Alkanes (C29 and C31)-Mediated Intracuticular Wax Accumulation Contributes to Melatonin- and ABA-Induced Drought Tolerance in Watermelon

Journal of Plant Growth Regulation - As the outermost hydrophobic layer, cuticular waxes serve as an essential waterproof barrier to protect plants from desiccation, but the mechanism of wax...     

Structural-functional state of thylakoid membranes of wheat genotypes under water stress

Plants were grown in field conditions in the wide area under normal water supply and severe water deficit. Two wheat (Triticum aestivum L.) genotypes contrasting by architectonics and differing in drought-resistance were used: Giymatli-2/17, short stature, with broad and drooping leaves, drought-sensitive, and Azamatli-95, short stature, with vertically oriented small leaves, drought-tolerant). It was found out that Giymatli-2/17 was characterized by relatively low content of Chl a-protein of PS I (CP I) and β-subunit of ATP-synthase complex, the high content of proteins in the 33-30.5 kDa region and LHC polypeptides (28-24.5 kDa), the intensive fluorescence at 740 nm and more high photochemical activity of PS II under normal irrigation compared with Azamatli-95. However, the content of CP I (M_r 115 kDa) and apoprotein of P700 with M_r 63 kDa insignificantly increases in the drought-resistant genotype Azamatli-95 under extreme water supply condition while their content decreases in drought-sensitive cv Giymatli-2/17. Intensity of synthesis α- and β-subunits of CF₁ (55 and 53.5 kDa) also decreases in Giymatli-2/17. The levels of the core antenna polypeptides of FS II with M_r 46 and 44.5 kDa (CP47 and CP43) remains stable both in normal, and stressful conditions. At the same time the significant reduction is observed in the content of polypeptides in the 33-30.5 kDa region in the more sensitive genotype Giymatli-2/17. There is an increase in the LHC II polypeptides level in tolerant genotype Azamatli-95 in contrast to Giymatli-2/17 (where the content of these subunits is observed decreasing). The intensity of short wavelength peaks at 687 and 695 nm sharply increases in the fluorescence spectra (77 K) of chloroplasts from sensitive genotype Giymatli-2/17 under water deficiency and there is a stimulation of the ratio of fluorescence band intensity F687/F740. After exposure to drought, cv Giymatli-2/17 shows a larger reduction in the actual PS II photochemical efficiency of chloroplasts than cv Azamatli-95.     

Structural-functional state of thylakoid membranes of wheat genotypes under water stress

Plants were grown in field conditions in the wide area under normal water supply and severe water deficit. Two wheat (Triticum aestivum L.) genotypes contrasting by architectonics and differing in drought-resistance were used: Giymatli-2/17, short stature, with broad and drooping leaves, drought-sensitive, and Azamatli-95, short stature, with vertically oriented small leaves, drought-tolerant). It was found out that Giymatli-2/17 was characterized by relatively low content of Chl a-protein of PS I (CP I) and beta-subunit of ATP-synthase complex, the high content of proteins in the 33-30.5 kDa region and LHC polypeptides (28-24.5 kDa), the intensive fluorescence at 740 nm and more high photochemical activity of PS II under normal irrigation compared with Azamatli-95. However, the content of CP I (M(r) 115 kDa) and apoprotein of P700 with M(r) 63 kDa insignificantly increases in the drought-resistant genotype Azamatli-95 under extreme water supply condition while their content decreases in drought-sensitive cv Giymatli-2/17. Intensity of synthesis alpha- and beta-subunits of CF(1) (55 and 53.5 kDa) also decreases in Giymatli-2/17. The levels of the core antenna polypeptides of FS II with M(r) 46 and 44.5 kDa (CP47 and CP43) remains stable both in normal, and stressful conditions. At the same time the significant reduction is observed in the content of polypeptides in the 33-30.5 kDa region in the more sensitive genotype Giymatli-2/17. There is an increase in the LHC II polypeptides level in tolerant genotype Azamatli-95 in contrast to Giymatli-2/17 (where the content of these subunits is observed decreasing). The intensity of short wavelength peaks at 687 and 695 nm sharply increases in the fluorescence spectra (77 K) of chloroplasts from sensitive genotype Giymatli-2/17 under water deficiency and there is a stimulation of the ratio of fluorescence band intensity F687/F740. After exposure to drought, cv Giymatli-2/17 shows a larger reduction in the actual PS II photochemical efficiency of chloroplasts than cv Azamatli-95.     

Comparative bio-efficacy of nuclear polyhedrosis virus (NPV) and Spinosad against American bollwormm,Helicoverpa armigera (Hubner)

American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, Gossypium hirsutum, all over the globe. Due to its destructive feeding nature and continuous consumption of the same chemicals, it devolved resistant against many insecticides. Therefore, a combined application of bio- and synthetic-pesticide need to evaluate against this pest. The entomopathogenic viruses like nuclear polyhedrosis virus (NPV), a member of baculoviruses, can be the potential candidates for better control against ABW. The present study was conducted to assess the comparative efficacy of NPV and Spinosad 240SC (with the concentration of 250 mL · ha￣?) against ABW in the controlled environment. The ABW was treated with different concentrations of NPV and Spinosad separately and in a combination of NPV with 0.1% Spinosad. The results revealed that highest concentrations showed highest mortality (95%) followed by 95%, 92%, 84%, 82% and 78% mortality at 1 × 10⁹, 1 × 10⁸, 1 × 10⁷, 1 × 10⁶ and 1 × 10⁵ POBs, respectively. Spinosad when mixed in diet give 100% mortality at 0.8% followed by 50.87%, 42.10%, 29.82%, 26.31% and 22.80% mortality at 0.4%, 0.2%, 0.1%, 0.5% and 0.025% respectively. The results of this study revealed that microbial control of ABW through NPV is an effective tool. The repeated use of synthetic pesticides caused the resurgence of many insect pests, and this study results would provide useful insight to build a framework for future investigations for the management of many major insect pests.     

Colonization and extinction dynamics among the plant species at tree bases in Paris (France)

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Tissue Distribution of Anidulafungin in Neonatal Rats

Anidulafungin, an echinocandin, is currently approved for treatment of fungal infections in adults. There is a high unmet medical need for treatment of fungal infections in neonatal patients, who may be at higher risk of infections involving bone, brain, and heart tissues. This in vivo preclinical study investigated anidulafungin distribution in plasma, bone, brain, and heart tissues in neonatal rats. Postnatal day (PND) 4 and PND 8 Fischer (F344/DuCrl) rats were dosed subcutaneously once with anidulafungin (10 mg/kg) or once daily for 5 days (PND 4–8). Plasma and tissue samples were collected and anidulafungin levels were measured by liquid chromatography‐tandem mass spectrometry. The mean plasma C_max and AUC_0‐24 values were consistent with single‐dose plasma pharmacokinetics (dose normalized) reported previously for adult rats. Observed bone concentrations were similar to plasma concentrations regardless of dosing duration, with bone‐to‐plasma concentration ratios of approximately 1.0. Heart concentrations were higher than plasma, with heart to plasma concentration ratios of 1.3‐ to 1.8‐fold. Brain concentrations were low after single dose, with brain‐to‐plasma concentration ratio of approximately 0.23, but increased to approximately 0.71 after 5 days of dosing. Tissue concentrations were nearly identical after single‐dose administration in both PND 4 and PND 8 animals, indicating that anidulafungin does not appear to differentially distribute in this period in neonatal rats. In conclusion, anidulafungin distributes to bone, brain, and heart tissues of neonatal rats; such results are supportive of further investigation of efficacy against infections involving bone, brain, and heart tissues.