IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Switching between the pathogenic smooth (1116S) and nonpathogenic rough (1116R) forms of Pseudomonas tolaasii occurs due to the reversible duplication of a 661-bp element within the pheN locus. Disruption of the chromosomal recA locus of 1116S and 1116R produced strains 1116SrecA and 1116RrecA, respectively, which showed typical loss of UV resistance. Switching from the smooth to the rough form was virtually eliminated in the 1116SrecA strain, whereas the extent of switching from the rough to the smooth form was almost identical in 1116R and 1116RrecA. It is concluded that phenotypic switching from 1116S to 1116R is recA dependent whereas that from 1116R to 1116S is recA independent.

Department Of Biotechnology

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Journal of Bacteriology

Analysis of the role of recA in phenotypic switching of Pseudomonas tolaasii

Leaf explants of 4 sugarcane varieties, CoJ 64, CoJ 83, CoJ 84 and CoP 84-211, were cultured on MS medium supplemented with 4 mg 2,4-D, 0.5 mg kinetin and 30 g sucrose/litre. Embryogenic calli was subsequently subcultured onto MS medium containing 0.5 mg benzyladenine and 0.5 mg kinetin/litre. The extent of callus proliferation, somatic embryogenesis and plantlet induction was recorded on different media containing 2 mg abscisic acid, 560 mg proline, 30 g maltose, and 2 and 6 mg 2,4-D/litre. Low auxin concentrations resulted in white, compact embryogenic callus. Maltose and proline gave an increased mass of yellow, compact embryogenic callus. CoJ 64 gave the highest somatic embryo production and all treatments, except 6 mg 2,4-D/litre, showed enhanced regeneration response compared with controls. The best treatment was abscisic acid followed by partial desiccation and proline addition.

Indian Journal of Agricultural Sciences

Regulation of somatic embryogenesis and plant regeneration in sugarcane (Saccharum officinarum)

A septin gene homologue designated Pyrenopeziza brassicae septin 1 (Pbs1) has been identified and cloned from the plant pathogenic fungus Pyrenopeziza brassicae and its expression analysed. Pbs1 is present in both mating types and in a single copy within each genome and is transcribed in proportionate levels during both vegetative and sexual growth. © 2000 Elsevier Science B.V.