Organogenesis andin vitro flowering ofEchinochloa colona. Effect of growth regulators and explant types

Echinochloa colona regeneration via organogenesis in callus cultures derived from leaf base and mesocotyl expiants andin vitro flowering were achived. Shoot bud regeneration was achieved on Murashige and Skoog’s (MS) basal medium supplemented with 6.66 μM 6-benzylaminopurine (BAP), 2.68 μM 1-naphthalene acetic acid (NAA) and 3 % (m/v) saccharose. Regenerated shoots were rooted on half strength basal MS medium with 2 % (m/v) saccharose devoid of growth regulators. About 90 -95 % of rooted plantlets survived in the greenhouse.In vitro flowering was induced in the regenerated shoots derived from callus on half strength MS medium supplemented with 4.4 μM BAP, 74.07 μM adeninesulphate, 0.72 μM gibberellic acid, and 3 % (m/v) saccharose. The frequency ofin vitro flowering was 80 – 90 % in three repeated experiments. Fertile seeds were recovered fromin vitro grown plantlets which were subsequently germinated into plants. Acknowledgement: The authors wish to thank to the Department of Environment and Forests, Government of India for financial assistance to undertake this investigation.     

Somatic embryogenesis and plant regeneration from callus culture of Acacia catechu-a multipurpose leguminous tree

Plant regeneration via somatic embryogenesis was achieved from callus derived from immature cotyledons of Acacia catechu Willd. on Woody Plant Medium (WPM) supplemented with 13.9 M kinetin and 2.7 M 1-naphthaleneacetic acid. The addition of 0.9–3.5 mM L-proline to the medium influenced development of somatic embryos and also promoted secondary somatic embryogenesis. The light-green somatic embryos germinated on half-strength MS medium supplemented with 2% (w/v) sucrose. Somatic embryos germinated into plantlets that were acclimatized in the greenhouse and subsequently transferred to the field.     

Revisiting the use of Iprodione and Trichoderma in the integrated management of onion white rot

The biocontrol properties of Trichoderma species are well documented, but their effectiveness in antagonism of the problematic Sclerotium cepivorum, the causal agent of white rot in Allium species, appears limited with reports of significant control only relating to deliberately-mutated strains of Trichoderma. Our previous studies have indicated the possibility of using selected naturally-occurring strains of the antagonist in the suppression of other diseases; now in vitro and controlled environment in vivo studies have indicated that a degree of control of Onion White Rot is possible, and that the selected antagonist strains can be used in integrated treatments with Iprodione to good effect. The possible value of such treatments is considered in light of other approaches to the suppression of this continuing problem.     

In vitro micropropagation of Lawsonia inermis (Lythraceae)

A successful protocol was developed for mass propagation of Lawsonia inermis Linn., an important medicinal plant. Multiple shoots were induced in apical and axillary meristems derived from mature explants of L. inermis on Murashige and Skoog (1962) medium supplemented with 0.25 mg/l 6-benzylaminopurine (BA), 0.25 mg/l Kinetin (Kn), 0.5 mg/l ascorbic acid and 3% (w/v) sucrose. The rate of multiplication was higher when the cultures were incubated under continuous light rather than the 14 hr photoperiod. Rooting was readily achieved upon transferring the microshoots onto MS basal semi-solid medium supplemented with 0.25 mg/l indole-3-butyric acid (IBA) after ten days of culture. Micropropagated plantlets were acclimatized and successfully grown in soil.     

A spatiotemporal characterization of the effect of p53 phosphorylation on its interaction with MDM2

The interaction of p53 and MDM2 is modulated by the phosphorylation of p53. This mechanism is key to activating p53, yet its molecular determinants are not fully understood. To study the spatiotemporal characteristics of this molecular process we carried out Brownian dynamics simulations of the interactions of the MDM2 protein with a p53 peptide in its wild type state and when phosphorylated at Thr18 (pThr18) and Ser20 (pSer20). We found that p53 phosphorylation results in concerted changes in the topology of the interaction landscape in the diffusively bound encounter complex domain. These changes hinder phosphorylated p53 peptides from binding to MDM2 well before reaching the binding site. The underlying mechanism appears to involve shift of the peptide away from the vicinity of the MDM2 protein, peptide reorientation, and reduction in peptide residence time relative to wild-type p53 peptide. pThr18 and pSr20 p53 peptides experience reduction in residence times by factors of 13.6 and 37.5 respectively relative to the wild-type p53 peptide, indicating a greater role for Ser20 phosphorylation in abrogating p53 MDM2 interactions. These detailed insights into the effect of phosphorylation on molecular interactions are not available from conventional experimental and theoretical approaches and open up new avenues that incorporate molecular interaction dynamics, for stabilizing p53 against MDM2, which is a major focus of anticancer drug lead development.     

MAP Kinase analyser: A tool for plant kinase and substrate analysis

MAPK (Mitogen Activated Protein Kinase) is a Ser/Thr kinase, which plays a crucial role in plant growth and development, transferring the extra cellular stimuli into intracellular response etc. Manual identification of these MAPK in the plant genome is tedious and time taking process. There are number of online servers which predict the P-site (phosphorylation site), find the motifs and domain but there is no specific tool which can identify all them together. In order to identify the P-Site, phosphorylation site consensus sequences and domain of the MAPK in plant genome, we developed a tool, MAP Kinase analyzer. MAP kinase analyzer take protein sequence as input in the fasta format and the output of tool includes: 1) The prediction of the phosphorylation site viz., Serine (S), Threonine (T), and Tyrosine (Y), Contex, Position, Score and phosphorylating kinase as well as the graphical output; 2) Phosphorylation site consensus sequence pattern for different kinases and 3) Domain information about the MAPK's. The MAP kinase analyser tool and supplementary files can be downloaded from http://www.bioinfogbpuat/mapk_OWN_1/.     

Phosphorylation of Enoyl-Acyl Carrier Protein Reductase InhA Impacts Mycobacterial Growth and Survival

InhA, the primary target for the first line anti-tuberculosis drug isoniazid, is a key enzyme of the fatty-acid synthase II system involved in mycolic acid biosynthesis in Mycobacterium tuberculosis. In this study, we show that InhA is a substrate for mycobacterial serine/threonine protein kinases. Using a novel approach to validate phosphorylation of a substrate by multiple kinases in a surrogate host (Escherichia coli), we have demonstrated efficient phosphorylation of InhA by PknA, PknB, and PknH, and to a lower extent by PknF. Additionally, the sites targeted by PknA/PknB have been identified and shown to be predominantly located at the C terminus of InhA. Results demonstrate in vivo phosphorylation of InhA in mycobacteria and validate Thr-266 as one of the key sites of phosphorylation. Significantly, our studies reveal that the phosphorylation of InhA by kinases modulates its biochemical activity, with phosphorylation resulting in decreased enzymatic activity. Co-expression of kinase and InhA alters the growth dynamics of Mycobacterium smegmatis, suggesting that InhA phosphorylation in vivo is an important event in regulating its activity. An InhA-T266E mutant, which mimics constitutive phosphorylation, is unable to rescue an M. smegmatis conditional inhA gene replacement mutant, emphasizing the critical role of Thr-266 in mediating post-translational regulation of InhA activity. The involvement of various serine/threonine kinases in modulating the activity of a number of enzymes of the mycolic acid synthesis pathway, including InhA, accentuates the intricacies of mycobacterial signaling networks in parallel with the changing environment.     

Ground wētā in vines of the Awatere Valley,Marlborough: biology,density and distribution

The endemic New Zealand ground wētā (Hemiandrus sp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation.     

in Vitro Somatic Embryogenesis in Typhonium Trilobatum Schott.

An in vitro protocol was developed for the production of plants via somatic embryogenesis in callus cultures derived from petiole and leaf explants of Typhonium trilobatum. Optimum callus formation was achieved on semisolid Murashige and Skoog's [9] medium supplemented with 0.25 mg L–1 kinetin and 3.0 mgL–1 1-naphthaleneacetic acid (NAA) after 6 weeks of culture. Somatic embryogenesis was achieved upon transferring the callus to a medium containing 1.0 mg Lminus 1 kinetin and 0.25 mg Lminus 1 NAA. In vitro tuberization was also achieved on medium containing 1/2 strength MS basal salts supplemented with 1.0 mg L–1 Kinetin and 0.1 mg L–1 NAA. Embryo maturation and germination was achieved on the MS basal salts supplemented with 0.01 mg L–1 NAA and 2% (w/v) sucrose. Some thousands somatic embryo derived plantlets were hardened in the greenhouse and eventually planted in the open field.