/metabolismo , Proteínas de Plantas/metabolismo , Inibidores de Proteases/metabolismo , Solanum tuberosum/metabolismo , Catecol Oxidase/antagonistas & inibidores , Catecol Oxidase/genética , Catecol Oxidase/metabolismo , Cor , Cisteína Proteases/genética , Cisteína Proteases/metabolismo , Proteínas de Plantas/genética , Solanum tuberosum/enzimologia , Solanum tuberosum/genética
12.
Artigo em Inglês | MEDLINE | ID: mdl-32065919

RESUMO

The mechanisms regulating, and modulating potato wound-healing processes are of great importance in reducing tuber infections, reducing shrinkage and maintaining quality and nutritional value for growers and consumers. Wound-induced changes in tuber polyamine metabolism have been linked to the modulation of wound healing (WH) and in possibly providing the crucial amount of H2O2 required for suberization processes. In this investigation we determined the effect of inhibition of specific steps within the pathway of polyamine metabolism on polyamine content and the initial accumulation of suberin polyphenolics (SPP) during WH. The accumulation of SPP represents a critical part of the beginning or inchoate phase of tuber WH during closing-layer formation because it serves as a barrier to bacterial infection and is a requisite for the accumulation of suberin polyaliphatics which provide the barrier to fungal infection. Results showed that the inhibitor treatments that caused changes in polyamine content generally did not influence wound-induced accumulation of SPP. Such lack of correlation was found for inhibitors involved in metabolism and oxidation of putrescine (arginine decarboxylase, ornithine decarboxylase, and diamine oxidase). However, accumulation of SPP was dramatically reduced by treatment with guazatine, a potent inhibitor of polyamine oxidase (PAO), and methylglyoxal-bis(guanylhydrazone), a putative inhibitor of S-adenosylmethione decarboxylase which may also cross-react to inhibit PAO. The mode of action of these inhibitors is presumed to be blockage of essential H2O2 production within the WH cell wall. These results are of great importance in understanding the mechanisms modulating WH and ultimately controlling related infections and associated postharvest losses.


Assuntos
Diaminas/antagonistas & inibidores , Lipídeos/biossíntese , Proteínas de Plantas/metabolismo , Tubérculos/metabolismo , Poliaminas/antagonistas & inibidores , Solanum tuberosum/metabolismo , Carboxiliases/metabolismo , Diaminas/metabolismo , Guanidinas/metabolismo , Mitoguazona/metabolismo , Oxirredução , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Poliaminas/metabolismo , Putrescina/metabolismo , Solanum tuberosum/enzimologia
13.
J Agric Food Chem ; 68(5): 1390-1396, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31935098

RESUMO

Potato juice is a byproduct of starch processing currently used as feed. However, potato proteins are an untapped source of high-protein food for human nutrition if harmful constituents notably glycoalkaloids (GAs) are detoxified. The two principle GAs found in potato are α-chaconine and α-solanine, both consisting of a solanidine aglycone with a carbohydrate side chain. The first step in the detoxification of these compounds is the removal of the trisaccharide. Whole-genome sequencing of a bacterial isolate, Arthrobacter sp. S41, capable of completely degrading α-chaconine and α-solanine, revealed the presence of a gene cluster possibly involved in the deglycosylation of GAs. Functional characterization confirmed the enzymatic activity of the gene cluster involved in the complete deglycosylation of both α-chaconine and α-solanine. The novel enzymes described here may find value in the bioconversion of feed proteins to food proteins suitable for human nutrition.


Assuntos
Arthrobacter/metabolismo , Proteínas de Bactérias/metabolismo , Família Multigênica , Solanina/análogos & derivados , Solanum tuberosum/toxicidade , Arthrobacter/classificação , Arthrobacter/enzimologia , Arthrobacter/genética , Proteínas de Bactérias/genética , Biotransformação , Glicosilação , Filogenia , Solanina/química , Solanina/metabolismo , Solanina/toxicidade , Solanum tuberosum/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-31928669

RESUMO

Both suberin and its associated waxes contribute to the formation of apoplastic barriers that protect plants from the environment. Some transcription factors have emerged as regulators of the suberization process. The potato StNAC103 gene was reported as a repressor of suberin polyester and suberin-associated waxes deposition because its RNAi-mediated downregulation (StNAC103-RNAi) over-accumulated suberin and associated waxes in the tuber phellem concomitantly with the induction of representative biosynthetic genes. Here, to explore if other genes of the large NAC gene family participate to this repressive function, we extended the silencing to other NAC members by targeting the conserved NAC domain of StNAC103 (StNAC103-RNAi-c). Transcript profile of the StNAC103-RNAi-c phellem indicated that StNAC101 gene was an additional potential target. In comparison with StNAC103-RNAi, the silencing with StNAC103-RNAi-c construct resulted in a similar effect in suberin but yielded an increased load of associated waxes in tuber phellem, mainly alkanes and feruloyl esters. Globally, the chemical effects in both silenced lines are supported by the transcript accumulation profile of genes involved in the biosynthesis, transport and regulation of apoplastic lipids. In contrast, the genes of polyamine biosynthesis were downregulated. Altogether these results point out to StNAC101 as a candidate to repress the suberin-associated waxes.


Assuntos
Inativação Gênica , Lipídeos/genética , Proteínas de Plantas/genética , Solanum tuberosum/genética , Proteínas de Plantas/metabolismo , Solanum tuberosum/metabolismo
15.
Planta ; 251(2): 45, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915930

RESUMO

MAIN CONCLUSION: Adaptation of the xylem under dehydration to smaller sized vessels and the increase in xylem density per stem area facilitate water transport during water-limiting conditions, and this has implications for assimilate transport during drought. The potato stem is the communication and transport channel between the assimilate-exporting source leaves and the terminal sink tissues of the plant. During environmental stress conditions like water scarcity, which adversely affect the performance (canopy growth and tuber yield) of the potato plant, the response of stem tissues is essential, however, still understudied. In this study, we investigated the response of the stem tissues of cultivated potato grown in the greenhouse to dehydration using a multidisciplinary approach including physiological, biochemical, morphological, microscopic, and magnetic resonance imaging techniques. We observed the most significant effects of water limitation in the lower stem regions of plants. The light microscopy analysis of the potato stem sections revealed that plants exposed to this particular dehydration stress have higher total xylem density per unit area than control plants. This increase in the total xylem density was accompanied by an increase in the number of narrow-diameter xylem vessels and a decrease in the number of large-diameter xylem vessels. Our MRI approach revealed a diurnal rhythm of xylem flux between day and night, with a reduction in xylem flux that is linked to dehydration sensitivity. We also observed that sink strength was the main driver of assimilate transport through the stem in our data set. These findings may present potential breeding targets for drought tolerance in potato.


Assuntos
Solanum tuberosum/metabolismo , Solanum tuberosum/fisiologia , Xilema/metabolismo , Xilema/fisiologia , Adaptação Fisiológica/fisiologia , Transporte Biológico/fisiologia , Secas , Imagem por Ressonância Magnética , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Transpiração Vegetal/fisiologia
16.
J Food Sci ; 85(1): 57-64, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31769514

RESUMO

This study investigated effects of fermentation on compositions, color, and functional properties of gelatinized potato flours from Atlantic and Kexin No.1 cultivars. Atlantic flour (AF) and Kexin No.1 flour (KF) were fermented using 1% yeast concentration, respectively. Fermentation further improved the nutritional and physicochemical features of gelatinized potato flours by means of increased protein and ash contents, and decreased the levels of moisture, lipid, soluble amylose, amylopectin, and total starch. The lightness and whiteness of potato flours were enhanced with the increase in fermentation time. There are gradual increases in water absorption index, emulsifying capacity and emulsifying stability of potato flours during fermentation. However, bulk density of them slightly reduced with the increase in fermentation time. In addition, fermentation has no significant effect on freeze-thaw stability of gelatinized potato flours. These results indicate that yeast fermentation could enhance certain processing characteristics of potato flours and improve the applicability of them in food formulations. PRACTICAL APPLICATION: Lately, China has started national project regarding the use of potato flour in foods. However, due to dark color and low protein content of potato flours, their application in food formulations was limited. This study analyzed the possible mechanisms by which yeast fermentation improved the nutritional and functional characteristics of Atlantic flour (AF) and Kexin No. 1 flour (KF). From applications standpoint, findings of this study could provide knowledge on the selection of potato flours for various food formulations.


Assuntos
Farinha/análise , Solanum tuberosum/química , Leveduras/metabolismo , Amilose/química , Amilose/metabolismo , China , Cor , Fermentação , Farinha/microbiologia , Géis/química , Géis/metabolismo , Solanum tuberosum/metabolismo , Solanum tuberosum/microbiologia , Amido/química , Amido/metabolismo
17.
Ecotoxicol Environ Saf ; 190: 110048, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31837570

RESUMO

Phosphite (Phi), an analog of phosphate (Pi) anion, is emerging as a potential biostimulator, fungicide and insecticide. Here, we reported that Phi also significantly enhanced thermotolerance in potatoes under heat stress. Potato plants with and without Phi pretreatment were exposed to heat stress and their heat tolerance was examined by assessing the morphological characteristics, photosynthetic pigment content, photosystem II (PS II) efficiency, levels of oxidative stress, and level of DNA damage. In addition, RNA-sequencing (RNA-Seq) was adopted to investigate the roles of Phi signals and the underlying heat resistance mechanism. RNA-Seq revealed that Phi orchestrated plant immune responses against heat stress by reprograming global gene expressions. Results from physiological data combined with RNA-Seq suggested that the supply of Phi not only was essential for the better plant performance, but also improved thermotolerance of the plants by alleviating oxidative stress and DNA damage, and improved biosynthesis of osmolytes and defense metabolites when exposed to unfavorable thermal conditions. This is the first study to explore the role of Phi in thermotolerance in plants, and the work can be applied to other crops under the challenging environment.


Assuntos
Fosfitos/farmacologia , Solanum tuberosum/efeitos dos fármacos , Termotolerância/efeitos dos fármacos , Dano ao DNA , Resposta ao Choque Térmico/efeitos dos fármacos , Estresse Oxidativo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , RNA-Seq , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/imunologia , Plântula/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/imunologia , Solanum tuberosum/metabolismo
18.
Food Chem ; 309: 125608, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31678673

RESUMO

Benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) can improve wound healing of potato tubers; however, how the chemical regulates reactive oxygen species (ROS) generation and scavenging during wound healing is not completely understood. BTH at 100 mg·L-1 regulated changes in ROS generation and scavenging in healing tissues of potato tubers. A higher H2O2 content was presented in healing tissues of potato tubers, while cell membrane permeability and malondialdehyde content declined due to BTH treatment. Additionally, the activities and transcript level of enzymes related with ROS generation, including NADPH oxidase, peroxidase and polyamine oxidase, as well as enzymes involved in ROS scavenging, such as superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, were significantly enhanced by BTH treatment. It is suggested that ROS metabolism might play a crucial role in wound healing of potato tubers mediated by BTH during postharvest.


Assuntos
Tubérculos/efeitos dos fármacos , Tubérculos/metabolismo , Solanum tuberosum/efeitos dos fármacos , Solanum tuberosum/metabolismo , Tiadiazóis/farmacologia , Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Enzimas/genética , Enzimas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo
19.
Food Chem ; 308: 124832, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31648093

RESUMO

Potatoes usually suffer from greatly decrease of hardness after boiling, which limits their processing potential in food industry. Moreover, methods for enhancing the hardness of potatoes after boiling are underexplored. In this study, the hardness of potato slices after boiling were increased from 288 g to 2342 g by the combined treatment of lactic acid (LA) and calcium chloride (CC). Through the analysis of the microstructure of the potato cells, the molecular weight distribution and natural sugar ratio of different soluble pectin fractions, and the enzymatic activities (polygalacturonase, PG and pectin methylesterase, PME), the possible mechanism behind the hardness enhancement by LA and CC pretreatment, namely the direct link between pectin and potato structure was revealed. The obtained results confirmed the target spot for enhancing the hardness of potatoes after boiling lay in PG activity and gelation of the pectin, which also could be used to help other plants resist the heat process if pectin existed in their cell wall.


Assuntos
Cloreto de Cálcio/farmacologia , Ácido Láctico/farmacologia , Solanum tuberosum/efeitos dos fármacos , Hidrolases de Éster Carboxílico/metabolismo , Dureza , Temperatura Alta , Pectinas/química , Poligalacturonase/metabolismo , Solanum tuberosum/química , Solanum tuberosum/metabolismo
20.
Chem Commun (Camb) ; 55(100): 15137-15140, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31789333

RESUMO

A fluorescent probe (TPA-BTD-MT) was designed to monitor cyanide ions (CN-) with a "turn-on" response, changing from "turn-off" behavior due to the structural change. TPA-BTD-MT exhibited high selectivity for sensing CN- in several food samples and was successfully used for imaging CN- in living cells and animals with strong "turn-on" fluorescence.


Assuntos
Cianetos/análise , Corantes Fluorescentes/química , Análise de Alimentos/métodos , Imagem Óptica , Compostos de Anilina/química , Animais , Linhagem Celular Tumoral , Limite de Detecção , Manihot/química , Manihot/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Teoria Quântica , Solanum tuberosum/química , Solanum tuberosum/metabolismo
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