Photosynthetic responses of corn and soybean to foliar application of salicylates.

Spraying mustard (Sinapis alba L.) seedlings with salicylic acid (SA) solutions between 10 and 500 μm significantly improved their tolerance to a subsequent heat shock at 55°C for 1.5 h. The effects of SA were concentration dependent, with higher concentrations failing to induce thermotolerance. The time course of thermotolerance induced by 100 μm SA was similar to that obtained with seedlings acclimated at 45°C for 1 h. We examined the hypothesis that induced thermotolerance involved H2O2. Heat shock at 55°C caused a significant increase in endogenous H2O2 and reduced catalase activity. A peak in H2O2 content was observed within 5 min of either SA treatment or transfer to the 45°C acclimation temperature. Between 2 and 3 h after SA treatment or heat acclimation, both H2O2 and catalase activity significantly decreased below control levels. The lowered H2O2 content and catalase activity occurred in the period of maximum thermoprotection. It is suggested that thermoprotection obtained either by spraying SA or by heat acclimation may be achieved by a common signal transduction pathway involving an early increase in H2O2.

http://www.plantphysiol.org/content/plantphysiol/116/4/1351.full.pdf

Parallel Changes in H2O2 and Catalase during Thermotolerance Induced by Salicylic Acid or Heat Acclimation in Mustard Seedlings

The addition of 0.5 mM salicylic acid (SA) to the hydroponic growth solution of young maize (Zea mays L.) plants under normal growth conditions provided protection against subsequent low-temperature stress. This observation was confirmed by chlorophyll fluorescence parameters and electrolyte leakage measurements. In addition, 1 d of 0.5 mM SA pre-treatment decreased net photosynthesis, stomatal conductivity and transpiration at the growth temperature (22/20 °C). Since there was only a slight decrease in the ratio of variable to maximal fluorescence (Fv/Fm) the decrease in photosynthetic activity is not due to a depression in photosystem II. The analysis of antioxidant enzymes showed that whereas SA treatment did not cause any change in ascorbate peroxidase (EC 1.11.1.11) and superoxide dismutase (EC 1.15.1.1) activities, there was a decrease in catalase (EC 1.11.1.6) activity, and an increase in guaiacol peroxidase (EC 1.11.1.7) and glutathione reductase (EC 1.6.4.2) activities after the 1-d SA treatment at 22/20 °C. In native polyacrylamide gels there was, among the peroxidase isoenzymes, a band which could be seen only in SA-treated plants. It is suggested that the pre-treatment of maize plants with SA at normal growth temperature may induce antioxidant enzymes which lead to increased chilling tolerance.

Hydroponic treatment with salicylic acid decreases the effects of chilling injury in maize (Zea mays L.) plants

Does exogenous application of salicylic acid through the rooting medium modulate growth and photosynthetic capacity in two differently adapted spring wheat cultivars under salt stress

Salicylic acid alleviates decreases in photosynthesis under salt stress by enhancing nitrogen and sulfur assimilation and antioxidant metabolism differentially in two mungbean cultivars

Rai, V. K., Sharma, S. S. and Sharma, S. 1986. Reversal of ABA-induced storaatal closure by phenolic

Reversal of ABA-Induced Stomatal Closure by Phenolic Compounds

Caralluma fimbriata extract induced green synthesis, structural, optical and photocatalytic properties of ZnO nanostructure modified with Gd

SUMMARY
Effects of abscisic acid and certain phenolic compounds have been studied, individually and in combination, on in vitro amylase activity from Triticum aestivum L. seeds. ABA suppressed the amylase activity, in vitro, while salicylic acid, cinnamic acid and ferulic acid applied alone promoted it; vanillic acid caused a slight inhibition. Irrespective of their individual effects, all the phenolic compounds studied reverted the inhibitory action of ABA on amylase activity. This behaviour suggests that phenolic compounds could have a role in regulating mobilization of carbohydrates through degradation of starch, and in turn some role in the regulation of seed germination.

Reversal by phenolic compounds of abscisic acid-induced inhibition of in vitro activity of amylase from seeds of triticum aestivum l.

Microorganisms striving in extreme environments and exhibiting optimal growth and reproduction at low temperatures, otherwise known as psychrophilic microorganisms, are potential sources of cold-active enzymes. Owing to higher stability and cold activity, these enzymes are gaining enormous attention in numerous industrial bioprocesses. Applications of several cold-active enzymes have been established in the food industry, e.g., β-galactosidase, pectinase, proteases, amylases, xylanases, pullulanases, lipases, and β-mannanases. The enzyme engineering approaches and the accumulating knowledge of protein structure and function have made it possible to improve the catalytic properties of interest and express the candidate enzyme in a heterologous host for a higher level of enzyme production. This review compiles the relevant and recent information on the potential uses of different cold-active enzymes in the food industry.

Biotechnological potential of psychrophilic microorganisms as the source of cold-active enzymes in food processing applications.

Cancer cell line selection serves as a milestone step for anti-cancer drug discovery. In this brief communication an attempt has been made to reviewed distinct human cancer (liver cancer, lung cancer, breast cancer, lymphoma, colon cancer, melanoma, leukemia, myeloma tumors, gastric cancer, promyelocytic leukemia, pancreatic adenocarcinoma, skin fibroblast cells, colorectal adenocarcinoma, oral squamous cell carcinoma, gynaecological cancer, larynx cancer, epithelial carcinoma etc.) cell lines (BEL-7402, NSCLC, NCI-H125, H157, MCF-7, MDA-MB- 435, KATOIII, HL-60, Mia PaCa-2, NF-103, MCF-7, SK-OV-3, CAOV-3, RL95–2, KLE etc.) which have been screened by Cell proliferation/cytotoxicity assay, MTT assay, Radioimmunoassay, TUNEL assay, Anchorage independent clonogenic assay, Neyfakh assay, Caspase-3/9 assay etc. After the in vitro screen, the most sensitive cancer cell lines can be selected for further tested in xenograft or orthotopic tumor models in mice or rats (in vivo).

/pdf/human-cancer-cell-lines-a-brief-communication-4ojzpxi8vn.pdf

Swati Sharma

Papers

Reversal of ABA-Induced Stomatal Closure by Phenolic Compounds

Caralluma fimbriata extract induced green synthesis, structural, optical and photocatalytic properties of ZnO nanostructure modified with Gd

Reversal by phenolic compounds of abscisic acid-induced inhibition of in vitro activity of amylase from seeds of triticum aestivum l.

Biotechnological potential of psychrophilic microorganisms as the source of cold-active enzymes in food processing applications.

Human cancer cell lines- A brief communication