Project description:Tiger nut (Cyperus esculentus), a perennial C4 plant of the Cyperaceae family, is an unconventional crop that is distinguished by its oil-rich tubers, which also possesses the advantages of strong resistance, wide adaptability, short life periods, and large biomass. To facilitate studies on gene expression in this species, we identified and validated a series of reference genes (RGs) based on transcriptome data, which can be employed as internal controls for qRT-PCR analysis in tiger nut. Fourteen putative candidate RGs were identified and evaluated across nine different tissues of two cultivars, and the RGs were analyzed using three different algorithms (geNorm, NormFinder, and BestKeeper). The stability rankings of the candidate RGs were merged into consensus lists with RankAggreg. For the below-ground storage organ of tiger nut, the optimal RGs were TUB4 and UCE2 in different developmental stages of tubers. UCE2 and UBL5 were the most stably expressed RGs among all tissues, while Rubisco and PGK exhibited the lowest expression stability. UCE2, UBL5 and Rubisco were compared to normalize the expression levels of the caleosin (CLO) and diacylglycerol acyltransferase 2-2 (DGAT2-2) genes across the same tissues. Our results showed that the RGs identified in this study, which exhibit more uniform expression patterns, may be utilized for the normalization of qRT-PCR results, promoting further research on gene expression in various tissues of tiger nut.
Project description:This study aimed to extract tiger nut polysaccharides (TNPs) by the cellulase method which were graded using the DEAE-cellulose ion exchange method to obtain neutral (TNP-N) and acidic (TNP-A) polysaccharide classes. Analysis of the physical structures and monosaccharide compositions of TNP-A (3.458 KDa) and TNP-N (10.640 KDa) revealed lamellar and dense flocculent structures, with both primarily containing the monosaccharides glucose, galactose, and arabinose (Glc, Gal, and Ara). Single-factor and orthogonal tests were used to select three hydrocolloids, and the optimal ratio of the composite hydrocolloids was determined. Peanut protein drinks with a centrifugal sedimentation rate of 9.71% and a stability factor of 69.28% were obtained by adding 2.78% polysaccharide extract, 0.1% monoglyceride, and peanut pulp at a ratio of 1:15.5 g/mL. Polysaccharide protein drinks are more stable than commercially available protein drinks, with nutritional parameters either comparable to or better than those of the non-polysaccharide protein drinks.
Project description:Dormancy release pattern, sprout growth and later reproduction were studied among various tuber sizes of Cyperus esculentus to determine effective methods to release dormancy and further to select suitable tuber size of this species in production. The results showed that medium tubers performed better during sprouting than large and small tubers under all pre-sprouting treatments. Pre-sprouting treatments at 25°C, 35°C, RT (room temperature) and -2°C were effective in relieving dormancy in medium tubers. Tiller number from medium tubers were significantly higher under 25°C, RT and 45°C than under 35°C and -2°C. Shoot and root mass from medium tubers were significantly higher under the 25°C, 35°C and RT than under other treatments. Tiller and tuber numbers both decreased with decreasing tuber size, as did tuber yield after three months of growth. Furthermore, leftover mass decreased with decreasing tuber mass and remained unchanged at sprouting and maturity periods. A significantly negative allometric correlation was found between plant mass and tuber mass from small tubers. However, a significantly positive allometric correlation was found between tuber size and tuber number from large tubers. In conclusion, medium tubers had a competitive advantage in sprouting, growth and reproduction.
Project description:Tigernut (Cyperus esculentus Lativum) is an important but understudied and underutilized crop in Ghana. The tubers are highly appreciated for their health benefits and nutritive value. To contribute to the conservation process of tiger nut and identify elite genotypes, this study was conducted to assess phenotypic variability in tiger nut genotypes in Ghana. Sixty-four (64) genotypes were collected from major tiger nut growing areas in Ghana. The genotypes were field-grown and characterized based on phenotypic and yield traits. Similarity coefficient (Bray-Curtis) was between 0.82 and 0.98, indicating low variability in both qualitative and quantitative characters. The cophenetic correlation coefficient was 0.64. The genotypes were mainly brown with only a few black (6) tubers from the central region. Materials collected from parts of the eastern region (Aduamoah) generally recorded the highest tuber weight. Tuber weight depended on plant height and number of tillers. There were high tillering genetic materials among the genotypes. Tubers were categorised as oval (10), ovoid (33), or oblong (15). The genotypes clustered into two groups based on shoot and tuber characteristics, rather than on geographical origin. The low genetic diversity among the genotypes suggested either the possible existence of a network among tiger nut farmers in Ghana in circulating the planting material or some form of seed sorting for uniform and homogenous planting materials has been carried out over the years. Our results point to the imperativeness to expand the genetic base of the tiger nuts to facilitate its improvement in Ghana.
Project description:BackgroundCyperus esculentus is unique in that it can accumulate significant amounts of oil, starch and sugar as major storage reserves in tubers with high tuber yield and therefore considered as a novel model to study carbon allocation into different storage reserves in underground sink tissues such as tubers and roots. Sucrose (Suc) plays a central role in control of carbon flux toward biosynthesis of different storage reserves; however, it remains unclear for the molecular mechanism underlying Suc metabolism in underground oil-rich storage tissues. In the present study, a comprehensive transcriptome analysis of C. esculentus oil tuber compared to other plant oil- or carbohydrate-rich storage tissues was made for the expression patterns of genes related to the Suc metabolism.ResultsThe results revealed some species-specific features of gene transcripts in oil tuber of C. esculentus, indicating that: (i) the expressions of genes responsible for Suc metabolism are developmentally regulated and displayed a pattern dissimilar to other plant storage tissues; (ii) both of Suc breakdown and biosynthesis processes might be the major pathways associated with Suc metabolism; (iii) it was probably that Suc degradation could be primarily through the action of Suc synthase (SUS) other than invertase (INV) during tuber development. The orthologs of SUS1, SUS3 and SUS4 are the main SUS isoforms catalyzing Suc breakdown while the vacuolar INV (VIN) is the leading determinant controlling sugar composition; (iv) cytosolic hexose phosphorylation possibly relies more on fructose as substrate and uridine diphosphate glucose pyrophosphorylase (UGP) plays an important role in this pathway; (v) it is Suc-phosphate synthase (SPS) B- and C-family members rather than SPS A that are the principal contributors to SPS enzymes and play crucial roles in Suc biosynthesis pathway.ConclusionsWe have successfully identified the Suc metabolic pathways in C. esculentus tubers, highlighting several conserved and distinct expressions that might contribute to sugar accumulation in this unique underground storage tissue. The specific and differential expression genes revealed in this study might indicate the special molecular mechanism and transcriptional regulation of Suc metabolism occurred in oil tubers of C. esculentus.
Project description:Four hundred tubers of four genotypes, two brown and two black tiger nuts were subjected to Ethyl Methanesulfonate (EMS) and Colchicine treatments at concentrations of 0 %, 0.1 %, 0.25 %, 0.5 % and 1.0 % for 24 h. Each genotype had twenty tubers treated with each of the five different concentrations and were planted using Complete Randomized Design (CRD) in a greenhouse. Quantitative data was collected and LD50 and RD50 were analysed using Excell 2016 and Genstat 11.2. A general decreasing trend in percentage germination and plant height was observed with increasing concentrations of mutagens applied. An EMS treatment had LD50 and RD50 values of 0.97 % and 1.49 % for black and 0.63 % and 1.63 % for brown genotypes. Similarly, the percentage colchicine treatment had LD50 and RD50 values of 1.65 % and 19.51 % concentrations for black and 0.91 % and 1.71 % concentrations for brown genotypes.
Project description:Several plant species synthesize biologically active secondary metabolites. Pyrrolizidine alkaloids are a large group of biotoxins produced by thousands of plant species to protect against the attack of insects and herbivores, but they are highly toxic for humans and animals. In this study, extracts from the aerial part of Senecio brasiliensis were obtained using different technologies: ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and microwave hydrodiffusion and gravity (MHG). The study aimed to evaluate the effectiveness of these technologies for the extraction of chemical compounds found in this plant, focusing on two pyrrolizidine alkaloids: integerrimine and senecionine. Influential parameters on yield and chemical composition were also evaluated: for UAE and MHG, temperature and pressure; for PLE, temperature, and percentage of ethanol. All the extraction techniques were efficient for the extraction of integerrimine and senecionine. The UAE and PLE stood out for the higher yields and number of compounds. The PLE presented a maximum yield of 18.63% for the matrix leaf and the UAE a maximum yield of 11.82% for the same matrix. These two techniques also stood out in terms of the number of compounds, once 36 different compounds were found via PLE and 17 via UAE.Supplementary informationThe online version contains supplementary material available at 10.1007/s13205-021-02845-1.