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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]

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]

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]

Highlights: [•] Stomatal closure and osmotic adjustment are key physiological responses to salt stress displayed by R. communis. [•] Na+ and Cl− effectively participate in the osmotic adjustment of R. communis to salinity. [•] The contribution to the osmotic adjustment of Na+ was higher in leaves, while roots contributed to the Cl− osmotic adjustment more effectively. [ABSTRACT FROM AUTHOR]

Abstract: Castor plants (Ricinus communis) cv. BRS Nordestina were submitted to biweekly defoliations in order to evaluate the influence on development and yield components. Leaf area was calculated from the length of the main vein of each leaf. Defoliation treatments of 0, 15, 30, 45 or 60% of the total leaf area were applied. Each raceme was individually harvested and the date was recorded. Castor plants were able to completely regrow its leaf area when the defoliation occurred during the vegetative stage; however, this initial damage reduced the maximum leaf area obtained by the plant. Maturation of fruits occurred earlier when plants were subjected to defoliation. Defoliation treatments did not influence the number of fruits per raceme, but caused a steep reduction of the number of racemes per plant. Adaptations in the yield components were observed in the number of seeds per plant and in the seed oil content, but not in the mean seed weight. Any level of defoliation repeated along the plant growth cycle was found to cause a reduction of the oil yield. The loss of 1m2 of leaf area caused the reduction of 37.8g of castor seed or 24.4g of castor oil. [ABSTRACT FROM AUTHOR]

This paper investigates the commonalities in ethnoveterinary medicine used for horses between Trinidad (West Indies) and British Columbia (Canada). These research areas are part of a common market in pharmaceuticals and are both involved in the North American racing circuit. There has been very little research conducted on medicinal plants used for horses although their use is widespread. The data on ethnoveterinary medicines used for horses was obtained through key informant interviews with horse owners, trainers, breeders, jockeys, grooms and animal care specialists in two research areas: Trinidad and British Columbia (BC). A participatory validation workshop was held in BC. An extensive literature review and botanical identification of the plants was also done. In all, 20 plants were found to be used in treating racehorses in Trinidad and 97 in BC. Of these the most-evidently effective plants 19 of the plants used in Trinidad and 66 of those used in BC are described and evaluated in this paper. Aloe vera, Curcuma longa and Ricinus communis are used in both research areas. More research is needed in Trinidad to identify plants that respondents claimed were used in the past. Far more studies have been conducted on the temperate and Chinese medicinal plants used in BC and therefore these ethnoveterinary remedies reflect stronger evidence of efficacy. [ABSTRACT FROM AUTHOR]

ABSTRACTA new method for simultaneously quantifying rates of flow in xylem and phloem using the FLASH imaging capabilities of nuclear magnetic resonance (NMR) spectrometry was applied in this study. The method has a time resolution of up to 4 min (for the xylem) and was used to measure the velocity of flows in phloem and xylem for periods of several hours to days. For the first time, diurnal time course measurements of flow velocities and apparent volume flows in phloem and xylem in the hypocotyl of 40-d-old Ricinus communis L were obtained. Additional data on gas exchange and the chemical composition of leaves, xylem and phloem sap were used to assess the role of leaves as sinks for xylem sap and sources for phloem. The velocity in the phloem (0·250 ± 0·004 mm s-1) was constant over a full day and not notably affected by the light/dark cycle. Sucrose was loaded into the phloem and transported at night, owing to degradation of starch accumulated during the day. Concentrations of solutes in the phloem were generally less during the night than during the day but varied little within either the day or night. In contrast to the phloem, flow velocities in the xylem were about 1·6-fold higher in the light (0·401 ± 0·004 mm s-1) than in the dark (0·255 ± 0·003 mm s-1) and volume flow varied commensurately. Larger delays were observed in changes to xylem flow velocity with variation in light than in gas exchange. The relative rates of solute transport during day and night were estimated on the basis of relative flow and solute concentrations in xylem and phloem. In general, changes in relative flow rates were compensated for by changes in solute concentration during the daily light/dark cycle. However, the major solutes (K+, NO3-) varied appreciably in relative concentrations. Hence the regulation of loading into transport systems seems to be more important to the overall process of solute transport than do changes in mass flow. Due to transport behaviour, the chemical composition of leaves varied during the day only with regard to starch and soluble carbohydrates. [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]

Studies the intracellular routing of ricin, a ribosome-inactivating protein, and the strategy used by castor oil plants to avoid its own suicide during ricin biosynthesis. Different isoforms of ricin; Sensitivity of ribosomes from different sources to the catalytically active A-chain action of ricin; Relationship between degradation, refolding and ribosome inactivation in mammalian and yeast cells.