<Emphasis Type="Italic">Pseudomonas</Emphasis> sp. strain AKM-P6 enhances tolerance of sorghum seedlings to elevated temperatures

A thermotolerant strain AKM-P6 of Pseudomonas sp. possessing plant growth-promoting properties was isolated from rhizosphere of pigeon pea grown under semiarid conditions in India. The effect of inoculation with AKM-P6 on survival and growth of sorghum seedlings at elevated temperatures (ET) was investigated under sterile and nonsterile soil conditions. Inoculation with strain AKM-P6 helped sorghum (var CSV-15) seedlings to survive and to grow at elevated temperatures (47–50°C day/30–33°C night) up to 15 days while uninoculated plants died by the fifth day of exposure to elevated temperature. Under sterile and nonsterile conditions, significantly higher root and shoot biomass were recorded in inoculated seedlings as compared to uninoculated control at ET, but this difference was nonsignificant at ambient temperature. Inoculation induced the biosynthesis of high-molecular weight proteins in leaves under elevated temperature, reduced membrane injury, and improved the levels of cellular metabolites like proline, chlorophyll, sugars, amino acids, and proteins. Scanning electron microscopy studies confirmed the colonization and establishment of the organism on the root surface. The 16SrDNA sequence of the strain AMK-P6 showed 97% homology with that of Pseudomonas aeruginosa in the existing database. The results indicate that Pseudomonas sp. strain AKM-P6 can enhance tolerance of sorghum seedlings to elevated temperatures by inducing physiological and biochemical changes in the plant.     

In vitro inhibition of α-amylase and protease by nematocides in Cicer arietinum L

The in vitro effects of four systemic nematocides, i.e., aldicarb, carbofuran, oxamyl, and phorate, on the α-amylase and protease activities in Cicer arietinum has been revealed. All four nematocides markedly inhibited the activities of both the enzymes, with a general tendency of increased inhibition with corresponding increase in the concentrations of the nematocides. There was complete inhibition of α-amylase activity by the highest concentration (500 μM) of aldicarb and carbofuran, while oxamyl at the same concentration showed the same effects on protease activity. The lowest concentration (10 μM) was almost ineffective.     

Plasmid profile and phage type of Salmonella typhimurium strains encountered in different regions of India

A total of 190 Salmonella typhimurium strains encountered in different parts of India were characterized on the basis of plasmid profile, phage type and antimicrobial resistance pattern. Recent trends in the epidemiology of R-plasmids were also studied.

The majority of S. typhimurium strains (90.5%) were untypable by phage typing. Only 18 strains (9.5%) were phage typable. The phage untypable strains isolated from northern (57) central (65), and southern (50) regions of India could be subgrouped into 24, 12 and 16 different plasmid profiles respectively. Heterogeneity was the prominent feature although most of the plasmid profiles were related among strains isolated from particular place. A great diversity among small plasmids (2.7–8.3 kb) made subgrouping of majority strains (71%) with R-pattern ApCmKmSmSuTcTp possible. Conjugation studies and plasmid profile analysis of transconjugants revealed all the strains to harbour non conjugative non-auto transmissible plasmids with the exception of 7.2 and 2.7 kb plasmids which were not mobilizable.     

Impacts of fiber orientation and milling on observed crystallinity in jack pine

Influences of fiber orientation and milling on wood cellulose crystallinity were studied using jack pine wood. The fiber orientation effects were measured by sampling rectangular wood blocks in radial, tangential, and cross-sectional orientations. The influence of milling was studied by analyzing the unsieved and sieved milled wood fractions (all <1,000 μm). Fiber orientation effect was manifested in both X-ray and Raman measurements and was dependent upon the orientation of the sampled wood blocks. In Raman, the observed crystallinity was similar between the blocks sampled on the tangential and the radial faces. However, the estimated values were 5.5 % lower compared to that measured in a powdered sample pellet. Moreover, in these sampling modes, the orientation of the block with respect to the direction of the electric vector of the laser made a difference only for the tangential mode of sampling. When a wood block was sampled on the cross-sectional face, the observed Raman crystallinity was 3.9 % higher from that of the pellet. The observed crystallinity did not significantly differ with change in sample orientation with respect to the electric vector direction. In contrast, the Segal-WAXS study of the blocks indicated that compared to the pellet, the estimated crystallinities in the radial, tangential, and cross-sectional sampling modes were 5, 2, and 11 % lower, respectively. This suggested that the radial and the tangential faces of the blocks can be used to estimate the crystallinity of wood. With regard to the effect of milling on Raman and Segal-WAXS estimates, the wood crystallinity did not depend upon the particle sizes of the fractionated samples and was similar to that of the original unfractionated ground wood.     

Anti-abortion and Fertility Vaccine Potential of Defined Double Deletion (ΔaroAΔhtrA) Mutant (S30) of Salmonella Abortusequi in Equids

The present study on defined double deletion (ΔaroAΔhtrA) mutant (S30) of Salmonella enterica serovar Abortusequi evaluated it for safety, immunogenicity, and efficacy as a vaccine candidate in equids. The candidate strain was found safe in equids (foals, male and female horses and donkeys, and pregnant and nonpregnant mares) and induced good humoral and cell-mediated immunity on administration through oral route. The strain was not excreted in feces of vaccinated animals. The vaccine candidate administered orally (1 × 10¹¹ cfu per animal) protected mares even after 180 days of inoculation against abortion on challenge with wild-type S. Abortusequi strain whereas in nonvaccinated control, all mares aborted. The vaccination in infertile mares resulted in regaining of fertility in 67%–80% thoroughbred mares at two different breeding farms. Further, the humoral immunity was transferred to foals from vaccinated mothers through colostrum, but no placental transfer was evident. Thus, the vaccine under study may be recommended for use in equids to control S. Abortusequi infection–associated abortions and also to enhance fertility of temporarily infertile mares in endemic areas.     

Ovipositional responses of Chilo partellus (Swinhoe) (Lepidoptera: pyralidae) to natural products from leaves of two maize (Zea mays L.) Cultivars

Ovipositional responses of Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae) to hexane extracts of leaves of two maize (Zea mays L.) cultivars, one resistant (Kisan) and one susceptible (Basilocal), were studied in two-choice bioassays. Gravid females laid a significantly higher percentage of eggs on substrates smeared with extract of Basilocal leaves (HEBL) (69%) than on those smeared with extracts of Kisan leaves (HEKL) (31%). Several chemicals were isolated from HEKL, three of which were characterized as dotriacontanol, heptadecanol, and nonadecanol. These chemicals were either absent or were present in very small amounts in HEBL, but in HEKL they were detected in much larger amounts. Each isolated chemical was tested for its effect on C. partellus oviposition in two-choice bioassays. Maximum ovipositional deterrence (90%) was observed for the compound MR-22a, followed in decreasing order by nonadecanol, MR-7, and heptadecanol. The identity of the remaining compounds is being investigated. The results indicate that the relative resistance of Kisan maize compared to Basilocal is partly due to the presence of certain ovipositional deterrents in its leaves.     

Extracting work from a single heat bath via vanishing quantum coherence

We present here a quantum Carnot engine in which the atoms in the heat bath are given a small bit of quantum coherence. The induced quantum coherence becomes vanishingly small in the high-temperature limit at which we operate and the heat bath is essentially thermal. However, the phase phi, associated with the atomic coherence, provides a new control parameter that can be varied to increase the temperature of the radiation field and to extract work from a single heat bath. The deep physics behind the second law of thermodynamics is not violated; nevertheless, the quantum Carnot engine has certain features that are not possible in a classical engine.     

Raman microprobe evidence for lignin orientation in the cell walls of native woody tissue

Raman microprobe spectra from the secondary wall of earlywood tissue from Picea mariana (black spruce) reveal evidence of the orientation of lignin relative to the plane of the cell wall. In most instances, the aromatic rings of the phenyl propane structural units are parallel to the plane of the cell-wall surface.