Transgenic tobacco expressing an Arisaema heterophyllum agglutinin gene displays enhanced resistance to aphids

2004 ◽  
Vol 84 (3) ◽  
pp. 785-790 ◽  
Author(s):  
Jianhong Yao, Xiuyun Zhao ◽  
Huaxiong Qi, Bingliang Wan ◽  
Fei Chen, Xiaofen Sun ◽  
Shanqian Yu ◽  
Kexuan Tang

Tobacco leaf discs were transformed with a plasmid, pBIAHA, containing the selectable marker neomycin phosphotransferase gene (nptII) and an Arisaema heterophyllum agglutinin gene (aha) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that multiple copies of the aha gene had integrated into the plant genome. Northern blot analysis revealed that the aha gene was expressed at various levels in the transgenic plants. Insect bioassay test showed that transgenic plants expressing multiple copies of the aha gene reduced the rate of population increase of the peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic tobacco plants expressing the aha gene display enhanced resistance to aphids. Key words: Insect bioassay, Arisaema heterophyllum agglutinin, transformation, transgenic tobacco, peach potato aphid (Myzus persicae Sulzer)

2021 ◽  
Author(s):  
Noroza Umer ◽  
Rubab Zahra Naqvi ◽  
Imran Rauf ◽  
Naveed Anjum ◽  
Hamid Anees Siddiqui ◽  
...  

Abstract Globally, aphid, Myzus persicae is an economically significant, polyphagous crop pest that feeds on more than 400 plant species and transmits more than 100 plant viruses. Aphid infestation is mostly managed by insecticides that cause heavy environmental contamination and insect resistance. Cloning of plant derived insecticidal genes to develop transgenic plants under suitable promoter is a promising technology. In the present study, ASAL (MN820725) was isolated from native garlic and cloned in plant transformation vector, pGA482 through Agrobacterium mediated tobacco transformation. PCR of genomic DNA of transgenic tobacco plants using gene specific primers confirmed the presence of asal gene of 546 bp. To detect the integration of gene Southern blot analysis was conducted that revealed stable integration of asal gene while, gene expression was analyzed through qRT-PCR that showed variable expression of asal gene in transgenic tobacco plants. Efficacy of asal gene was evaluated through aphid bioassay. Aphid bioassay revealed that transgenic tobacco lines LS-17, LS-20, LR-1, and LR-7 exhibited 100% aphid mortality and significantly reduced the aphid population. These findings suggested the potential of ASAL against aphids that can be further used against other notorious sap sucking pests.


Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.


1999 ◽  
Vol 125 (3) ◽  
pp. 431-435 ◽  
Author(s):  
M. Ohshimax ◽  
I. Mitsuhara ◽  
M. Okamoto ◽  
S. Sawano ◽  
K. Nishiyama ◽  
...  

2012 ◽  
Vol 102 (6) ◽  
pp. 663-671 ◽  
Author(s):  
M. Rivi ◽  
V. Monti ◽  
E. Mazzoni ◽  
S. Cassanelli ◽  
M. Panini ◽  
...  

AbstractIn this study, we present cytogenetic data regarding 66 Myzus persicae strains collected in different regions of Italy. Together with the most common 2n = 12 karyotype, the results showed different chromosomal rearrangements: 2n = 12 with A1–3 reciprocal translocation, 2n = 13 with A1–3 reciprocal translocation and A3 fission, 2n = 13 with A3 fission, 2n = 13 with A4 fission, 2n = 14 with X and A3 fissions. A 2n = 12–13 chromosomal mosaicism has also been observed. Chromosomal aberrations (and in particular all strains showing A1–3 reciprocal translocation) are especially frequent in strains collected on tobacco plants, and we suggest that a clastogenic effect of nicotine, further benefited by the holocentric nature of aphid chromosomes, could be at the basis of the observed phenomenon.


2021 ◽  
Author(s):  
Alireza Abbasi ◽  
Meysam Malekpour ◽  
Sajjad Sobhanverdi

Abstract Expansins are cell wall proteins that, due to changes in pH, causing the expansion of the cell walls. In this study, a previously gene construct designed based on a root-specific gene, AtEXPA18, was utilized to assess its potential roles on different morphological, physiological, and cellular levels of generated transgenic tobacco plants in response to moderate and severe drought stress. AtEXPA18 gene was successfully transferred to the tobacco plants through an agrobacterium-mediate transformation system. Upon obtaining the second generation, tobacco transgenic plants were confirmed by conventional polymerase chain reaction (PCR) technique alongside reverse transcription PCR (RT-PCR) using specific primers. Under drought stress, the transgenic lines showed remarkable growth and significantly improved based on morphological traits such as height and stem diameter, leaf area, leaf number, root dry weight, and Abscisic acid (ABA) levels of leaves compared control plants. As a result, the Cytokinin content of transgenic plants has increased under severe stress levels. Notably, the area's expansion for abaxial epidermal cells under the microscope confirmed in transgene cells compared with the -transgene cells. These results, altogether, could support the AtEXPA18 gene implication in cell expansion and improving tolerance capacity of transgenic crops under drought stress.


2020 ◽  
Vol 21 (4) ◽  
pp. 1323 ◽  
Author(s):  
Wei Li ◽  
Changxi Dang ◽  
Yuxiu Ye ◽  
Zunxin Wang ◽  
Laibao Hu ◽  
...  

In plants, auxin/indoleacetic acid (Aux/IAA) proteins are transcriptional regulators that regulate developmental process and responses to phytohormones and stress treatments. However, the regulatory functions of the Vitis vinifera L. (grapevine) Aux/IAA transcription factor gene VvIAA18 have not been reported. In this study, the VvIAA18 gene was successfully cloned from grapevine. Subcellular localization analysis in onion epidermal cells indicated that VvIAA18 was localized to the nucleus. Expression analysis in yeast showed that the full length of VvIAA18 exhibited transcriptional activation. Salt tolerance in transgenic tobacco plants and Escherichia. coli was significantly enhanced by VvIAA18 overexpression. Real-time quantitative PCR analysis showed that overexpression of VvIAA18 up-regulated the salt stress-responsive genes, including pyrroline-5-carboxylate synthase (NtP5CS), late embryogenesis abundant protein (NtLEA5), superoxide dismutase (NtSOD), and peroxidase (NtPOD) genes, under salt stress. Enzymatic analyses found that the transgenic plants had higher SOD and POD activities under salt stress. Meanwhile, component analysis showed that the content of proline in transgenic plants increased significantly, while the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) decreased significantly. Based on the above results, the VvIAA18 gene is related to improving the salt tolerance of transgenic tobacco plants. The VvIAA18 gene has the potential to be applied to enhance plant tolerance to abiotic stress.


2009 ◽  
Vol 46 (2) ◽  
pp. 63-75 ◽  
Author(s):  
Roya Razavizadeh ◽  
Ali Ehsanpour

Effects of salt stress on proline content, expression of delta-1-pyrroline-5-carboxylate synthetase, and activities of catalase and ascorbate peroxidase in transgenic tobacco plantsIn arid and semiarid regions, soil salinity limits crop production. Proline accumulation in transgenic plants results in increased stress tolerance, but the underlying mechanism was unclear. To elucidate it, effects of salt stress on the expression pattern of Δ1-pyrroline-5-carboxylate synthetase (P5CS), proline content, catalase (CAT), and ascorbate peroxidase (APX) activities were analyzed in transgenic tobacco (Nicotiana tabacumcv. Wisconsin). Transgenic tobacco plants containing CaMV 35S promoter and theP5CSgene from moth bean (Vigna aconitifolia), linked to theNPTIIgene, were culturedin vitrowith or without 300 mM NaCl. The expression pattern ofP5CSwas evaluated using semiquantitative RT-PCR (reverse transcription-polymerase chain reaction). Time-course experiments showed an increase in proline content after 4 h of the treatment. The level ofP5CStranscripts was increased significantly in leaves and roots of transgenic plants after 24 and 48 h of treatment. This rise in transcripts was concomitant with the highest increase in proline content. In addition, CAT and APX activities increased under salt stress, and their highest activities were observed after 24 and 48 h of NaCl treatment. These results suggest thatP5CSis an inducible gene regulating the activities of CAT and APX and the accumulation of proline in plants subjected to salt stress.


1999 ◽  
Vol 80 (11) ◽  
pp. 2813-2822 ◽  
Author(s):  
Liliana F. Franco-Lara ◽  
Kara D. McGeachy ◽  
Uli Commandeur ◽  
Robert R. Martin ◽  
Mike A. Mayo ◽  
...  

A full-length cDNA copy of the genome of Potato leafroll virus (PLRV) was introduced into the genome of tobacco and potato plants by Agrobacterium tumefaciens-mediated transformation. Transgenic lines were obtained in which the transgene was readily detected by PCR with DNA extracted from T1 tobacco seedlings and clonally multiplied potato plants. PLRV-specific genomic and sub- genomic RNAs, coat protein antigen and virus particles were detected in transgenic plants. Aphids fed on the transgenic tobacco plants readily transmitted PLRV to test plants. Infected transgenic tobacco plants, like non-transgenic (WT) PLRV-infected plants, displayed no symptoms of the infection but transgenic plants of potato were severely stunted. In parallel tests, the mean PLRV titres in WT tobacco plants and transgenic tobacco plants were 600 and 630 ng virus/g leaf, respectively, although differences in PLRV titres among transgenic plants were much greater than those among infected WT plants. In similar tests with potato, the mean PLRV titre of WT plants was 50 ng virus/g leaf whereas higher concentrations (up to 3400 ng virus/g leaf) accumulated in transgenic potato plants. In tissue prints of stems, PLRV was detected in similar proportions of phloem cells in transgenic and infected WT plants. In transgenic tobacco and potato plants, but not in infected WT plants, a few stem epidermal cells also contained virus. From tissue prints of transgenic tobacco leaves, it was estimated that about one in 40000 mesophyll cells contained virus, but in transgenic potato, a greater proportion of mesophyll cells was infected.


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