scholarly journals Improvement of enzymatic saccharification in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

2015 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julian Mario Peña-Castro
Keyword(s):  
Transcription Factor ◽  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Biofuel Production ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Photosynthetic Parameters ◽  
Wild Type ◽  
Submergence Stress ◽  
Saccharification Yield

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This high saccharification yield was developmentally controlled since juvenile transgenic plants yielded 200-300% more glucose than Col-0. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

scholarly journals Improvement of enzymatic saccharification in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

2015 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julian Mario Peña-Castro
Keyword(s):  
Transcription Factor ◽  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Biofuel Production ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Photosynthetic Parameters ◽  
Wild Type ◽  
Submergence Stress ◽  
Saccharification Yield

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This high saccharification yield was developmentally controlled since juvenile transgenic plants yielded 200-300% more glucose than Col-0. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

scholarly journals Human gastrin-releasing peptide receptor gene regulation requires transcription factor binding at two distinct CRE sites

2008 ◽  
Vol 295 (1) ◽  
pp. G153-G162 ◽  
Author(s):  
Dharmaraj Chinnappan ◽  
Xiangping Qu ◽  
Dongmei Xiao ◽  
Anita Ratnasari ◽  
H. Christian Weber
Keyword(s):  
Transcription Factor ◽  
Cancer Cells ◽  
Transcriptional Activation ◽  
Gastrointestinal Cancer ◽  
Molecular Mechanisms ◽  
Receptor Gene ◽  
Ectopic Expression ◽  
Migration And Invasion ◽  
Wild Type ◽  
Gastrin Releasing Peptide

Ectopic expression of the gastrin-releasing peptide (GRP) receptor (GRP-R) occurs frequently in human malignancies of the gastrointestinal tract. Owing to paracrine and autocrine interaction with its specific high-affinity ligand GRP, tumor cell proliferation, migration, and invasion might ensue. Here we provide the first insights regarding molecular mechanisms of GRP-R regulation in gastrointestinal cancer cells. We identified by EMSA and chromatin immunoprecipitation assays two cAMP response element (CRE) binding sites that recruited transcription factor CRE binding protein (CREB) to the human GRP-R promoter. Transfection studies with a wild-type human GRP-R promoter reporter and corresponding CRE mutants showed that both CRE sites are critical for basal transcriptional activation in gastrointestinal cancer cells. Forced expression of cAMP-dependent effectors CREB and PKA resulted in robust upregulation of human GRP-R transcriptional activity, and this overexpression strictly required intact wild-type CRE sites. Direct cAMP stimulation with forskolin resulted in enhanced human GRP-R promoter activity only in HuTu-80 cells, but not in Caco-2 cells, coinciding with forskolin-induced CREB phosphorylation occurring only in HuTu-80 but not Caco-2 cells. In summary, CREB is a critical regulator of human GRP-R expression in gastrointestinal cancer and might be activated through different upstream intracellular pathways.

scholarly journals The Evolutionary Duplication and Probable Demise of an Endodermal GATA Factor in Caenorhabditis elegans

Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 575-588 ◽  
Author(s):  
Tetsunari Fukushige ◽  
Barbara Goszczynski ◽  
Helen Tian ◽  
James D McGhee
Keyword(s):  
Transcription Factor ◽  
Caenorhabditis Elegans ◽  
Zinc Finger ◽  
Specific Binding ◽  
Ectopic Expression ◽  
Intestinal Development ◽  
Wild Type ◽  
C Elegans ◽  
Dna Binding Domains ◽  
Binding Domains

Abstract We describe the elt-4 gene from the nematode Caenorhabditis elegans. elt-4 is predicted to encode a very small (72 residues, 8.1 kD) GATA-type zinc finger transcription factor. The elt-4 gene is located ∼5 kb upstream of the C. elegans elt-2 gene, which also encodes a GATA-type transcription factor; the zinc finger DNA-binding domains are highly conserved (24/25 residues) between the two proteins. The elt-2 gene is expressed only in the intestine and is essential for normal intestinal development. This article explores whether elt-4 also has a role in intestinal development. Reporter fusions to the elt-4 promoter or reporter insertions into the elt-4 coding regions show that elt-4 is indeed expressed in the intestine, beginning at the 1.5-fold stage of embryogenesis and continuing into adulthood. elt-4 reporter fusions are also expressed in nine cells of the posterior pharynx. Ectopic expression of elt-4 cDNA within the embryo does not cause detectable ectopic expression of biochemical markers of gut differentiation; furthermore, ectopic elt-4 expression neither inhibits nor enhances the ectopic marker expression caused by ectopic elt-2 expression. A deletion allele of elt-4 was isolated but no obvious phenotype could be detected, either in the gut or elsewhere; brood sizes, hatching efficiencies, and growth rates were indistinguishable from wild type. We found no evidence that elt-4 provided backup functions for elt-2. We used microarray analysis to search for genes that might be differentially expressed between L1 larvae of the elt-4 deletion strain and wild-type worms. Paired hybridizations were repeated seven times, allowing us to conclude, with some confidence, that no candidate target transcript could be identified as significantly up- or downregulated by loss of elt-4 function. In vitro binding experiments could not detect specific binding of ELT-4 protein to candidate binding sites (double-stranded oligonucleotides containing single or multiple WGATAR sequences); ELT-4 protein neither enhanced nor inhibited the strong sequence-specific binding of the ELT-2 protein. Whereas ELT-2 protein is a strong transcriptional activator in yeast, ELT-4 protein has no such activity under similar conditions, nor does it influence the transcriptional activity of coexpressed ELT-2 protein. Although an elt-2 homolog was easily identified in the genomic sequence of the related nematode C. briggsae, no elt-4 homolog could be identified. Analysis of the changes in silent third codon positions within the DNA-binding domains indicates that elt-4 arose as a duplication of elt-2, some 25–55 MYA. Thus, elt-4 has survived far longer than the average duplicated gene in C. elegans, even though no obvious biological function could be detected. elt-4 provides an interesting example of a tandemly duplicated gene that may originally have been the same size as elt-2 but has gradually been whittled down to its present size of little more than a zinc finger. Although elt-4 must confer (or must have conferred) some selective advantage to C. elegans, we suggest that its ultimate evolutionary fate will be disappearance from the C. elegans genome.

Requirement for the Drosophila COE transcription factor Collier in formation of an embryonic muscle: transcriptional response to notch signalling

Development ◽  
1999 ◽  
Vol 126 (7) ◽  
pp. 1495-1504 ◽  
Author(s):  
M. Crozatier ◽  
A. Vincent
Keyword(s):  
Transcription Factor ◽  
Progenitor Cell ◽  
Ectopic Expression ◽  
Transcriptional Response ◽  
Notch Signalling ◽  
Specific Gene ◽  
Wild Type ◽  
Specific Restriction ◽  
Founder Cells

During Drosophila embryogenesis, mesodermal cells are recruited to form a stereotyped pattern of about 30 different larval muscles per hemisegment. The formation of this pattern is initiated by the specification of a special class of myoblasts, called founder cells, that are uniquely able to fuse with neighbouring myoblasts. We report here the role of the COE transcription factor Collier in the formation of a single muscle, muscle DA3([A])(DA4([T])). Col expression is first observed in two promuscular clusters (in segments A1-A7), the two corresponding progenitors and their progeny founder cells, but its transcription is maintained in only one of these four founder cells, the founder of muscle DA3([A]). This lineage-specific restriction depends on the asymmetric segregation of Numb during the progenitor cell division and involves the repression of col transcription by Notch signalling. In col mutant embryos, the DA3([A]) founder cells form but do not maintain col transcription and are unable to fuse with neighbouring myoblasts, leading to a loss-of-muscle DA3([A]) phenotype. In wild-type embryos, each of the DA3([A])-recruited myoblasts turns on col transcription, indicating that the conversion, by the DA3([A]) founder cell, of ‘naive’ myoblasts to express its distinctive pattern of gene expression involves activation of col itself. We find that muscles DA3([A]) and DO5([A]) (DA4([T]) and DO5([T])) derive from a common progenitor cell. Ectopic expression of Col is not sufficient, however, to switch the DO5([A]) to a DA3([A]) fate. Together these results lead us to propose that specification of the DA3([A]) muscle lineage requires both Col and at least one other transcription factor, supporting the hypothesis of a combinatorial code of muscle-specific gene regulation controlling the formation and diversification of individual somatic muscles.

ELONGATED HYPOCOTYL 5 mediates blue light-induced starch degradation in tomato

2020 ◽  
Author(s):  
Han Dong ◽  
Chaoyi Hu ◽  
Chaochao Liu ◽  
Jiachun Wang ◽  
Yanhong Zhou ◽  
...  
Keyword(s):  
Blue Light ◽  
Soluble Sugars ◽  
Light Signal ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Sugar Accumulation ◽  
Wild Type ◽  
Mobility Shift ◽  
Storage Carbohydrate ◽  
In The Wild

Abstract Starch is the major storage carbohydrate in plants, and its metabolism in chloroplasts depends mainly on light. However, the mechanism through which photoreceptors regulate starch metabolism in chloroplasts is unclear. In this study, we found that the cryptochrome 1a (CRY1a)-mediated blue light signal is critical for regulating starch accumulation by inducing starch degradation through the HY5 transcription factor in the chloroplasts in tomato. cry1a mutants and HY5-RNAi plants accumulated more starch and presented lower transcript levels of starch degradation-related genes in their leaves than did the wild-type (WT) plants. Blue light significantly induced the transcription of starch degradation-related genes in the wild-type and CRY1a- or HY5-overexpressing plants but had little effect in the cry1a and HY5-RNAi plants. Dual-luciferase assays, electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP)-qPCR revealed that HY5 could activate the starch degradation-related genes PWD, BAM1, BAM3, BAM8, MEX1 and DPE1 by directly binding to their promoters. Silencing of HY5 and these starch degradation-related genes in CRY1a-overexpressing plants led to increased accumulation of starch and decreased accumulation of soluble sugars. These findings presented here not only deepen our understanding of how light control starch degradation and sugar accumulation but also allow us to explore potential targets for improving crop quality.

scholarly journals Optimization of Enzymatic Saccharification of Alkali Pretreated Parthenium sp. Using Response Surface Methodology

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
K. Pandiyan ◽  
Rameshwar Tiwari ◽  
Surender Singh ◽  
Pawan K. S. Nain ◽  
Sarika Rana ◽  
...  
Keyword(s):  
Enzymatic Saccharification ◽  
Sugar Yield ◽  
Biofuel Production ◽  
Optimum Conditions ◽  
Alkali Pretreatment ◽  
Yield Data ◽  
Saccharification Yield ◽  
Noxious Weed ◽  
Central Composite ◽  
Good Agreement

Parthenium sp. is a noxious weed which threatens the environment and biodiversity due to its rapid invasion. This lignocellulosic weed was investigated for its potential in biofuel production by subjecting it to mild alkali pretreatment followed by enzymatic saccharification which resulted in significant amount of fermentable sugar yield (76.6%). Optimization of enzymatic hydrolysis variables such as temperature, pH, enzyme, and substrate loading was carried out using central composite design (CCD) in response to surface methodology (RSM) to achieve the maximum saccharification yield. Data obtained from RSM was validated using ANOVA. After the optimization process, a model was proposed with predicted value of 80.08% saccharification yield under optimum conditions which was confirmed by the experimental value of 85.80%. This illustrated a good agreement between predicted and experimental response (saccharification yield). The saccharification yield was enhanced by enzyme loading and reduced by temperature and substrate loading. This study reveals that under optimized condition, sugar yield was significantly increased which was higher than earlier reports and promises the use of Parthenium sp. biomass as a feedstock for bioethanol production.

scholarly journals Improvement of enzymatic saccharification yield inArabidopsis thalianaby ectopic expression of the riceSUB1A-1transcription factor

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e817 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julián Mario Peña-Castro
Keyword(s):  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Saccharification Yield
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