ARTICLE | doi:10.20944/preprints202311.0875.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: quinoa, stress, fatty acids, hippocampus, memory
Online: 14 November 2023 (10:27:27 CET)
Brain physiology and morphology are vulnerable to chronic stress, affecting cognitive performance and behavior. However, functional compounds found in food may alleviate these alterations. White quinoa (Chenopodium quinoa, Wild) seeds have high content of n-3 fatty acids, including alpha-linolenic acid. This work aimed to evaluate the possible neuroprotective role of a quinoa-based functional food (QFF) in rats. Prepubertal male Sprague-Dawley rats were fed with rat chow or QFF (50% rat chow + 50% dehydrated quinoa seeds) and exposed or not to restraint stress protocol (2 hours/day; 15 days). Four experimental groups were used: Non-stressed (rat chow), Non-stressed + QFF, Stressed (rat chow) and Stressed + QFF. Weight gain, locomotor activity (open field), anxiety (elevated plus maze, light-dark box), spatial memory (Y-maze), and dendritic length in the hippocampus were measured in all animals. QFF intake did not affect anxiety-like behaviors, while the memory of stressed rats fed with QFF improved compared to those fed with rat chow. In addition, QFF intake countered the stress-induced dendritic atrophy in pyramidal neurons located in CA3 area of the hippocampus. The results suggest that a quinoa-supplemented diet could have a protective role on the memory of chronically stressed rats.
ARTICLE | doi:10.20944/preprints202108.0381.v2
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: quinoa; genotype; nutritional traits; seed quality
Online: 8 September 2021 (12:37:08 CEST)
Exploiting the relationship between the nutritional properties of seeds and the genetic background, constitutes an essential analysis which contributes to broadening our knowledge regarding the control of the nutritional quality of seeds or any other edible plant structure. This constitutes an important aspect when aiming at improving the nutritional characteristics properties of crops, including those of Chenopodium quinoa Willd (quinoa) which is intended to be one of the main nutrient sources ensuring food security worldwide. Changes in the nutritional properties of quinoa seeds due to the influence exerted by the environment, the genotype, or their interaction, have been already described in previous works, but there is an important limitation in the analyses carried out, including the outcomes that can be translated into agronomical practices by which quality can be improved selecting the most adequate genotype. In the present study, several seed nutritional-related parameters from fifteen quinoa cultivars grown in a particular environmental context were analyzed aiming at targeting compounds that can be determinants of seed quality. Important agronomical and nutritional differences were found among cultivars such as distinct mineral or protein contents and seed viability. More importantly, our analyses revealed key correlations between seed quality-related traits in some cultivars, including those that relate yield and antioxidants or the germination rate. These results highlight the importance of considering the genotypic variation in quinoa when selecting improved quinoa varieties with the best nutritional characteristics for new cultivation environments.
ARTICLE | doi:10.20944/preprints202308.0359.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: dry fractionation; quinoa flour; sorghum flour; gluten-free bread; sourdough fermentation
Online: 3 August 2023 (14:37:15 CEST)
Roller milling of sorghum and quinoa seeds into flour fractions (course, middle, and fine) was investigated, chemically analysed and applied in the baking of gluten-free sourdough bread. Gap settings were adjusted to 0, 5, 8 and 10 for quinoa and 3, 5, and 7 for sorghum. The fine fractions reached values of up to about 41% (gap 8) for quinoa and around 20% for sorghum (gap 5). SEM pictographs illustrated clear separation of each fraction with chemical analysis showing high contents of protein, TDF (total dietary fibre) and IDF (insoluble dietary fibre) in the course fraction. Up to 77% starch content was obtained in the fine fraction with significant amounts of SDF (soluble dietary fibre) which has good health benefits. Increasing the dough moisture up to 90% helped in decreasing the bread crumb firmness, while low Avrami parameters and RVA pasting behaviour indicated slow bread staling rate for both sourdough breads.
ARTICLE | doi:10.20944/preprints202311.1886.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Protein phosphatase 2C (PP2C), Chenopodium quinoa, genome-wide, abiotic stress
Online: 29 November 2023 (11:03:10 CET)
Plant protein phosphatase 2Cs (PP2Cs) serve as negative regulators of protein kinase cascades activated in different processes and play important roles in plant development and abiotic-stress-mediated signaling pathways. In this study, a genome-wide study was conducted on the CqPP2C gene family. A total of putative 117 CqPP2C genes were identified. Comprehensive analyses of physical and chemical feature, chromosome localization and subcellular localization were conducted. According to phylogenetic analysis, CqPP2Cs were divided into 13 subfamilies. CqPP2Cs in the same subfamily had similar gene structure, conserved motif and all the CqPP2C proteins had the type 2C phosphatase domains. Gene duplication revealed that segmental duplication was the major driving force for CqPP2Cs expansion and all duplicated CqPP2Cs evolved from purifying selection. The expression of CqPP2Cs in various tissues under different abiotic stresses was analyzed using RNA-seq data. The results revealed that CqPP2C genes were involved in regulating development and stress responses of quinoa. Real-time quantitative reverse transcription PCR (qRT-PCR) analysis of six CqPP2C genes in subfamily A revealed that they were up-regulated or down-regulated under salt and drought treatments. Furthermore, the results of yeast two-hybrid assays revealed that subfamily A CqPP2Cs interacted not only with subclass III CqSnRK2s, but also with subclass II CqSnRK2s. Subfamily A CqPP2Cs could interact with CqSnRK2s in different combinations and intensities to respond to various biological processes and stresses. Overall, our results will be useful for understanding the functions of CqPP2C in regulating ABA signals and responding to abiotic stress.
ARTICLE | doi:10.20944/preprints202310.1805.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: quinoa polysaccharides; chemical composition; antioxidant activity; anti-proliferation activity; anti-microbial activity
Online: 27 October 2023 (12:15:48 CEST)
Quinoa, known as the "golden grain" for its high nutritional value, is a significant source of essential nutrients, including proteins, minerals, vitamins, polyphenols, phytosterols, and flavonoids. However, the biological functions of quinoa polysaccharides remain understudied. In this research, two crude quinoa polysaccharides extracts (Q-40 and Q-60) were obtained extracting by 40% and 60% alcohol. The purity of Q-40 and Q-60 was 58.29% and 62.15%, with protein contents of 8.27% and 9.60%, respectively. Monosaccharide analysis revealed that Q-40 contained glucose (Glc), galacturonic acid (GalA), and arabinose (Ara) in a molar ratio of 0.967:0.027:0.006. Q-60 was composed of xylose (xyl), arabinose (Ara), galactose, and galacturonic acid (GalA) with a molar ratio of 0.889:0.036:0.034:0.020. The average molecular weight of Q-40 ranged from 47484 to 626488 Da, while Q-60 showed a range of 10025 to 47990 Da. Rheological experiments showed that Q-40 exhibited higher viscosity, while Q-60 demonstrated more elastic properties. Remarkably, Q-60 showed potent antioxidant abilities, with scavenging rates of 98.49% for DPPH and 57.5% for ABTS. Antibacterial experiments using the microdilution method revealed that Q-40 inhibited the growth of Methicillin-resistant Staphylococcus aureus (MRSA) and E. coli, while Q-60 specifically inhibited MRSA. At lower concentrations, both polysaccharides inhibited MDA cell proliferation, but at higher concentrations, they promoted proliferation. Similar proliferation-promoting effects were observed in HepG2 cells. The research provides important information in application of quinoa in food and functional food industries.
ARTICLE | doi:10.20944/preprints202309.1620.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Chenopodium quinoa; Germination sensu stricto; Reference gene; quantitative PCR; Salt stress; Seed
Online: 26 September 2023 (02:51:17 CEST)
Chenopodium quinoa Willd (quinoa), a member of the Amaranthaceae family, is an allotetraploid annual plant, endemic to South America. The plant of C. quinoa presents significant ecological plasticity with exceptional adaptability to several environmental stresses, including salinity. The resilience of quinoa to several abiotic stresses, as well as its nutritional attributes have led to significant shifts in quinoa cultivation worldwide over the past century. This work first defines germination sensu stricto in quinoa where the breakage of the pericarp and the testa is followed by endosperm rupture (ER). Transcriptomic changes in early seed germination stages lead to unstable expression levels in commonly used reference genes that are typically stable in vegetative tissues. Noteworthy, no suitable reference genes have been previously identified specifically for quinoa seed germination under salt stress conditions. This work aims to identify these genes as a prerequisite step for normalizing qPCR data. To this end, germinating seeds from UDEC2 and UDEC4 accessions, with different tolerance to salt, have been analyzed under conditions of absence (0 mM NaCl) and in the presence (250 mM NaCl) of sodium chloride. Based on relevant literature, six candidate reference genes: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Monensin sensitivity1 (MON1), Polypyrimidine tract-binding protein (PTBP), Actin-7 (ACT7), Ubiquitin-conjugating enzyme (UBC), and 18S ribosomal RNA (18S), were selected and assessed for stability using the RefFinder Tool encompassing the statistical algorithms geNorm, NormFinder, BestKeeper, and ΔCt in the evaluation. The data presented supports the suitability of CqACT7 and CqUBC as reference genes for normalizing gene expression during seed germination under salinity stress. These recommended reference genes can be valuable tools for consistent qPCR studies in quinoa seeds.