Nutritional Value and Bioactive Compounds of Leaves and Grains from Quinoa (Chenopodium quinoa Willd.)

Quinoa is an important crop for food security and food sovereignty in Ecuador. In this study, we evaluated the nutritional value, bioactive compounds, and antinutrient compounds of leaves and grains of the Ecuadorian quinoa variety Tunkahuan, and we identified significant differences between the nutrient content in the leaves and grains. The quinoa leaves presented a higher protein content than the grains, as well as inorganic nutrients such as calcium, phosphorus, iron, and zinc. Both the grains and leaves had an appreciable phenolic content. In addition, the quinoa grains presented a higher content of the antinutrient saponin than the leaves, while the leaves contained more nitrates and oxalates than the grains. Thus, quinoa leaves and grains exhibit excellent potential for application in the food and pharmaceutical industries.

Chenopodium quinoa to Modulate Innate Myeloid Cells in the Induction of Obesity

Complex interactions between innate and adaptive immune effectors are an important component in the induction of obesity. Particularly, different subsets of myeloid cells play key roles in metabolic liver diseases and, therefore, are promising targets for intervention strategies. Chenopodium quinoa seeds constitute a good source of immunonutritional compounds, which help prevent high-fat, diet-enhanced innate immune signaling via TLR4/MyD88 that boosts inflammation. Herein, two metabolic mouse models—wild type (WT) and tributyltin treated (TBT)—were used to examine the effects associated with non-alcoholic fatty liver disease (NAFLD); mice were fed with a high-fat diet (HFD) and administered with wheat or C. quinoa bread. Variations in myeloid cells were obtained from a hemogram analysis, and rt-qPCR (mRNA) served to evaluate macrophage markers (i.e., CD68/CD206 ratio) as well as liver inflammation (i.e., Lyve-1) to gain insights into their selective functional differentiation into metabolically injured livers. Only administration of C. quinoa bread prevented alterations in the liver/body weight ratio either in WT animals or those treated with TBT. These effects were associated with significantly increased variations in the peripheral myeloid cell population. Hepatic mRNA markers revealed that C. quinoa enables a selective functional differentiation and function of intrahepatic monocyte-derived macrophages preserving tissue integrity and function.

How Does Quinoa (Chenopodium quinoa Willd.) Respond to Phosphorus Fertilization and Irrigation Water Salinity?

Soil salinity is a major problem in arid and semi-arid regions, causing land degradation, desertification, and subsequently, food insecurity. Salt-affected soils and phosphorus (P) deficiency are the common problems in the sub-Sahara, including the Southern region of Morocco. Soil salinity limits plant growth by limiting water availability, causing a nutritional imbalance, and imparting osmotic stress in the plants. The objective of this study was to determine the positive effects of P on growth and productivity and understand the major leaf mineral nutrient content of quinoa (Chenopodium quinoa Willd.) cv. “ICBA Q5” irrigated with saline water. A field experiment applying three salinity (Electrical Conductivity, EC) levels of irrigation water (ECw = 5, 12, and 17 dS·m−1) and three P fertilizer rates (0, 60, and 70 kg of P2O5 ha−1) were evaluated in a split-plot design with three replications. The experiment was conducted in Foum El Oued, South of Morocco on sandy loam soil during the period of March–July 2020. The results showed that irrigation with saline water significantly reduced the final dry biomass, seed yield, harvest index, and crop water productivity of quinoa; however, P application under saline conditions minimized the effect of salinity and improved the yield. The application of 60 and 70 kg of P2O5 ha−1 increased (p < 0.05) the seed yield by 29 and 51% at low salinity (5 dS·m−1), by 16 and 2% at medium salinity (12 dS·m−1), and by 13 and 8% at high salinity (17 dS·m−1), respectively. The leaf Na+ and K+ content and Na+/K+ ratio increased with irrigation water salinity. However, the leaf content of Mg, Ca, Zn, and Fe decreased under high salinity. It was also found that increasing P fertilization improved the essential nutrient content and nutrient uptake. Our finding suggests that P application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy under saline conditions.

Presence of a Mitovirus Is Associated with Alteration of the Mitochondrial Proteome, as Revealed by Protein–Protein Interaction (PPI) and Co-Expression Network Models in Chenopodium quinoa Plants

Plant mitoviruses belong to Mitoviridae family and consist of positive single-stranded RNA genomes replicating exclusively in host mitochondria. We previously reported the biological characterization of a replicating plant mitovirus, designated Chenopodium quinoa mitovirus 1 (CqMV1), in some Chenopodium quinoa accessions. In this study, we analyzed the mitochondrial proteome from leaves of quinoa, infected and not infected by CqMV1. Furthermore, by protein–protein interaction and co-expression network models, we provided a system perspective of how CqMV1 affects mitochondrial functionality. We found that CqMV1 is associated with changes in mitochondrial protein expression in a mild but well-defined way. In quinoa-infected plants, we observed up-regulation of functional modules involved in amino acid catabolism, mitochondrial respiratory chain, proteolysis, folding/stress response and redox homeostasis. In this context, some proteins, including BCE2 (lipoamide acyltransferase component of branched-chain alpha-keto acid dehydrogenase complex), DELTA-OAT (ornithine aminotransferase) and GR-RBP2 (glycine-rich RNA-binding protein 2) were interesting because all up-regulated and network hubs in infected plants; together with other hubs, including CAT (catalase) and APX3 (L-ascorbate peroxidase 3), they play a role in stress response and redox homeostasis. These proteins could be related to the higher tolerance degree to drought we observed in CqMV1-infected plants. Although a specific causative link could not be established by our experimental approach at this stage, the results suggest a new mechanistic hypothesis that demands further in-depth functional studies.

Synergistic Association With Root Endophytic Fungi Improves Morpho-Physiological and Biochemical Responses of Chenopodium quinoa to Salt Stress

Symbiotic associations with microbes can contribute to mitigating abiotic environmental stress in plants. In this study, we investigated individual and interactive effects of two root endophytic fungal species on physiological and biochemical mechanisms of the crop Chenopodium quinoa in response to salinity. Fungal endophytes (FE) Talaromyces minioluteus and Penicillium murcianum, isolated from quinoa plants that occur naturally in the Atacama Desert, were used for endophyte inoculation. A greenhouse experiment was developed using four plant groups: (1) plants inoculated with T. minioluteus (E1+), (2) plants inoculated with P. murcianum (E2+), (3) plants inoculated with both fungal species (E1E2+), and (4) non-inoculated plants (E-). Plants from each group were then assigned to either salt (300 mM) or control (no salt) treatments. Differences in morphological traits, photosynthesis, stomatal conductance, transpiration, superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase, (POD), phenylalanine ammonia-lyase (PAL), phenolic content, and lipid peroxidation between plant groups under each treatment were examined. We found that both endophyte species significantly improved morphological and physiological traits, including plant height, number of shoots, photosynthesis, stomatal conductance, and transpiration, in C. quinoa in response to salt, but optimal physiological responses were observed in E1E2+ plants. Under saline conditions, endophyte inoculation improved SOD, APX, and POD activity by over 50%, and phenolic content by approximately 30%, with optimal enzymatic responses again observed in E1E2+ plants. Lipid peroxidation was significantly lower in inoculated plants than in non-inoculated plants. Results demonstrate that both endophyte species enhanced the ability of C. quinoa to cope with salt stress by improving antioxidative enzyme and non-enzyme systems. In general, both FE species interacting in tandem yielded better morphological, physiological, and biochemical responses to salinity in quinoa than inoculation by a single species in isolation. Our study highlights the importance of stress-adapted FE as a biological agent for mitigating abiotic stress in crop plants.

Arbuscular mycorrhiza symbiosis in quinoa (Chenopodium quinoa Willd.): A systematic review

The crop of quinoa has gained relevance during the last decade in different parts of the world, due to its adaptability to difficult edaphic and climatic conditions and the great nutritional potential of its seeds. However, climate change scenarios are increasingly adverse, so the search for strategies that favor greater adaptability of quinoa to areas where other crops fail to adapt is a scientific priority. For this reason, a systematic review was carried out, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis methodology, with documents published on Scopus and Clarivate Web of Science databases. This methodology describes the diversity of fungi that favors symbiosis and the services offered by arbuscular mycorrhizal fungi in the physiological activity of the quinoa plant, in addition to their interaction with the edaphic conditions, mainly related to nitrogen and phosphorus. The results identified a projection of interest in research related to the symbiosis between these two organisms, but a very limited advance in relation to the study that has been developed around the microbiological activity of quinoa in the soil.