Molecular Biology Lab

Department of Biochemistry & Molecular Biology, University of Dhaka.

Development of jute EST/cDNA libraries and identification of genes of economic importance.


Objectives:


Identification of genes conferring stress tolerance in traditional jute varieties and use of these genes or markers linked to these traits to obtain stress tolerant jute suitable for growing in adverse conditions like drought, low temperature, salinity etc.

Achievements:


1) Identification of gene(s) associated with low temperature tolerance in jute.

2) A complete gene sequence and mRNA sequence of a Putative Leucine Rich Transmembrane Protein Kinase has been deduced using degenerate PCR, RT-PCR, 3 RACE and 5 RACE. The expression of this putative Leucine Rich Transmembrane Protein Kinase has been also observed by Semi-quantitative PCR and Real Time PCR.

3) A total 2249 bp of a putative vps51/vps67 gene sequence has been deduced by using degenerate PCR, RT-PCR, 3 RACE and 5 RACE. The characterization of this putative gene is the present focus of our lab.

4) Non radioactive differential display identified a fragment of gene from low temperature tolerant jute (SDLT, Short Day Low Temperature) variety. The sequence of this putative gene has homology with sequences from prokaryotes only and bioinformatics studies suggest that this sequence contains a domain called EAL/GGDEF which has no homology with any of the eukaryotes sequenced till today. Expression of this gene has been studied by Semi-quantitative PCR and Real Time PCR and the presence of this gene in jute has been confirmed by Southern hybridization.

5) Development of efficient genetic transformation protocol of jute We successfully established a tissue culture independent transformation protocol for jute. In this approach young jute plants were transformed at shoot apical meristematic region using Agrobacterium tumefaciens. Heritable transmission of the transgene to progeny from genetically modified plants was confirmed by gus gene expression by histochemical analysis, selection on kanamycin containing medium, RT-PCR, PCR amplification and Southern hybridization. Efficiency of transformation was determined by selection on medium containing kanamycin, and inheritance of transgene to T2 generation plants.

6) DNA fingerprinting key for different jute genotypes was generated using jute specific SSR markers on 10 jute cultivars from two Corchorus species ( C. olitorius and C. capsularis) and the genetic relatedness among the cultivars was estimated.

7) Identification of SSR markers linked to mite tolerance in jute. SSR markers for jute have been successfully used in distinguishing mite sensitive and tolerance jute varieties. This marker has the potential of being useful in Marker Assisted Selection (MAS) in jute breeding programs for selection of lines resistant to mite.

8) Identification of genes conferring fungus resistance. Some differentially expressed genes have been amplified from fungus susceptible plants and not from the resistant ones. In other cases of differential expression, amplifications occurred only with samples at certain period of infection. Therefore, both constitutive and induced pattern of differential gene expression can be observed.