Effect of chitinase antisense RNA expression on disease susceptibility of Arabidopsis plants (original) (raw)
Related papers
Current View on Chitinase for Plant Defence
Plant pathogen is serious problem worldwide amongst the crop cultivars. Large number of plants suffers from range of infectious diseases caused by different pathogens, amongst them fungi are responsible for majority of infectious plant diseases that limiting the crop yield and impact the post-harvest quality of food. So it is important to protect the plants from fungal infection. Substantial approaches have been done with fungicides or heavy metals and by conventional breeding for combating the fungal diseases but so far no conclusive solution has been developed. Genetic engineering paves a new way to protect the plants from harmful fungal afflictions by introducing genes encoding chitinase enzyme that degrade the chitin, which are the key component of fungal cell wall.
Activation of a Bean Chitinase Promoter in Transgenic Tobacco Plants by Phytopathogenic Fungi
THE PLANT CELL ONLINE, 1990
The temporal and spatial expression of a bean chitinase promoter has been investigated in response to fungal attack. Analysis of transgenic tobacco plants containing a chimeric gene composed of a 1.7-kilobase fragment carrying the chitinase 5B gene promoter fused to the coding region of the gus A gene indicated that the chitinase promoter is activated during attack by the fungal pathogens Botrytis cinerea, Rhizoctonia solani, and Sclerotium rolfsii. Although induction of 8-glucuronidase activity was observed in tissues that had not been exposed to these phytopathogens, the greatest induction occurred in and around the site of fungal infection. The increase in 8-glucuronidase activity closely paralleled the increase in endogenous tobacco chitinase activity produced in response to fungal infection. Thus, the chitinase 5B-gus A fusion gene may be used to analyze the cellular and molecular details of the activation of the host defense system during pathogen attack.
FEBS Letters, 1997
Endochitinases are widely distributed among higher plants, including a number of important crop species. They are generally considered to be involved in plant defence against potential pathogens. We have cloned a class IV chitinase gene {AtchitIV) from Arabidopsis thaliana. Southern blot analysis allowed the detection of two cross-hybridising genes in the A. thaliana genome. AtchitIV transcripts are detected in seedpods, but not in roots, inflorescence stems, leaves and flowers of healthy plants. The transcripts accumulated very rapidly in leaves after inoculation with Xanthomonas campestris. Maximum mRNA accumulation was reached one hour after infection and decreased to very low levels 72 hours after induction. This result suggests an involvement of AtchitIV in the initial events of the hypersensitive reaction. Nevertheless, A. thaliana plants transformed with the gus gene under the control of a class IV chitinase bean promoter, showed GUS activity in seed embryos. These data, together with the constitutive expression of the endogenous gene in the seedpods, points to additional physiological roles for this protein.
Applied Biochemistry and Biotechnology, 2010
The chit1 gene from the entomopathogenic fungus Metarhizium anisopliae, encoding the endochitinase CHIT42, was placed under the control of the CaMV 35S promoter, and the resulting construct was transferred to tobacco. Seventeen kanamycinresistant transgenic lines were recovered, and the presence of the transgene was confirmed by polymerase chain reactions and Southern blot hybridization. The number of chit1 copies was determined to be varying from one to four. Copy number had observable effects neither on plant growth nor development. Substantial heterogeneity concerning production of the recombinant chitinase, and both general and specific chitinolytic activities were detected in leaf extracts from primary transformants. The highest chitinase activities were found in plants harboring two copies of chit1 inserts at different loci. Progeny derived from selfpollination of the primary transgenics revealed a stable inheritance pattern, with transgene segregation following a mendelian dihybrid ratio. Two selected plants expressing high levels of CHIT42 were consistently resistant to the soilborne pathogen Rhizoctonia solani, suggesting a direct relationship between enzyme activity and reduction of foliar area affected by fungal lesions. To date, this is the first report of resistance to fungal attack in plants mediated by a recombinant chitinase from an entomopathogenic and acaricide fungus.
Transgenic research, 2006
Plants of strawberry (cultivar Pa´jaro) were transformed with three defense related genes: ch5B, gln2 and ap24 using Agrobacterium tumefaciens. The ch5B gene encodes for a chitinase from Phaseolus vulgaris, while gln2 and ap24 encode for a glucanase and a thaumatin-like protein, respectively, both from Nicotiana tabacum. Sixteen transgenic lines expressing one or a combination of two defense genes were obtained. Phytopathological tests showed that two transgenic lines expressing only the ch5B gene displayed high levels of resistance to gray mold disease (Botrytis cinerea). The resistance was correlated with the presence of the foreign protein CH5B and the increase of chitinolytic activity in leaves. However, resistance toward Colletotrichum acutatum, the etiological agent of the anthracnose disease, was not enhanced in the transgenic plants. These results suggest that the ch5B gene can be used to introduce transgene-mediated resistance to gray mold in strawberry, due to the lack of natural resistance to this disease in the crop.
Developmental and Pathogen-Induced Activation of the Arabidopsis Acidic Chitinase Promoter
The Plant Cell, 1991
Expression of the Arabidopsis acidic chitinase promoter was investigated during plant development and in response to inoculation with fungal pathogens. A chimeric gene composed of 1129 bp of 5' upstream sequence from the acidic chitinase gene was fused to the 8-glucuronidase (GUS) coding region and used to transform Arabidopsis and tomato. Promoter activity was monitored by histochemical and quantitative assays of GUS activity. In healthy transgenic plants, the acidic chitinase promoter activity was restricted to roots, leaf vascular tissue, hydathodes, guard cells, and anthers, whereas GUS expression was induced in mesophyll cells surrounding lesions caused by Rhizoctonia solani infection of transgenic Arabidopsis. In transgenic tomato plants, GUS expression was induced around necrotic lesions caused by Alternaria solani and Phytophthora infestam. Expression of the acidic chitinase promoter-GUS transgene was weakly induced by infiltrating leaves with salicylic acid. Analysis of a series of 5' deletions of the acidic chitinase promoter in Arabidopsis indicated that the proximal 192 bp from the transcription initiation site was sufficient to establish both the constitutive and induced pattern of expression. Elements further upstream were involved in quantitative expression of the gene. The location of a negative regulatory element was indicated between -384 and -590 and positive regulatory elements between -1 129 and -590.
Developmental and Pathogen-lnduced Activation of the Arabidopsis Acidic Chitinase Promoter
1991
Expression of the Arabidopsis acidic chitinase promoter was investigated during plant development and in response to inoculation with fungal pathogens. A chimeric gene composed of 1129 bp of 5' upstream sequence from the acidic chitinase gene was fused to the 8-glucuronidase (GUS) coding region and used to transform Arabidopsis and tomato. Promoter activity was monitored by histochemical and quantitative assays of GUS activity. In healthy transgenic plants, the acidic chitinase promoter activity was restricted to roots, leaf vascular tissue, hydathodes, guard cells, and anthers, whereas GUS expression was induced in mesophyll cells surrounding lesions caused by Rhizoctonia solani infection of transgenic Arabidopsis. In transgenic tomato plants, GUS expression was induced around necrotic lesions caused by Alternaria solani and Phytophthora infestam. Expression of the acidic chitinase promoter-GUS transgene was weakly induced by infiltrating leaves with salicylic acid. Analysis of a series of 5' deletions of the acidic chitinase promoter in Arabidopsis indicated that the proximal 192 bp from the transcription initiation site was sufficient to establish both the constitutive and induced pattern of expression. Elements further upstream were involved in quantitative expression of the gene. The location of a negative regulatory element was indicated between -384 and -590 and positive regulatory elements between -1 129 and -590.
PLANT PHYSIOLOGY, 1997
The concept of systemic acquired resistance (SAR) enables a novel approach to crop protection, and particular pathogenesis-related proteins, i.e. an acidic chitinase, have been classified as markers of the SAR response. Basic class I (VCHIT1b) and a class III (VCH3) chitinase cDNAs were cloned from cultured Vitis vinifera L. cv Pinot Noir cells and used to probe the induction response of grapevine cells to salicylic acid or yeast elicitor. Furthermore, the cells were treated with the commercial SAR activators 2,6-dichloroiso-nicotinic acid or benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester. Elicitor or salicylic acid induced both VCHIT1b and VCH3 transcript abundances, whereas 2,6-dichloroiso-nicotinic acid or benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester enhanced exclusively the expression of VCH3. To assess the systemic sensation of chitinase expression, single leaves of Vitis vinifera L. cv Pinot Noir or Vitis rupestris plants were inoculated with Plasmopara viticola spore suspensions, and the VCH3 and VCHIT1b mRNA amounts in the infected versus the adjacent, healthy leaf were monitored. Two VCH3 mRNA maxima were observed 2 and 6 d postinoculation in the infected, susceptible V. vinifera tissue, whereas in the healthy leaf the transcript increased from low levels d 2 postinoculation to prominent levels d 6 to 8 postinoculation. The level of VCH3 mRNA increased also over 4 d in the inoculated, resistant V. rupestris tissue. However, necrotic spots rapidly limited the infection, and the VCH3 transcript was undetectable in the upper-stage, healthy leaf. The expression of VCHIT1b remained negligible under either experimental condition. Overall, the results suggest that the selective expression of VCH3 might be a reliable indicator of the SAR response in V. vinifera L.
Euphytica, 1995
Simultaneous expression of a tobacco class I chitinase and a class I /3-1,3-glucanase gene in tomato resulted in increased fungal resistance, whereas transgenic tomato plants expressing either one of these genes were not protected against fungal infection. After infection with Fusarium oxysporum f.sp. lycopersici, a 36% to 58% reduction in disease severity was observed in resistant tomato lines. Two transgenic lines largely recovered from the initial infection by the time wild-type tomato plants had died. The overall results are consistent with the observation that class I chitinases and class I /3-1,3-glucanases synergistically inhibit the growth of fungi in vitro and provide the first experimental support to the hypothesis that such synergy can contribute to enhanced fungal resistance in planta .