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BMC Plant Biol ; 21(1): 376, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399701


BACKGROUND: Glycolytic pathway is common in all plant organs, especially in oxygen-deficient tissues. Phosphofructokinase (PFK) is a rate-limiting enzyme in the glycolytic pathway and catalyses the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate. Cassava (M. esculenta) root is a huge storage organ with low amount of oxygen. However, less is known about the functions of PFK from M. esculenta (MePFK). We conducted a systematic analysis of MePFK genes to explore the function of the MePFK gene family under hypoxic stress. RESULTS: We identified 13 MePFK genes and characterised their sequence structure. The phylogenetic tree divided the 13 genes into two groups: nine were MePFKs and four were pyrophosphate-fructose-6-phosphate phosphotransferase (MePFPs). We confirmed by green fluorescent protein fusion protein expression that MePFK03 and MePFPA1 were localised in the chloroplast and cytoplasm, respectively. The expression profiles of the 13 MePFKs detected by quantitative reverse transcription polymerase chain reaction revealed that MePFK02, MePFK03, MePFPA1, MePFPB1 displayed higher expression in leaves, root and flower. The expression of MePFK03, MePFPA1 and MePFPB1 in tuber root increased gradually with plant growth. We confirmed that hypoxia occurred in the cassava root, and the concentration of oxygen was sharply decreasing from the outside to the inside root. The expression of MePFK03, MePFPA1 and MePFPB1 decreased with the decrease in the oxygen concentration in cassava root. Waterlogging stress treatment showed that the transcript level of PPi-dependent MePFP and MeSuSy were up-regulated remarkably and PPi-dependent glycolysis bypass was promoted. CONCLUSION: A systematic survey of phylogenetic relation, molecular characterisation, chromosomal and subcellular localisation and cis-element prediction of MePFKs were performed in cassava. The expression profiles of MePFKs in different development stages, organs and under waterlogging stress showed that MePFPA1 plays an important role during the growth and development of cassava. Combined with the transcriptional level of MeSuSy, we found that pyrophosphate (PPi)-dependent glycolysis bypass was promoted when cassava was under waterlogging stress. The results would provide insights for further studying the function of MePFKs under hypoxic stress.

Genoma de Planta , Manihot/enzimologia , Manihot/genética , Fosfofrutoquinases/genética , Fosfofrutoquinases/metabolismo , Cloroplastos/enzimologia , Mapeamento Cromossômico , Cromossomos de Plantas , Sequência Conservada , Citoplasma/enzimologia , Éxons , Flores/enzimologia , Íntrons , Família Multigênica , Oxigênio/metabolismo , Filogenia , Folhas de Planta/enzimologia , Raízes de Plantas/enzimologia , Regiões Promotoras Genéticas , Estresse Fisiológico/genética , Transcriptoma
PLoS One ; 12(5): e0177456, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28493955


Cassava is the third largest food crop of the world and has strong ability of drought tolerance. In order to evaluate the molecular diversity and to discover novel alleles for drought tolerance in cassava germplasms, we examined a total of 107 abiotic stress related expressed sequence tags-simple sequence repeat (EST-SSR) markers in 134 cassava genotypes coming from planting regions worldwide and performed drought related marker-traits association mapping. As results, we successfully amplified 98 of 107 markers in 97 polymorphic loci and 279 alleles, with 2.87 alleles per locus, gene diversity of 0.48 and polymorphic information content (PIC) of 0.41 on average. The genetic coefficient between every two lines was 0.37 on average, ranging from 0.21 to 0.82. According to our population structure analysis, these samples could be divided into three sub-populations showing obvious gene flow between them. We also performed water stress experiments using 100-day old cassava plants in two years and calculated the drought tolerance coefficients (DTCs) and used them as phenotypes for marker-trait association mapping. We found that 53 markers were significantly associated with these drought-related traits, with a contribution rate for trait variation of 8.60% on average, ranging between 2.66 and 28.09%. Twenty-four of these 53 associated genes showed differential transcription or protein levels which were confirmed by qRT-PCR under drought stress when compared to the control conditions in cassava. Twelve of twenty-four genes were the same differential expression patterns in omics data and results of qRT-PCR. Out of 33 marker-traits combinations on 24 loci, 34 were positive and 53 negative alleles according to their phenotypic effects and we also obtained the typical materials which carried these elite alleles. We also found 23 positive average allele effects while 10 loci were negative according to their allele effects (AAEs). Our results on molecular diversity, locus association and differential expression under drought can prove beneficial to select excellent materials through marker assisted selection and for functional genes research in the future.

Secas , Etiquetas de Sequências Expressas , Repetições de Microssatélites/genética , Alelos , Biomarcadores , Mapeamento Cromossômico , Variação Genética/genética , Genótipo , Manihot/química , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética
Sci Rep ; 7: 45981, 2017 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-28387315


Cold and drought stresses seriously affect cassava (Manihot esculenta) plant growth and yield. Recently, long noncoding RNAs (lncRNAs) have emerged as key regulators of diverse cellular processes in mammals and plants. To date, no systematic screening of lncRNAs under abiotic stress and their regulatory roles in cassava has been reported. In this study, we present the first reference catalog of 682 high-confidence lncRNAs based on analysis of strand-specific RNA-seq data from cassava shoot apices and young leaves under cold, drought stress and control conditions. Among them, 16 lncRNAs were identified as putative target mimics of cassava known miRNAs. Additionally, by comparing with small RNA-seq data, we found 42 lncNATs and sense gene pairs can generate nat-siRNAs. We identified 318 lncRNAs responsive to cold and/or drought stress, which were typically co-expressed concordantly or discordantly with their neighboring genes. Trans-regulatory network analysis suggested that many lncRNAs were associated with hormone signal transduction, secondary metabolites biosynthesis, and sucrose metabolism pathway. The study provides an opportunity for future computational and experimental studies to uncover the functions of lncRNAs in cassava.

Temperatura Baixa , Secas , Genoma de Planta , Manihot/genética , Manihot/fisiologia , RNA Longo não Codificante/genética , Sequência de Bases , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , MicroRNAs/metabolismo , Fases de Leitura Aberta/genética , RNA Longo não Codificante/metabolismo , RNA Interferente Pequeno/metabolismo , Reprodutibilidade dos Testes , Plântula/genética , Estresse Fisiológico/genética , Transcriptoma/genética
J Exp Bot ; 66(5): 1477-88, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25547914


Cassava is one of the most drought-tolerant crops, however, the underlying mechanism for its ability to survive and produce under drought remains obscure. In this study, two cassava cultivars, SC124 and Arg7, were treated by gradually reducing the soil water content. Their responses to the drought stress were examined through their morphological and physiological traits and isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis. SC124 plants adapted a 'survival' mode under mild drought stress as evidenced by early stomatal closure and a reduction in the levels of various photosynthetic proteins and photosynthetic capacity, resulting in early growth quiescence. In contrast, Arg7 plants underwent senescence of older leaves but continued to grow, although at a reduced rate, under mild drought. SC124 plants were more capable of surviving prolonged severe drought than Arg7. The iTRAQ analysis identified over 5000 cassava proteins. Among the drought-responsive proteins identified in the study were an aquaporin, myo-inositol 1-phosphate synthases, and a number of proteins involved in the antioxidant systems and secondary metabolism. Many proteins that might play a role in signalling or gene regulation were also identified as drought-responsive proteins, which included several protein kinases, two 14-3-3 proteins, several RNA-binding proteins and transcription factors, and two histone deacetylases. Our study also supports the notion that linamarin might play a role in nitrogen reallocation in cassava under drought.

Manihot/crescimento & desenvolvimento , Manihot/fisiologia , Secas , Regulação da Expressão Gênica de Plantas , Manihot/classificação , Manihot/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteômica , Estresse Fisiológico , Água/metabolismo
J Agric Food Chem ; 62(19): 4475-9, 2014 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-24754373


RNA silencing or RNA interference (RNAi), which is triggered by double-stranded RNA (dsRNA), is an evolutionarily conserved process that is active in a wide variety of eukaryotic organisms. Engineering plants with hairpin construct in which the viral gene is arranged in inverted repeats (IR) renders plants resistant to plant virus infection. However, there is no report on whether biologically important changes occurred by the insertion of IR, which confer transgenic plants virus resistance. In the present study, the compositions of virus-resistant transgenic soybean seeds developed by insertion of three short IRs, each containing the specific, highly conserved sequences derived from one virus, were compared with those of nontransgenic counterparts by applying the principle of substantial equivalence to determine whether significant undesirable biological changes occurred by IR insertion. The results revealed that the nutrient components as well as antinutrient contents of these virus-resistant soybean lines are substantially equivalent to those of the nontransgenic counterparts, and the majority of the measured amounts of nutritional components and antinutrient contents are well within the range of values reported for other commercial soybean lines. The results imply that no biologically important changes occurred by the insertion of IRs in the RNAi-mediated virus-resistant transgenic soybeans. The results can serve as baseline information for developing RNAi-mediated transgenic soybean cultivars or other crops with broader spectrum virus resistance.

Doenças das Plantas/virologia , Extratos Vegetais/análise , Plantas Geneticamente Modificadas/química , Interferência de RNA , Soja/química , Soja/genética , Aminoácidos/análise , Ácidos Graxos/análise , Sequências Repetidas Invertidas , Doenças das Plantas/imunologia , Vírus de Plantas/química , Vírus de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/virologia , RNA de Cadeia Dupla/química , RNA de Cadeia Dupla/genética , RNA Viral/química , RNA Viral/genética , Soja/imunologia , Soja/virologia
Appl Biochem Biotechnol ; 160(4): 988-1003, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19277485


Raw starch degrading enzymes (RSDE) refer to enzymes that can directly degrade raw starch granules below the gelatinization temperature of starch. These promising enzymes can significantly reduce energy and simplify the process in starch industry. RSDE are ubiquitous and produced by plants, animals, and microorganisms. However, microbial sources are the most preferred one for large-scale production. During the past few decades, RSDE have been studied extensively. This paper reviews the recent development in the production, purification, properties, and application of microbial RSDE. This is the first review on microbial RSDE to date.

Bactérias/enzimologia , Fungos/enzimologia , Amido/metabolismo , Adsorção , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Meios de Cultura , Estabilidade Enzimática , Glucana 1,4-alfa-Glucosidase/biossíntese , Glucana 1,4-alfa-Glucosidase/isolamento & purificação , Glucosiltransferases/biossíntese , Glucosiltransferases/isolamento & purificação , Glicosídeo Hidrolases/biossíntese , Glicosídeo Hidrolases/isolamento & purificação , Concentração de Íons de Hidrogênio , Microbiologia Industrial , Temperatura , alfa-Amilases/biossíntese , alfa-Amilases/isolamento & purificação , beta-Amilase/biossíntese , beta-Amilase/isolamento & purificação