Infection of maize inbred B73 by Ustilago maydis and Fusarium proliferatum triggers differential expression of the β-glucosidase genes (original) (raw)
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Genome-wide analysis of the beta-glucosidase gene family in maize ( Zea mays L. var B73
Plant Molecular Biology
The hydrolysis of beta-d-glucosidic bonds which is required for the liberation of many physiologically important compounds is catalyzed by the enzyme beta-glucosidase (BGLU, EC 3.2.1.21). BGLUs are implicated in several processes in plants, such as the timely response to biotic and abiotic stresses through activation of phytohormones and defense compounds. We identified 26 BGLU isozymes in the genome of the maize inbred B73 and propose a standardized nomenclature for all Zea mays BGLU paralogs (Zmbglu1-Zmbglu26). We characterized their intron–exon structure, protein features, phylogenetic relationships, and measured their expression and activity in various tissues under different environmental conditions. Sequence alignments revealed some characteristic motifs (conserved amino acids) and specific differences among different isozymes. Analysis of putative signal peptides suggested that some BGLUs are plastidic, whereas others are mitochondrial, cytosolic, vacuolar or secreted. Microarray and RT–PCR analysis showed that each member of the Zmbglu family had a characteristic expression pattern with regard to tissue specificity and response to different abiotic conditions. The source of variance for gene expression was highest for the type of organ analyzed (tissue variance) than for the growth conditions (environmental variance) or genotype (genetic variance). Analysis of promoter sequences revealed that each Zmbglu paralog possesses a distinct set of cis elements and transcription factor binding sites. Since there are no two Zmbglu paralogs that have identical molecular properties, we conclude that gene subfunctionalization in maize occurs much more rapidly than gene duplication.
Environmental and Experimental Botany, 2012
Fusarium ear rot is one of the most important diseases of maize, that is of concern because Fusarium verticillioides produces the mycotoxins known as fumonisins. F. verticillioides can be transmitted either through infected silks or seed-to-kernel. In order to better understand the virulence of F. verticillioides, the effect of the fungus on the defense systems was investigated both in immature kernels and in seedlings. The molecular mechanisms involved in compatible and incompatible responses were also studied. Gene expression data were obtained from microarray hybridizations, comparing healthy and infected kernels of resistant and susceptible maize inbreds 48 h after infection with a fumonisin-producing strain of F. verticillioides. A total of 739 transcripts were differentially expressed between the two inbred lines at one time point after infection. Among all the differentially regulated genes, 7.3% of encoded proteins play a role in cell rescue and defense. The qRT-PCR analysis confirmed that most of the defense genes had already been transcribed before infection occurred in the maize-resistant line. The study was extended to the analysis of enzymes involved in removing reactive oxygen species, namely ascorbate peroxidase, catalase, total peroxidase and superoxide dismutase. In resistant seedlings, before infection, ascorbate peroxidase and superoxide dismutase enzyme activities were higher than in the susceptible ones and, 5 days after treatment, they remained unchanged. On the other hand, in the susceptible seedlings, except for superoxide dismutase, all enzymes assayed were activated after pathogen attack. These results support our previous findings of a basal defense response provided by maize genotypes resistant against F. verticillioides infection, both in kernels and seedlings.
Biochemical Journal, 2007
GH5BG, the cDNA for a stress-induced GH5 (glycosyl hydrolase family 5) β-glucosidase, was cloned from rice (Oryza sativa L.) seedlings. The GH5BG cDNA encodes a 510-amino-acid precursor protein that comprises 19 amino acids of prepeptide and 491 amino acids of mature protein. The protein was predicted to be extracellular. The mature protein is a member of a plant-specific subgroup of the GH5 exoglucanase subfamily that contains two major domains, a β-1,3-exoglucanase-like domain and a fascin-like domain that is not commonly found in plant enzymes. The GH5BG mRNA is highly expressed in the shoot during germination and in leaf sheaths of mature plants. The GH5BG was up-regulated in response to salt stress, submergence stress, methyl jasmonate and abscisic acid in rice seedlings. A GUS (glucuronidase) reporter tagged at the C-terminus of GH5BG was found to be secreted to the apoplast when expressed in onion (Allium cepa) cells. A thioredoxin fusion protein produced from the GH5BG cDNA ...
Revista de la Facultad de Agronomía, Universidad del Zulia
The glyoxalase system plays an important role in various physiological processes in plants when they are subjected to different types of stress, whether physical, chemical or biological. Aspergillus flavus is an aflatoxin-producing fungus that contaminates dry grains, leading to a gradual deterioration of the grains and a significant reduction in their nutritional value. The objective of the present study was to evaluate the activity of the enzyme glyoxalase I (GLX-I) in maize coleoptiles from Oaxaca in response to infection caused by Aspergillus flavus. Nine maize samples from four different races were analyzed. The samples were inoculated with a suspension of Aspergillus flavus spores of known concentration and total protein extraction and quantification were performed on the coleoptiles, and GLX-I activity was determined by quantifying the amount of S-lactoylglutathione produced per minute. In addition, analysis of gene expression by reverse transcriptase polymerase chain reactio...
2000
Maize (Zea mays L.) β-glucosidase was extracted from shoots of a wild-type (K55) and a “null” (H95) maize genotype. Enzyme activity assays and electrophoretic data showed that extracts from the null genotype had about 10% of the activity present in the normal genotype. Zymograms of the null genotype were devoid of any activity bands in the resolving gel, but had a smeared zone of activity in the stacking gel after native polyacrylamide gel electrophoresis. When extracts were made with buffers containing 0.5% to 2% sodium dodecyl sulfate, the smeared activity zone entered the resolving gel as a distinct band. These data indicated that the null genotypes have β-glucosidase activity, but the enzyme occurs as insoluble or poorly soluble large quaternary complexes mediated by a β-glucosidase-aggregating factor (BGAF). BGAF is a 35-kD protein and binds specifically to β-glucosidase and renders it insoluble during extraction. BGAF also precipitates β-glucosidase that is added exogenously t...
Induction of β-1,3-Glucanase in Seeds of Maize Defective-Kernel Mutant (827Kpro1)
Protein & Peptide Letters, 2011
1,3-glucanases are found in organisms as diverse as plants, animals, bacteria and fungi. In plants, such enzymes are not only associated with defense mechanisms against pathogens, but also play critical roles in physiological and developmental processes. Here we identified a new-1,3-glucanase in maize seeds, and named it ZmGlucA. Sequence analysis revealed that ZmGlucA belongs to the class A of-1,3-glucanase, a class related to defense and physiological processes in plants. mRNA and protein assays showed that zmGlucA is expressed exclusively in seeds, and it is differentially regulated during seed development. Additionally, zmGlucA expression is strongly induced in seeds of the mutant dek 827Kpro1, which is defective for embryo and endosperm development. Our data support the idea that ZmGlucA protein is relevant to seed development.
Expression of β-1,3-glucanase in flax causes increased resistance to fungi
Physiological and Molecular Plant Pathology, 2004
Flax (Linum usitatissimum L.) is an annual plant cultivated in moderate climates. Although the genus Linum contains about 230 species, Linum usitatissimum is the only species which fulfills a commercial function, serving as a fiber donor for the textile industry and the production of linseed oil. The flax breeding is often limited due to the decrease in yield caused by fungi infection. The ectopic expression of a potato b-1,3-glucanase cDNA in flax has improved the plant's defence against pathogen. The resistance of transgenic lines against Fusarium oxysporum and Fusarium culmorum was about threefold higher than for the non-transformed plants. In an in vitro experiment the transgenic plant extract inhibited fungi growth and the inhibition was abolished by extract heating and anti-b-glucanase antibody treatment. By further investigation into the molecular basis of transgenic flax resistance, the metabolic profiling of the plant was performed. The significant decrease in the content of carbohydrate, fatty acids and organic acids and the increase in the level of selected amino acids, polyamines and antioxidant were revealed. What is interesting is that the transgenic plants showed a significant decrease in lignin content, which may lead to the improvement of flax fibre retting. q
Plant Journal, 2000
In order to elucidate more fully the function of a potato gene (MAL1) encoding a-glucosidase activity, transgenic plants in which MAL1 expression was down-regulated were generated using antisense technology. In transgenic lines severely down-regulated in the expression of MAL1, total a-glucosidase activity was not decreased in leaves and tubers, and the contents of starch, glucose, fructose and sucrose remained unchanged in tubers. Phylogenetic analysis indicated that the MAL1 gene product was more similar to the glycoprotein-processing a-glucosidase II of mammalian and yeast origin than to other plant a-glucosidases. Using [ 14 C-Glc]-labelled Glc 2 Man 9 GlcNAc 2 as a substrate , it was demonstrated that glucosidase II activity was markedly down-regulated in microsomes isolated from tubers of four independent antisense lines studied in detail, strongly suggesting that MAL1 encodes glucosidase II activity. In ®eld trials (but not in the glasshouse), MAL1 down-regulation produced an extremely stunted phenotype ± the leaves were curled and tuber yield was decreased by 90% compared to control values. Microscopic analysis of leaves revealed signi®cant differences between the antisense and control samples. Plants with down-regulated glucosidase II activity showed a greater degree of plasmolysis, and an increase in the size of mesophyll intracellular spaces. Analysis of cell walls also indicated changes in structure as a result of MAL1 down-regulation. In leaves from four antisense lines, the steady-state transcript level corresponding to the endoplasmic reticulum chaperone, BiP, was enhanced. This is diagnostic of stress in the endoplasmic reticulum.
2019
Indonesia is a tropical country with highest level of biodiversity, especially in the agricultural sector. Chili (Capsicum annumm. L) is a very well-known and widely used agricultural product in the world, which makes chili becomes one of the most considerable national product. The chili production is oftentimes very susceptible to some diseases caused by virus, fungi, or bacteria. One of the most common diseases in chili cultivation is Fusarium wilt, which is caused by Fusarium oxysporum. This disease can cause a major loss and up to 50% crop failure. Many procedures have been done to find the best cultivar with a resistance trait to Fusarium oxysporum, including by observing and testing the chili's genetic resistance. One of the resistance genes in chili is β-1, 3glucanase-encoding gene, which produces an enzyme to hydrolize the cell wall of pathogenic fungi. This research aimed to determine the expression of the glucanase-encoding gene (CaβGlu) in chili as a response to Fusarium oxysporum infection. The methods including chili cultivation, F. oxysporum inoculation, isolation of chili leaves RNA, glucanase-encoding gene expression analysis used qRT-PCR, and data analysis. The result of CaβGlu gene expression is higher than the control in the first 6 hours after inoculation, and decreasing in the 48th and 96th hours. The conclusion was the infection of Fusarium oxysporum is activating the expression of CaβGlu gene which was expressed best in the first 6 hours after inoculation.
Expression of b-1,3-glucanase in flax causes increased resistance to fungi
Flax (Linum usitatissimum L.) is an annual plant cultivated in moderate climates. Although the genus Linum contains about 230 species, Linum usitatissimum is the only species which fulfills a commercial function, serving as a fiber donor for the textile industry and the production of linseed oil. The flax breeding is often limited due to the decrease in yield caused by fungi infection. The ectopic expression of a potato b-1,3-glucanase cDNA in flax has improved the plant's defence against pathogen. The resistance of transgenic lines against Fusarium oxysporum and Fusarium culmorum was about threefold higher than for the non-transformed plants. In an in vitro experiment the transgenic plant extract inhibited fungi growth and the inhibition was abolished by extract heating and anti-b-glucanase antibody treatment. By further investigation into the molecular basis of transgenic flax resistance, the metabolic profiling of the plant was performed. The significant decrease in the content of carbohydrate, fatty acids and organic acids and the increase in the level of selected amino acids, polyamines and antioxidant were revealed. What is interesting is that the transgenic plants showed a significant decrease in lignin content, which may lead to the improvement of flax fibre retting.