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Molecular Plant Breeding Provisional Publishing
Molecular Plant Breeding 2012, Vol.3, No.4, 37 -49
http://mpb.sophiapublisher.com
37
Research Report Open Access
Over Expression of Chitinase and Chitosanase Genes from Trichoderma
harzianum under Constitutive and Inducible Promoters in order to Increase
Disease Resistance in Wheat (Triticum aestivum L)
Iqrar Ahmad Rana1,3 , Horst Loerz1 , Wilhelm Schaeffer2 , Dirk Becker1
1. Department of Developmental Biology and Biotechnology, Ohnhorststr. 18, D-22609 Hamburg, Germany,
2. Department of Molecular Phytopathology and Genetics, Ohnhorststr. 18, D-22609 Hamburg, Germany,
3. Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad-38040-Pakistan
Corresponding authors email: iqrar_rana@uaf.edu.pk; Authors
Molecular Plant Breeding, 2012, Vol.3, No.4 doi: 10.5376/mpb.2012.03.0004
Received: 05 Mar., 2012
Accepted: 16 Apr., 2012
Published: 30 Apr., 2012
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Preferred citation for this article:
Rana et al., 2012, Over Expression of Chitinase and Chitosanase Genes from Trichoderma harzianum under Constitutive and Inducible Promoters in order to
Increase Disease Resistance in Wheat (Triticum aestivum L), Molecular Plant Breeding, Vol.3, No.4 37-49 (doi: 10.5376/mpb.2012.03.0004)
Abstract Powdery mildew of wheat, caused by Erysiphe graminis f. sp. tritici is a serious threat to wheat grain production in many
parts of the world. Efforts have been made to engineer resistance into wheat using single gene technology which culminated in the
improved resistance efficiency but never a complete control. Some efforts of expressing genes for disease resistance under the control
of constitutive promoter resulted in the production of abnormal plants. We used double gene technology and over expressed a couple
of antifungal genes i.e., chitinase and chitosanase from Trichoderma harzianum simultaneously into winter wheat genotype Florida.
They were expressed separately under the constitutive promoter (Ubiquitin -1) from Maize and stress cum disease inducible promoter
(Vst- 1) from Vitis vinefera. Six lines achieved under constitutive promoter and five lines under inducible promoter showed the
co-integration and expression of chitinase and chitosanase genes. All these lines showed multiple copy integration of both these
genes except one line which showed single copy integration of chitinase under ubiquitin promoter. The copy number varied for
Chitinase (1- 3) and Chitosanase (2 -10). Different promoters did not seem to have any impact on transformation efficiency.
Pathological analyses were done with E. gramonis showed a decrease in the susceptibility for in both types of transgenic plants. A
decrease in susceptibility was seen upto 75% when the transgenics were under inducible promoter. While in transgenics under
constitutive promoter the decrease in susceptibility of upto 60% was seen. All the primary transforments with the exception of a
couple showed normal growth.
Keywords Inducible and constitutive promoter; Chitinase; Chitosanase; Vst- 1; Ubiquitin-1; Wheat; Transformation
Introduction
Wheat is one of the most important food crops of the
world. It is grown almost throughout the world, is the
most grown crop and ranks second after Maize in
terms of production. It is the staple food in many parts
of the world and is rich source of proteins,
carbohydrates and vitamins. Wheat is consumed
throughout the world as an important part of the diet,
i.e., in the form of bread, noodles, spaghetti, cakes,
biscuits and other sweets in Europe and America,
while in the form of chapatti in Asia and Africa. In
Indo-Pak subcontinent wheat is the most popular
staple food and is the symbol of food security
(Hammad et al., 2011, Khan and Khan, 2010). Wheat
is attacked by many pathogens including fungi,
viruses, bacteria and nematodes but the fungal
diseases are the most common. Rusts, smuts, powdery
mildews and scab are of global importance and have
caused from little damage to 70% yield losses (Naz et
al., 2007).
Plant diseases can be controlled by cultural practices,
biological control, use of fungitoxic chemicals and/or
by the development of resistant genotypes. Only the
resistant genotype is the stable and risk free method to
control plant diseases. However the resistance sources
are limited in wheat. Genetic engineering provides a
source for interphyletic gene transfer to create new
resistance sources. Wheat transformation was started
in the early 1990’s. Since then many reports have