Thumbnail Image

Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

Browse

20171
Reset filters
Subject: Agricultural Biotechnology × Author: Baruah, Geetanjali × End date: 2017 × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Analysis of the putative promoter of Indian Cassava Mosaic Virus, a Geminivirus
    (AAU, Jorhat, 2017-07) Baruah, Geetanjali; Sen, Priyabrata
    Geminiviruses are single-stranded DNA viruses, considered as the largest group of plant pathogenic viruses having nine genera. Geminiviruses are considered as a rich source of promoter elements as the intergenic region (IR) of their genomes harbor a bi-directional promoter driving expression in the viral-sense and complementary-sense directions. Indian cassava mosaic virus (ICMV; genus: Begomoviridae) is a bipartite (having two circular genomes, DNA-A and DNA-B) geminivirus; and in this study, we tried to define and delineate its bi-directional promoter of the DNA-A. This promoter drives the expression of Coat Protein (CP) in the viral-sense and Replication associated protein (Rep) genes in complementary-sense direction. Four sequential deletion-constructs for each of these promoters were made, after a prior in silico analysis using plantCARE to ensure that no key regulatory motif such as TATA box get deleted, driving expression of Gus gene in pBI121. In transient expression assay in Agrobacterium, and tobacco, the deleted versions (del-1) showed higher expression than the full-length promoters of both CP and Rep. Transgenic Nicotiana tabacum plants were raised using the full-length CP, full-length Rep and their del-1 constructs and same observations were made. Besides, their phloem-specific activity of the CP promoter constructs was also observed. Subsequently, Arabidopsis transgenic plants were raised for all the constructs and a similar expression pattern was observed. However, visually higher Gus expression in Arabidopsis flowers was observed. In silico analyses showed that the transcription factor (TF), CDC5 (a known transcription enhancer), was over-represented in CP del-1 construct showing highest expression. Besides, another transcription factor, the MADS Box 13, was over-represented in the CP promoter constructs; this TF plays role in development of gametophytes and embryo. Copy number, as determined by quantitative PCR, was found to be 2, 1, 4 and 2 for CP, CP del-1, Rep and Rep del-1, respectively. The expression was also quantified, that showed a similar pattern. Based on the observations, putative positive and negative regulatory elements of the promoters were also identified. Two transcripts were mapped in the viral-sense direction; the longer starting at position 138, and the shorter at position 170; while the longer could express both the AV1 and AV2 ORFs, the shorter transcript could express only the AV1 ORF. It is the first report of a comparison of deletion constructs of viral-sense and complementary-sense cassava mosaic virus promoters and their phloem-limited expression.