Search Results (77)

Phosphoglucose isomerase (PGI), which catalyzes the interconversion of glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P), plays a key role in regulating carbohydrate synthesis and catabolism in plant growth and development. In higher plants, two PGI isoenzymes, plastidic (PGIp) and cytosolic (PGIc), have diverged significantly in sequence, structure, activity, and functional roles, despite catalyzing the same reaction. However, whether they experience distinct selection pressures during intraspecific population differentiation remains unknown. In this study, we identified the PGIc and PGIp genes in castor beans, an important industrial and horticultural crop, and revealed their different expression patterns across tissues, particularly during seed development. Population genetic analyses (Tajima’s D, ML-HKA, and CODEML) detected strong evidence of positive selection on RcPGIc, but not RcPGIp during domestication. Four positively selected sites in RcPGIc (114T, 310T, 338A, and 613S) were inferred with posterior probabilities > 95% in BEB analysis, and two of them (114T and 613S) were found to be significantly associated with higher seed oil content, suggesting that these two sites could potentially influence oil accumulation in castor seeds. This study provides the first evidence of differential selection pressures on PGIc and PGIp during intraspecific population differentiation, offering new insights into their functional divergence. Full article

Castor bean (Ricinus communis L.) can tolerate long periods of dehydration, allowing the investigation of gene circuits involved in drought tolerance. Genes from gibberellins, jasmonates, and auxin signaling are important for crosstalk in the developmental and environmental adaptation process to drought conditions. However, the genes related to these signals, as well as their transcription profiles under drought, remain poorly characterized in the castor bean. In the present work, genes from gibberellins, jasmonates, and auxin signaling were identified and molecularly characterized. These analyses allowed us to identify genes encoding receptors, inhibitory proteins, and transcription factors from each signaling pathway in the castor bean genome. Chromosomal distribution, gene structure, evolutionary relationships, and conserved motif analyses were performed. Expression analysis through RNA-seq and RT-qPCR revealed that gibberellins, jasmonates, and auxin signaling were modulated at multiple levels under drought, with notable changes in specific genes. The gibberellin receptor RcGID1c was downregulated in response to drought, and RcDELLA3 was strongly repressed, whereas its homologues were not, reinforcing the suggestion of a nuanced regulation of gibberellin signaling during drought. Considering jasmonate signaling, the downregulation of the transcription factor RcMYC2 aligned with the drought tolerance observed in mutants lacking this gene. Altogether, these analyses have provided insights into hormone signaling in the castor bean, unveiling transcriptional responses that enhance our understanding of high drought tolerance in this plant. This knowledge opens avenues for identifying potential candidate genes suitable for genetic manipulation in biotechnological approaches. Full article

Only about 30% of coffee bean mass can be transformed into coffee drinks; thus, a larger fraction ends up as spent coffee grounds (SCGs), which have been mainly disposed of as waste. The promising direction of SCG reuse is in the cosmetic industry. The aim of this study was to prepare stable cosmetic emulsion bases to create a coffee scrub using SCGs. As the emulsion base and its stability are crucial for the production of cosmetic scrubs, eco-friendly emulsifiers based on apricot kernel oil, soya lecithin and a natural emulsifier from olive oil were included in the study. Apricot kernel oil proved to be the only stable emulsifier. The prepared bases were subjected to microscopic analysis and visual assessment of stability. Cosmetic emulsions with this emulsifier are a good base for coffee scrubs, both with glycerine and castor oil, as well as with the addition of macadamia oil. In emulsions with apricot kernel oil emulsifier and castor oil, macadamia oil increases the percentage of droplets with the smallest diameters, improving the stability of the system. Based on this study, it can be concluded that SCGs are a promising raw material for the production of scrubs with a pleasant coffee aroma. Full article

The fall armyworm, Spodoptera frugiperda, is a major migratory polyphagous insect pest of various crops. The essential nutrient and mineral profile of the host plants determines the feeding fitness of herbivorous insects. As a result, the growth and development of insects is affected. To determine the effect of the nutrient and mineral profile of different host plants (maize, castor bean, cotton, cabbage, okra, and sugarcane) on the growth and development of S. frugiperda, biological parameters like larval weight, pupal weight (male/female), and feeding and growth indices were calculated. The proximate compositions such as crude protein, crude fat, crude fibre, and ash and mineral contents of the tested host plants showed significant differences (p < 0.05). The feeding indices on these host plants also differed significantly (p < 0.05). The maximum relative growth rate (RGR), relative consumption rate (RCR), and consumption index (CI) were recorded in S. frugiperda larvae that fed on maize and castor bean leaves. The crude protein, dry matter, and ash contents in maize and castor bean were significantly higher and positively correlated with the RGR and RCR of S. frugiperda larvae. The larval, male and female pupal weights were the maximum in the larvae feeding on the castor bean host plant. These findings provide novel information based on nutritional ecology to develop sustainable integrated pest management strategies using selective crop rotation. Full article

Aseptic seedlings of different ages derived from surface-sterilized mature seeds were applied as an explant source. Various explants such as 7- and 21-day-old hypocotyl fragments, 42-day-old nodal stem segments, and transverse nodal segments of stem, as well as leaf petioles, were cultured on the agar-solidified Murashige and Skoog (MS) basal medium supplemented with 0.1 mg/L IAA, 5 mg/L AgNO₃ and different types and concentrations of cytokinin (1 mg/L zeatin, 0.25 mg/L thidiazuron (TDZ), and 5 mg/L 6-benzylaminopurine (6-BAP)). Consequently, it was found that 7- and 21-day-old hypocotyl fragments, as well as nodal stem segments obtained from adult aseptic seedlings, are characterized by a high explant viability and callus formation capacity with a frequency of 79.7–100%. However, the success of in vitro somatic shoot organogenesis was significantly determined not only by the culture medium composition and explant type but also depending on its age, as well as on the size and explant preparation in cases of hypocotyl and age-matched nodal stem fragments, respectively. Multiple somatic shoot organogenesis (5.7 regenerants per explant) with a frequency of 67.5% was achieved during 3 subcultures of juvenile hypocotyl-derived callus tissue on MS culture medium containing 0.25 mg/L TDZ as cytokinin source. Castor bean regenerants were excised from the callus and successfully rooted on ½ MS basal medium without exogenous auxin (81%). In vitro plantlets with well-developed roots were adapted to ex vitro conditions with a frequency of 90%. Full article

Hybridization is an important evolutionary force, and heterosis describes the phenomenon where hybrids exhibit superior traits compared to their parents. This study aimed to evaluate the one-hundred-seed weight and fatty acid content in F₁ generations, investigating the effects of different parental crosses using a 9 × 3 incomplete diallel design (NCII). One of the challenges faced in this study was the complexity of accurately determining the influence of both genetic and environmental factors on trait inheritance. A total of 36 F₁ crosses were analyzed for general combining ability (GCA), specific combining ability (SCA), and heritability. The results showed that the level of each index in F₁ is closely related to its parents. Significant differences in GCA and SCA were observed among parental traits in most crosses. The ratio of GCA to SCA ranged from 0 to 3, indicating the pivotal role of SCA over GCA in castor breeding efforts. High narrow-sense heritability was recorded in palmitic acid (30.98%), oleic acid (28.68%), and arachidonic acid (21.34%), suggesting that these traits are predominantly under the control of additive gene action, and hence these characters can be improved by selection. Additionally, heterosis exhibited diverse patterns across traits. Based on the evaluated combining ability, heritability, and heterosis, the inbred lines CSR181 and 20111149 were recommended for castor crossbreeding due to their potential to yield progeny with optimal oil-related traits. This research contributes valuable knowledge to the field of castor breeding, providing a foundation for developing superior castor cultivars. Full article

The natural pesticide phenazine-1-carboxylic acid (PCA) is known to lack phloem mobility, whereas Metalaxyl is a representative phloem systemic fungicide. In order to endow PCA with phloem mobility and also enhance its antifungal activity, thirty-two phenazine-1-carboxylic acid-N-phenylalanine esters conjugates were designed and synthesized by conjugating PCA with the active structure N-acylalanine methyl ester of Metalaxyl. All target compounds were characterized by ¹H NMR, ¹³C NMR and HRMS. The antifungal evaluation results revealed that several target compounds exhibited moderate to potent antifungal activities against Sclerotinia sclerotiorum, Bipolaris sorokiniana, Phytophthora parasitica, Phytophthora citrophthora. In particular, compound F7 displayed excellent antifungal activity against S. sclerotiorum with an EC₅₀ value of 6.57 µg/mL, which was superior to that of Metalaxyl. Phloem mobility study in castor bean system indicated good phloem mobility for the target compounds F1–F16. Particularly, compound F2 exhibited excellent phloem mobility; the content of compound F2 in the phloem sap of castor bean was 19.12 μmol/L, which was six times higher than Metalaxyl (3.56 μmol/L). The phloem mobility tests under different pH culture solutions verified the phloem translocation of compounds related to the “ion trap” effect. The distribution of the compound F2 in tobacco plants further suggested its ambimobility in the phloem, exhibiting directional accumulation towards the apical growth point and the root. These results provide valuable insights for developing phloem mobility fungicides mediated by exogenous compounds. Full article

The length of internodes plays a crucial role in determining the height of the castor plant (Ricinus communis L.). However, the specific mechanisms underlying internode elongation, particularly in the main stem of the castor plant, remain uncertain. To further investigate this, we conducted a study focusing on the internode tissue of the dwarf castor variety 071113, comparing it with the control high-stalk Zhuansihao. Our study included a cytological observation, physiological measurement, transcriptome sequencing, and metabolic determination. Our integrated findings reveal that the dwarf variety 071113 undergoes an earlier lignification development in the main stem and has a more active lignin synthesis pathway during internode intermediate development. In addition, the dwarf variety exhibited lower levels of the plant hormone indole-3-acetic acid (IAA), which had an impact on the development process. Furthermore, we identified specific enzymes and regulators that were enriched in the pathways of the cell cycle, auxin signal transduction, and secondary cell wall synthesis. Using these findings, we developed a model that explained the intermediate secondary growth observed in castor internode elongation and enhanced our comprehension of the dwarfing mechanism of the 071113 variety. This research provides a theoretical groundwork for the future breeding of dwarf castor varieties. Full article

Castor (Ricinus communis L.) seeds produce abundant ricinoleic acid during seed maturation, which is important for plant development and human demands. Ricinoleic acid, as a unique hydroxy fatty acid (HFA), possesses a distinct bond structure that could be used as a substitute for fossil fuels. Here, we identified all homologous genes related to glycolysis, hydroxy fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in castor seeds. Furthermore, we investigated their expression patterns globally during five seed development stages. We characterized a total of 66 genes involved in the glycolysis pathway, with the majority exhibiting higher expression levels during the early stage of castor bean seed development. This metabolic process provided abundant acetyl-CoA for fatty acid (FA) biosynthesis. Subsequently, we identified 82 genes involved in the processes of de novo FA biosynthesis and TAG assembly, with the majority exhibiting high expression levels during the middle or late stages. In addition, we examined the expression patterns of the transcription factors involved in carbohydrate and oil metabolism. For instance, RcMYB73 and RcERF72 exhibited high expression levels during the early stage, whereas RcWRI1, RcABI3, and RcbZIP67 showed relatively higher expression levels during the middle and late stages, indicating their crucial roles in seed development and oil accumulation. Our study suggests that the high HFA production in castor seeds is attributed to the interaction of multiple genes from sugar transportation to lipid droplet packaging. Therefore, this research comprehensively characterizes all the genes related to glycolysis, fatty acid biosynthesis, and triacylglycerol (TAG) accumulation in the castor and provides novel insight into exploring the genetic mechanisms underlying seed oil accumulation in the endosperm of castor beans. Full article

Polyamide 11 (PA11) is a plant-based nylon made from castor beans. Powder bed fusion laser sintering (PBF-LS) is an additive manufacturing process used for PA11 which allows for the reuse of the unsintered powder. The unsintered powder is mixed with virgin powders at different refresh rates, a process which has been studied extensively for most semi-crystalline polyamides. However, there is lack of information on the effect of using 100% reused PA11 powder and the effect of the number of times it is reused on its own, during powder bed fusion laser sintering. This paper investigates the effect of reusing PA11 powder in PBF-LS and the effect of the number of times it is reused on the dimensional accuracy, density and thermal and tensile properties. From the 100% virgin powder to the third reuse of the powder, there is a decrease in powder wastage, crystallinity and tensile strength. These are associated with the polymerisation and cross-linking process of polymer chains, upon exposure to high temperatures. This results in a higher molecular weight and, hence, a higher density. From the fourth reuse to the tenth reuse, the opposite is observed, which is associated with an increase in high-viscosity unmolten particles, resulting in defects in the PBF-LS parts. Full article

Intercrops can lower pest densities by increasing plant diversity, altering chemical communication in the arthropod community, and integrating well with other IPM tactics. We used two years of field observations and Y-tube olfactometer assays to explore the effects of intercropping a pear orchard with okra and castor bean on the cosmopolitan fruit-boring pest Grapholita molesta (Lepidoptera: Tortricidae). Intercropping okra reduced G. molesta trap catches in the pear orchard in both years, and intercropping with castor bean reduced them in the second year. Hydrocarbons, phenols, and ketones predominated in the GC-MS assay of okra volatiles, whereas castor bean volatiles were rich in aldehydes, ketones, and esters. Five of the commercially available volatiles released by these plants exhibited repellency to G. molesta in olfactometer trials, especially cinnamaldehyde, dibutyl phthalate, and thymol; the former compound also exhibited attraction to the egg parasitoid Trichogamma dendrolimi (Hymenoptera: Trichogrammatidae). In addition to their repellent properties, okra and castor bean may enhance integrated control of G. molesta in orchards by hosting prey that support populations of generalist predators that either provide biological pest control services within the orchard ecosystem or generate non-consumptive effects that contribute to pest deterence. Among the plant volatiles evaluated, cinnamaldehyde has the best potential for deployment in orchards to repel G. molesta without disrupting augmentative releases of T. dendrolimi. Full article

Based on a literature review, as well as on our own data, 14 ixodid tick species belonging to 5 genera were registered for the lizard hosts of the genus Lacerta (L. agilis, L. media, and L. strigata) in the Caucasus and the adjacent territories: Haemaphysalis sulcata, Haem. punctata, Haem. parva, Haem. caucasica, Haem. concinna, Haem. inermis, Ixodes ricinus, I. redikorzevi, Dermacentor marginatus, D. reticulatus, Hyalomma marginatum, Rhipicephalus bursa, Rh. rossicum, and Rh. turanicum. Tick species Haem. caucasica were recorded from Armenia for the first time. Our findings of Haem. punctata represent the first record of this species for Chechnya, Ingushetia (Russia), Armenia, and Azerbaijan. Most of the parasite species are associated with L. agilis (13) and L. strigata (12); L. media is a host of 6 tick species. Data on the infestation of Lacerta spp. by four tick species from our material (I. ricinus, Haem. punctata, Haem. caucasica, and Hyal. marginatum) are presented in the article. In addition, our article contains information on the range of infections associated with the above tick species. Castor bean tick I. ricinus (236 specimens), the most represented species in our collection, parasitizes all available terrestrial vertebrates including humans and can be vector of many various pathogens, so our study provides significant epidemiological information. Full article

Castor bean (Ricinus communis L.) originated in East Africa and then diffused to warm-temperate, subtropical, and tropical regions of the world. The high lipid content in the castor beans is extracted for use in pharmaceutical and industrial applications. The castor oil lipid profile is naturally composed of 90% ricinoleic acid and the remaining 10% is mainly composed of linoleic, oleic, stearic, and linolenic fatty acids. The highly toxic compound ricin within the seeds is insoluble in oil, making castor oil free from this toxin and safe to use for industrial and cosmetic applications. Among the main uses of castor oil are reported industrial uses such as component for lubricants, paints, coatings, polymers, emulsifiers, cosmetics, and medicinal uses as a laxative. There is also significant commercial potential for utilization of the whole castor bean plant such as animal feed, fertilizer, biofuel, and also for phytoremediation. Several breeding programs have been planned to improve the castor’s characteristics needed for its current or potential uses. In this review, after summarizing data on castor bean agronomy and uses, we focus on the main advances in Castor bean classical and biotechnological breeding programs, underlining the high potential of this oil crop. In particular, the main challenges of castor breeding programs are to increase yield, mainly through the selection of growth habits allowing mechanized harvest, and beneficial compound content, mainly the oil, and to decrease the toxic compounds content, mainly ricin. Full article

Germination of castor seeds of seven dwarf hybrid genotypes, compared to a ‘Local’ genotype, selected from a Tunisian population by the University of Catania well adapted to the Mediterranean environment, were studied at six different temperatures (8, 12, 16, 25, 32, and 40 °C). The results indicate that the optimal temperature (25 °C) and near-optimal temperature (32 °C) are the best temperatures for ensuring castor germination (final germination percentage (FGP) ≥ 82.81%). Furthermore, these temperatures positively influenced the vigour index (VI) and the radicle elongation. At a temperature of 8 °C, no germination occurred, while temperatures of 12 and 40 °C negatively affected the seed germination, which, in some genotypes, was null or negligible (<21.25%). A temperature of 16 °C allowed good results to be reached for the FGP and the other considered parameters. Overall, the dwarf hybrids performed better at high temperatures than at low temperatures, thus, making them suitable for late sowings, with the exception of the genotype ‘C1020’, which resulted the best performance at 16 and 40 °C, being suitable for both early and late sowings. On the other hand, the ‘Local’ castor genotype, being the best-performing genotype at 12 and 16 °C, and the most tolerant to low temperature (base temperature (Tb) 12.1 °C), could be used in the early sowing in spring. Full article