scholarly journals Gibberellin 20-Oxidase Gene OsGA20ox3 Regulates Plant Stature and Disease Development in Rice

2013 ◽  
Vol 26 (2) ◽  
pp. 227-239 ◽  
Author(s):  
Xue Qin ◽  
Jun Hua Liu ◽  
Wen Sheng Zhao ◽  
Xu Jun Chen ◽  
Ze Jian Guo ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Critical Role ◽  
Insertion Site ◽  
Insertion Mutant ◽  
Wild Type Plant ◽  
Wild Type ◽  
Oxidase Gene ◽  
Dna Insertion ◽  
Flanking Sequences ◽  
Plant Stature

Gibberellin (GA) 20-oxidase (GA20ox) catalyses consecutive steps of oxidation in the late part of the GA biosynthetic pathway. A T-DNA insertion mutant (17S-14) in rice, with an elongated phenotype, was isolated. Analysis of the flanking sequences of the T-DNA insertion site revealed that an incomplete T-DNA integration resulted in enhanced constitutively expression of downstream OsGA20ox3 in the mutant. The accumulation of bioactive GA1 and GA4 were increased in the mutant in comparison with the wild-type plant. Transgenic plants overexpressing OsGA20ox3 showed phenotypes similar to those of the 17S-14 mutant, and the RNA interference (RNAi) lines that had decreased OsGA20ox3 expression exhibited a semidwarf phenotype. Expression of OsGA20ox3 was detected in the leaves and roots of young seedlings, immature panicles, anthers, and pollens, based on β-glucuronidase (GUS) activity staining in transgenic plants expressing the OsGA20ox3 promoter fused to the GUS gene. The OsGA20ox3 RNAi lines showed enhanced resistance against rice pathogens Magnaporthe oryzae (causing rice blast) and Xanthomonas oryzae pv. oryzae (causing bacterial blight) and increased expression of defense-related genes. Conversely, OsGA20ox3-overexpressing plants were more susceptible to these pathogens comparing with the wild-type plants. The susceptibility of wild-type plants to X. oryzae pv. oryzae was increased by exogenous application of GA3 and decreased by S-3307 treatment. Together, the results provide direct evidence for a critical role of OsGA20ox3 in regulating not only plant stature but also disease resistance in rice.

scholarly journals OsASN1 Plays a Critical Role in Asparagine-Dependent Rice Development

2018 ◽  
Vol 20 (1) ◽  
pp. 130 ◽  
Author(s):  
Le Luo ◽  
Ruyi Qin ◽  
Tao Liu ◽  
Ming Yu ◽  
Tingwen Yang ◽  
...  
Keyword(s):  
Critical Role ◽  
Tiller Number ◽  
Insertion Mutant ◽  
Wild Type ◽  
Long Distance ◽  
Long Distance Transport ◽  
Similar Phenotype ◽  
Dna Insertion ◽  
Mutant Lines ◽  
Distance Transport

Asparagine is one of the important amino acids for long-distance transport of nitrogen (N) in plants. However, little is known about the effect of asparagine on plant development, especially in crops. Here, a new T-DNA insertion mutant, asparagine synthetase 1 (asn1), was isolated and showed a different plant height, root length, and tiller number compared with wild type (WT). In asn1, the amount of asparagine decreased sharply while the total nitrogen (N) absorption was not influenced. In later stages, asn1 showed reduced tiller number, which resulted in suppressed tiller bud outgrowth. The relative expression of many genes involved in the asparagine metabolic pathways declined in accordance with the decreased amino acid concentration. The CRISPR/Cas9 mutant lines of OsASN1 showed similar phenotype with asn1. These results suggest that OsASN1 is involved in the regulation of rice development and is specific for tiller outgrowth.

scholarly journals Degradation of trinitrotoluene by transgenic nitroreductase in Arabidopsis plants

2018 ◽  
Vol 64 (No. 8) ◽  
pp. 379-385 ◽  
Author(s):  
Zhu Bo ◽  
Han Hongjuan ◽  
Fu Xiaoyan ◽  
Li Zhenjun ◽  
Gao Jianjie ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Arabidopsis ◽  
Environmental Pollutant ◽  
Specific Rate ◽  
Wild Type Plant ◽  
Wild Type ◽  
Fresh Weight ◽  
Human Carcinogen ◽  
Specific Rate Constant ◽  
Nitroreductase Activity

The explosive 2,4,6-trinitrotoluene (TNT) is a highly toxic and persistent environmental pollutant. TNT is toxic to many organisms, it is known to be a potential human carcinogen, and is persistent in the environment. This study presents a system of phytoremediation by Arabidopsis plants developed on the basis of overexpression of NAD(P)H-flavin nitroreductase (NFSB) from the Sulfurimonas denitrificans DSM1251. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerance and a strikingly higher capacity to remove TNT from their media. The highest specific rate constant of TNT disappearance rate was 1.219 and 2.297 mL/g fresh weight/h for wild type and transgenic plants, respectively. Meanwhile, the nitroreductase activity in transgenic plant was higher than wild type plant. All this indicates that transgenic plants show significantly enhanced tolerances to TNT; transgenic plants also exhibit strikingly higher capabilities of removing TNT from their media and high efficiencies of transformation.

scholarly journals Plastid-Localized EMB2726 Is Involved in Chloroplast Biogenesis and Early Embryo Development in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Chuanling Li ◽  
Jian-Xiu Shang ◽  
Chenlei Qiu ◽  
Baowen Zhang ◽  
Jinxue Wang ◽  
...  
Keyword(s):  
Chloroplast Development ◽  
Developmental Process ◽  
Higher Plants ◽  
Critical Role ◽  
Elongation Factor ◽  
Early Embryo ◽  
The Body ◽  
Insertion Mutant ◽  
Cell Stage ◽  
Dna Insertion

Embryogenesis is a critical developmental process that establishes the body organization of higher plants. During this process, the biogenesis of chloroplasts from proplastids is essential. A failure in chloroplast development during embryogenesis can cause morphologically abnormal embryos or embryonic lethality. In this study, we isolated a T-DNA insertion mutant of the Arabidopsis gene EMBRYO DEFECTIVE 2726 (EMB2726). Heterozygous emb2726 seedlings produced about 25% albino seeds with embryos that displayed defects at the 32-cell stage and that arrested development at the late globular stage. EMB2726 protein was localized in chloroplasts and was expressed at all stages of development, such as embryogenesis. Moreover, the two translation elongation factor Ts domains within the protein were critical for its function. Transmission electron microscopy revealed that the cells in emb2726 embryos contained undifferentiated proplastids and that the expression of plastid genome-encoded photosynthesis-related genes was dramatically reduced. Expression studies of DR5:GFP, pDRN:DRN-GFP, and pPIN1:PIN1-GFP reporter lines indicated normal auxin biosynthesis but altered polar auxin transport. The expression of pSHR:SHR-GFP and pSCR:SCR-GFP confirmed that procambium and ground tissue precursors were lacking in emb2726 embryos. The results suggest that EMB2726 plays a critical role during Arabidopsis embryogenesis by affecting chloroplast development, possibly by affecting the translation process in plastids.

Influence of overexpression of a gibberellin 20-oxidase gene on the kinetics of xylem cell development in hybrid poplar (Populus tremula L. and P. tremuloides Michx.)

Holzforschung ◽  
2006 ◽  
Vol 60 (6) ◽  
pp. 608-617 ◽  
Author(s):  
Oliver Dünisch ◽  
Matthias Fladung ◽  
Satoshi Nakaba ◽  
Yoko Watanabe ◽  
Ryo Funada
Keyword(s):  
Transgenic Plants ◽  
Cell Expansion ◽  
Hybrid Poplar ◽  
Cell Development ◽  
Populus Tremula ◽  
Uv Spectrophotometry ◽  
Wild Type ◽  
Oxidase Gene ◽  
Xylem Cell ◽  
Kinetics Of

Abstract Gibberellins (GAs) are important regulators of shoot growth in trees. We studied the kinetics of xylem formation in hybrid poplar (Populus tremula L.×P. tremuloides Michx.) in which the key regulatory gene gibberellin acid 20 oxidase (GA20-oxidase) isolated from Arabidopsis is overexpressed. Increments in the height and radius of shoots were registered by high-resolution laser measurements. The anatomical and chemical structure of mature xylem cells was studied by light electron microscopy and UV spectrophotometry. Transgenic plants showed an increase in height growth, but a lower speed of cell elongation during primary growth compared to wild-type plants. During the first year of growth, transgenic plants showed a higher radius increment, an increase in the period of cell expansion of vessels and fibres and their final size, and a higher lignin content of the compound middle lamella between fibres compared to wild-type plants. In contrast, during the third year of growth, only a slight increase in the period of cell expansion of fibre cells was observed in transgenic compared to wild-type plants. Analyses of GA20-oxidase expression in leaves and shoots of 6-month- and 3-year-old plants of three different independent transgenic lines revealed a decrease in its expression only in shoots but not in leaves of the 3-year-old plants. The results indicate that overexpression of the GA20-oxidase gene in young shoots of transgenic poplar predominately affects cell expansion, while no GA20-oxidase expression was observed in shoots of 3-year-old transgenic plants, resulting in wild-type xylem cell development.

scholarly journals Improved Salinity Tolerance in Carrizo Citrange Rootstock through Overexpression of Glyoxalase System Genes

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Ximena Alvarez-Gerding ◽  
Rowena Cortés-Bullemore ◽  
Consuelo Medina ◽  
Jesús L. Romero-Romero ◽  
Claudio Inostroza-Blancheteau ◽  
...  
Keyword(s):  
Salt Stress ◽  
Transgenic Plants ◽  
Stress Tolerance ◽  
Salinity Tolerance ◽  
Dry Weight ◽  
Wild Type Plant ◽  
Wild Type ◽  
Salt Stress Tolerance ◽  
Glyoxalase System ◽  
Carrizo Citrange

Citrus plants are widely cultivated around the world and, however, are one of the most salt stress sensitive crops. To improve salinity tolerance, transgenic Carrizo citrange rootstocks that overexpress glyoxalase I and glyoxalase II genes were obtained and their salt stress tolerance was evaluated. Molecular analysis showed high expression for both glyoxalase genes (BjGlyIandPgGlyII) in 5H03 and 5H04 lines. Under control conditions, transgenic and wild type plants presented normal morphology. In salinity treatments, the transgenic plants showed less yellowing, marginal burn in lower leaves and showed less than 40% of leaf damage compared with wild type plants. The transgenic plants showed a significant increase in the dry weight of shoot but there are no differences in the root and complete plant dry weight. In addition, a higher accumulation of chlorine is observed in the roots in transgenic line 5H03 but in shoot it was lower. Also, the wild type plant accumulated around 20% more chlorine in the shoot compared to roots. These results suggest that heterologous expression of glyoxalase system genes could enhance salt stress tolerance in Carrizo citrange rootstock and could be a good biotechnological approach to improve the abiotic stress tolerance in woody plant species.

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.

scholarly journals Physiological and transcriptome analysis of indica rice 'MH86' overexpressing OsSPL14

2018 ◽  
Author(s):  
Ling Lian ◽  
Wei He ◽  
Qiu hua Cai ◽  
Hui Zhang ◽  
Cheng rong Ren ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Plant ◽  
Transcriptome Analysis ◽  
Indica Rice ◽  
Critical Role ◽  
Lignin Biosynthesis ◽  
Growth Period ◽  
Carotenoid Biosynthesis ◽  
Maturity Stage ◽  
Wild Type Plant

OsSPL14, identified as IDEAL PLANT ARCHITECTURE1 (IPA1) or WEALTHY FARMER'S PANICLE (WFP) gene, plays a critical role in regulating rice plant architecture. Here, the study showed that OsSPL14-overexpression transgenic rice plants had shorter growth period, short-narrow flag leaves, and thick-green leaves. Compared with wild type plant 'MH86', transgenic plants had higher chlorophyll a (Ca), chlorophyll b (Cb) and carotenoid (Cx) content at both seedling and maturity stage. Meanwhile, transcriptome analysis identified 473 up-regulated and 103 down-regulated genes in transgenic plant. The expression of differentially expressed genes (DEGs) involved in carotenoid biosynthesis, abscisic acid (ABA) metabolism and lignin biosynthesis increased significantly. Most of DEGs participated in 'plant hormone signal transduction' and 'starch and sucrose metabolism' are also up-regulated in transgenic plant. In addition, there were higher levels of ABA and gibberellin acid (GA3) in OsSPL14-overexpression transgenic plants. Moreover, the content of culm lignin, cellulose, silicon and potassium all increased dramatically. Thus, these results demonstrate that overexpression of OsSPL14 has influence on leaf development, hormone level and culm composition in rice, which provide more insight into understanding the function of OsSPL14.

scholarly journals Seed-Specific Expression of Arabidopsis AtCYP85A2 Produces Biologically Active Brassinosteroids Such as Castasterone and Brassinolide to Improve Grain Yield and Quality in Seeds of Brachypodium Distachyon

2021 ◽  
Vol 12 ◽  
Author(s):  
Jeehee Roh ◽  
Jinyoung Moon ◽  
Ye Eun Lee ◽  
Chan Ho Park ◽  
Seong-Ki Kim
Keyword(s):  
Transgenic Plants ◽  
Grain Yield ◽  
Brachypodium Distachyon ◽  
Biologically Active ◽  
Wild Type Plant ◽  
Wild Type ◽  
Specific Expression ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Seed Specific Expression

Brachypodium distachyon is a monocotyledonous model plant that contains castasterone (CS) but no brassinolide (BL) as the end product of brassinosteroids (BR) biosynthesis, indicating dysfunction of BL synthase, which catalyzes the conversion of CS to BL. To increase BR activity, Arabidopsis cytochrome P450 85A2 (AtCYP85A2) encoding BR 6-oxidase/BL synthase was introduced into B. distachyon with the seed-specific promoters pBSU1, pAt5g10120, and pAt5g54000. RT-PCR analysis and GUS activity revealed that AtCYP85A2 was only expressed in the seeds of the transgenic plants pBSU1-AtCYP85A2::Bd21-3, pAt5g10120-AtCYP85A2::Bd21-3, and pAt5g54000-AtCYP85A2::Bd21-3. The crude enzyme prepared from the seeds of these three transgenic plants catalyzed the conversion of 6-deoxoCS to CS. The transgenic plants showed greater specific enzyme activity than the wild-type plant for the conversion of 6-deoxoCS to CS, indicating enhanced BR 6-oxidase activity in the transgenic plants. The enzyme solution also catalyzed the conversion of CS into BL. Additionally, BL was identified from the seeds of transgenic plants, verifying that seed-specific AtCYP85A2 encodes a functional BL synthase to increase BR activity in the seeds of transgenic Brachypodium. In comparison with wild-type Brachypodium, the transgenic plants showed better growth and development during the vegetative growing stage. The flowers of the transgenic plants were remarkably larger, resulting in increments in the number, size, and height of seeds. The total starch, protein, and lipid contents in transgenic plants were higher than those in wild-type plants, indicating that seed-specific expression of AtCYP85A2 improves both grain yield and quality in B. distachyon.

scholarly journals Whole-Genome Resequencing using Next-Generation and Nanopore Sequencing for Molecular Characterization of T-DNA Integration in Transgenic Poplar 741

2020 ◽  
Author(s):  
Xinghao Chen ◽  
Yan Dong ◽  
Yali Huang ◽  
Jianmin Fan ◽  
Minsheng Yang ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Insertion Site ◽  
Nanopore Sequencing ◽  
Transgenic Poplar ◽  
Next Generation ◽  
Genome Resequencing ◽  
Dna Integration ◽  
Dna Insertion ◽  
Insertion Sites ◽  
Safety Assessments

Abstract BackgroundWith the rapid development of transgenic technology, transgenic plants have been planted all over the world, and transgenic forest trees have also been commercialized. At the same time, the potential threat of transgenic plants to human health and the natural environment has aroused widespread concern. Therefore, safety assessments before field release and commercial planting of transgenic plants are necessary. By determining the copy number and integration sites of T-DNA in transgenic plants, the safety of transgenic plants at the genomic level can be assessed.ResultsIn this study, we performed genome resequencing of Pb29, a transgenic high-resistance poplar 741 line that has been commercialized, using next-generation and Nanopore sequencing. The results revealed that there are two T-DNA insertion sites, located at 9,283,905–9,283,937 bp on chromosome 3 (Chr03) and 10,868,777–10,868,803 bp on Chr10. The accuracy of the T-DNA insertion locations and directions was verified using polymerase chain reaction amplification. Through sequence alignment, different degrees of base deletions were detected on the T-DNA left and right border sequences, and in the flanking sequences of the insertion sites. An unknown fragment was inserted between the Chr03 insertion site and the right flanking sequence, but the Pb29 genome did not undergo chromosomal rearrangement. It is worth noting that we did not detect the API gene in the Pb29 genome, indicating that Pb29 is a transgenic line containing only the BtCry1AC gene. On Chr03, the insertion of T-DNA disrupted a gene encoding TAF12 protein, but the transcriptional abundance of this gene did not change significantly in the leaves of Pb29. Additionally, except for the gene located closest to the T-DNA integration site, the expression levels of four other neighboring genes did not change significantly in the leaves of Pb29. ConclusionsThis study provides important molecular information for safety assessments and management of transgenic poplar 741. Our findings also provide a theoretical basis for safety assessments of other transgenic poplar.

scholarly journals Analysis of the Involvement of an Inducible Arabidopsis RNA-Dependent RNA Polymerase in Antiviral Defense

2003 ◽  
Vol 16 (3) ◽  
pp. 206-216 ◽  
Author(s):  
Diqiu Yu ◽  
Baofang Fan ◽  
Stuart A. MacFarlane ◽  
Zhixiang Chen
Keyword(s):  
Viral Vector ◽  
Potato Virus X ◽  
Insertion Mutant ◽  
Antiviral Defense ◽  
Wild Type ◽  
Knockout Mutant ◽  
General Role ◽  
Viral Rnas ◽  
Posttranscriptional Gene Silencing ◽  
Dna Insertion

RNA-dependent RNA polymerases (RdRPs) have been implicated in posttranscriptional gene silencing (PTGS) and antiviral defense. An Arabidopsis RdRP (SDE1/SGS2) has been previously shown to be required for transgene-induced PTGS but has no general role in antiviral defense. On the other hand, we have recently shown that transgenic tobacco deficient in an inducible RdRP (NtRdRP1) activity became more susceptible to both Tobacco mosaic virus and Potato virus X. Thus, different RdRPs may have distinct roles in closely related PTGS and antiviral defense. In the present study, we analyzed roles of a newly identified Arabidopsis RdRP gene (AtRdRP1) in plant antiviral defense. AtRdRP1 encodes an RdRP closely related structurally to NtRdRP1 and is also induced by salicylic acid treatment and virus infection. A T-DNA insertion mutant for AtRdRP1 has been isolated and analyzed for possible alterations in response to viral infection. When infected by a to-bamovirus and a tobravirus, the knockout mutant accumulated higher and more persistent levels of viral RNAs in both the lower, inoculated and in upper, systemically infected leaves than did wild-type plants. These results suggest that the inducible AtRdRP1 is the Arabidopsis ortholog of NtRdRP1 and plays a role in antiviral defense. Examination of short viral RNAs and silencing studies using a viral vector harboring an endogenous plant gene suggest that, while not required for virus-induced PTGS, AtRdRP1 can apparently promote turnover of viral RNAs in infected plants.

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