Genome-wide identification of the GDSL-type esterase/lipase protein (GELP) gene family in Ricinus communis and its transcriptional regulation during germination and seedling establishment under different abiotic stresses.

GDSL-type esterase/lipase protein (GELP) genes are crucial in the specialized lipid metabolism, in the responses to abiotic stresses, and in the regulation of plant homeostasis. R. communis is an important oilseed crop species that can sustain growth and productivity when exposed to harsh environmental conditions. Herein, we raised the question of whether the GELP gene family could be involved in the acquisition of R. communis tolerance to abiotic stresses during seed germination and seedling establishment. Thus, we used bioinformatics and transcriptomics to characterize the R. communis GELP gene family. R. communis genome possesses 96 GELP genes that were characterized by extensive bioinformatics, including phylogenetic analysis, subcellular localization, exon-intron distribution, the analysis of regulatory cis-elements, tandem duplication, and physicochemical properties. Transcriptomics indicated that numerous RcGELP genes are readily responsive to high-temperature and salt stresses and might be potential candidates for genome editing techniques to develop abiotic stress-tolerant crops.

An efficient method for protoplast-mediated production of transformed castor bean (Ricinus communis) lines.

OBJECTIVE: The purpose of this study was to develop a method for the isolation, culture, and PEG-mediated protoplast transfection from leaves of in vitro-grown plants of Ricinus communis. RESULTS: Factors such as the enzymatic composition and the incubation time were evaluated. The enzymatic solution, containing 1.6% Cellulase-R10 and 0.8% Macerozyme-R10, with 16 h of incubation, was the best condition to achieve a high protoplast yield (481.16 × 104 protoplasts/g FW) with a high percentage of viability (95%). The combination and concentration of enzymes have been shown to affect the protoplast isolation efficiency significantly. Furthermore, we found that a higher number of protoplasts (8.5 × 105 protoplast/g FW) was obtained at a longer incubation time, but their viability decreased. We obtained a simple and efficient protocol to isolate protoplast from Ricinus communis leaves and culture. A PEG-mediated protoplast transfection protocol was also established to introduce plasmid DNA into Ricinus communis genotypes cultivated in Colombia. Thus, strengthening advances in the genetic improvement processes for this crop are presented.

Genome-wide identification of core components of ABA signaling and transcriptome analysis reveals gene circuits involved in castor bean (Ricinus communis L.) response to drought.

Castor bean (Ricinus communis L.) can withstand long periods of water deficit and high temperatures, and therefore has been recognized as a drought-resistant plant species, allowing the study of gene networks involved in drought response and tolerance. The identification of genes networks related to drought response in this plant may yield important information in the characterization of molecular mechanisms correlating changes in the gene expression with the physiological adaptation processes. In this context, gene families related to abscisic acid (ABA) signaling play a crucial role in developmental and environmental adaptation processes of plants to drought stress. However, the families that function as the core components of ABA signaling, as well as genes networks related to drought response, are not well understood in castor bean. In this study 7 RcPYL, 63 RcPP2C, and 6 RcSnRK2 genes were identified in castor bean genome, which was further supported by chromosomal distribution, gene structure, evolutionary relationships, and conserved motif analyses. The castor bean general expression profile was investigated by RNAseq in root and leaf tissues in response to drought stress. These analyses allowed the identification of genes differentially expressed, including genes from the ABA signaling core, genes related to photosynthesis, cell wall, energy transduction, antioxidant response, and transcription factors. These analyses provide new insights into the core components of ABA signaling in castor bean, allow the identification of several molecular responses associated with the high physiological adaptation of castor bean to drought stress, and contribute to the identification of candidate genes for genetic improvement.

Development of TRAP primers for Ricinus communis L.

The objective of this article was to develop TRAP (target region amplification polymorphism) primers for castor bean, with the goal of making functional markers available for genetic studies about the species. To do this, oligonucleotides were designed based on ESTs, obtained from the NCBI (National Center for Biotechnology Information) databank, which code enzymes involved in metabolic routes of fatty acid synthesis, ricin synthesis, and resistance to castor bean pathogens. The forward primers were designed with the help of the Primer3 software and, for the reverse, six arbitrary primers were used. To standardize the amplification reactions, the following criteria were used to select the primers: sizes between 18 and 20 bp, guanine/cytosine (GC) in the range of 40 to 60%, and average annealing temperature between 55° and 62°C. The design quality of the primers was verified using the Net Primer application. Fifty-six primers were designed, which had an average GC percentage of 53.2%. A total of 336 combinations were obtained using the 56 fixed and 6 arbitrary primers. Based on polymerase chain reaction, 330 combinations (89%) presented good amplification patterns for the genomic DNA of castor bean. The size of the fragments amplified varied between 50 and 2072 bp. The TRAP primers designed and validated in this study are the first for castor bean and represent a significant increase in the molecular markers for this species.

Effect of temperature on biomass allocation in seedlings of two contrasting genotypes of the oilseed crop Ricinus communis.

Ricinus communis is becoming an important crop for oil production, and studying the physiological and biochemical aspects of seedling development may aid in the improvement of crop quality and yield. The objective of this study was to assess the effect of temperature on biomass allocation in two R. communis genotypes. Biomass allocation was assessed by measuring dry weight of roots, stems, and cotyledons of seedlings grown at three different temperatures. Root length of each seedling was measured. Biomass allocation was strongly affected by temperature. Seedlings grown at 25°C and 35°C showed greater biomass than seedlings grown at 20°C. Cotyledon and stem dry weight increased for both genotypes with increasing temperature, whereas root biomass allocation showed a genotype-dependent behavior. Genotype MPA11 showed a continuous increase in root dry weight with increasing temperature, while genotype IAC80 was not able to sustain further root growth at higher temperatures. Based on metabolite and gene expression profiles, genotype MPA11 increases its level of osmoprotectant molecules and transcripts of genes encoding for antioxidant enzymes and heat shock proteins to a higher extent than genotype IAC80. This might be causal for the ability to maintain homeostasis and support root growth at elevated temperatures in genotype MPA11.

Determination of genetic divergence among castor bean accesses by using binary and multicategorical characters / Determinação de divergência genética entre acessos de mamoneira por meio de caracteres multicategóricos

The objective of this work was to characterize morphologically and to evaluate the genetic diversity between fifteen groups of castor bean (Ricinus communis). The experiment was conducted in a randomized blocks design with fifteen treatments and three replications and was carried out in dystroferric Red Latosol in Lavras, MG, Brazil. Data was submitted to variance analysis, getting the genetic distances between the groups and on the basis of these distances, based on multivariate analysis, the genetic divergence was determined by using cluster analysis and principal components analysis. Three groups were formed, so that it was evidenced genetic divergence in the dissimilarity matrix. Group I formed by twelve genotypes, group II formed by two genotype and group III formed by one genotype, access nine. The use of multicategorical characters was efficient for the determination of genetic divergence among castor beans.

O objetivo deste trabalho foi caracterizar morfologicamente e avaliar a diversidade genética entre 15 acessos de mamona (Ricinus communis). O experimento em delineamento em blocos ao acaso, com 15 tratamentos e três repetições, foi implantado em Latossolo Vermelho distroférrico em Lavras, MG. Os dados foram submetidos à análise de variância, obtendo-se as distâncias genéticas entre os acessos e com base nessas distâncias realizou-se análise de agrupamento e análise dos componentes principais para determinação da divergência genética. Houve formação de três grupos, ou seja, constatou-se a divergência genética na matriz de dissimilaridade. O grupo I formado por 12 genótipos, o grupo II, por dois genótipos e o grupo III, apenas por um, o acesso nove. A utilização dos caracteres multicategóricos mostrou-se efi ciente para a determinação da divergência genética entre acessos de mamona.

Determination of genetic divergence among castor bean accesses by using binary and multicategorical characters / Determinação de divergência genética entre acessos de mamoneira por meio de caracteres multicategóricos

The objective of this work was to characterize morphologically and to evaluate the genetic diversity between fifteen groups of castor bean (Ricinus communis). The experiment was conducted in a randomized blocks design with fifteen treatments and three replications and was carried out in dystroferric Red Latosol in Lavras, MG, Brazil. Data was submitted to variance analysis, getting the genetic distances between the groups and on the basis of these distances, based on multivariate analysis, the genetic divergence was determined by using cluster analysis and principal components analysis. Three groups were formed, so that it was evidenced genetic divergence in the dissimilarity matrix. Group I formed by twelve genotypes, group II formed by two genotype and group III formed by one genotype, access nine. The use of multicategorical characters was efficient for the determination of genetic divergence among castor beans.(AU)

O objetivo deste trabalho foi caracterizar morfologicamente e avaliar a diversidade genética entre 15 acessos de mamona (Ricinus communis). O experimento em delineamento em blocos ao acaso, com 15 tratamentos e três repetições, foi implantado em Latossolo Vermelho distroférrico em Lavras, MG. Os dados foram submetidos à análise de variância, obtendo-se as distâncias genéticas entre os acessos e com base nessas distâncias realizou-se análise de agrupamento e análise dos componentes principais para determinação da divergência genética. Houve formação de três grupos, ou seja, constatou-se a divergência genética na matriz de dissimilaridade. O grupo I formado por 12 genótipos, o grupo II, por dois genótipos e o grupo III, apenas por um, o acesso nove. A utilização dos caracteres multicategóricos mostrou-se efi ciente para a determinação da divergência genética entre acessos de mamona.(AU)

New efficient DNA extraction method to access the microbiome of Ricinus communis seeds.

Ricinus communis (castor bean) seeds are used to produce an alcohol-soluble oil that is used in more than 400 industrial processes. Despite its economic importance, there has been little research on the endophytic microbiota of castor bean seeds. This microbiota is important for plant metabolic processes and may have considerable biotechnological potential, such as production of lipases and plant growth promoter agents. We evaluated several DNA extraction methodologies in order to access the microbial diversity of castor bean through a metagenomic approach. Based on our observations, we developed a new methodology that takes advantage of the low solubility of calcium phosphates and the high affinity of these phosphates for proteins and polysaccharides. The extracted DNA quality was evaluated by PCR, using a selective primer pair for bacterial and mitochondrial 16S rDNA genes (799F and 1492R). We found this methodology quantitatively and qualitatively more efficient than the other approaches. In evaluating this new extraction methodology, we found that the difficulties of DNA extraction from castor bean seeds, such as abundant oil, polysaccharides, phenolic compounds, and plant enzymes, could be overcome. The resulting extracts had high concentration and purity, and they were obtained faster than with previous methods. The samples contained virtually all of the DNA, including the microbial DNA; this was validated by PCR analysis.

Development of a novel set of microsatellite markers for castor bean, Ricinus communis (Euphorbiaceae).

PREMISE OF STUDY: Microsatellite primers were developed for castor bean (Ricinus communis L.) to investigate genetic diversity and population structure, and to provide support to germplasm management. METHODS AND RESULTS: Eleven microsatellite loci were isolated using an enrichment cloning protocol and used to characterize castor bean germplasm from the collection at the Instituto Agronômico de Campinas (IAC). In a survey of 76 castor bean accessions, the investigated loci displayed polymorphism ranging from two to five alleles. CONCLUSIONS: The information derived from microsatellite markers led to significant gains in conserved allelic richness and provides support to the implementation of several molecular breeding strategies for castor bean.