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Diverse source of early genotypes is obligatory for breeding high yielding early castor (Ricinus communis L.) cultivars. One hundred and twenty-five medium duration genotypes including three checks were evaluated for the presence of genetic diversity and variability. Genetic distance, variance components and correlation coefficients were estimated for seven seed related quantitative traits. Significant genotypic differences were observed among the collections for these traits. High heritability and high genetic advance were noticed for seed length, seed breadth, Length/Breadth ratio, shelling percentage, 100 seed weight and seed yield per plant, thus mode of gene action reported was additive. Genetic diversity analysis based on dendrogram, phenogram and circular form grouped the entries into seven groups and it computed inter and intra cluster distance. Principal Component Analysis (PCA) revealed that the first three components cumulatively accounted for 72.57 per cent of the total variation. Seed yield per plant showed a significant association with shelling percentage and 100 seed weight. Also, direct effects were high and positive through seed breadth, Length/Breadth ratio and 100 seed weight. The promising genotypes identified (ICIRG 2272103 and RG 1673) and the information generated would be useful for breeding early/medium cultivars as well to understand the physiological mechanism related to earliness in castor. [ABSTRACT FROM AUTHOR]

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Various physiological and biochemical responses of two good biomonitor plant species i.e. Datura alba and Ricinus communis were studied along two roads in the Punjab, Pakistan. Chlorophyll a , b , total chlorophylls, carotenoids, total free amino acids, total soluble proteins, total antioxidant activity, stomatal conductance, photosynthetic rate, internal CO 2 concentration, transpiration rate, and water use efficiency of D. alba and R. communis were examined at different sites along both roads. Photosynthetic rate of both plant species was found to be affected. Reduced transpiration rate and stomatal conductance were also noted. However, elevated internal CO 2 concentration and water use efficiency were recorded. Total soluble proteins got reduced, but, we found a tremendous increase in total antioxidant activity and total free amino acids in both plant species. D. alba was found to be more affected by the adverse effects of roadside air borne pollutants. Although R. communis was also affected but it showed minimal variation in all parameters compared to the control. Hence, our results suggest that R. communis is more resistant to urban roadside air pollution compared to D. alba and would be a good choice as phytoremediator of traffic borne pollutants, whereas, D. alba could be a better biomonitoring plant. • Vehicle exhaust is the biggest sources of air pollution these days. • Biological effects of vehicle pollution can be assessed by the use of biomonitoring plants. • R. communis and D. alba are two effective biomonitoring plants. • They responded differently to vehicle exhaust pollution at roadsides. • R. communis could be a good phytoremediator, while, D. alba can be used as a bioindicator plant at roadsides. [ABSTRACT FROM AUTHOR]

The castor bean tick, Ixodes ricinus (L.) (Ixodida: Ixodidae), is the principal vector of pathogens causing tick-borne encephalitis or Lyme borreliosis in Europe. It is therefore of general interest to make an estimate of the density of I. ricinus for the whole year at the beginning of the tick season. There are two necessary conditions for making a successful prediction: a long homogeneous time series of observed tick density and a clear biological relationship between environmental predictors and tick density. A 9-year time series covering the period 2009-2017 of nymphal I. ricinus flagged at monthly intervals in southern Germany has been used. With the hypothesis that I. ricinus density is triggered by the fructification of the European beech 2 years before, the mean annual temperature of the previous year, and the current mean winter temperature (December-February), a forecast of the annual nymphal tick density has been made. Therefore, a Poisson regression model was generated resulting in an explained variance of 93.4% and an error of RMSE=21 ticks per 100m2 (annual MEAN=260 collected ticks/100m2). An independent verification of the forecast for the year 2017 resulted in 187 predicted versus 180 observed nymphs per 100m2. For the year 2018 a relatively high number of 443 questing I. ricinus nymphs per 100m2 is forecasted, i.e., a “good” tick year. [ABSTRACT FROM AUTHOR]

Castor (Ricinus communis L.) is an important oilseed crop worldwide, and is also considered as one of the most promising plants for alkali-affected soil amelioration in the northeast of China. Seed germination plays a vital role in seedling establishment, and is always sensitive to alkali stress. However, little is known about the dynamic changes and regulatory mechanisms of gene expression and metabolic processes of this species during germination stage under alkali stress. In the present study, physiological, metabolome and transcriptome responses in germinating seeds of castor were investigated when exposed to 0, 50, 100 and 150 mM alkalinity (NaHCO 3). The results showed that alkali stress sharply decreased germination percentage. The Na+ content increased but K+ content decreased under alkalinity. In addition, the malondialdehyde and proline contents increased with the increasing alkalinities. Meanwhile, 50, 100 and 150 mM alkalinity induced 31, 48 and 113 differential metabolites, respectively. Furthermore, transcriptome profiling result showed that there were 138, 845 and 694 differentially expressed genes in the seeds under different concentrations alkali stresses, respectively. The integrating analysis of metabolite and gene expression changes indicating that germination response of castor seeds under alkali stress was closely related to amino acid metabolism, carbohydrate metabolism, lipid metabolism and nucleotide metabolism. The adaptive strategies of castor seeds under alkaline stress were promoting amino acid metabolism and tricarboxylic acid cycle to regulate osmotic balance and ROS level; as well as providing materials and energy for secondary metabolism, although alkali stress affected the membrane fluidity due to the reduction of unsaturated fatty acid content. Moreover, castor seeds increased metabolites on nucleotide biosynthesis to ensure their germination process under alkaline salt stress. The present research provides a deeper insight into overall understanding alkali-tolerant mechanisms of oil crops during germination in a holistic level. • l Using metabolomics and transcriptomics explored physiological adaptation mechanisms of castor seeds under alkali stress. • l 31, 48 and 113 differential metabolites and 138, 845 and 694 differentially expressed genes were found under alkali stress. • l Germination of castor at alkalinity was closely related to amino acid, carbohydrate, lipid and nucleotide metabolisms. • l Seeds of castor promoted amino acid metabolism and tricarboxylic acid cycle under stress. l Seeds of castor provided materials and energy for secondary metabolism under stress. [ABSTRACT FROM AUTHOR]

An estimated 5 million m³ of sewage sludge is produced annually in Malaysia. By 2020 it is expected to increase to 7 million m3. Phytoremediation is a method using plants to reduce soil contamination. An experiment was conducted to evaluate the potential of Ricinus communis as a phytoremediator. A greenhouse study was conducted at Universiti Putra Malaysia. Treatments (soil + sewage sludge) were: T1 (100% soil, control), T2 (25% sewage sludge + 75% soil), T3 (50% sewage sludge + 50% soil), T4 (75% sewage sludge + 25% soil) and T5 (100% sewage sludge). Cd and Zn concentrations were analyzed using atomic absorption spectrophotometer (AAS), texture by the pipette gravimetric method, pH by glass electrode pH meter and total carbon by CHNS analyzer. Cd was highly concentrated in the stems (0.29 ppm) while Zn in the leaves (43.29 ppm). The highest translocation factor for Cd was in treatment T4 (3.53) while for Zn in treatment T3 (2.18). The highest bioconcentration factor of Cd was in treatment T5 (0.21) while treatment T2 for Zn (0.69). This species was able tolerate and accumulate high concentrations of Cd and Zn and can be used as a potential phytoremediator for sewage sludge contaminated soils to reduce soil pollution. [ABSTRACT FROM AUTHOR]

Ricin A chain (RTA) depurinates the sarcin/ricin loop (SRL) by interacting with the C-termini of the ribosomal P stalk. The ribosome interaction site and the active site are located on opposite faces of RTA. The interaction with P proteins allows RTA to depurinate the SRL on the ribosome at physiological pH with an extremely high activity by orienting the active site towards the SRL. Therefore, if an inhibitor disrupts RTA–ribosome interaction by binding to the ribosome binding site of RTA, it should inhibit the depurination activity. To test this model, we synthesized peptides mimicking the last 3 to 11 amino acids of P proteins and examined their interaction with wild-type RTA and ribosome binding mutants by Biacore. We measured the inhibitory activity of these peptides on RTA-mediated depurination of yeast and rat liver ribosomes. We found that the peptides interacted with the ribosome binding site of RTA and inhibited depurination activity by disrupting RTA–ribosome interactions. The shortest peptide that could interact with RTA and inhibit its activity was four amino acids in length. RTA activity was inhibited by disrupting its interaction with the P stalk without targeting the active site, establishing the ribosome binding site as a new target for inhibitor discovery. [ABSTRACT FROM AUTHOR]