Some physiological and morphological responses of Pyrus boissieriana to flooding

European pear is a flooding-sensitive species, and for its cultivation in lowland areas, it is necessary to carry out the grafting of scions of commercial pear varieties into rootstocks belonging to flooding-tolerant wild pear species. Flooding tolerance of Pyrus boissieriana—a type of wild pear—was studied as a promissory rootstock for commercial pear. For this purpose, 3-month-old plants of P. boissieriana were subjected for 30 days to control (C), well-irrigated treatment, short-term (15 days) flooding plus 15 days recovery (F + R) and long-term (30 days) continuous flooding (F). Physiological performance, plant morphological changes and biomass accumulation were assessed. Results showed that, although stomatal conductance, transpiration and photosynthesis were progressively decreased by flooding, when flooding was short term (i.e., 2 weeks, F + R treatment) plants were able to adequately recover their physiological activity (50–74 % with respect to controls). In contrast, when plants continued to be flooded (F treatment), the physiological activity became null and the plants died quickly after the water subsided. Adventitious rooting was the most conspicuous registered morphological response to flooding, despite that flooded plants had shorter shoots and roots than control plants. Leaf and root biomass were 63 and 89 % higher under short-term flooding (F + R) than under continuous flooding (F), condition in which plants did not survive. In conclusion, P. boissieriana appears to be a promising species for its use as rootstock of commercial pear in lowland areas prone to flooding of up to 2 weeks. However, if the flooding period is extended, plants of this species are at risk of perishing.     

Cultivation of newly isolated microalgae Coelastrum sp. in wastewater for simultaneous CO2 fixation,lipid production and wastewater treatment

Bioprocess and Biosystems Engineering - Cultivation of microalgae in wastewater is a promising and cost-effective approach for both CO2 biofixation and wastewater remediation. In this study, a new...     

Comparison of the effects of poultry manure and its biochar on barley growth in petroleum-contaminated soils

This study was conducted to evaluate and compare the effectiveness of two organic amendments [poultry manure (PM) and poultry manure biochar (PMB)] for the degradation of petroleum hydrocarbons in contaminated soils by barley plant at three levels of total petroleum hydrocarbons (TPHs) during 5 months under greenhouse conditions. TPHs removal efficiency and microbial respiration were shown to be higher at soil-cultivated plant than at uncultivated soil and in lowest level of contamination rather than other levels of contamination and at organic amendment treatment than unamended soil. Soil microbial respiration and TPHs degradation in the rhizosphere of barley increased by 15.64 and 12.74% for PM-amended treatment and 28.07 and 26.83% for PMB-amended treatment, respectively, in the 4% TPHs level compared with unamended treatment. Comparison of two amendments showed that in PMB treatment soil, highest dry weight, microbial respiration, and TPHs degradation potential were observed.     

17th Chromosome‐Centric Human Proteome Project Symposium in Tehran

This report describes the 17th Chromosome‐Centric Human Proteome Project which was held in Tehran, Iran, April 27 and 28, 2017. A brief summary of the symposium's talks including new technical and computational approaches for the identification of novel proteins from non‐coding genomic regions, physicochemical and biological causes of missing proteins, and the close interactions between Chromosome‐ and Biology/Disease‐driven Human Proteome Project are presented. A synopsis of decisions made on the prospective programs to maintain collaborative works, share resources and information, and establishment of a newly organized working group, the task force for missing protein analysis are discussed.     

How salinity stress influences the thermal time requirements of seed germination in <Emphasis Type="Italic">Silybum marianum</Emphasis> and <Emphasis Type="Italic">Calendula officinalis</Emphasis>

Salinity is a major problem of many agricultural lands that is usually associated with drought stress in arid and semi-arid regions. In this study we examine the role of salinity stress on temperature requirements of two herbaceous species and how it could be modeled to quantify alterations. We applied four non-linear regression models (segmented, beta, beta modified, and dent-like) to describe the germination rate–temperature relationships of Silybum marinum L. and Calendua officinalis L. over six constant temperatures exposed to different levels of salinity stress. Our results revealed that salinity could affect the cardinal temperatures in both plants and, as a result, it is not possible to suggest one model for all levels of salinity stress. The best model to fit data to predict cardinal temperatures of Silybum marianum and Calendula officinalis at the no-salinity condition were dent-like (AICc?=?4.03) and beta (AICc = ??2.30), respectively. Knowing the thermal time constant (f_o) value helps us predict the minimum number of hours required for completion of germination at the optimal temperature. All models in this study were estimated higher f_o due to higher salinity stress in both Silybum marianum and Calendula officinalis seeds. The highest estimated f_o for Silybum marianum (91.5?±?59.6) and Calendula officinalis (178.9?±?26.5) was obtained from the results of germination rate prediction using a dent-like model at 200 mM salinity.     

Cold-induced physiological and biochemical responses of three grapevine cultivars differing in cold tolerance

In this study the cold tolerance potential of three Vitis vinifera cultivars including ‘Red Sultana’, ‘White Sultana,’ and ‘Flame Seedless’ was evaluated under greenhouse condition. After 15 leaves stage in average, the grapevine plants were subjected to cold stress regimes (4, 0 and ? 4 °C) and compared with control plants (24 °C). A clear increase in leaf electrolyte leakage (EL), thiobarbituric acid reactive substances (TBARS), and H₂O₂ concentrations was observed with decreasing temperature from 4 to ? 4 °C in all grapevine cultivars. Chilled plants showed marked increases in their abscisic acid (ABA), soluble sugars, and proline contents in compared to control vines. Upon exposure to cold stress, the EL, TBARS, H₂O₂, and relative water content of ‘Red Sultana’ were found to be lower compared to ‘White Sultana’ and ‘Flame Seedless’. Under 0 °C condition, ‘Red Sultana’ had the highest superoxide dismutase, guaiacol peroxidase and catalase activities, which was approximately twofold higher than those of all other cultivars. Soluble sugars such as glucose, fructose, and sucrose increased from 4 to ? 4 °C. These increments were higher in ‘Red Sultana’ compared to other cultivars which was concomitant with higher accumulation of endogenous ABA concentration in this cultivar. Higher accumulation of ABA and soluble sugars in ‘Red Sultana’ confirmed the key roles of these compounds in cold tolerance which could be applied as a cold tolerance marker for early selection of grapevine cultivars with the aim to establish vineyards in cold winter regions.     

Glial Metabolism of Valine

The three essential amino acids, valine, leucine and isoleucine, constitute the group of branched-chain amino acids (BCAAs). BCAAs are rapidly taken up into the brain parenchyma, where they serve several distinct functions including that as fuel material in brain energy metabolism. As one function of astrocytes is considered the production of fuel molecules that support the energy metabolism of adjacent neural cells in brain. Astroglia-rich primary cultures (APC) were shown to rapidly dispose of the BCAAs, including valine, contained in the culture medium. While the metabolisms of leucine and isoleucine by APC have already been studied in detail, some aspects of valine metabolism remained to be determined. Therefore, in the present study an NMR analysis was performed to identify the ¹³C-labelled metabolites that are generated by APC during catabolism of [U-¹³C]valine and that are subsequently released into the incubation medium. The results presented show that APC (1) are potently disposing of the valine contained in the incubation medium; (2) are capable of degrading valine to the tricarboxylic acid (TCA) cycle member succinyl-CoA; and (3) release into the extracellular milieu valine catabolites and compounds generated from them such as [U-¹³C]2-oxoisovalerate, [U-¹³C]3-hydroxyisobutyrate, [U-¹³C]2-methylmalonate, [U-¹³C]isobutyrate, and [U-¹³C]propionate as well as several TCA cycle-dependent metabolites including lactate. This article is dedicated to Dr. George DeVries.