Genomic regions associated with resistance to Fusarium wilt in castor identified through linkage and association mapping approaches.

Fusarium wilt, caused by Fusarium oxysporum f. sp. ricini, is the most destructive disease in castor. Host plant resistance is the best strategy for the management of wilt. Identification of molecular markers linked to wilt resistance will enhance the efficiency and effectiveness of breeding for wilt resistance. In the present study, genomic regions linked to wilt resistance were mapped using a bi-parental population of 185 F6-RILs and a genetically diverse panel of 300 germplasm accessions. Quantitative trait loci (QTL) analysis performed using a linkage map consisting of 1090 SNP markers identified a major QTL on chromosome 7 with an LOD score of 18.7, which explained 44% of the phenotypic variance. The association mapping performed using genotypic data from 3465 SNP loci revealed 69 significant associations (p < 1 × 10-4) for wilt resistance. The phenotypic variance explained by the individual SNPs ranged from 0.063 to 0.210. The QTL detected in the bi-parental mapping population was not identified in the association analysis. Thus, the results of this study indicate the possibility of vast gene diversity for Fusarium wilt resistance in castor.

The effects of plant growth substances on the oil content and fatty acid composition of Ricinus communis L.: an in vitro study.

BACKGROUND: Ricinus communis L. (castor bean) is valued for its oil and the performance of oil is closely related to its fatty acid composition. Thus, producing oil in vitro with favored fatty acid profiles is a promising research area and may also offer industrial opportunities. MATERIAL AND METHOD: In line with this, the total amount of oil and the fatty acid composition of the samples, which were endosperm and calli obtained by treatment of various doses of plant growth regulators were determined. RESULTS: Results showed that the type and amount of the plant growth regulator used in the media affect the fatty acid composition. In detail, the biggest change was shown by Indole-3-Acetic Acid (IAA), in general, using the plant growth regulators at 5 mg L-1, instead of 20 mg L-1, was found to have induced larger differentiations. The effect of a natural plant growth regulator (IAA) on fatty acid profiles was bigger than the synthetic ones (NAA, 1-Naphthaleneacetic acid, and 2,4 D, 2,4-Dichlorophenoxyacetic acid). The media containing 5 mg L-1 of NAA, 20 mg L-1 of NAA, 20 mg L-1 of 2,4 D, or 5 mg L-1 of 2,4 D gave similar results.

Assisted phytostabilization of Pb-spiked soils amended with charcoal and banana compost and vegetated with Ricinus communis L. (Castor bean).

A greenhouse experiment was performed to elucidate the potency of Prosopis juliflora charcoal (PJC) and banana waste compost (BWC) to improve soil fertility and enhance plant growth rate. Plantlets of Ricinus communis were grown in 0, 400, and 800 mg kg-1 Pb-spiked soil ameliorated with P. juliflora charcoal and banana waste compost at 0, 5%, and 10% (w/w) for 60 days. PJC and BWC significantly (p < 0.05) increased plant growth parameters, that is, number of leaves, node number, plant height, and leaf diameter and reduced oxidative stress manifested by the lesser production of proline, hydrogen peroxide (H2O2), and malondialdehyde (MDA) with respect to control plants. Soil usage of PJC at 10% decreased the Pb accumulation by 61%, whereas BWC decreased Pb concentration in roots by 56% concerning control. Field emission scanning electron microscope (FE-SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) showed high macro and microspores on the surface of charcoal while banana compost showed significant raise in the nutrient content (N, P, K, Zn, Ca, Fe, and Mg). Thermogravimetric (TG) and Fourier-transform infrared spectroscopy (FTIR) analysis of banana compost showed enhanced molar convolution of carbohydrate composites and nitrogen content. These findings pave a clear understanding that PJC and BWC are recalcitrant for Pb phytotoxicity and can also be used as nutrient-rich composites for increased crop production.

Intake, digestibility, ingestive behavior, production, and composition of goat milk supplemented with detoxified castor bean meal added urea as a replacement of soybean meal.

This study evaluated the castor bean meal detoxified with calcium hydroxide [Ca(OH)2] added urea replacing soybean meal in the diet of lactating goats from milk production and composition, intake, digestibility, and ingestive behavior. Eight Alpine multiparous goats weighting 44.3 ± 5.3 kg and at approximately 60 days of lactation were confined and randomly distributed in 4 × 4 double Latin squares, with four inclusion levels of detoxified castor meal: control (0), 25, 50, and 75 g/kg dry matter (DM) total. Detoxified castor bean meal replacing soybean meal (P > 0.05) in goats diet did not affect intake and digestibility of DM, crude protein, ether extract, neutral detergent fiber (NDF), total carbohydrates, non-fibrous carbohydrates and total digestible nutrients, times spent for eating, and efficiency ratios of rumination and eating. However, the times spent for rumination and idling showed a quadratic trend decrease (P < 0.01) from the level of 50.0-g/kg DM. The milk production, and the milk production correction showed a quadratic trend increase and feeding efficiency a quadratic decrease (P = 0.03) due inclusion of detoxified castor bean meal replacing soybean meal up to the level of 25.0 g/kg. The fat, protein, lactose, total solids, nonfat solids, and milk urea nitrogen content (g/day) presented a quadratic increase (P < 0.05) by detoxified castor meal inclusion. Detoxified castor bean meal added urea in the Alpine goats diet could be included up to the 25.0 g/kg level replacing soybean meal in the diet because improve milk production and composition and feeding efficiency of goats without negatively effect on intake, digestibility and ingestive behavior.

RcPAL, a key gene in lignin biosynthesis in Ricinus communis L.

BACKGROUND: Castor (Ricinus communis L.) is an important seed oil crop. Castor oil is a highly demanded oil for several industrial uses. Current castor bean varieties suffer from low productivity and high risk of insect pests and diseases. High productive and pest/disease resistance varieties are needed. Lignin has been associated to the resistance for pest, disease and lodging. Lignin is produced from several metabolites of the phenylpropanoid pathway. PAL is the key enzyme of the phenylpropanoid pathway. The gene PAL may assist in the improvement of resistance of castor bean. RESULTS: The RcPAL CDs was amplified and its function was examined by transgenic overexpression and antisense expression, lignin histochemical staining, real-time PCR, lignin content measurement and morphological investigation. Its full length was 2145 bp, encoding 714 amino acids. The overexpression of RcPAL (7.2 times) increased significantly the PAL activity, dyeing depth of xylem cells and lignin content (14.44%), resulting in a significantly lower plant height, deeper and thicker blade, more green leaves, shorter internode, thicker stem diameter, and opposite in antisense expression plants (lignin content lowered by 27.1%), demonstrated that the gene RcPAL was a key gene in castor lignin biosynthesis. CONCLUSIONS: The gene RcPAL is a key gene in castor lignin biosynthesis and can be induced to express under mechanical damage stress. When up-regulated, it increased the lignin content significantly and dwarfed the plant height, and opposite when down-regulated. The gene RcPAL may assist in the improvement of resistance and plant type of castor bean.

Tissue-specific transcriptional regulation of seven heavy metal stress-responsive miRNAs and their putative targets in nickel indicator castor bean (R. communis L.) plants.

R.communis L. has high capability to accumulate nickel which is a trace nutrient for higher plants and also an environmental contaminant causes toxicity related symptoms at higher concentrations. MicroRNAs (miRNAs) are known to be important modulators of responses against heavy metal stress for detoxification of the metal. In this study, we experimentally measured and validated the transcript levels of the seven heavy metal stress response-related miRNAs and the expression levels of target genes in both leaf and root tissues of R. communis L. subjected to three different concentrations of nickel stress via qRT-PCR quantification. The results demonstrated differential regulations of heavy metal stress-responsive miRNAs and their putative targets in both tissues in same stress treatments. This dynamic regulation suggest that regulatory processes differ between the tissues under nickel stress. Our data suggest that, miR838 was the most responsive to the Ni2+ stress. miR398 target gene Cu-Zn/SOD was found to be up-regulated in both root and leaf tissues. The relations between TCP and expression levels of miR159 and miR319 were also found statistically significant exclusive to leaf tissues. In leaf tissue, changes in miR395 level and its putative target genes, sulphate transporter and sulphate adenyltransferase gene were found in relation whereas, only expression level of sulphate transporter represented a statistically significant relation in root tissue. The sharp decrease in transcript levels of 2r3 myb gene at lower nickel dose suggest to investigate the role of r2r3 myb and the all MYB family members in primary and secondary metabolisms against nickel stress.

Biochar and rice husk ash assisted phytoremediation potentials of Ricinus communis L. for lead-spiked soils.

Soil contamination with lead (Pb) is a serious global concern, adversely affecting crop production. Pot experiments were conducted to assess the efficacy of Prosopis biochar and rice husk ash for plant growth and mitigating Pb translocation in Ricinus communis. Physico-chemical characterization of both the amendments was carried out on a dry weight basis. Seedlings of R.communis were grown in 0, 400 and 800 mg kg-1 Pb spiked soil amended with Prosopis juliflora biochar (PJB) and rice husk ash (RHA) at 0, 2.5% and 5% (w/w) of soil for 60 days. Addition of biochar and rice husk ash to soils increased the Pb tolerance in R.communis, improved soil pH, nutrient intake, and antioxidant enzymatic activities. The biochar amendment significantly (p < 0.05) increased plant growth parameters (height, leaf diameter, nodes, and leaf number), protein (72%) and chlorophyll contents (38-52%), as did RHA to a lesser extent (increase of 10-31% in chlorophyll and 77% protein content) compared to unamended plants. Soil usage of RHA resulted in a more consistent decrease in Pb accumulation in the root, shoot, and leaf relative to PJB. Treatment with PJB at 5% decreased the accumulation of Pb in roots by 59% whereas RHA decreased Pb concentration in roots by 87%. The two distinct amendments significantly reduced the availability of soil Pb and decreased oxidative damage, as evidenced by the lower production of proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) in plants. Changes in infrared spectra confirmed that oxygenated phosphate, amide, ester and ether functional groups played a key role in binding accumulated Pb in roots as well as alleviation of Pb-induced phytotoxicity. Our findings conclude the amendments can be used as a stress regulator in mitigating Pb toxicity, which is important for all economic crop plants, including R.communis.

Quantitative Proteomic Analysis of Castor (Ricinus communis L.) Seeds During Early Imbibition Provided Novel Insights into Cold Stress Response.

Early planting is one of the strategies used to increase grain yield in temperate regions. However, poor cold tolerance in castor inhibits seed germination, resulting in lower seedling emergence and biomass. Here, the elite castor variety Tongbi 5 was used to identify the differential abundance protein species (DAPS) between cold stress (4 °C) and control conditions (30 °C) imbibed seeds. As a result, 127 DAPS were identified according to isobaric tag for relative and absolute quantification (iTRAQ) strategy. These DAPS were mainly involved in carbohydrate and energy metabolism, translation and posttranslational modification, stress response, lipid transport and metabolism, and signal transduction. Enzyme-linked immunosorbent assays (ELISA) demonstrated that the quantitative proteomics data collected here were reliable. This study provided some invaluable insights into the cold stress responses of early imbibed castor seeds: (1) up-accumulation of all DAPS involved in translation might confer cold tolerance by promoting protein synthesis; (2) stress-related proteins probably protect the cell against damage caused by cold stress; (3) up-accumulation of key DAPS associated with fatty acid biosynthesis might facilitate resistance or adaptation of imbibed castor seeds to cold stress by the increased content of unsaturated fatty acid (UFA). The data has been deposited to the ProteomeXchange with identifier PXD010043.

Splice Variants of the Castor WRI1 Gene Upregulate Fatty Acid and Oil Biosynthesis When Expressed in Tobacco Leaves.

The plant-specific WRINKLED1 (WRI1) is a member of the AP2/EREBP class of transcription factors that positively regulate oil biosynthesis in plant tissues. Limited information is available for the role of WRI1 in oil biosynthesis in castor bean (Ricinus connunis L.), an important industrial oil crop. Here, we report the identification of two alternatively spliced transcripts of RcWRI1, designated as RcWRI1-A and RcWRI1-B. The open reading frames of RcWRI1-A (1341 bp) and RcWRI1-B (1332 bp) differ by a stretch of 9 bp, such that the predicted RcWRI1-B lacks the three amino acid residues "VYL" that are present in RcWRI1-A. The RcWRI1-A transcript is present in flowers, leaves, pericarps and developing seeds, while the RcWRI1-B mRNA is only detectable in developing seeds. When the two isoforms were individually introduced into an Arabidopsiswri1-1 loss-of-function mutant, total fatty acid content was almost restored to the wild-type level, and the percentage of the wrinkled seeds was largely reduced in the transgenic lines relative to the wri1-1 mutant line. Transient expression of each RcWRI1 splice isoform in N. benthamiana leaves upregulated the expression of the WRI1 target genes, and consequently increased the oil content by 4.3-4.9 fold when compared with the controls, and RcWRI1-B appeared to be more active than RcWRI1-A. Both RcWRI1-A and RcWRI1-B can be used as a key transcriptional regulator to enhance fatty acid and oil biosynthesis in leafy biomass.

Use of Energy Crop (Ricinus communis L.) for Phytoextraction of Heavy Metals Assisted with Citric Acid.

Ricinus communis L. is a bioenergetic crop with high-biomass production and tolerance to cadmium (Cd) and lead (Pb), thus, the plant is a candidate crop for phytoremediation. Pot experiments were performed to study the effects of citric acid in enhancing phytoextraction of Cd/Pb by Ricinus communis L. Citric acid increased Cd and Pb contents in plant shoots in all treatments by about 78% and 18-45%, respectively, at the dosage of 10 mM kg(-1) soil without affecting aboveground biomass production. Addition of citric acid reduced CEC, weakened soil adsorption of heavy metals and activated Cd and Pb in soil solutions. The acid-exchangeable fraction (BCR-1) of Pb remained lower than 7% and significantly increased with citric acid amendment. Respective increases in soil evaluation index induces by 14% and 19% under the Cd1Pb50 and Cd1Pb250 treatments upon addition of citric acid resulted in soil quality improvement. Ricinus communis L. has great potential in citric acid-assisted phytoextraction for Cd and Pb remediation.

The impact of retrotransposons on castor bean genomes.

Castor bean (Ricinus communis L.) is an important oil crop. However, the influence of transposable elements (TEs) on the dynamics of castor bean evolution awaits further investigation. This study explored the role of transposable elements in the genomes of wild castor bean accessions from Ethiopia (Rc039) and Kenya (WT05) as well as in the cultivated variety (Hale). The distribution and composition of repeat sequences in these three lineages exhibited relative consistency, collectively accounting for an average of 36.7% of the genomic sequences. Most TE families displayed consistent lengths and compositions across these lineages. The dynamics of TEs significantly differed from those of genes, showing a lower correlation between the two. Additionally, the distribution of TEs on chromosomes showed an inverse trend compared to genes. Furthermore, Hale may have originated from the ancestor of Rc039. The divergent evolutionary paths of TEs compared to genes indicate the crucial role of TEs in shaping castor bean genetics and evolution, providing insights into the fields of castor bean and plant genomics research.

[Screening and Stress Responsive Characteristics of Potential Hyperaccumulator of Pb, Zn, and Cd Compound Heavy Metals].

To screen for Pb, Zn, and Cd composite heavy metal hyperaccumulator plants, a survey, sampling, and analysis of dominant plants in typical lead-zinc mines and smelter areas in Baoji City were conducted. Potential Pb, Zn, and Cd composite heavy metal hyperaccumulator plants were initially screened, and a pot experiment of soil cultivation was carried out to observe the response characteristics of chlorophyll （chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll）, antioxidant enzymes （SOD, CAT, and POD）, and other physiological indicators （MDA and proline） under the stress of Pb, Zn, and Cd composite heavy metals. A field experiment was also conducted to further verify and determine their enrichment ability for Pb, Zn, and Cd composite heavy metals, aiming to provide scientific basis and technical support for the remediation of Pb, Zn, and Cd composite heavy metal-polluted soil. The field survey revealed that Symphytum officinale L. met the international hyperaccumulator plant index requirements for the enrichment of Pb, Zn, and Cd, with enrichment quantity, bioconcentration factor （BCF）, and transfer factor （TF） all meeting the requirements. It was a potential hyperaccumulator plant for Pb, Zn, and Cd composite heavy metals. The soil cultivation pot experiment showed that as the gradient of Pb, Zn, and Cd composite heavy metal stress increased, the content of chlorophyll a, chlorophyll b, and total chlorophyll in S. officinale L. leaves gradually decreased, causing disruption to the plant's photosynthetic system when the gradient was greater than or equal to IV. The chlorophyll content in Ricinus communis L. leaves exhibited a "low-stimulation-high-inhibition" phenomenon, while excessive stress stimulated the activation of its own protective systems, leading to reduced toxicity. In addition, there were significant differences （P < 0.05） in the content of chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll between S. officinale L. and R. communis L. both compared to the control treatment and between stress gradients. The SOD activity in the leaves of S. officinale L. and R. communis L. showed a trend of increasing first, then decreasing, and then increasing. The CAT activity in the leaves of S. officinale L. exhibited a "low-stimulation-high-inhibition" effect, whereas the CAT activity in the leaves of R. communis L. showed a trend of continuous decrease. The POD activity in the leaves of S. officinale L. generally increased, whereas in the leaves of R. communis L., it increased first, then decreased, and then increased. The MDA content in the leaves of S. officinale L. generally decreased, whereas in the leaves of R. communis L., it exhibited an upward trend. In addition, whether compared to the control between stress gradients, there were significant differences （P < 0.05） in the SOD, CAT, POD, MDA, and proline content of S. officinale L. and R. communis L. The field experiment results indicated that S. officinale L. could meet the hyperaccumulator plant index requirements for the enrichment of Pb, Zn, and Cd, making it a potential germplasm resource for Pb, Zn, and Cd composite heavy metal hyperaccumulator plants. It can be an ideal choice for the remediation of Pb, Zn, and Cd composite heavy metal-polluted soil.

An Efficient and Rapid Protocol for Somatic Shoot Organogenesis from Juvenile Hypocotyl-Derived Callus of Castor Bean cv. Zanzibar Green.

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%.

The root-associated Fusarium isolated based on fungal community analysis improves phytoremediation efficiency of Ricinus communis L. in multi metal-contaminated soils.

Phytoremediation is a widely accepted bioremediation method of treating heavy metal contaminated soils. Nevertheless, the remediation efficiency in multi-metal contaminated soils is still unsatisfactory attributable to susceptibility to different metals. To isolate root-associated fungi for improving phytoremediation efficiency in multi-metal contaminated soils, the fungal flora in root endosphere, rhizoplane, rhizosphere of Ricinus communis L. in heavy metal contaminated soils and non-heavy metal contaminated soils were compared by ITS amplicon sequencing, and then the critical fungal strains were isolated and inoculated into host plants to improve phytoremediation efficiency in Cd, Pb, and Zn-contaminated soils. The fungal ITS amplicon sequencing analysis indicated that the fungal community in root endosphere was more susceptible to heavy metals than those in rhizoplane and rhizosphere soils and Fusarium dominated the endophytic fungal community of R. communis L. roots under heavy metal stress. Three endophytic strains (Fusarium sp. F2, Fusarium sp. F8, and Fusarium sp. F14) isolated from Ricinus communis L. roots showed high resistances to multi-metals and possessed growth-promoting characteristics. Biomass and metal extraction amount of R. communis L. with Fusarium sp. F2, Fusarium sp. F8, and Fusarium sp. F14 inoculation in Cd-, Pb- and Zn-contaminated soils were significantly higher than those without the inoculation. The results suggested that fungal community analysis-guided isolation could be employed to obtain desired root-associated fungi for enhancing phytoremediation of multi-metal contaminated soils.

Phytochemical screening, green synthesis of gold nanoparticles, and antibacterial activity using seeds extract of Ricinus communis L.

In the current research study, the phytochemical tests of the Ricinus communis L methanolic extract detected the presence of coumarin, reducing sugar, emodines, terpenoids, flavonoids, and steroids while water extract showed the presence of alkaloids, terpenoids, steroids, and soluble starch. The methanolic extract was further subjected to synthesize Au nanoparticles. The synthesized nanoparticles were confirmed by UV-Vis through the appearance of a peak at 550 nm which correspond to the existence of Au nanoparticles. The size and morphology of synthesized nanoparticle were further studied by the dynamic light scattering technique which shows that nanoparticles were in the range of 100 nm which were further confirmed by transmission electron microscopy. The synthesized nanoparticles and extracts were tested against different bacterial strains. The results revealed that methanolic extract showed maximum inhibition of 19.5 mm against Klebsiella pneumoniae and 20.33 mm against Bacillus cereus while water extract showed maximum inhibition of 18.16 mm against Pseudomonas aeruginosa and 19.33 mm against B. cereus. On the other hand, Au nanoparticles showed maximum inhibition of 18.5 mm against Escherichia coli.

A Chromosome-level Genome Assembly of Wild Castor Provides New Insights into its Adaptive Evolution in Tropical Desert.

Wild castor grows in the high-altitude tropical desert of the African Plateau, a region known for high ultraviolet radiation, strong light, and extremely dry condition. To investigate the potential genetic basis of adaptation to both highland and tropical deserts, we generated a chromosome-level genome sequence assembly of the wild castor accession WT05, with a genome size of 316 Mb, a scaffold N50 of 31.93 Mb, and a contig N50 of 8.96 Mb, respectively. Compared with cultivated castor and other Euphorbiaceae species, the wild castor exhibits positive selection and gene family expansion for genes involved in DNA repair, photosynthesis, and abiotic stress responses. Genetic variations associated with positive selection were identified in several key genes, such as LIG1, DDB2, and RECG1, involved in nucleotide excision repair. Moreover, a study of genomic diversity among wild and cultivated accessions revealed genomic regions containing selection signatures associated with the adaptation to extreme environments. The identification of the genes and alleles with selection signatures provides insights into the genetic mechanisms underlying the adaptation of wild castor to the high-altitude tropical desert and would facilitate direct improvement of modern castor varieties.

Biodegradable scaffolds based on plant stems for application in regenerative medicine.

Several synthetic and natural materials have been studied for the confection of temporary grafts for application in regenerative medicine, however, the development of a material with adequate properties remains a challenge, mainly because its degradation kinetics in biological systems. Nature provides materials with noble properties that can be used as such for many applications, thus, taking advantage of the available morphology and assembled structures of plants, we propose to study the vegetable stems for use as temporary graft. Since thein vivodegradation is maybe one of the most important features of the temporary grafts, here we have implanted the plant stems from pumpkin, papaya, and castor into the subepithelial tissue of animals and followed their biodegradation process and the local inflammatory response. Mechanical tests, FTIR and contact angle with water were also analysed. The results indicated the mechanical properties and the contact angle were adequate for use in regenerative medicine. The results of thein vivostudies indicated a beneficial inflammatory process and a gradual disintegration of the materials within 60 days, suggesting the plants stems as new and potential materials for development of grafts for use in the field of regenerative medicine.

Castor Oil Plant (Ricinus communis L.) Leaves Improve Dexamethasone-Induced Muscle Atrophy via Nrf2 Activation.

Skeletal muscle atrophy is characterized by reduced muscle function and size. Oxidative stress contributes to muscle atrophy but can be treated with antioxidants. This study investigated the antioxidant activity of a castor oil plant leaf (Ricinus communis L.) extract (RC) and its effects on muscle atrophy. Rutin was identified as the major compound among the thirty compounds identified in RC via LC-MS/MS and was found to inhibit dexamethasone (DEX)-induced muscle atrophy and mitochondrial oxidative stress. Rutin-rich RC showed DPPH and ABTS radical scavenging activities and efficiently reduced the DEX-induced myotube atrophy and mitochondrial oxidative damage in C2C12 cells. RC supplementation prevented the loss of muscle function and muscle mass in DEX-administered mice and ameliorated DEX-induced oxidative stress via Nrf2 signaling. Taken together, both RC and rutin ameliorated muscle atrophy and helped in maintaining redox homeostasis; hence, rutin-rich RC could be a promising functional food that is beneficial for muscle health.

Suppression of Physaria fendleri SDP1 Increased Seed Oil and Hydroxy Fatty Acid Content While Maintaining Oil Biosynthesis Through Triacylglycerol Remodeling.

Physaria fendleri is a burgeoning oilseed crop that accumulates the hydroxy fatty acid (HFA), lesquerolic acid, and can be a non-toxic alternative crop to castor for production of industrially valuable HFA. Recently, P. fendleri was proposed to utilize a unique seed oil biosynthetic pathway coined "triacylglycerol (TAG) remodeling" that utilizes a TAG lipase to remove common fatty acids from TAG allowing the subsequent incorporation of HFA after initial TAG synthesis, yet the lipase involved is unknown. SUGAR DEPENDENT 1 (SDP1) has been characterized as the dominant TAG lipase involved in TAG turnover during oilseed maturation and germination. Here, we characterized the role of a putative PfeSDP1 in both TAG turnover and TAG remodeling. In vitro assays confirmed that PfeSDP1 is a TAG lipase and demonstrated a preference for HFA-containing TAG species. Seed-specific RNAi knockdown of PfeSDP1 resulted in a 12%-16% increase in seed weight and 14%-19% increase in total seed oil content with no major effect on seedling establishment. The increase in total oil content was primarily due to ~4.7% to ~14.8% increase in TAG molecular species containing two HFA (2HFA-TAG), and when combined with a smaller decrease in 1HFA-TAG content the proportion of total HFA in seed lipids increased 4%-6%. The results are consistent with PfeSDP1 involved in TAG turnover but not TAG remodeling to produce 2HFA-TAG. Interestingly, the concomitant reduction of 1HFA-TAG in PfeSDP1 knockdown lines suggests PfeSDP1 may have a role in reverse TAG remodeling during seed maturation that produces 1HFA-TAG from 2HFA-TAG. Overall, our results provide a novel strategy to enhance the total amount of industrially valuable lesquerolic acid in P. fendleri seeds.

Transcriptome analysis of salt stress responsiveness in the seedlings of wild and cultivated Ricinus communis L.

Soil salinity is one of the major environmental factors, influencing agricultural productivity of crops. As a non-edible and ideal oilseed crop, castor (Ricinus communis L.) has great industrial value in biofuel, but molecular mechanisms of salt stress regulation are still unknown. In this study, the differentially expressed genes (DEGs) for differential salt tolerance in two castor cultivar (wild castor : Y, cultivated castor 'Tongbi 5': Z) were identified. 12 libraries were sampled for Illumina high-throughput sequencing to consider 132,426 nonredundant unigenes and 31,221 gene loci. Multiple phytohormones and transcription factors (TFs) were correlated with salt-tolerance and differently enriched in these two genotypes. The type 2C protein phosphatases (PP2C) homologs were all upregulated under salt stress. Importantly, IAA (1), DELLA (1) and Jasmonate zim domain (JAZ) (1) were also identified and found to be differentially expressed. Based on the co-expressed module by regulatory networks and heatmap analysis, ERF/AP2, WRKY and bHLH families were prominently participate in high salt stress response of wild and cultivated castor. Finally, these results highlight that the hub DEGs and families were more accumulated in cultivated castor than those in wild castor, providing novel insights into the salinity adaptive mechanisms and genetic improvement in castor.