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1.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445676

RESUMO

Starch is the most abundant storage carbohydrate and a major component in pea seeds, accounting for about 50% of dry seed weight. As a by-product of pea protein processing, current uses for pea starch are limited to low-value, commodity markets. The globally growing demand for pea protein poses a great challenge for the pea fractionation industry to develop new markets for starch valorization. However, there exist gaps in our understanding of the genetic mechanism underlying starch metabolism, and its relationship with physicochemical and functional properties, which is a prerequisite for targeted tailoring functionality and innovative applications of starch. This review outlines the understanding of starch metabolism with a particular focus on peas and highlights the knowledge of pea starch granule structure and its relationship with functional properties, and industrial applications. Using the currently available pea genetics and genomics knowledge and breakthroughs in omics technologies, we discuss the perspectives and possible avenues to advance our understanding of starch metabolism in peas at an unprecedented level, to ultimately enable the molecular design of multi-functional native pea starch and to create value-added utilization.


Assuntos
Metabolismo dos Carboidratos/fisiologia , Ervilhas/metabolismo , Amido/metabolismo , Ervilhas/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Amido/isolamento & purificação
2.
BMC Plant Biol ; 21(1): 365, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34380415

RESUMO

BACKGROUND: Kiwifruit (Actinidia Lindl.) is considered an important fruit species worldwide. Due to its temperate origin, this species is highly vulnerable to freezing injury while under low-temperature stress. To obtain further knowledge of the mechanism underlying freezing tolerance, we carried out a hybrid transcriptome analysis of two A. arguta (Actinidi arguta) genotypes, KL and RB, whose freezing tolerance is high and low, respectively. Both genotypes were subjected to - 25 °C for 0 h, 1 h, and 4 h. RESULTS: SMRT (single-molecule real-time) RNA-seq data were assembled using the de novo method, producing 24,306 unigenes with an N50 value of 1834 bp. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEGs showed that they were involved in the 'starch and sucrose metabolism', the 'mitogen-activated protein kinase (MAPK) signaling pathway', the 'phosphatidylinositol signaling system', the 'inositol phosphate metabolism', and the 'plant hormone signal transduction'. In particular, for 'starch and sucrose metabolism', we identified 3 key genes involved in cellulose degradation, trehalose synthesis, and starch degradation processes. Moreover, the activities of beta-GC (beta-glucosidase), TPS (trehalose-6-phosphate synthase), and BAM (beta-amylase), encoded by the abovementioned 3 key genes, were enhanced by cold stress. Three transcription factors (TFs) belonging to the AP2/ERF, bHLH (basic helix-loop-helix), and MYB families were involved in the low-temperature response. Furthermore, weighted gene coexpression network analysis (WGCNA) indicated that beta-GC, TPS5, and BAM3.1 were the key genes involved in the cold response and were highly coexpressed together with the CBF3, MYC2, and MYB44 genes. CONCLUSIONS: Cold stress led various changes in kiwifruit, the 'phosphatidylinositol signaling system', 'inositol phosphate metabolism', 'MAPK signaling pathway', 'plant hormone signal transduction', and 'starch and sucrose metabolism' processes were significantly affected by low temperature. Moreover, starch and sucrose metabolism may be the key pathway for tolerant kiwifruit to resist low temperature damages. These results increase our understanding of the complex mechanisms involved in the freezing tolerance of kiwifruit under cold stress and reveal a series of candidate genes for use in breeding new cultivars with enhanced freezing tolerance.


Assuntos
Aclimatação/genética , Actinidia/genética , Actinidia/fisiologia , Congelamento , Regulação da Expressão Gênica de Plantas , Frutas/genética , Frutas/fisiologia , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Sistema de Sinalização das MAP Quinases , Anotação de Sequência Molecular , Fosfatidilinositóis/metabolismo , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Amido/metabolismo , Sacarose/metabolismo
3.
BMC Genomics ; 22(1): 617, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34388974

RESUMO

BACKGROUND: Chestnut seeds are important kinds of edible nuts rich in starch and protein. The characteristics and nutrient contents of chestnut have been found to show obvious metaxenia effects in previous studies. To improve the understanding of the effect of metaxenia on chestnut starch and sucrose metabolism, this study used three varieties of chestnut, 'Yongfeng 1', 'YongRen Zao' and 'Yimen 1', as male parents to pollinate the female parent, 'Yongfeng 1', and investigated the mechanisms of starch and sucrose metabolism in three starch accumulation stages (70 (S1), 82 (S2), and 94 (S3) days after pollination, DAP) in chestnut seed kernels. RESULT: Most carbohydrate metabolism genes were highly expressed in YFF (self-pollinated 'Yongfeng 1') in stage S2 and in YFR ('Yongfeng 1' × 'Yongren Zao') and YFM ('Yongfeng 1' × 'Yimen 1') in stage S3. In stage S3, hub genes encoding HSF_DNA-binding, ACT, Pkinase, and LIM proteins and four transcription factors were highly expressed, with YFF showing the highest expression, followed by YFR and YFM. In addition, transcriptome analysis of the kernels at 70, 82 and 94 DAP showed that the starch granule-bound starch synthase (EC 2.4.1.242) and ADP-glucose pyrophosphorylase (EC 2.7 .7.27) genes were actively expressed at 94 DAF. Chestnut seeds regulate the accumulation of soluble sugars, reducing sugars and starch by controlling glycosyl transferase and hydrolysis activity during development. CONCLUSION: These results and resources have important guiding significance for further research on starch and sucrose metabolism and other types of metabolism related to chestnut metaxenia.


Assuntos
Amido , Transcriptoma , Metabolismo dos Carboidratos , China , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Humanos , Masculino , Amido/metabolismo
4.
BMC Plant Biol ; 21(1): 318, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217217

RESUMO

BACKGROUND: Cassava (Manihot esculenta Crantz) efficiently accumulates starch in its storage roots. However, how photosynthates are transported from the leaves to the phloem (especially how they are unloaded into parenchymal cells of storage roots) remains unclear. RESULTS: Here, we investigated the sucrose unloading pattern and its impact on cassava storage root development using microstructural and physiological analyses, namely, carboxyfluorescein (CF) and C14 isotope tracing. The expression profiling of genes involved in symplastic and apoplastic transport was performed, which included enzyme activity, protein gel blot analysis, and transcriptome sequencing analyses. These finding showed that carbohydrates are transported mainly in the form of sucrose, and more than 54.6% was present in the stem phloem. Sucrose was predominantly unloaded symplastically from the phloem into storage roots; in addition, there was a shift from apoplastic to symplastic unloading accompanied by the onset of root swelling. Statistical data on the microstructures indicated an enrichment of plasmodesmata within sieve, companion, and parenchyma cells in the developing storage roots of a cultivar but not in a wild ancestor. Tracing tests with CF verified the existence of a symplastic channel, and [14C] Suc demonstrated that sucrose could rapidly diffuse into root parenchyma cells from phloem cells. The relatively high expression of genes encoding sucrose synthase and associated proteins appeared in the middle and late stages of storage roots but not in primary fibrous roots, or secondary fibrous roots. The inverse expression pattern of sucrose transporters, cell wall acid invertase, and soluble acid invertase in these corresponding organs supported the presence of a symplastic sucrose unloading pathway. The transcription profile of genes involved in symplastic unloading and their significantly positive correlation with the starch yield at the population level confirmed that symplastic sucrose transport is vitally important in the development of cassava storage roots. CONCLUSIONS: In this study, we revealed that the cassava storage root phloem sucrose unloading pattern was predominantly a symplastic unloading pattern. This pattern is essential for efficient starch accumulation in high-yielding varieties compared with low-yielding wild ancestors.


Assuntos
Manihot/metabolismo , Floema/fisiologia , Fotossíntese/fisiologia , Raízes de Plantas/metabolismo , Amido/metabolismo , Transporte Biológico , Biomassa , Parede Celular/metabolismo , Difusão , Fluoresceínas/metabolismo , Regulação da Expressão Gênica de Plantas , Manihot/genética , Modelos Biológicos , Floema/citologia , Floema/ultraestrutura , Plasmodesmos/metabolismo , Frações Subcelulares/metabolismo , Sacarose/metabolismo , Açúcares/metabolismo
5.
Bioresour Technol ; 337: 125490, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34320769

RESUMO

In the present study, starch-based potato peel waste biomass (PWB) was utilized as a potential substrate for hydrogen production via dark fermentation by the thermophillic amylase producing strain Parageobacillus thermoglucosidasius KCTC 33548. Supplementation of Fe3O4 nanoparticles (300 mg/L) led to a 4.15-fold increase in hydrogen production as compared to the control. The addition of optimized concentrations of both Fe3O4 nanoparticles (300 mg/L) and L-cysteine (250 mg/L) during hydrogen fermentation using pure starch and PWB generated maximum cumulative hydrogen yields of 167 and 71.9 mL with maximum production rates of 2.81 and 1.26 mL/h, respectively. Further, the correlation between Fe3O4 and the expression of hydrogenase isoforms and the related hydrogenase activity was explored. The possible mechanisms of the action of Fe3O4 on enhanced hydrogenase activity and hydrogen production was elucidated. To our knowledge, there are no such studies reported on enhanced hydrogen production from PWB in a single step.


Assuntos
Nanopartículas , Solanum tuberosum , Bacillaceae , Biomassa , Fermentação , Hidrogênio , Amido/metabolismo
6.
Int J Mol Sci ; 22(13)2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34281256

RESUMO

Plants are often challenged by an array of unfavorable environmental conditions. During cold exposure, many changes occur that include, for example, the stabilization of cell membranes, alterations in gene expression and enzyme activities, as well as the accumulation of metabolites. In the presented study, the carbohydrate metabolism was analyzed in the very early response of plants to a low temperature (2 °C) in the leaves of 5-week-old potato plants of the Russet Burbank cultivar during the first 12 h of cold treatment (2 h dark and 10 h light). First, some plant stress indicators were examined and it was shown that short-term cold exposure did not significantly affect the relative water content and chlorophyll content (only after 12 h), but caused an increase in malondialdehyde concentration and a decrease in the expression of NDA1, a homolog of the NADH dehydrogenase gene. In addition, it was shown that the content of transitory starch increased transiently in the very early phase of the plant response (3-6 h) to cold treatment, and then its decrease was observed after 12 h. In contrast, soluble sugars such as glucose and fructose were significantly increased only at the end of the light period, where a decrease in sucrose content was observed. The availability of the monosaccharides at constitutively high levels, regardless of the temperature, may delay the response to cold, involving amylolytic starch degradation in chloroplasts. The decrease in starch content, observed in leaves after 12 h of cold exposure, was preceded by a dramatic increase in the transcript levels of the key enzymes of starch degradation initiation, the α-glucan, water dikinase (GWD-EC 2.7.9.4) and the phosphoglucan, water dikinase (PWD-EC 2.7.9.5). The gene expression of both dikinases peaked at 9 h of cold exposure, as analyzed by real-time PCR. Moreover, enhanced activities of the acid invertase as well as of both glucan phosphorylases during exposure to a chilling temperature were observed. However, it was also noticed that during the light phase, there was a general increase in glucan phosphorylase activities for both control and cold-stressed plants irrespective of the temperature. In conclusion, a short-term cold treatment alters the carbohydrate metabolism in the leaves of potato, which leads to an increase in the content of soluble sugars.


Assuntos
Metabolismo dos Carboidratos , Resposta ao Choque Frio/fisiologia , Solanum tuberosum/metabolismo , Amilases/metabolismo , Metabolismo dos Carboidratos/genética , Clorofila/metabolismo , Temperatura Baixa/efeitos adversos , Resposta ao Choque Frio/genética , Complexo I de Transporte de Elétrons/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Sistema da Enzima Desramificadora do Glicogênio/metabolismo , Malondialdeído/metabolismo , Fosforilases/metabolismo , Fosfotransferases (Aceptores Pareados)/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Solanum tuberosum/genética , Amido/metabolismo , Água/metabolismo , beta-Frutofuranosidase/metabolismo
7.
BMC Plant Biol ; 21(1): 323, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225663

RESUMO

BACKGROUND: Sufficient low temperature accumulation is the key strategy to break bud dormancy and promote subsequent flowering in tree peony anti-season culturing production. Exogenous gibberellins (GAs) could partially replace chilling to accelerate dormancy release, and different kinds of GAs showed inconsistent effects in various plants. To understand the effects of exogenous GA3 and GA4 on dormancy release and subsequent growth, the morphological changes were observed after exogenous GAs applications, the differentially expressed genes (DEGs) were identified, and the contents of endogenous phytohormones, starch and sugar were measured, respectively. RESULTS: Morphological observation and photosynthesis measurements indicated that both GA3 and GA4 applications accelerated bud dormancy release, but GA3 feeding induced faster bud burst, higher shoot and more flowers per plant. Full-length transcriptome of dormant bud was used as the reference genome. Totally 124 110 459, 124 015 148 and 126 239 836 reads by illumina transcriptome sequencing were obtained in mock, GA3 and GA4 groups, respectively. Compared with the mock, there were 879 DEGs and 2 595 DEGs in GA3 and GA4 group, 1 179 DEGs in GA3 vs GA4, and 849 DEGs were common in these comparison groups. The significant enrichment KEGG pathways of 849 DEGs highlighted plant hormone signal transduction, starch and sucrose metabolism, cell cycle, DNA replication, etc. Interestingly, the contents of endogenous GA1, GA3, GA4, GA7 and IAA significantly increased, ABA decreased after GA3 and GA4 treatments by LC-MS/MS. Additionally, the soluble glucose, fructose and trehalose increased after exogenous GAs applications. Compared to GA4 treatment, GA3 induced higher GA1, GA3 and IAA level, more starch degradation to generate more monosaccharide for use, and promoted cell cycle and photosynthesis. Higher expression levels of dormancy-related genes, TFL, FT, EBB1, EBB3 and CYCD, and lower of SVP by GA3 treatment implied more efficiency of GA3. CONCLUSIONS: Exogenous GA3 and GA4 significantly accelerated bud dormancy release and subsequent growth by increasing the contents of endogenous bioactive GAs, IAA, and soluble glucose such as fructose and trehalose, and accelerated cell cycle process, accompanied by decreasing ABA contents. GA3 was superior to GA4 in tree peony forcing culture, which might because tree peony was more sensitive to GA3 than GA4, and GA3 had a more effective ability to induce cell division and starch hydrolysis. These results provided the value data for understanding the mechanism of dormancy release in tree peony.


Assuntos
Flores/fisiologia , Giberelinas/metabolismo , Paeonia/fisiologia , Flores/efeitos dos fármacos , Congelamento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Giberelinas/farmacologia , Modelos Biológicos , Paeonia/efeitos dos fármacos , Paeonia/genética , Reguladores de Crescimento de Plantas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Amido/metabolismo , Sacarose/metabolismo , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
8.
BMC Plant Biol ; 21(1): 308, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193032

RESUMO

BACKGROUND: Rice (Oryza sativa L.) Chalkiness, the opaque part in the kernel endosperm formed by loosely piled starch and protein bodies. Chalkiness is a complex quantitative trait regulated by multiple genes and various environmental factors. Phytohormones play important roles in the regulation of chalkiness formation but the underlying molecular mechanism is still unclear at present. RESULTS: In this research, Xiangzaoxian24 (X24, pure line of indica rice with high-chalkiness) and its origin parents Xiangzaoxian11 (X11, female parent, pure line of indica rice with high-chalkiness) and Xiangzaoxian7 (X7, male parent, pure line of indica rice with low-chalkiness) were used as materials. The phenotype, physiological and biochemical traits combined with transcriptome analysis were conducted to illustrate the dynamic process and transcriptional regulation of rice chalkiness formation. Impressively, phytohormonal contents and multiple phytohormonal signals were significantly different in chalky caryopsis, suggesting the involvement of phytohormones, particularly ABA and auxin, in the regulation of rice chalkiness formation, through the interaction of multiple transcription factors and their downstream regulators. CONCLUSION: These results indicated that chalkiness formation is a dynamic process associated with multiple genes, forming a complex regulatory network in which phytohormones play important roles. These results provided informative clues for illustrating the regulatory mechanisms of chalkiness formation in rice.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Oryza/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Transcrição Genética/efeitos dos fármacos , Endosperma/efeitos dos fármacos , Endosperma/metabolismo , Endosperma/ultraestrutura , Perfilação da Expressão Gênica , Ontologia Genética , Oryza/efeitos dos fármacos , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reprodutibilidade dos Testes , Amido/metabolismo , Amido/ultraestrutura , Sacarose/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Molecules ; 26(14)2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34299392

RESUMO

The present paper reports the determination of the activation energies and the optimum temperatures of starch hydrolysis by porcine pancreas α-amylase. The parameters were estimated based on the literature data on the activity curves versus temperature for starch hydrolysis by α-amylase from porcine pancreas. It was assumed that both the hydrolysis reaction process and the deactivation process of α-amylase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on porcine pancreas α-amylase activity was used. The determine deactivation energies Ea were from 19.82 ± 7.22 kJ/mol to 128.80 ± 9.27 kJ/mol, the obtained optimum temperatures Topt were in the range from 311.06 ± 1.10 K to 326.52 ± 1.75 K. In turn, the values of deactivation energies Ed has been noted in the range from 123.57 ± 14.17 kJ/mol to 209.37 ± 5.17 kJ/mol. The present study is related to the starch hydrolysis by α-amylase. In the industry, the obtained results the values Ea, Ed, Topt can be used to design and optimize starch hydrolysis by α-amylase porcine pancreas. The obtained results might also find application in research on the pharmaceutical preparations used to treat pancreatic insufficiency or prognosis of pancreatic cancer.


Assuntos
Pâncreas/enzimologia , Amido/metabolismo , alfa-Amilases/metabolismo , Animais , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Fenômenos Físicos , Suínos , Temperatura
10.
Molecules ; 26(13)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34279388

RESUMO

Prolonged exposure to cold temperatures often results in a relatively low flowering rate in litchi (Litchi chinensis Sonn.) trees with younger leaves. This study aimed to verify the impact of stem girdling on litchi flowering by identifying and characterizing the induced metabolic changes. After a 60 day exposure to cold treatment at 15 °C/10 °C (12 h/12 h), the flowering rate of the girdled trees was 100%, while that of the non-girdled trees was 20%, indicating that girdling improved litchi flowering at its turning stage. The metabolic profiles of litchi leaves with and without stem girdling during floral induction were compared and 505 metabolites potentially associated with litchi flowering were detected. Most metabolites were involved in the metabolism of starch and sucrose, fatty acid, and phenylpyruvic acid. The metabolic pathways concerned with the biosynthesis of epinephrine, sucrose, and d-maltose were induced in leaves after girdling treatment. The level of galactitol, phenylpyruvic acid, acetyl-CoA, linoleic acid, alpha-linolenic acid, and 13-HPOT biosynthesis remained stable in the leaves from girdled trees but changed drastically in the leaves from non-girdled trees. In addition, 379 metabolites concerning flowering rate were characterized. Metabolism pathways of starch and sucrose, galactose, and linoleic acid are of great significance to the flowering of litchi. Linoleic acid exhibited the most significant variations between girdled trees and non-girdled trees with fold changes of up to 13.62. These results contribute to understanding the biological mechanism of litchi floral induction and the metabolic changes after stem girdling.


Assuntos
Litchi/metabolismo , Metaboloma , Folhas de Planta/metabolismo , Flores/crescimento & desenvolvimento , Flores/metabolismo , Ácido Linoleico/metabolismo , Litchi/crescimento & desenvolvimento , Ácidos Fenilpirúvicos/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/metabolismo , Amido/metabolismo , Sacarose/metabolismo
11.
Int J Mol Sci ; 22(12)2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34203082

RESUMO

Ideal Plant Architecture 1 (IPA1) encodes SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 14 (SPL14) with a pleiotropic effect on regulating rice development and biotic stress responses. To investigate the role of IPA1 in early seedling development, we developed a pair of IPA1/ipal-NILs and found that seed germination and early seedling growth were retarded in the ipa1-NIL. Analysis of the soluble sugar content, activity of amylase, and expression of the α-amylase genes revealed that the starch metabolism was weakened in the ipa1-NIL germinating seeds. Additionally, the content of bioactive gibberellin (GA) was significantly lower than that in the IPA1-NIL seeds at 48 h of imbibition. Meanwhile, the expression of GA synthesis-related gene OsGA20ox1 was downregulated, whereas the expression of GA inactivation-related genes was upregulated in ipa1-NIL seeds. In addition, the expression of OsWRKY51 and OsWRKY71 was significantly upregulated in ipa1-NIL seeds. Using transient dual-luciferase and yeast one-hybrid assays, IPA1 was found to directly activate the expression of OsWRKY51 and OsWRKY71, which would interfere with the binding affinity of GA-induced transcription factor OsGAMYB to inhibit the expression of α-amylase genes. In summary, our results suggest that IPA1 negatively regulates seed germination and early seedling growth by interfering with starch metabolism via the GA and WRKY pathways.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Giberelinas/metabolismo , Oryza/fisiologia , Desenvolvimento Vegetal , Plântula/crescimento & desenvolvimento , Transdução de Sinais , Amido/metabolismo , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/genética , Fenótipo , Ligação Proteica , alfa-Amilases/metabolismo
12.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206151

RESUMO

The saccharification of sweetpotato storage roots is a common phenomenon in the cooking process, which determines the edible quality of table use sweetpotato. In the present study, two high saccharified sweetpotato cultivars (Y25, Z13) and one low saccharified cultivar (X27) in two growth periods (S1, S2) were selected as materials to reveal the molecular mechanism of sweetpotato saccharification treated at high temperature by transcriptome sequencing and non-targeted metabolome determination. The results showed that the comprehensive taste score, sweetness, maltose content and starch change of X27 after steaming were significantly lower than those of Y25 and Z13. Through transcriptome sequencing analysis, 1918 and 1520 differentially expressed genes were obtained in the two periods of S1 and S2, respectively. Some saccharification-related transcription factors including MYB families, WRKY families, bHLH families and inhibitors were screened. Metabolic analysis showed that 162 differentially abundant metabolites related to carbohydrate metabolism were significantly enriched in starch and sucrose capitalization pathways. The correlation analysis between transcriptome and metabolome confirmed that the starch and sucrose metabolic pathways were significantly co-annotated, indicating that it is a vitally important metabolic pathway in the process of sweetpotato saccharification. The data obtained in this study can provide valuable resources for follow-up research on sweetpotato saccharification and will provide new insights and theoretical basis for table use sweetpotato breeding in the future.


Assuntos
Metabolismo dos Carboidratos , Temperatura Alta , Ipomoea batatas/metabolismo , Raízes de Plantas/metabolismo , Transcriptoma , Manipulação de Alimentos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Metabolômica , Amido/metabolismo , Sacarose/metabolismo
13.
Plant Cell Rep ; 40(9): 1647-1663, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34215912

RESUMO

KEY MESSAGE: AIL7 over-expression modulates fatty acid biosynthesis and triacylglycerol accumulation in Arabidopsis developing seeds through the transcriptional regulation of associated genes. Seed fatty acids (FAs) and triacylglycerol (TAG) contribute to many functions in plants, and seed lipids have broad food, feed and industrial applications. As a result, an enormous amount of attention has been dedicated towards uncovering the regulatory cascade responsible for the fine-tuning of the lipid biosynthetic pathway in seeds, which is regulated in part through the action of LEAFY COTYLEDON1, ABSCISSIC ACID INSENSITIVE 3, FUSCA3 and LEC2 (LAFL) transcription factors. Although AINTEGUMENTA-LIKE 7 (AIL7) is involved in meristematic function and shoot phyllotaxy, its effect in the context of lipid biosynthesis has yet to be assessed. Here, we generated AIL7 seed-specific over-expression lines and found that they exhibited significant alterations in FA composition and decreased total lipid accumulation in seeds. Seeds and seedlings from transgenic lines also exhibited morphological deviations compared to wild type. Correspondingly, RNA-Seq analysis demonstrated that the expression of many genes related to FA biosynthesis and TAG breakdown were significantly altered in developing siliques from transgenic lines compared to wild-type plants. The seed-specific over-expression of AIL7 also altered the expression profiles of many genes related to starch metabolism, photosynthesis and stress response, suggesting further roles for AIL7 in plants. These findings not only advance our understanding of the lipid biosynthetic pathway in seeds, but also provide evidence for additional functions of AIL7, which could prove valuable in downstream breeding and/or metabolic engineering endeavors.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/genética , Ácidos Graxos/biossíntese , Sementes/metabolismo , Fatores de Transcrição/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ácidos Graxos/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Óleos Vegetais/metabolismo , Plantas Geneticamente Modificadas , Plântula/genética , Plântula/crescimento & desenvolvimento , Sementes/genética , Sementes/crescimento & desenvolvimento , Amido/genética , Amido/metabolismo , Fatores de Transcrição/metabolismo , Triglicerídeos/metabolismo
14.
Nat Metab ; 3(6): 810-828, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34099926

RESUMO

Reduced protein intake, through dilution with carbohydrate, extends lifespan and improves mid-life metabolic health in animal models. However, with transition to industrialised food systems, reduced dietary protein is associated with poor health outcomes in humans. Here we systematically interrogate the impact of carbohydrate quality in diets with varying carbohydrate and protein content. Studying 700 male mice on 33 isocaloric diets, we find that the type of carbohydrate and its digestibility profoundly shape the behavioural and physiological responses to protein dilution, modulate nutrient processing in the liver and alter the gut microbiota. Low (10%)-protein, high (70%)-carbohydrate diets promote the healthiest metabolic outcomes when carbohydrate comprises resistant starch (RS), yet the worst outcomes were with a 50:50 mixture of monosaccharides fructose and glucose. Our findings could explain the disparity between healthy, high-carbohydrate diets and the obesogenic impact of protein dilution by glucose-fructose mixtures associated with highly processed diets.


Assuntos
Dieta , Carboidratos da Dieta/metabolismo , Proteínas na Dieta/metabolismo , Metabolismo Energético , Homeostase , Animais , Glucose/metabolismo , Nível de Saúde , Masculino , Camundongos , Obesidade/etiologia , Obesidade/metabolismo , Amido/metabolismo
15.
J Dairy Sci ; 104(9): 9735-9751, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34176630

RESUMO

The aim of this study was to investigate the effect of controlled daily alternations in dietary starch level on changes in rumen environment, blood, urine, and milk metabolites of dairy cows. Six multiparous mid-lactation Holstein cows were used in a replicated 3 × 3 Latin square design with 14-d periods and 3 alternating levels of dietary starch as treatments. Each 14-d period consisted of a 7-d baseline period and 7-d alternating period where diets alternated day to day. During the baseline period, all cows were fed a control diet containing 21% starch (dry matter basis). During the alternating period, the control diet was replaced with 1 of the 3 experimental diets on d 8, 10, 12, and 14. The 3 experimental diets contained 28% (low), 35% (medium), and 42% (high) starch (dry matter basis). At d 7 (baseline), 8 (ALT1), and 14 (ALT4) of each period, rumen fluid, blood, urine, and quarter milk (i.e., back right quarter) samples were collected at -0.5, 1, 2.5, 4, 5.5, and 7 h relative to morning feeding (0800 h). No differences were observed in dry matter intake, milk yield, and milk chemical composition. Rumen medial pH was lower in the high alternation level compared with the low or medium alternation levels at ALT1 but did not differ among starch alternation levels at ALT4. Similarly, the difference between rumen pH in medial and ventral contents was reduced at ALT1 with high alternation level but was not affected at ALT4. Total volatile fatty acid (VFA) concentrations were higher in the rumen medial fluid of the high alternation level at 7 h relative to morning feeding compared with those from the low and medium alternation levels. Similarly, total VFA concentrations constantly increased and were the highest in the ventral rumen fluid at 7 h relative to morning feeding, although no differences were detected among starch alternation levels. In both rumen medial and ventral fluids, the high alternation level showed higher propionate and lower acetate proportions compared with low and medium alternation levels. No differences in blood pH were detected among starch alternation levels. However, glucose concentrations tended to be higher in cows from the high alternation level. l-Lactate concentrations in blood were higher in ALT1 than in ALT4 but were not affected by the starch alternation level. In urine, no differences in pH or l-lactate concentrations were detected among alternation levels (i.e., low, medium, and high). Similarly, no differences in milk pH were detected among alternation levels. According to these results, it seems that the daily dietary starch alternation from 21% up to 42% (dry matter basis) is able to affect the ruminal fluid, especially during the first alternation. However, these changes in rumen fluid did not cause any effect on the variables measured in blood, urine, or milk. This study indicates that cows can cope with day-to-day alternations in type of rumen fermentable organic matter; however, longer-term effects on performance and health should be addressed in future studies.


Assuntos
Lactação , Rúmen , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Carboidratos da Dieta/metabolismo , Feminino , Fermentação , Leite/metabolismo , Rúmen/metabolismo , Amido/metabolismo
16.
Int J Mol Sci ; 22(9)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062942

RESUMO

A field experiment was established to study sweet potato growth, starch dynamic accumulation, key enzymes and gene transcription in the sucrose-to-starch conversion and their relationships under six K2O rates using Ningzishu 1 (sensitive to low-K) and Xushu 32 (tolerant to low-K). The results indicated that K application significantly improved the biomass accumulation of plant and storage root, although treatments at high levels of K, i.e., 300-375 kg K2O ha-1, significantly decreased plant biomass and storage root yield. Compared with the no-K treatment, K application enhanced the biomass accumulation of plant and storage root by 3-47% and 13-45%, respectively, through promoting the biomass accumulation rate. Additionally, K application also enhanced the photosynthetic capacity of sweet potato. In this study, low stomatal conductance and net photosynthetic rate (Pn) accompanied with decreased intercellular CO2 concentration were observed in the no-K treatment at 35 DAT, indicating that Pn was reduced mainly due to stomatal limitation; at 55 DAT, reduced Pn in the no-K treatment was caused by non-stomatal factors. Compared with the no-K treatment, the content of sucrose, amylose and amylopectin decreased by 9-34%, 9-23% and 6-19%, respectively, but starch accumulation increased by 11-21% under K supply. The activities of sucrose synthetase (SuSy), adenosine-diphosphate-glucose pyrophosphorylase (AGPase), starch synthase (SSS) and the transcription of Susy, AGP, SSS34 and SSS67 were enhanced by K application and had positive relationships with starch accumulation. Therefore, K application promoted starch accumulation and storage root yield through regulating the activities and genes transcription of SuSy, AGPase and SSS in the sucrose-to-starch conversion.


Assuntos
Glucose-1-Fosfato Adenililtransferase/genética , Glucosiltransferases/genética , Raízes de Plantas/crescimento & desenvolvimento , Potássio/farmacologia , Amilopectina/genética , Amilose/genética , Fertilização/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ipomoea batatas/crescimento & desenvolvimento , Ipomoea batatas/metabolismo , Fotossíntese/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Amido/metabolismo , Sacarose/metabolismo
17.
Appl Microbiol Biotechnol ; 105(12): 4899-4918, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34097119

RESUMO

The second-generation (2G) fermentation environment for lignocellulose conversion presents unique challenges to the fermentative organism that do not necessarily exist in other industrial fermentations. While extreme osmotic, heat, and nutrient starvation stresses are observed in sugar- and starch-based fermentation environments, additional pre-treatment-derived inhibitor stress, potentially exacerbated by stresses such as pH and product tolerance, exist in the 2G environment. Furthermore, in a consolidated bioprocessing (CBP) context, the organism is also challenged to secrete enzymes that may themselves lead to unfolded protein response and other stresses. This review will discuss responses of the yeast Saccharomyces cerevisiae to 2G-specific stresses and stress modulation strategies that can be followed to improve yeasts for this application. We also explore published -omics data and discuss relevant rational engineering, reverse engineering, and adaptation strategies, with the view of identifying genes or alleles that will make positive contributions to the overall robustness of 2G industrial strains. KEYPOINTS: • Stress tolerance is a key driver to successful application of yeast strains in biorefineries. • A wealth of data regarding stress responses has been gained through omics studies. • Integration of this knowledge could inform engineering of fit for purpose strains.


Assuntos
Lignina , Saccharomyces cerevisiae , Fermentação , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Amido/metabolismo , Leveduras/metabolismo
18.
Int J Mol Sci ; 22(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073516

RESUMO

Transitory starch granules result from complex carbon turnover and display specific situations during starch synthesis and degradation. The fundamental mechanisms that specify starch granule characteristics, such as granule size, morphology, and the number per chloroplast, are largely unknown. However, transitory starch is found in the various cells of the leaves of Arabidopsis thaliana, but comparative analyses are lacking. Here, we adopted a fast method of laser confocal scanning microscopy to analyze the starch granules in a series of Arabidopsis mutants with altered starch metabolism. This allowed us to separately analyze the starch particles in the mesophyll and in guard cells. In all mutants, the guard cells were always found to contain more but smaller plastidial starch granules than mesophyll cells. The morphological properties of the starch granules, however, were indiscernible or identical in both types of leaf cells.


Assuntos
Arabidopsis/metabolismo , Metabolismo dos Carboidratos , Células do Mesofilo/metabolismo , Folhas de Planta/metabolismo , Amido/metabolismo , Arabidopsis/ultraestrutura , Células do Mesofilo/ultraestrutura , Folhas de Planta/ultraestrutura
19.
J Dairy Sci ; 104(8): 8857-8869, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33985782

RESUMO

The objective of this work was to characterize rumen volatile fatty acid (VFA) concentrations, rumen epithelial gene expression, and blood metabolite responses to diets with different starch and fiber sources. Six ruminally cannulated yearling Holstein heifers (body weight = 330 ± 11.3 kg) were arranged in a partially replicated Latin square experiment with 4 treatments consisting of different starch [barley (BAR) or corn (CRN)] and fiber [timothy hay (TH) or beet pulp (BP)] sources. Treatments were arranged as a 2 × 2 factorial. Beet pulp and TH were used to create relative changes in apparent ruminal fiber disappearance, whereas CRN and BAR were used to create relative changes in apparent ruminal starch disappearance. Each period consisted of 3 d of diet adaptation and 15 d of dietary treatment. In situ disappearance of fiber and starch were estimated from bags incubated in the rumen from d 10 to 14. From d 15 to 17, rumen fluid was collected every hour from 0500 to 2300 h. Rumen fluid samples were pooled by animal/period and analyzed for pH and VFA concentrations. On d 18, 60 to 80 papillae were biopsied from the epithelium and preserved for gene expression analysis. On d 18, one blood sample per heifer was collected from the coccygeal vessel. In situ ruminal starch disappearance rate (7.30 to 8.72%/h for BAR vs. 7.61 to 10.5%/h for CRN) and the extent of fiber disappearance (22.2 to 33.4% of DM for TH vs. 34.4 to 38.7% of DM for BP) were affected by starch and fiber source, respectively. Analysis of VFA molar proportions showed a shift from propionate to acetate, and valerate to isovalerate on TH diets compared with BP. Corn diets favored propionate over butyrate in comparison to BAR diets. Corn diets also had higher molar proportions of valerate. Expression of 1 gene (SLC9A3) were increased in BP diets and 2 genes (BDH1 and SLC16A4) tended to be increased in TH diets. Plasma acetate demonstrated a tendency for a starch by fiber interaction with BAR-BP diets having the highest plasma acetate, but other metabolites measured were not significant. These results suggest that TH has the greatest effect on shifts in VFA molar proportions and epithelial transporters, but does not demonstrate shifts in blood metabolite concentrations.


Assuntos
Rúmen , Amido , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Digestão , Ácidos Graxos Voláteis/metabolismo , Feminino , Fermentação , Expressão Gênica , Concentração de Íons de Hidrogênio , Dente Molar/metabolismo , Rúmen/metabolismo , Amido/metabolismo , Zea mays/metabolismo
20.
Plant Cell ; 33(3): 603-622, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33955492

RESUMO

In wheat (Triticum aestivum L.), breeding efforts have focused intensively on improving grain yield and quality. For quality, the content and composition of seed storage proteins (SSPs) determine the elasticity of wheat dough and flour processing quality. Moreover, starch levels in seeds are associated with yield. However, little is known about the mechanisms that coordinate SSP and starch accumulation in wheat. In this study, we explored the role of the endosperm-specific NAC transcription factor TaNAC019 in coordinating SSP and starch accumulation. TaNAC019 binds to the promoters of TaGlu-1 loci, encoding high molecular weight glutenin (HMW-GS), and of starch metabolism genes. Triple knock-out mutants of all three TaNAC019 homoeologs exhibited reduced transcript levels for all SSP types and genes involved in starch metabolism, leading to lower gluten and starch contents, and in flour processing quality parameters. TaNAC019 directly activated the expression of HMW-GS genes by binding to a specific motif in their promoters and interacting with the TaGlu-1 regulator TaGAMyb. TaNAC019 also indirectly regulated the expression of TaSPA, an ortholog of maize Opaque2 that activates SSP accumulation. Therefore, TaNAC019 regulation of starch- and SSP-related genes has key roles in wheat grain quality. Finally, we identified an elite allele (TaNAC019-BI) associated with flour processing quality, providing a candidate gene for breeding wheat with improved quality.


Assuntos
Endosperma/metabolismo , Proteínas de Plantas/metabolismo , Amido/metabolismo , Fatores de Transcrição/metabolismo , Alelos , Endosperma/genética , Glutens/genética , Glutens/metabolismo , Proteínas de Plantas/genética , Amido/genética , Fatores de Transcrição/genética , Triticum/genética , Triticum/metabolismo
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