Peanut Testa Research Articles

Bioactive compounds of peanut skin in prevention and adjunctive treatment of chronic non-communicable diseases.

The global prevalence of cancer continues to increase, so does its mortality. Strategies that can prevent/treat this condition are therefore required, especially low-cost and low-toxicity strategies. Bioactive compounds of plant origin have been presented as a good alternative. In this scenario, due to its abundant polyphenolic content (around 60 to 120 times greater than that of the grain), peanut skin by-products stand out as a sustainable source of food bioactives beneficial to human health. Investigated studies highlighted the importance of peanut skin for human health, its phytochemical composition, bioactivity and the potential for prevention and/or adjuvant therapy in cancer, through the advanced search for articles in the Virtual Health Library (VHL), Science direct and the Mourisco platform of the FioCruz Institute, from 2012 to 2022. Using the keywords, "peanut skin" AND "cancer" AND NOT "allergy", the words "peanut testa" and "peanut peel" were included replacing "peanut skin". 18 articles were selected from Plataforma Mourisco, 26 from Science Direct and 26 from VHL. Of these, 7 articles evaluated aspects of cancer prevention and/or treatment. Promising benefits were found in the prevention/treatment of chronic non-communicable diseases in the use of peanut and peanut skin extracts, such as cholesterolemia and glucose control, attenuation of oxidative stress and suppressive action on the proliferation and metabolism of cancer cells.

Phylogenomic Analysis of Cytochrome P450 Gene Superfamily and Their Association with Flavonoids Biosynthesis in Peanut (Arachis hypogaea L.).

Cytochrome P450s (CYPs) constitute extensive enzyme superfamilies in the plants, playing pivotal roles in a multitude of biosynthetic and detoxification pathways essential for growth and development, such as the flavonoid biosynthesis pathway. However, CYPs have not yet been systematically studied in the cultivated peanuts (Arachis hypogaea L.), a globally significant cash crop. This study addresses this knowledge deficit through a comprehensive genome-wide analysis, leading to the identification of 589 AhCYP genes in peanuts. Through phylogenetic analysis, all AhCYPs were systematically classified into 9 clans, 43 gene families. The variability in the number of gene family members suggests specialization in biological functions. Intriguingly, both tandem duplication and fragment duplication events have emerged as pivotal drivers in the evolutionary expansion of the AhCYP superfamily. Ka/Ks analysis underscored the substantial influence of strong purifying selection on the evolution of AhCYPs. Furthermore, we selected 21 genes encoding 8 enzymes associated with the flavonoid pathway. The results of quantitative real-time PCR (qRT-PCR) experiments unveiled stage-specific expression patterns during the development of peanut testa, with discernible variations between pink and red testa. Importantly, we identified a direct correlation between gene expression levels and the accumulation of metabolites. These findings offer valuable insights into elucidating the comprehensive functions of AhCYPs and the underlying mechanisms governing the divergent accumulation of flavonoids in testa of different colors.

Transcriptional networks orchestrating red and pink testa color in peanut

BackgroundTesta color is an important trait of peanut (Arachis hypogaea L.) which is closely related with the nutritional and commercial value. Pink and red are main color of peanut testa. However, the genetic mechanism of testa color regulation in peanut is not fully understood. To elucidate a clear picture of peanut testa regulatory model, samples of pink cultivar (Y9102), red cultivar (ZH12), and two RNA pools (bulk red and bulk pink) constructed from F4 lines of Y9102 x ZH12 were compared through a bulk RNA-seq approach.ResultsA total of 2992 differential expressed genes (DEGs) were identified among which 317 and 1334 were up-regulated and 225 and 1116 were down-regulated in the bulk red-vs-bulk pink RNA pools and Y9102-vs-ZH12, respectively. KEGG analysis indicates that these genes were divided into significantly enriched metabolic pathways including phenylpropanoid, flavonoid/anthocyanin, isoflavonoid and lignin biosynthetic pathways. Notably, the expression of the anthocyanin upstream regulatory genes PAL, CHS, and CHI was upregulated in pink and red testa peanuts, indicating that their regulation may occur before to the advent of testa pigmentation. However, the differential expression of down-stream regulatory genes including F3H, DFR, and ANS revealed that deepening of testa color not only depends on their gene expression bias, but also linked with FLS inhibition. In addition, the down-regulation of HCT, IFS, HID, 7-IOMT, and I2’H genes provided an alternative mechanism for promoting anthocyanin accumulation via perturbation of lignin and isoflavone pathways. Furthermore, the co-expression module of MYB, bHLH, and WRKY transcription factors also suggested a fascinating transcriptional activation complex, where MYB-bHLH could utilize WRKY as a co-option during the testa color regulation by augmenting anthocyanin biosynthesis in peanut.ConclusionsThese findings reveal candidate functional genes and potential strategies for the manipulation of anthocyanin biosynthesis to improve peanut varieties with desirable testa color.

Ion Exchange Properties of Crosslinked and Carboxylated Peanut (Arachis Hypogaea L.) Testa Extract

After polymerization via polycondensation of catechin units in the acetone extract of peanut (arachis hypogaea L.) testa (PTE) using phosphorus oxychloride (POCl3) as a crosslinking agent, POCl3-crosslinked PTE (Crosslinked-PPTE) was functionalized by etherification (PC-PTE) using monochloroacetic acid (MCAA) in the presence of an alkali according to the method of Williamson ether synthesis. Subsequent to characterization by Fourier Transform Infrared spectroscopy (FTIR) as well as physical properties, Crosslinked-PPTE was assessed for cation exchange capacity (CEC) and pH at point of zero charge (ZPHC) following demonstrated capacity to remove heavy metal ions in single and multi-elements aqueous solutions by Atomic Absorption Spectrometry (AAS) technique while functionalized (carboxymethylated) Crosslinked-PPTE (PC-PTE) was further characterized by degree of substitution (DS). FTIR absorption bands due to -C-O-P=O, -P=O, P-O-C- and R-O-P-OH stretching vibrations were seen at 1350/1250, 1244/1246, 997/993 cm-1 respectively. Asymmetric and symmetric stretching vibrations of the -C=O of a COOH, Ar-O-C- of an aromatic ether as well as -P-O-C - of an aromatic PO43-, R-P=O of a -PO43-, -R-O-P- and R-O-P-OH of a PO43- ester created by crosslinked and carboxymethylated PTE respectively were seen at 1743, 1377, 1278, 1190, 1062 and 823 cm-1. The results obtained showed that 0.6 was the DS of PC-PTE while 6.72 meq/g and 3.57 defined the CEC and pH (zpc) respectively of Crosslinked-PPTE. Quantitative removal of Fe2+, Ni2+, Pb2+, Cu2+ and Zn2+ in laboratory simulated metal ion wastewater (LSW) to the levels of 84.4, 81.7, 76.5, 72.0 and 75.1% respectively was achieved using Crosslinked-PPTE resin in batch adsorption experiments in which the efficiency was found to depend significantly on the temperature and pH of the water as well as initial adsorbate concentration and contact time but partially on the amount of adsorbent used was observed to be independent of the speed of stirring of the wastewater. Stable, Matakana and fine powder crosslinked-PPTE which is insoluble in water and common laboratory solvents holds great potential in the purification of heavy metal ions polluted water

Metabolomics combined with transcriptomics analyses of mechanism regulating testa pigmentation in peanut.

Peanut testa (seed coat) contains large amounts of flavonoids that significantly influence seed color, taste, and nutritional qualities. There are various colors of peanut testa, however, their precise flavonoid components and regulatory mechanism of pigmentation remain unclear. In this study, a total of 133 flavonoids were identified and absolutely quantified in the seed coat of four peanut cultivars with different testa color using a widely targeted metabolomic approach. Black peanut skin had more types and substantial higher levels of cyanidin-based anthocyanins, which possibly contribute to its testa coloration. Procyanidins and flavan-3-ols were the major co-pigmented flavonoids in the red, spot and black peanuts, while flavanols were the most abundant constitutes in white cultivar. Although the concentrations as well as composition characteristics varied, the content ratios of procyanidins to flavan-3-ols were similar in all samples except for white peanut. Furthermore, MYB-like transcription factors, anthocyanidin reductases (ANR), and UDP-glycosyltransferases (UGT) were found to be candidate genes involved in testa pigmentation via RNA-seq and weighted gene co-expression network analysis. It is proposed that UGTs and ANR compete for the substrate cyanidin and the prevalence of UGTs activities over ANR one will determine the color pattern of peanut testa. Our results provide a comprehensive report examining the absolute abundance of flavonoid profiles in peanut seed coat, and the finding are expected to be useful for further understanding of regulation mechanisms of seed coat pigmentation in peanut and other crops.

Targeted metabolome analysis reveals accumulation of metabolites in testa of four peanut germplasms.

Cultivated peanut (Arachis hypogaea L.) is an important source of edible oil and protein. Peanut testa (seed coat) provides protection for seeds and serves as a carrier for diversity metabolites necessary for human health. There is significant diversity available for testa color in peanut germplasms. However, the kinds and type of metabolites in peanut testa has not been comprehensively investigated. In this study, we performed metabolite profiling using UPLC-MS/MS for four peanut germplasm lines with different testa colors, including pink, purple, red, and white. A total of 85 metabolites were identified in four peanuts. Comparative metabolomics analysis identified 78 differentially accumulated metabolites (DAMs). Some metabolites showed significant correlation with other metabolites. For instance, proanthocyanidins were positively correlated with cyanidin 3-O-rutinoside and malvin, and negatively correlated with pelargonidin-3-glucoside. We observed that the total proanthocyanidins are most abundant in pink peanut variety WH10. The red testa accumulated more isoflavones, flavonols and anthocyanidins compared with that in pink testa. These results provided valuable information about differential accumulation of metabolites in testa with different color, which are helpful for further investigation of the molecular mechanism underlying biosynthesis and accumulation of these metabolites in peanut.

Multi-Omics and miRNA Interaction Joint Analysis Highlight New Insights Into Anthocyanin Biosynthesis in Peanuts (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is one of the most important economic and oil crops in the world. At present, peanut varieties with rich anthocyanin in testa are rare in the market, but the selection and breeding of varieties with the related traits has always attracted the attention of breeders. In this study, two peanut varieties with the pink and purple testa, G110 (G) and Z18-40 (Z) were used to conduct interaction joint analysis of multi-omics and miRNA-target gene. The anthocyanin content of Z18-40 was 7.49–8.62-folds higher than G110 on 30 DAF (days after flowering) and 45 DAF via Ultraviolet-visible Spectrophotometer (UV-5800, Shanghai, China). And then, a total of 14 candidate genes related with the anthocyanin biosynthesis were identified for correlation in different comparison groups (R2 ≥ 0.80), among of a novel gene Ah21440 related with hydroxycinnamoyl transferase (HCT) biosynthesis was identified. In addition, Cyanidin 3-O-glucoside (Kuromanin, pmb0550) was the only common differentially accumulated metabolite (DAM) identified using multi-omics joint analysis in G1_vs_G2, Z1_vs_Z2, G1_vs_Z1, and G2_vs_Z2, respectively. Correlation analysis of miRNA-target genes and DEGs in the transcriptome shows that, AhmiR2950, AhmiR398, AhmiR50, and AhmiR51 regulated to HCT and chalcone biosynthesis related candidate genes (Ah21440, AhCHS, AhCHI). Lastly, all of 14 candidate genes and 4 differentially expressed miRNAs were validated using quantitative real-time PCR (qRT-PCR), which trends were consistent with that of the former transcriptome data. The results provide important reference for in-depth research on the anthocyanin metabolism mechanism in peanut testa.

BSA‑seq and genetic mapping reveals AhRt2 as a candidate gene responsible for red testa of peanut.

The candidate recessive gene AhRt2 responsible for red testa of peanut was identified through combined BSA-seq and linkage mapping approaches. The testa colorof peanuts (Arachis hypogaea L.) is an important trait, and those with red testa are particularly popular owing to the high-anthocyanin content. However, the identification of genes underlying the regulation of the red testa trait in peanut are rarely reported. In order to fine map red testa gene, two F2:4 populations were constructed through the cross of YZ9102 (pink testa) with ZH12 (red testa) and ZH2 (red testa). Genetic analysis indicated that red testa was controlled by a single recessive gene named as AhRt2 (Red testa gene 2). Using BSA-seq approach, AhRt2 was preliminary identified on chromosome 12, which was further mapped to a 530-kb interval using 220 recombinant lines through linkage mapping. Furthermore, functional annotation, expression profiling, and the analyses of sequence variation confirmed that the anthocyanin reductase namely (Arahy.IK60LM) was the most likely candidate gene for AhRt2. It was found that a SNP in the third exon of AhRt2 altered the encoding amino acids, and was associated with red testa in peanut. In addition, a closely linked molecular marker linked with red testa trait in peanut was also developed for future studies. Our results provide valuable insight into the molecular mechanism underlying peanut testa color and present significant diagnostic marker resources for marker-assisted selected breeding in peanut.

Transcriptome and Metabolome Analysis Unveil Anthocyanin Metabolism in Pink and Red Testa of Peanut (Arachis hypogaea L.).

Peanut (Arachis hypogaea L.) is an important source of oil and food around the world, and the testa color affects its appearance and commercial value. However, few studies focused on the mechanism of pigment formation in peanut testa. In this study, cultivars Shanhua 15 with pink testa and Zhonghua 12 with red testa were used as materials to perform the combined analysis of transcriptome and metabolome. A total of 198 flavonoid metabolites were detected, among which petunidin 3-O-glucoside and cyanidin O-acetylhexoside in Zhonghua12 were 15.23 and 14.72 times higher than those of Shanhua 15 at the R7 stage, revealing the anthocyanins underlying the red testa. Transcriptome analysis showed that there were 6059 and 3153 differentially expressed genes between Shanhua 15 and Zhonghua 12 in different growth periods, respectively. These differentially expressed genes were significantly enriched in the flavonoid biosynthesis, biosynthesis of secondary metabolites, and metabolic pathways. Integrated analysis of transcriptome and metabolome indicated CHS gene (arahy.CM90T6), F3′H genes (arahy. 8F7PE4 and arahy. K8H9R8), and DFR genes (arahy. LDV9QN and arahy. X8EVF3) may be the key functional genes controlling the formation of pink and red testa in peanut. Transcription factors MYB (arahy.A2IWKV, arahy.US2SKM, arahy.SJGE27, arahy.H8DJRL, and arahy.PR7AYB), bHLH (arahy.26781N, arahy.HM1IVV, and arahy.MP3D3D), and WD40 (arahy.L6JJW9) in the biosynthetic pathway of anthocyanin were significantly upregulated in Zhonghua 12 which may be the key regulatory genes in testa pigment formation. This is a comprehensive analysis on flavonoid metabolites and related genes expression in peanut testa, providing reference for revealing the regulatory mechanism of pigment accumulation in peanut testa.

Localization of Flavan-3-ol Species in Peanut Testa by Mass Spectrometry Imaging.

Flavan-3-ols, procyanidins and their monomers are major flavonoids present in peanuts that show a wide range of biological properties and health benefits, based on their potent antioxidant activity. Procyanidin oligomers, especially A-type, are reportedly abundant in peanut skin; however, their localization in the raw peanut testa remains poorly understood. Therefore, we performed matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to investigate the localization of flavan-3-ols in peanut testa. 1,5-Diaminonaphthalene was coated onto the peanut section by matrix vapor deposition/recrystallization, and MALDI-MSI measurements were performed in the negative-ion mode. Peaks matching the m/z values of flavan-3-ol [M − H]− ions were observed in the mass spectrum extracted from the outer epidermis of the peanut testa, using the region of interest function. Catechin and/or epicatechin, five A-type, and one B-type procyanidins were assigned by the fragment ions generated by retro-Diels-Alder, heterocyclic ring fission, and quinone methide reactions detected in MALDI-tandem MS spectra. These flavan-3-ols were localized in the outer epidermis of the peanut testa. This information will contribute to improving the extraction and purification efficiencies of flavan-3-ols from peanut testa. As flavan-3-ols display anti-microbial activity, it is speculated that flavan-3-ols present in the outer epidermis of peanut testa act to prevent pathogen infection.

Comparative transcriptome analysis of anthocyanin synthesis in black and pink peanut

ABSTRACT In recent years, black testa peanut (Arachis hypogaea L.) has been favored because of its nutritional value and health function. To explore the genetic basis of peanut testa color, high-throughput sequencing technology was used to sequence the transcriptome of black testa peanut ‘ZH9ʹ and pink testa peanut ‘ZH8.ʹ Over 18 million high-quality reads were assembled into 49,404–52,578 genes for these two cultivars using a combined assembly strategy. Totally, 4,122 differentially expressed genes (DEGs) were identified between ZH8 and ZH9, among which 1317 (32%) were up-regulated and 2805 (68%) were down-regulated. KEGG analysis showed that the pathways of anthocyanin biosynthesis, isoflavonoid biosynthesis, flavone and flavonol biosynthesis, and phenylpropanoid biosynthesis were in the top 20 differentially expressed genes enriched pathways. Further analysis showed that the formation of the black color of ZH9 testa was mainly due to the reduction of lignin biosynthesis and isoflavonoid biosynthesis, and as a result, more substrate flow to anthocyanin biosynthesis. The up-regulation of all genes associated with DFR, a key enzyme determining flavonoid synthesis or anthocyanin synthesis in the flavonoid metabolic pathway, is also a strategy for increasing dihydroflavonol, a substrate for anthocyanin and flavonol biosynthesis. In addition, we identified three up-regulated R2R3MYB transcription factors associated with anthocyanin biosynthesis in ZH9. Finally, we verified the expressions of 15 genes that encode key enzymes and transcription factors using quantitative real-time PCR (qRT-PCR).

Peanut testa extracts enhance anticancer effect of cisplatin against human cholangiocarcinoma cells via modulation of histone deacetylase inhibitory activity

Objective: To investigate the effect of combination treatments of cisplatin and KK4 and ICG15042 peanut testa extracts against cholangiocarcinoma cells in vitro. Methods: The growth inhibition, cell cycle arrest and apoptosis of cholangiocarcinoma cells were determined by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis, respectively. The levels of proteins involved in apoptosis were assessed using Western blotting assays. The caspase activity was assessed using a colorimetric caspase activity assay. Results: Cisplatin and peanut (KK4 and ICG15042) testa extracts inhibited the growth of cholangiocarcinoma cell lines (KKU- M214 and KKU-100 cells) in a dose- and time-dependent manner. The combination treatments reduced cell viability and induced apoptosis of cholangiocarcinoma cells more efficiently than singledrug treatments. Cancer cell death synergistically mediated by cisplatin and peanut testa extracts was observed in KKU-M214 cells (combination index 1.0). The combination treatments also increased the sub- G1 population and caused KKU-M214 cell cycle arrest at S and G2/ M phases, which were the combined effects of cisplatin (S phase arrest) and peanut testa extracts (G2/M phase arrest). In addition, pERK1/2, Ac-H3, Bcl-2 and proteins related to apoptosis, including Bax and caspases 3, 8, 9, exhibited enhanced expression in KKU- M214 cells. The combination treatments caused down-regulation of p53, whereas the expression of p21 was fairly constant when compared with cisplatin single drug treatment. Conclusions: Peanut testa extracts in combination with cisplatin synergistically reduce cell viability and induce apoptosis through stimulation of caspases 3, 8 and 9 in KKU-M214 cells.

Transcriptomic profiling reveals pigment regulation during peanut testa development

Although peanut (Arachis hypogaea L.) is one of the most important edible oil crops globally, pigments present in the testa influence both the processing efficiency and the quality of the oil. In peanut, polymeric phenolic compounds are present in the episperm rather than in the endothelium and their levels increase during ripening; therefore, to better understand testa development, and especially the accumulation of pigments, RNA-Seq was applied to elucidate the mechanisms underlying the regulation of peanut testae at three different developmental stages (i.e., at 20 days after flowering – 20DAF – and at 40DAF and 60DAF). A total of 5452 differentially expressed unigenes (DEGs) were obtained encompassing these three stages; comparative results showed that phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, and plant hormone signal transduction comprised the principal KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways expressed during peanut testa development. Further studies revealed that the expression patterns of the flavonoid biosynthesis pathway genes PAL, C4H, CHS, and CHI (early biosynthetic genes – EBGs) were consistent with the accumulation of testa pigments. Thus, the results of this study demonstrate that EBGs, as well as the homologs of AtMYB111 (i.e., c35101_g4 and c37398_g2), are likely the principal regulators of testa pigment accumulation; the gene database assembled here is therefore a sequencing resource for future research and provides a foundation for understanding the regulation of pink testa pigmentation in peanuts.

Peanut testa extracts possessing histone deacetylase inhibitory activity induce apoptosis in cholangiocarcinoma cells

Previous studies demonstrated that peanut testa extracts (KK4 and ICG15042) containing natural histone deacetylase (HDAC) inhibitors inhibited the growth of several human cancer cell lines via apoptosis induction. The aims of this study were to investigate the anti-proliferative effects and the mechanism(s) responsible for apoptosis induction mediated by these peanut testa extracts in human cholangiocarcinoma cell lines (KKU-M214 and KKU-100). The anti-proliferative effects were assessed by MTT assay. Apoptotic cell death and cell cycle arrest were analyzed by flow cytometry. The caspase activities were studied using colorimetric caspase activity assay and western blot analysis. Our results revealed that KK4 and ICG15042 extracts inhibited cell proliferation of both KKU-M214 and KKU-100 cells in a dose- and time-dependent manner, with IC50 values of 38.28 ± 0.29 (KK4), 43.91 ± 1.94 (ICG15042) μg/mL for KKU-M214 and 78.40 ± 1.74 (KK4), 82.77 ± 0.94 (ICG15042) μg/mL for KKU-100 at 72 h. Apoptosis induction by these peanut testa extracts were observed in both KKU-M214 and KKU-100 cells in a concentration-dependent manner. Moreover, the percentage of cells in the sub-G1 phase was significantly increased in both KKU-M214 and KKU-100 cells. Cell cycle arrest was not observed in other cell cycle phases. Activation of caspases 8 and 3 were apparent integral parts of apoptosis induction in both cells. Both peanut testa extracts also caused down-regulation of p53, p21, Bcl-2 and pERK1/2 protein expression in these cells. These results suggest that peanut testa extracts may be potential anti-cancer agents for cholangiocarcinoma chemoprevention or chemotherapy.

Cytotoxic effects of peanut phenolic compounds possessing histone deacetylase inhibitory activity on human colon cancer cell lines

Phenolic compounds present in our diet play an important role in colon cancer chemoprevention. Previous results demonstrated that peanut testa extract inhibited both histone deacetylase (HDAC) activity and the growth of colon cancer cells. In this study, four identified phenolic compounds in peanut testae (resveratrol, p-coumaric acid, ferulic acid, and sinapinic acid) were investigated for their HDAC inhibitory and anticancer activities against colon cancer cell lines. In vitro study revealed that resveratrol exhibited the greatest HDAC inhibitory activity. Molecular docking studies demonstrated that all four compounds could bind both HDAC1 and HDAC2. Resveratrol exhibited the most effective antiproliferative activity against both human colon adenocarcinoma (HT29) and human colorectal carcinoma (HCT116) cells. Apoptosis induction by ferulic acid and resveratrol appeared to be associated with p53 activation in HCT116 cells. However, resveratrol, p-coumaric acid, ferulic acid, and sinapinic acid induced apoptosis of HT29 cells in a p53-independent manner. Low-concentration treatments of p-coumaric and ferulic acids resulted in cell cycle arrest of HCT116 cells. In contrast, high-concentration treatments of p-coumaric and ferulic acids showed cell death activation as evidenced by increased sub-G1 fractions. The induction of p21 by p-coumaric acid and resveratrol correlated well with the decreased CDK4 levels and cell cycle arrest. Resveratrol, p-coumaric acid, ferulic acid, and sinapinic acid caused activation of pERK1/2 in HCT116 cells, whereas ferulic and sinapinic acids caused downregulation of pERK1/2 in HT29 cells. These results suggest that these peanut phenolics may be potential antineoplastic agents for colon cancer chemoprevention/chemotherapy.

Histone Deacetylase Inhibitory Activity of Peanut Testa Extracts against Human Cancer Cell Lines

Inhibition of histone deacetylase (HDAC) is a promising strategy for cancer treatment. In this study, HDAC inhibitory activity of 15 Valencia-type peanut testa extracts was assessed in mammalian cell model. Nine of 15 testa extracts exhibited HDAC inhibitory activity. Two peanut testa extracts (genotypes ICG15042 and KK4) possessing the greatest HDAC inhibitory activity could inhibit the growth of all five human cancer cell lines tested. At 72-h treatment, both ICG15042 and KK4 testa extracts showed the most effective growth inhibition on Jurkat T-leukemia cells with IC50 values of 28.81 and 30.00 μg/mL, respectively. Both extracts were more toxic against the cancerous cell lines, but safer toward a noncancer cell line. Growth inhibitory effects of both extracts appeared to be mediated by induction of apoptosis in a dose-dependent manner. Moreover, some phenolic acids including protocatechuic, syringic, p-coumaric, ferulic and sinapinic acids, which may underpin their anticancer activity, were also identified and analyzed quantitatively. Practical Applications HDAC inhibitory potentials of phenolic-rich testa extracts of 15 Valencia-type peanut genotypes in mammalian cell model were evaluated. The results suggest that peanut skins (testae) of nine peanut genotypes possessed HDAC inhibitory activity and two of them (ICG15042 and KK4), with the highest HDAC inhibitory activity, could inhibit cancer cell growth via apoptosis induction. Accordingly, peanut skins could be useful for application in areas such as alternative medicine for cancer treatment and functional food for dietary prevention of cancer.

Measurement of strontium isotope ratio in nitric acid extract of peanut testa by ICP-Q-MS after removal of Rb by extraction with pure water

The difference in the distributions of Sr and Rb in peanut seeds was utilized to develop a precise method for Sr isotope ratio measurement by inductively coupled plasma quadruple mass spectrometry (ICP-Q-MS). The testa instead of the whole peanut seed was selected as the sample because apparent enrichment of Sr in comparison to Rb was found in the testa. Furthermore, Rb in the testa was removed by pure water extraction with the aid of sonication to remove the isobaric interference in Sr isotope ratio measurement. The testa taken from one peanut seed was treated as one sample for the analysis. After optimization of the operating conditions, pure water (10 mL for each sample) extraction in 30 min with sonication was able to remove over 95% of Rb in the testa, while after the Rb removal Sr could be completely extracted using 10 mL of 0.3 mol L(-1) HNO3 for each sample. The integration time in ICP-Q-MS measurement was optimized to achieve a lower measurement uncertainty in a shorter time; the results showed that 1s was required and enough for the precise measurement of Sr isotope ratios giving a relative standard uncertainty (n=10) of ca. 0.1%. The present method was applied to peanut seeds grown in Japan, China, USA, India, and South Africa.

Genetic Studies Involving Wine Testa Color in Peanut1

Abstract A better understanding of peanut (Arachis hypogaea L.) testa color genetics would be helpful to breeders in developing new cultivars to meet U.S. market acceptability. Wine is one of the least understood of all basic testa colors in peanut. The objective of this genetic study was to gain further knowledge on the inheritance of wine testa color and possible allelic interactions. Crosses were made using two true-breeding wine testa color genotypes (Wine-Frr and PI 264549) as females with the tan testa and recessive red testa male parents Krinkle-Leaf and Makulu Red, respectively. F1, F2, and F3 data suggest no difference between the two wine testa color genotypes. Inheritance of wine testa color was found to be recessive with a one gene difference between wine and the tan testa color of Krinkle-Leaf, and with two gene differences between wine and the recessive red testa color of Makulu Red. Inheritance of wine seems to closely parallel that for recessive red testa color in the cultivated peanut.

Inheritance of Peanut Testa Colors Involved in Market Acceptability

The only acceptable testa colors in the U.S. peanut (Arachis hypogaea L.) market are tan, pink, and red. A better understanding of peanut testa color genetics would be helpful to breeders in developing new cultivars to meethese marketing parameters for human consumption. The objective of this study was to gain further knowledge on the inheritance of these very important testa colors. Six single crosses using three tan testa germplasm accessions (PI 203395, PI 203396, and PI 203397) as female parents and two new peanut cultivars (Georgia Runner and Georgia Browne) as male parents were made in 1989. Seed harvested from F1, F2, and F3 generations were classified during 1990, 1991, and 1992, respectively, for testa color, and data were analyzed for goodness‐of‐fit to expected genetic ratios. Testa color segregation fit a 15 tan + pink:l red F2 ratio, which confirmed a duplicate recessive loci model for red testa color. Genotypes, R2R2r3r3 and r2r2R3R3, are proposed for the three germplasm and the two Georgia parental peanut lines, respectively.

A Note on Testcrosses Between Tan or Pink Testa Color and Recessive Red Peanut Genotypes1

Abstract Phenotypically distinguishing between tan and pink peanut (Arachis hypogaea L.) testa color can be difficult. Genetic separation was attempted by testcrosses with homozygously recessive red testa genotypes (r2r2, r3r3). The recessive red testa color was found to differ from all of the following pink and tan cultivars: Sunbelt Runner, Southern Runner, Starr, Toalson, and the tan colored Krinkle-leaf genotype (F1F2D1D2r1) by only one of the two recessive red loci. Even though these results show that testcrossing to recessive red genotypes is not a viable approach for discerning tan versus pink testa color, it does suggest that several peanut cultivars already carry one recessive red gene.