Antisense RNA inhibition of pyruvate, orthophosphate dikinase and NADP malate dehydrogenase in the C4 plant Flaveria bidentis: analysis of plants with a mosaic phenotype

1999 ◽  
Vol 26 (6) ◽  
pp. 537 ◽  
Author(s):  
Anthony R. Ashton ◽  
Robert T. Furbank ◽  
Stephen J. Trevanion
Keyword(s):  
Transgenic Plants ◽  
Malate Dehydrogenase ◽  
Antisense Rna ◽  
Wild Type ◽  
Pyruvate Orthophosphate Dikinase ◽  
Orthophosphate Dikinase ◽  
Transgenic Lines ◽  
Rna Inhibition ◽  
Target Enzyme ◽  
Flaveria Bidentis

Antisense RNA suppression of either pyruvate, orthophosphate dikinase [EC 2.7.9.1] or NADP malate dehydrogenase [EC 1.1.1.82] gene expression in the C4 dicot Flaveria bidentis L. var. Kuntze produced several independent transgenic lines with leaves showing heritable, mosaic phenotypes. The appearance of these plants was highly variable, with leaves that were either predominantly green, predominantly yellow, or a mixture of the two. The yellow sectors appeared to be clonal in origin. For both sets of transgenic plants, the green and yellow sectors showed a reduction in the activity of the respective target enzyme compared to wild-type leaves. The mRNA of the target enzyme was reduced in both green and yellow sectors of leaves of both types of transformants compared to leaves from wild-type plants. The yellow sectors had decreased amounts of other photosynthetic enzymes on an area basis, but most enzyme activities and electron transport rates were similar to the green sectors on a chlorophyll basis. The mosaic phenotype could not be attributed simply to the degree of suppression of the target enzyme, because we have also obtained uniformly green plants with similar or greater enzyme suppression. The importance of this spatial variability in the effectiveness of the antisense transgenes for the analysis of transgenic plants in general is discussed.

Enhancing Biosynthesis of Flavonol Protective Biomaterials Using FLS Transgenic Plants

2017 ◽  
Vol 866 ◽  
pp. 29-32
Author(s):  
Darin Dangrit ◽  
Kanokporn Sompornpailin
Keyword(s):  
Tissue Culture ◽  
Transgenic Plants ◽  
Photosynthetic Pigment ◽  
Flavonoid Biosynthesis ◽  
Carotenoid Pigments ◽  
Chlorophyll B ◽  
Wild Type ◽  
Flavonoid Synthesis ◽  
Transgenic Lines ◽  
Tissue Culture Condition

Flavonol synthase (FLS) gene encodes an enzyme that is involved in conversion substrates into flavonols, quercetin and kaempferol. These substances are a subgroup of flavonoids which have an important role in both plant and human health. Many environmental factors such as temperature, pH and UV-A radiation have been studied and presented relationship with flavonoid synthesis. In this experiment, the combination of visible and UV-A lights was used as factors for elevating flavonoid biosynthesis of wild type (WT) plant and two lines of FLS transgenic plant under tissue culture condition. Both transgenic lines significantly enhanced the accumulation of quercetin and kaempferol substances nearly one fold higher than WT plant did. The photosynthetic pigment levels of chlorophyll A, chlorophyll B and carotenoid in transgenic lines are in the range 45.20-46.88, 16.34-17.04 and 13.63-13.46, while those of WT plants are 35.93, 13.18 and 10.55 (µg/g FW), respectively. Therefore, FLS transgenic plants containing high flavonol content showed a better in the protection photosynthetic pigments by less reductions of chlorophyll and carotenoid pigments.

Genetic Manipulation of Key Photosynthetic Enzymes in the C4 Plant Flaveria bidentis

1997 ◽  
Vol 24 (4) ◽  
pp. 477 ◽  
Author(s):  
Robert T. Furbank ◽  
Julie A. Chitty ◽  
Colin L.D. Jenkins ◽  
William C. Taylor ◽  
Stephen J. Trevanion ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Malate Dehydrogenase ◽  
Genetic Manipulation ◽  
Photosynthetic Performance ◽  
Covalent Modification ◽  
Wild Type ◽  
Bisphosphate Carboxylase ◽  
Photosynthetic Enzymes ◽  
Flaveria Bidentis

The NADP-malic enzyme type C4 dicot Flaveria bidentis (L.) Kuntze was transformed with antisense and cosense gene constructs that resulted in specific decreases in single photosynthetic enzymes. The enzymes targeted were ribulose-1,5-bisphosphate carboxylase/oxygenase [EC 4.1.1.39] (Rubisco), pyruvate, Pi dikinase [EC 2.7.9.1] (PPDK) and NADP malate dehydrogenase [EC 1.1.1.82] (NADP-MDH). These enzymes were chosen as targets because they have low activity compared to photosynthetic rates (Rubisco), are subject to complex covalent regulation (NADP-MDH), or both (PPDK). T1 progeny of a number of lines of these transformants were examined for the effects of these gene constructs on enzyme levels and photosynthetic performance. Rubisco antisense transformants expressing between 15 and 100% of wild-type enzyme activity were obtained. Pyruvate, Pi dikinase antisense lines were obtained with 40–100% wild-type levels. NADP malate dehydrogenase sense constructs caused a co-suppression of enzyme activity with some lines containing less than 2% of wild- type activity. Under saturating illumination, the control coefficients for these enzymes were determined to be up to 0.7 for Rubisco, 0.2–0.3 for PPDK and effectively zero for NADP-MDH. The implications of these observations for the regulation of photosynthetic flux and metabolism in C4 plants and the role of regulation by covalent modification are discussed.

scholarly journals Restoration of Wild-Type Virus by Double Recombination of Tombusvirus Mutants with a Host Transgene

1999 ◽  
Vol 12 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Marise Borja ◽  
Teresa Rubio ◽  
Herman B. Scholthof ◽  
Andrew O. Jackson
Keyword(s):  
Coat Protein ◽  
Transgenic Plants ◽  
Coat Protein Gene ◽  
Protein Gene ◽  
Wild Type Virus ◽  
Type Virus ◽  
Virus Infections ◽  
Wild Type ◽  
Transgenic Lines ◽  
Double Recombination

Nicotiana benthamiana plants transformed with the coat protein gene of tomato bushy stunt virus (TBSV) failed to elicit effective virus resistance when inoculated with wild-type virus. Subsequently, R1 and R2 progeny from 13 transgenic lines were inoculated with a TBSV mutant containing a defective coat protein gene. Mild symptoms typical of those elicited in nontransformed plants infected with the TBSV mutant initially appeared. However, within 2 to 4 weeks, up to 20% of the transgenic plants sporadically began to develop the lethal syndrome characteristic of wild-type virus infections. RNA hybridization and immunoblot analyses of these plants and nontransformed N. benthamiana inoculated with virus from the transgenic lines indicated that wild-type virus had been regenerated by a double recombination event between the defective virus and the coat protein transgene. Similar results were obtained with a TBSV deletion mutant containing a nucleotide sequence marker, and with a chimeric cucumber necrosis virus (CNV) containing the defective TBSV coat protein gene. In both cases, purified virions contained wild-type TBSV RNA or CNV chimeric RNA derived by recombination with the transgenic coat protein mRNA. These results thus demonstrate that recombinant tombusviruses can arise frequently from viral genes expressed in transgenic plants.

scholarly journals Antisense RNA Inhibition of uidA Gene Expression in Transgenic Plants: Evidence for Interaction Between First and Second Transformation Events

Hereditas ◽  
2004 ◽  
Vol 118 (3) ◽  
pp. 273-280 ◽  
Author(s):  
Haile S. Yibrah ◽  
David H. Clapham ◽  
Sara Von Arnold
Keyword(s):  
Gene Expression ◽  
Transgenic Plants ◽  
Antisense Rna ◽  
Uida Gene ◽  
Rna Inhibition

scholarly journals Ethylene-inducible Expression of ipt Gene Produces a Dramatic Increase in Fower Bud Count in Transgenic Plants

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 821B-821
Author(s):  
Richard J. McAvoy* ◽  
Mariya V. Khodakovskaya ◽  
Hong Liu ◽  
Yi Li
Keyword(s):  
Transgenic Plants ◽  
Vegetative State ◽  
Crop Improvement ◽  
Marked Change ◽  
Acc Oxidase ◽  
Wild Type ◽  
Flower Bud ◽  
Vegetative Development ◽  
Wide Range ◽  
Transgenic Lines

Cytokinins play an important role in regulating plant growth and development. The cytokinin gene, isopentenyl transferase (ipt), was placed under the control of the ACC oxidase promoter from the LEACO1 gene from Lycopersicon esculentum and introduced into Nicotiana tabacum (cv. Havana) and chrysanthemum (Dendranthema × grandiflorum `Iridon'). Transformants were confirmed by PCR reaction and Southern blot and analyzed for phenotypical changes under both greenhouse and growth chamber conditions. With both species, LEACO1-ipt transgenic plants displayed a wide range of vegetative and generative phenotypes. With plants growing in the vegetative state, some LEACO1-ipt transgenic lines appeared similar to the non-transgenic wild-type cultivars while other lines showed excessive lateral branch development and short internodes. With plants grown under generative conditions, several LEACO1-ipt transgenic lines showed a 2 to 10-fold increase in the number of flower buds relative to the wild-type cultivars. With chrysanthemum, dramatic increases in bud count were observed on transgenic lines that otherwise displayed a morphology similar to the non-transgenic lines. Analysis of ipt expression indicated a marked change in gene expression between the most extreme phenotypes observed in this study. LEACO1-ipt lines that express normal vegetative development but increased flower bud counts appear to have great potential for ornamental crop improvement.

Transgenic lines of Begonia maculata generated by ectopic expression of PttKN1

Biologia ◽  
2011 ◽  
Vol 66 (2) ◽  
Author(s):  
Quan-le Xu ◽  
Jiang-ling Dong ◽  
Nan Gao ◽  
Mei-yu Ruan ◽  
Hai-yan Jia ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Ectopic Expression ◽  
Class I ◽  
Wild Type Plant ◽  
Wild Type ◽  
Knox Gene ◽  
Knox Genes ◽  
Pttkn1 Gene ◽  
Transgenic Lines ◽  
First Time

AbstractKNOX (KNOTTED1-like homeobox) genes encode homeodomain-containing transcription factors which play crucial roles in meristem maintenance and proper patterning of organ initiation. PttKN1 gene, isolated from the vascular cambium of hybrid aspen (Populus tremula × P. tremuloides), is a member of class I KNOX gene family. In order to understand the roles of PttKN1 gene in meristem activity and morphogenesis as well as to explore the possibility to generate novel ornamental lines via its ectopic expression, it was introduced into the genome of Begonia maculata Raddi by Agrobacterium tumefasciens-mediated gene transformation here. Four types of transgenic plants were observed, namely coral-like (CL) type, ectopic foliole (EF) type, phyllotaxy-irregular (IP) type and cup-shaped (CS) type, which were remarkably different from corresponding wild type and were not also observed in the regenerated plantlets of wild type plant. Among these four types of transgenic plants, the phenotype of coral-like was observed for the first time in the transformants ectopically expressed KNOX genes. The observation of scanning electron microscope (SEM) showed ectopic meristems on the adaxial leaf surface of the transformants. Interestingly, the plantlets with ectopic foliole could generate new ectopic folioles from the original ectopic folioles again, and the plants regenerated from the EF-type transformants could also maintain the original morphology. The same specific RT-PCR band of the four types of transgenic plantlets showed that PttKN1 was ectopically expressed. All these data demonstrated that the ectopic expression of PttKN1 caused a series of alterations in morphology which provided possibilities producing novel ornamental lines and that PttKN1 played important roles in meristem initiation, maintenance and organogenesis events as other class I KNOX genes.

Complementation and disruption of viral processes in transgenic plants

1993 ◽  
Vol 342 (1301) ◽  
pp. 259-263 ◽  
Keyword(s):  
Transgenic Plants ◽  
Alfalfa Mosaic Virus ◽  
Plant Genome ◽  
Wild Type Virus ◽  
Wild Type ◽  
Genomic Rnas ◽  
Cp Gene ◽  
Transgenic Lines ◽  
Gdd Motif ◽  
High Level

RNAs 1 and 2 of alfalfa mosaic virus (AIMV) encode the replicase genes P1 and P2, respectively, whereas RNA 3 encodes the movem ent protein and the viral coat protein (CP). To investigate the mechanism of cross-protection, tobacco plants were transformed with wild-type and mutant DNA copies of the AIMV CP gene and the two replicase genes P1 and P2. Expression of wild-type CP at relatively low levels resulted in a resistance against infection with AIMV virus particles whereas at higher expression levels CP protected against infection with either AIMV particles or RNAs. Plants transformed with a mutant AIMV CP gene were not resistant to the wild-type virus but were resistant to AIMV with the same mutation in the CP gene. Transformation of plants with the wild-type P1 gene (P1 plants), P2 gene (P2 plants) or both these genes (P12 plants) did not result in resistance to AIMV. Instead, these plants could be infected with an inoculum lacking the gene(s) that was (were) integrated in the plant genome. Infection of non-transgenic plants, P1 plants or P2 plants with a mixture of AIMV genomic RNAs requires the presence of CP in the inoculum but P12 plants could be infected with RNA3 without any requirement for CP in the inoculum. Infection conditions in which 355 promoter/AlMV cDNA fusions were present in the inoculum instead of in the plant genome were used to shed light on the early function of CP. Finally, plants were transformed with P2 genes with mutations in the GDD-motif. A number of these transgenic lines showed a high level of resistance to AIMV.

scholarly journals Genetic and Global Epigenetic Modification, Which Determines the Phenotype of Transgenic Rice?

2020 ◽  
Vol 21 (5) ◽  
pp. 1819
Author(s):  
Xiaoru Fan ◽  
Jingguang Chen ◽  
Yufeng Wu ◽  
CheeHow Teo ◽  
Guohua Xu ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Transgenic Plants ◽  
Plant Height ◽  
Epigenetic Modification ◽  
Epigenetic Changes ◽  
Wild Type ◽  
Global Methylation ◽  
Phenotypic Changes ◽  
Wide Range ◽  
Transgenic Lines

Transgenic technologies have been applied to a wide range of biological research. However, information on the potential epigenetic effects of transgenic technology is still lacking. Here, we show that the transgenic process can simultaneously induce both genetic and epigenetic changes in rice. We analyzed genetic, epigenetic, and phenotypic changes in plants subjected to tissue culture regeneration, using transgenic lines expressing the same coding sequence from two different promoters in transgenic lines of two rice cultivars: Wuyunjing7 (WYJ7) and Nipponbare (NP). We determined the expression of OsNAR2.1 in two overexpression lines generated from the two cultivars, and in the RNA interference (RNAi) OsNAR2.1 line in NP. DNA methylation analyses were performed on wild-type cultivars (WYJ7 and NP), regenerated lines (CK, T0 plants), segregation-derived wild-type from pOsNAR2.1-OsNAR2.1 (SDWT), pOsNAR2.1-OsNAR2.1, pUbi-OsNAR2.1, and RNAi lines. Interestingly, we observed global methylation decreased in the T0 regenerated line of WYJ7 (CK-WJY7) and pOsNAR2.1-OsNAR2.1 lines but increased in pUbi-OsNAR2.1 and RNAi lines of NP. Furthermore, the methylation pattern in SDWT returned to the WYJ7 level after four generations. Phenotypic changes were detected in all the generated lines except for SDWT. Global methylation was found to decrease by 13% in pOsNAR2.1-OsNAR2.1 with an increase in plant height of 4.69% compared with WYJ7, and increased by 18% in pUbi-OsNAR2.1 with an increase of 17.36% in plant height compared with NP. This suggests an absence of a necessary link between global methylation and the phenotype of transgenic plants with OsNAR2.1 gene over-expression. However, epigenetic changes can influence phenotype during tissue culture, as seen in the massive methylation in CK-WYJ7, T0 regenerated lines, resulting in decreased plant height compared with the wild-type, in the absence of a transformed gene. We conclude that in the transgenic lines the phenotype is mainly determined by the nature and function of the transgene after four generations of transformation, while the global epigenetic modification is dependent on the genetic background. Our research suggests an innovative insight in explaining the reason behind the occurrence of transgenic plants with random and undesirable phenotypes.

scholarly journals Antisense RNA Inhibition of RbcS Gene Expression Reduces Rubisco Level and Photosynthesis in the C4 Plant Flaveria bidentis

1996 ◽  
Vol 111 (3) ◽  
pp. 725-734 ◽  
Author(s):  
R. T. Furbank ◽  
J. A. Chitty ◽  
S. von Caemmerer ◽  
CLD. Jenkins
Keyword(s):  
Gene Expression ◽  
Antisense Rna ◽  
C4 Plant ◽  
Rbcs Gene ◽  
Rna Inhibition ◽  
Flaveria Bidentis
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