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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.

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20231
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Subject: Agricultural Biotechnology × Author: Baruah, Manjistha × Start date: 2022 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    A study of sulphur metabolizing bacteria from tea garden soil for improving sulphur uptake in crop plants.
    (2023) Baruah, Manjistha; Barooah, Madhumita
    Sulphur, an important element for plant growth, is required for the synthesis of several essential vitamins, amino acids, initiation of enzymes, formation of glucosides, chlorophyll, and glucosinolates. Bacteria with sulphur metabolizing ability are at the center of sulphur cycling taking part in the oxidation, reduction, assimilation and dissimilation of sulphur in the entire ecosystem. In acidic soil, the amount of sulphur is less which affects the plant growth. Sulphur metabolizing bacteria with low pH tolerance can be used as bioinoculum to facilitate sulphur availability to the crop plants. Towards this end, sulphur metabolizing bacteria was isolated from acidic soils and characterized for sulphur metabolizing activity. The most efficient sulphur metabolizing, acid tolerant bacteria along with plant growth promoting activities isolated was identified as Priestia aryabhattai MBM3 as deduced from morphological, biochemical and molecular studies. The genes involved in sulphur metabolic pathway in the bacterial isolate grown in acid stress were upregulated during the lag phase indicating to the low sulphur availability during acid stress and hence higher expression of the gens. Further studies of the isolate for plant growth promotion in Brassica campestris L. variety JT-90-1 (Jeuti) was evaluated through pot experiments. The pot soils with pH 5 were supplemented with 100%RDF (T1), 50% RDF+bio-primed seeds (T2), bio-primed seeds (T3), along with an absolute control. Agronomic and physiological traits in relation to plant height, number of leaves, flavonoid content and total carbohydrate fared better in plants treated with bacteria (T2 and T3) than in control and T1 plants. At a molecular level, the plant sulphur transporters (SULTR1 and SULTR4) and pathway genes such as APS reductase and sulfite reductase had lower expression in roots indicating to favorable uptake of sulphur by the plant and its subsequent transfer to the other parts. This was evidenced by higher expression of the transporter genes in leaves signifying its uptake followed by its subsequent assimilation by the pathway genes viz. ATP sulphurylase, APS reductase, and sulfite reductase. However, in the control and T1 plants, a significant high expression of APS reductase was observed indicating over production of sulfite. Increased sulfite production is reported to affect chlorophyll content and stunted growth in plants as evidenced by agronomic and physiological traits of the control and T1 plants. The above results suggest that isolate MBM3 was able to elicit a sulphur uptake response in Brassica campestris grown in acidic soil of pH 5 as compared to control revealing a delicate symbiosis between plant and bacterial signaling pathways. Further studies to unravel the plant signaling pathways involved in evoking an enhanced sulphur metabolism due to bacterial treatment will shed more light into role of the bioinoculum before it is taken to the field.