Jalal Soltani; Mahsa Yousefi-Pour H.; Sonbol Nazeri
Abstract
The fungus Colletotrichum gloeosporioides is the causative agent of anthracnose disease of many tropical, subtropical and temperate fruits, and a microbial source of the anticancer drug, Taxol. Here, we introduce an optimized Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for genetic ...
Read More
The fungus Colletotrichum gloeosporioides is the causative agent of anthracnose disease of many tropical, subtropical and temperate fruits, and a microbial source of the anticancer drug, Taxol. Here, we introduce an optimized Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for genetic manipulation of this fungus using hph and gfp-tagged hph genes as selection markers. Results showed that falcate spores can be easily used instead of protoplasts for transformation. Several experimental parameters were shown to affect transformation efficiencies, among which the length of co-cultivation, the ratio of fungal conidia to bacterium during co-cultivation, the kind of membrane during co-cultivation, and the kind of fungal growth medium during transformants selection, showed the highest influences on ATMT frequencies. Results indicated that the optimal ATMT of C. gloeosporioides was achived after 3 days of co-cultivation, at 107 per ml fungal conidia, via the use of Fabriano 808 filter paper and Czapek's culture medium. Successive subculturing of transformants on selective and non-selective media demonstrated the stable expression of transgens, and subsequent PCR based analyses of transformants revealed the presence (100%) of transferred genes. Flourescence microscopy analyses showed a punctuate pattern for localization of an expressed Gfp-tagged Hph protein inside fungal hyphae. The optimized ATMT protocol generated mutants that showed different phenotypes based on their vegetation and pigmentation. This suggests the possible applicability of this technique for functional genetics studies in C. gloeosporioides, through insertional mutagenesis.
Eisa B. Kohan; Mohammad B. Bagherieh-Najjar; Mahnaz Aghdasi; Ahmad Reza Bahrami
Abstract
Environmental stresses affect plant growth and cause losses worth hundreds of million dollars of agricultural industry each year. Many genes induced in response to environmental stresses. The DREB1A gene is a stress-inducible transcription factor that its overexpression increased tolerance to environmental ...
Read More
Environmental stresses affect plant growth and cause losses worth hundreds of million dollars of agricultural industry each year. Many genes induced in response to environmental stresses. The DREB1A gene is a stress-inducible transcription factor that its overexpression increased tolerance to environmental stress in transgenic plants. DNA was extracted from Arabidopsis thaliana var. Col.0 plants and DREB1A gene amplified by particular primers. After purification, PCR products were cloned into pGEMT-EASY vector and transferred into E. coli strain DH5α competent cells. Blue/white colonies were analyzed and present of the DREB1A gene revealed by restriction analysis and sequencing test. A 668-bp XbaI/BamHI digested fragment of DREB1A gene from pGEMT::DREB1A construct cloned in pBI121 plasmid. The recombinant plasmids were transferred into Agrobacterium tumefaciens cells strain of LBA4404 and transformed cells were cultured on selective medium that supplied with kanamycin and rifampycin. As a result of gel electrophoresis of Agrobacterium colonies-PCR product, band existing on expected size show that the DREB1A gene was cloned in to pBI121 binary vector. At time, Agrobacterium cells containing of pBI121::DREB1A construct are using for product of environmental stress tolerant plants.
