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Peter Ueng - One of the best experts on this subject based on the ideXlab platform.

  • Resistance to Cucumber mosaic virus in Gladiolus plants transformed with either a defective replicase or coat protein subgroup II gene from Cucumber mosaic virus
    Plant Cell Reports, 2010
    Co-Authors: Kathryn Kamo, Ramon Jordan, Mary Ann Guaragna, Hei-ti Hsu, Peter Ueng
    Abstract:

    Transgenic Gladiolus plants that contain either Cucumber mosaic virus (CMV) subgroup I coat protein, CMV subgroup II coat protein, CMV replicase, a combination of the CMV subgroups I and II coat proteins, or a combination of the CMV subgroup II coat protein and replicase genes were developed. These plants were multiplied in vitro and challenged with purified CMV isolated from Gladiolus using a hand-held gene gun. Three out of 19 independently transformed plants expressing the replicase gene under control of the duplicated CaMV 35S promoter were found to be resistant to CMV subgroup I. Three out of 21 independently transformed plants with the CMV subgroup II coat protein gene under control of the Arabidopsis UBQ3 promoter were resistant to CMV subgroup II. Eighteen independently transformed plants with either the CMV subgroup I coat protein or a combination of CMV subgroups I and II coat proteins were challenged and found to be susceptible to both CMV subgroups I or II. Virus resistant plants with the CMV replicase transgene expressed much lower RNA levels than resistant plants expressing the CMV subgroup II coat protein. This work will facilitate the evaluation of virus resistance in transgenic Gladiolus plants to yield improved floral quality and productivity.

Raja Ram - One of the best experts on this subject based on the ideXlab platform.

  • Screening carnation and Gladiolus cultivars for vascular wilt resistance.
    Indian phytopathology, 2009
    Co-Authors: Veerubommu Shanmugam, Raja Ram, Naosekpam Singh Ajit, Devendra Dhyani
    Abstract:

    Carnation (Dianthus caryophyllus Linn.)and Gladiolus(Gladiolus hortulanus L.H. Bailey)are important commercial cut flower crops,which suffer substantial losses during cultivation and storage by several diseases. Vascular wilt caused by Fusarium oxysporum f.sp. dianthi (FOD)(Prill. & Delacr.) Snyd.& Hans and Fusarium oxysporum f.sp. gladioli(FOG) (Massey) Synd.& Hans in carnation and Gladiolus, respectively, inflict heavy crop damage, leading to deterioration in quality and quantity of the marketable blooms and planting material.Disease incidence ranging from 7 to 64% has been reported in Himachal Pradesh due to Fusarium in Gladiolus (4,5). Though effective chemical control of these diseases, these are not economical to the farmers. Hence, a better way of managing these diseases is through host resistance. Screening cultivars is important to select those suitable for pathogen resistance and to indentify the presence of resistance-related genes.

  • first report of tobacco ringspot virus occurring in Gladiolus in india
    Plant Pathology, 2003
    Co-Authors: M Katoch, Raja Ram, A A Zaidi
    Abstract:

    Gladiolus ( Gladiolus grandiflorous ) is cultivated for its cut flowers in many countries worldwide, including India, where plants are commonly infected with Bean yellow mosaic virus (BYMV) and/or Cucumber mosaic virus (CMV). Also reported in Gladiolus in different parts of the world, but limited in distribution, are Tobacco ringspot virus (TobRSV), Tomato ringspot virus (TomRSV), Tomato black ring virus (TBRV), Arabis mosaic virus (ArMV), Strawberry latent ringspot virus (SLRV), Tobacco rattle virus (TRV) and Tomato spotted wilt virus (TSWV) (Stein, 1995). During a survey for viruses infecting Gladiolus in Palampur, some plants of 22 cultivars exhibited flower colour-break symptoms, whereas others were symptomless. When indexed by ELISA using specific antibodies to BYMV (obtained from Sanofi, France) (Katoch et al ., 2002), these plants were shown to be infected with BYMV. However, symptomless plants of Gladiolus cv. Yellow Supreme, when indexed by DAS-ELISA using antibodies to TobRSV (obtained from Agdia Inc, Elkhart, IN, USA), were shown to be infected with TobRSV. Sap from these symptomless TobRSV-infected gladioli induced necrotic local lesions 7‐10 days after inoculation followed by systemic leaf malformation characteristic of TobRSV (Brunt et al. , 1996) in mechanically inoculated Nicotiana clevelandii and Vigna unguiculata seedlings. The presence of TobRSV in these plants was confirmed by DAS-ELISA.

  • First report of Tobacco ringspot virus occurring in Gladiolus in India
    2003
    Co-Authors: Katoch M, Raja Ram, Zaidi A A
    Abstract:

    Gladiolus ( Gladiolus grandiflorous ) is cultivated for its cut flowers in many countries worldwide, including India, where plants are commonly infected with Bean yellow mosaic virus (BYMV) and/or Cucumber mosaic virus (CMV). Also reported in Gladiolus in different parts of the world, but limited in distribution, are Tobacco ringspot virus (TobRSV), Tomato ringspot virus (TomRSV), Tomato black ring virus (TBRV), Arabis mosaic virus (ArMV), Strawberry latent ringspot virus (SLRV), Tobacco rattle virus (TRV) and Tomato spotted wilt virus (TSWV) (Stein, 1995). During a survey for viruses infecting Gladiolus in Palampur, some plants of 22 cultivars exhibited flower colour-break symptoms, whereas others were symptomless. When indexed by ELISA using specific antibodies to BYMV (obtained from Sanofi, France) (Katoch et al ., 2002), these plants were shown to be infected with BYMV. However, symptomless plants of Gladiolus cv. Yellow Supreme, when indexed by DAS-ELISA using antibodies to TobRSV (obtained from Agdia Inc, Elkhart, IN, USA), were shown to be infected with TobRSV. Sap from these symptomless TobRSV-infected gladioli induced necrotic local lesions 7–10 days after inoculation followed by systemic leaf malformation characteristic of TobRSV (Brunt et al. , 1996) in mechanically inoculated Nicotiana clevelandii and Vigna unguiculata seedlings. The presence of TobRSV in these plants was confirmed by DAS-ELISA. This is the first report of TobRSV occurring in Gladiolus in India. TobRSV can be transmitted on contaminated tools used during harvesting of flowers and corms, by its nematode vectors and in Gladiolus seeds. To control the virus, therefore, the use of disease-free planting material, good sanitation practices and vector management is recommended

  • status of bean yellow mosaic virus on Gladiolus
    Crop Protection, 2002
    Co-Authors: Meenu Katoch, Raja Ram, A A Zaidi, I D Garg
    Abstract:

    Abstract The status of bean yellow mosaic virus (BYMV) in 32 cultivars of Gladiolus was investigated by examining the plants visually as well as by using the techniques like ELISA. Incidence of the disease was found to range from 0% to 100% on visual basis, whereas ELISA revealed almost 100% infection in plants, which were showing the symptoms. Almost 30% of the symptomless Gladiolus plants were also the carrier of the virus. Plants found positive for BYMV by ELISA were confirmed to carry the virus with immuno electron microscopy, cytopathological studies and by RT-PCR analysis employing primers specific to BYMV. The present investigation revealed the wide spread occurrence of BYMV in various Gladiolus cultivars whether with or without symptoms and the study suggested that symptomless plants must be examined for the presence of the virus before using them for healthy propagule production.

Xionghui Zhong - One of the best experts on this subject based on the ideXlab platform.

  • the npr1 homolog ghnpr1 plays an important role in the defense response of Gladiolus hybridus
    Plant Cell Reports, 2015
    Co-Authors: Xionghui Zhong, Shanshan Seng, Qinglong Lian, Xian Luo, Xue Yuan
    Abstract:

    GhNPR1 shares similar functions as Arabidopsis NPR1 . Silencing of GhNPR1 in Gladiolus results in an enhanced susceptibility to Curvularia gladioli. We propose that GhNPR1 plays important roles in plant immunity. Gladiolus plants and corms are susceptible to various types of pathogens including fungi, bacteria and viruses. Understanding the innate defense mechanism in Gladiolus is a prerequisite for the development of new protection strategies. The non-expressor of pathogenesis-related gene 1 (NPR1) and bzip transcription factor TGA2 play a key role in regulating salicylic acid (SA)-mediated systemic acquired resistance (SAR). In this study, the homologous genes, GhNPR1 and GhTGA2, were isolated from Gladiolus and functionally characterized. Expression of GhNPR1 exhibited a 3.8-fold increase in Gladiolus leaves following salicylic acid treatment. A 1332 bp fragment of the GhNPR1 promoter from Gladiolus hybridus was identified. Inducibility of the GhNPR1 promoter by SA was demonstrated using transient expression assays in the leaves of Nicotiana benthamiana. The GhNPR1 protein is located in the nucleus and cytomembrane. GhNPR1 interacts with GhTGA2, as observed using the bimolecular fluorescence complementation system. Overexpression of GhNPR1 in an Arabidopsis npr1 mutant can restore its basal resistance to Pseudomonas syringae pv. tomato DC3000. Silencing of GhNPR1, using a tobacco rattle virus-based silencing vector, resulted in an enhanced susceptibility to Curvularia gladioli. In conclusion, these results suggest that GhNPR1 plays a pivotal role in the SA-dependent systemic acquired resistance in Gladiolus.

  • virus induced gene silencing for comparative functional studies in Gladiolus hybridus
    Plant Cell Reports, 2014
    Co-Authors: Xionghui Zhong, Xue Yuan, Muhammad Ali Khan, Jin Chen, Benhe Gong, Yang Zhao
    Abstract:

    Functional analysis of genes in Gladiolus has previously been impractical due to the lack of an efficient stable genetic transformation method. However, virus-induced gene silencing (VIGS) is effective in some plants which are difficult to transform through other methods. Although the Tobacco rattle virus (TRV)-based VIGS system has been developed and used for verifying gene functions in diverse plants, an appropriate TRV-VIGS approach for Gladiolus has not been established yet. In this report we describe the first use of the TRV-VIGS system for gene silencing in Gladiolus. Vacuum infiltration of cormels and young plants with the GhPDS-VIGS vector effectively down-regulated the PHYTOENE DESATURASE ortholog GhPDS gene and also resulted in various degrees of photobleaching in Gladiolus hybridus. The reduction in GhPDS expression was tested after TRV-based vector infection using real-time RT-PCR. In addition, the progress of TRV infection was detected by fluorescence visualization using a pTRV2: CP-GFP vector. In conclusion, the TRV-mediated VIGS described here will be an effective gene function analysis mechanism in Gladiolus.

Zaidi A A - One of the best experts on this subject based on the ideXlab platform.

  • First report of Tobacco rattle virus occurring in Gladiolus in India
    2004
    Co-Authors: Katoch M, Abdin M Z, Zaidi A A
    Abstract:

    During a survey for viruses infecting Gladiolus ( Gladiolus grandiflorus ) around Palampur in the Kangra Valley, some plants were identified that showed notched leaf blade margin symptoms, which is characteristic of Tobacco rattle virus (Genus Tobravirus ; TRV) (Yamaji et al ., 1998). These symptoms were observed on the cultivars Top Brass, Aldebaran and Oscar. Using doubleantchibody sandwich (DAS) ELISA, plants showing symptoms gave a positive reaction with polyclonal antibodies specific to TRV (obtained from Agdia, Elkhart, IN, USA). After sap inoculation of Nicotiana tabacum , characteristic TRV symptoms of necrotic local lesions, followed by systemic mottling, were observed (Brunt et al ., 1996). The presence of TRV in these plants was confirmed using DAS-ELISA. The results of these tests confirm the presence of TRV in Gladiolus in India. TRV has previously been reported in Gladiolus from other parts of the world, including Holland, Israel, Egypt and Poland (Stein, 1995). However, this is the first report of the occurrence of TRV in Gladiolus from India and, as far as the authors can determine, the first formally published report of TRV in any crop in India

  • First report of Tobacco ringspot virus occurring in Gladiolus in India
    2003
    Co-Authors: Katoch M, Raja Ram, Zaidi A A
    Abstract:

    Gladiolus ( Gladiolus grandiflorous ) is cultivated for its cut flowers in many countries worldwide, including India, where plants are commonly infected with Bean yellow mosaic virus (BYMV) and/or Cucumber mosaic virus (CMV). Also reported in Gladiolus in different parts of the world, but limited in distribution, are Tobacco ringspot virus (TobRSV), Tomato ringspot virus (TomRSV), Tomato black ring virus (TBRV), Arabis mosaic virus (ArMV), Strawberry latent ringspot virus (SLRV), Tobacco rattle virus (TRV) and Tomato spotted wilt virus (TSWV) (Stein, 1995). During a survey for viruses infecting Gladiolus in Palampur, some plants of 22 cultivars exhibited flower colour-break symptoms, whereas others were symptomless. When indexed by ELISA using specific antibodies to BYMV (obtained from Sanofi, France) (Katoch et al ., 2002), these plants were shown to be infected with BYMV. However, symptomless plants of Gladiolus cv. Yellow Supreme, when indexed by DAS-ELISA using antibodies to TobRSV (obtained from Agdia Inc, Elkhart, IN, USA), were shown to be infected with TobRSV. Sap from these symptomless TobRSV-infected gladioli induced necrotic local lesions 7–10 days after inoculation followed by systemic leaf malformation characteristic of TobRSV (Brunt et al. , 1996) in mechanically inoculated Nicotiana clevelandii and Vigna unguiculata seedlings. The presence of TobRSV in these plants was confirmed by DAS-ELISA. This is the first report of TobRSV occurring in Gladiolus in India. TobRSV can be transmitted on contaminated tools used during harvesting of flowers and corms, by its nematode vectors and in Gladiolus seeds. To control the virus, therefore, the use of disease-free planting material, good sanitation practices and vector management is recommended

Kathryn Kamo - One of the best experts on this subject based on the ideXlab platform.

  • Resistance to Cucumber mosaic virus in Gladiolus plants transformed with either a defective replicase or coat protein subgroup II gene from Cucumber mosaic virus
    Plant Cell Reports, 2010
    Co-Authors: Kathryn Kamo, Ramon Jordan, Mary Ann Guaragna, Hei-ti Hsu, Peter Ueng
    Abstract:

    Transgenic Gladiolus plants that contain either Cucumber mosaic virus (CMV) subgroup I coat protein, CMV subgroup II coat protein, CMV replicase, a combination of the CMV subgroups I and II coat proteins, or a combination of the CMV subgroup II coat protein and replicase genes were developed. These plants were multiplied in vitro and challenged with purified CMV isolated from Gladiolus using a hand-held gene gun. Three out of 19 independently transformed plants expressing the replicase gene under control of the duplicated CaMV 35S promoter were found to be resistant to CMV subgroup I. Three out of 21 independently transformed plants with the CMV subgroup II coat protein gene under control of the Arabidopsis UBQ3 promoter were resistant to CMV subgroup II. Eighteen independently transformed plants with either the CMV subgroup I coat protein or a combination of CMV subgroups I and II coat proteins were challenged and found to be susceptible to both CMV subgroups I or II. Virus resistant plants with the CMV replicase transgene expressed much lower RNA levels than resistant plants expressing the CMV subgroup II coat protein. This work will facilitate the evaluation of virus resistance in transgenic Gladiolus plants to yield improved floral quality and productivity.