Biology subjects

Fujita, Y.

Publications and source records attributed to Fujita, Y..

At least 19 recordsLinked to original sources

bioRxiv2026

Lasp family proteins generated by teleost-specific genome duplication

Two rounds of whole-genome duplication (2R-WGD) in the vertebrate lineage are thought to have driven gene diversification. Mammals have four genes encoding five nebulin superfamily proteins (LASP1, LASP2/NEBL, NEB, and NRAP) hypothesised to have arisen from invertebrate LASP via WGD. Here, we examined the evolutionary fate of the nebulin superfamily after an additional WGD, teleost-specific genome duplication (TGD). Genome and transcriptome analysis of zebrafish (Danio rerio) and medaka (Oryzias latipes), of which the complete genomes were recently determined, showed only lasp family genes retained duplicate copies. Zebrafish retained two LASP2/NEBL-derived ohnologs; one (LASP2L) had been misidentified as a nebulette gene in the Zebrafish Information Network (ZFIN) despite lacking nebulette-specific exons. Another (LASP2/NEBL) is newly identified in this study because it lies in a newly determined region of the latest genome assembly. Contrastingly, medaka retained two LASP1 ohnologs and one LASP2/NEBL. The duplicated lasp family proteins showed overlapping and specific tissue expression patterns. We confirmed all three zebrafish lasp proteins bound actin and co-localized with actin-rich structures when ectopically expressed in cultured fibroblasts. This supports that TGD-derived lasp duplicates underwent lineage-specific retention and expression divergence in teleosts whilst conserving core actin-binding properties.

evolutionary biology↗

bioRxiv2026

Cube-based screening identifies a quinoa-derived synthetic microbial community that promotes plant growth and modulates root epidermal responses under salt stress

Plant-associated bacteria can improve plant performance under abiotic stress, but beneficial functions in plant microbiomes may depend on defined combinations of microorganisms rather than individual isolates alone. Here, we developed a cube-based screening strategy to identify functional synthetic microbial communities (SynComs) from 135 quinoa-associated bacterial isolates while preserving combinatorial diversity and traceability of isolate-level contributions. The isolates were divided into five 27-isolate sets, each arranged as a 3 x 3 x 3 cube in which each 3 x 3 layer was defined as a 9-isolate SynCom, generating 45 SynComs in total. Screening under 100 mM NaCl identified SynCom DY1 (SCDY1) as a candidate salt stress-mitigating consortium. SCDY1 consisted of nine taxonomically diverse isolates and exhibited a multifunctional profile, including siderophore production, phosphate solubilization, carboxymethyl cellulose degradation, indole compound production, and growth under saline conditions. In Arabidopsis thaliana, SCDY1 promoted primary root elongation and biomass accumulation in a salinity-dependent manner, with the clearest effect under 120 mM NaCl, and at least a subset of constituent bacteria was recoverable from inoculated seedlings. RNA sequencing and targeted RT-qPCR indicated that SCDY1 modulated host gene expression under moderate salinity stress, with responsive genes associated with oxidative stress, water- and oxygen-related processes, phenylpropanoid biosynthesis, glutathione metabolism, and root epidermis-related processes. Root hair phenotyping further showed that SCDY1 enhanced root hair-related traits and shifted visible root hair formation closer to the root apex. These findings identify a quinoa-derived SynCom that improves plant performance under salinity stress and provide a practical, traceable framework for discovering beneficial microbial consortia from plant-associated bacterial collections. Scope statementThis manuscript fits the Research Topic "Harnessing Plant Microbiomes for Climate Resilience: From Ecological Insight to Synthetic Community Design" in Frontiers in Plant Science because it presents a traceable strategy for discovering functional synthetic microbial communities from a stress-adapted plant-associated bacterial collection. We developed a cube-based screening strategy using 135 quinoa-associated bacterial isolates and identified a nine-isolate synthetic microbial community, SCDY1, that promotes Arabidopsis growth under moderate salinity stress. The study integrates microbiological screening, characterization of plant growth-promoting traits, bacterial re-isolation, plant growth phenotyping, RNA-seq, RT-qPCR, and root hair phenotyping. These analyses link SCDY1 treatment to salinity-dependent growth promotion, recoverable bacterial members, stress- and redox-associated transcriptional changes, phenylpropanoid-related responses, and modulation of root epidermal phenotypes. By connecting a defined SynCom with host transcriptional and root epidermal responses, this work advances understanding of beneficial plant-microbe interactions under salt stress. The cube-based design also provides a practical and traceable framework for discovering functional SynComs from large plant-associated bacterial collections, which should be of interest to researchers studying plant symbiosis, microbiome engineering, abiotic stress tolerance, and sustainable crop improvement.

plant biology↗

bioRxiv2026

CqFT1A and CqFT1B-1 are major flowering activators in quinoa

Flowering time is a key determinant of crop adaptation, plant architecture, and breeding efficiency. Quinoa (Chenopodium quinoa), a climate-resilient allotetraploid orphan crop, exhibits extensive variation in flowering behavior, yet which of its multiple FT homologs drive flowering remains unclear. Here, we used virus-mediated overexpression (VOX) and virus-induced gene silencing (VIGS) in quinoa, together with heterologous expression in Arabidopsis thaliana, to dissect the flowering-promoting activity of quinoa FLOWERING LOCUS T (FT) homologs. Although multiple CqFT homologs were transcriptionally induced during the floral transition, their functional outputs were markedly unequal. CqFT1A and CqFT1B-1 acted as the major florigenic activators: overexpression of either gene induced rapid and synchronized flowering, whereas the CqFT1-VIGS treatment delayed flowering. Although CqFT2A and CqFT2B showed weak flowering-promoting activity, their endogenous contribution remains unresolved because gene-specific silencing could not be achieved. CqFT1B-2 had no detectable promotive effect under the conditions tested. Domain-swapping analyses revealed that replacing the C-terminal region of CqFT2A with that of CqFT1A partially restored flowering-promoting activity, indicating that C-terminal variation contributes to, but does not fully explain, functional divergence among CqFT homologs. In late-flowering highland lines, elevated FT input accelerated flowering, induced coordinated floral transition, and shortened the time to seed production. These findings identify CqFT1A and CqFT1B-1 as the major florigenic activators in quinoa and demonstrate that transcriptional induction alone does not predict florigenic activity. More broadly, this work establishes a functional and methodological framework for resolving florigen activity in climate-resilient orphan crops of increasing agricultural importance.

plant biology↗

bioRxiv2026

A quinoa-associated Pantoea isolate displays salinity-responsive auxin production and promotes plant growth under salt stress

Plant-associated bacteria can promote plant growth under saline conditions, but salinity-dependent changes in bacterial physiological traits remain insufficiently understood. Here, we isolated bacteria from seedlings of quinoa (Chenopodium quinoa Willd.) lines maintained under laboratory propagation for more than 30 years and evaluated their activity under saline conditions. A quinoa-associated Pantoea isolate, strain 6PN, promoted primary root elongation and whole-plant dry weight of Arabidopsis thaliana under salt stress, whereas no significant effect was observed under non-saline conditions. Comparative analyses with reference Pantoea agglomerans strains showed that strain 6PN exhibited salinity-responsive indole-3-acetic acid (IAA) production. Genome analysis identified a putative ipdC gene and additional genes related to stress responses, nutrient acquisition, polysaccharide biosynthesis and export, flagellar biosynthesis, and chemotaxis. Phylogenomic analysis indicated that strain 6PN was genomically distinct from representative Pantoea species examined here. In an Arabidopsis trench-plate assay, GFP-labeled strain 6PN was recovered from spatially separated plant tissues at higher levels than a GFP-labeled reference strain under saline conditions. These results identify strain 6PN as a quinoa-associated Pantoea isolate with salinity-responsive IAA production and plant growth-promoting activity under defined salt-stress conditions.

plant biology↗

bioRxiv2026

Optical flow reveals motility signatures for inferring pathogenic bacterial mixture compositions via temporal convolutional networks

With the rapid expansion of global food demand, aquaculture has become a critical pillar for future food security. However, aquaculture systems remain highly vulnerable to pathogenic bacteria, and rapid identification of antagonistic microbes is essential for sustainable disease control. Conventional evaluation approaches rely on fluorescence labeling or post-culture assays, limiting the ability to quantify dynamic interactions in mixed microbial populations in a real-time and label-free manner. Here, we propose a computational framework for classifying the mixing ratio of Vibrio harveyi and environmental bacteria using time-series motion features extracted from microscopy videos. We defined 24 interpretable motility descriptors and employed a Temporal Convolutional Network (TCN) to learn their temporal structure. The proposed method achieved a classification accuracy of 93.3%, outperforming conventional static statistical approaches and alternative machine learning models. These findings indicate that mixture discrimination in microbial communities is governed not by absolute motility magnitude, but by collective alignment and its temporal stability. Our study establishes a time-resolved computational framework for quantifying dynamic collective order in mixed microbial populations and highlights its potential for label-free automated screening and robotic microbiological applications. Author summaryBacterial infections pose a major threat to aquaculture, and rapid identification of antagonistic microbes is essential for sustainable disease management. Existing screening approaches often require fluorescent labeling or post-culture analysis, making real-time evaluation of mixed bacterial populations difficult. In this study, we show that mixture ratios of Vibrio harveyi and environmental bacteria can be accurately classified from time-series motion features extracted from microscopy videos. By applying TCN to 24 interpretable motility descriptors, we achieved high classification accuracy without relying on fluorescent markers. Our analysis demonstrates that collective directional alignment and its temporal stability, rather than absolute swimming speed, are the key determinants of mixture discrimination. This work introduces a computational strategy for quantifying dynamic collective order in microbial communities and supports the development of label-free, automated screening platforms for microbiological applications.

microbiology↗

bioRxiv2026

The slow-acting G-protein Gz defines the duration of circadian rest time

Duration of nightly rest is a trait that varies between individuals, influenced by a complex interplay between multiple genetic and environmental factors. The central circadian clock that orchestrates daily rhythm in behavior/sleep resides in the suprachiasmatic nucleus (SCN). Yet, how the SCN encodes the "length" of the circadian rest phase ({rho}) remains an open question. Here we demonstrate that the unique G-protein-subtype Gz contributes to this process by sculpting the waveform of the circadian cAMP-PKA activity rhythm within the SCN. Genetic deletion and subsequent rescue of Gz expression reversibly altered the {rho} duration, shifting it from [~]10 h in Gz+/+ mice to [~]7.5 h in Gz-/-; mice, accompanied by proportional changes in peak cAMP-PKA activity duration and transcriptome remodeling in the SCN. Notably, intra-SCN cAMP activation led to behavioral rest, with Gz specifically shaping this response without affecting 24-h rhythmicity. These findings suggest that the SCN is not merely a rhythm-generator, but actively allocates the {rho}-rest period via Gz signaling.

neuroscience↗

bioRxiv2026

Horizontal gene transfer drives the emergence of nitrogen fixation in a unicellular Synechocystis lineage

Nitrogen fixation plays a central role in primary productivity and nitrogen cycling in aquatic ecosystems, yet its distribution among cyanobacterial lineages remains incompletely understood. Biological nitrogen fixation is energetically costly and highly oxygen-sensitive, imposing constraints in oxygenic phototrophs. The unicellular cyanobacterial genus Synechocystis has long been regarded as strictly non-diazotrophic. Here, we report that Synechocystis sp. LKSZ1 possesses a functional nitrogen fixation system. Comparative genomics revealed that LKSZ1 is distinct from other Synechocystis strains and uniquely harbors a complete nif gene. Phylogenetic and structural analyses indicate acquisition via horizontal gene transfer from filamentous cyanobacteria. Physiological assays demonstrated photoautotrophic growth under nitrogen-depleted conditions and nitrogenase activity under microoxic to anaerobic conditions. Disruption of nifK abolished both growth and activity. These findings show that ecological nitrogen limitation and host compatibility can enable functional integration of horizontally acquired nitrogen fixation.

microbiology↗

bioRxiv2026

Diurnal regulation of flagellar length and swimming speed in the red-tide raphidophyte Chattonella marina

The raphidophyte Chattonella marina is a harmful algal bloom (HAB) species known for its distinct diurnal vertical migration (DVM), a behavior important for its survival and bloom formation. However, the single-cell mechanisms governing this migration remain unclear. In this study, we investigated the swimming characteristics of individual C. marina cells during day (light) and night (dark) phases. We observed a strong positive correlation between the length of the propulsive anterior flagellum and the cells swimming speed. We discovered that the length distribution of the anterior flagellum is different during the day and at night. We also found that the beat frequency of the anterior flagellum was significantly higher during the day compared to the night. This resulted in faster mean swimming speeds during the light phase. To investigate the mechanism of length regulation, we tested the role of intraflagellar transport (IFT) using the IFT dynein inhibitor, ciliobrevin D. Treatment with ciliobrevin D induced a time- and concentration-dependent shortening of the anterior flagellum. This is the first pharmacological evidence to suggest that an IFT-like mechanism may actively control motile flagellar length in C. marina. These findings suggest that C. marina modulates its swimming speed through diurnal changes in both flagellar length and beat frequency, likely as an energy-saving strategy coupled to its DVM.

biophysics↗

bioRxiv2026

Accurate prediction of nitrogen fixation in cyanobacteria reveals the dynamic evolution driving high retention rate with mosaic distribution

Cyanobacteria are the only prokaryotic group capable of simultaneously performing oxygenic photosynthesis and nitrogen fixation by nitrogenase extremely sensitive to oxygen. However, systematic understanding of the phylogenetic distribution of nitrogen-fixing ability remains incomplete because of difficulties in accurately identifying genes based on genome information due to occasional confusion with nitrogenase-like enzymes and the high degree of fragmentation in nif genes in heterocystous species. In this study, we comprehensively evaluated the distribution of the minimal nitrogen fixation gene set (nifHDKENB) across 586 major cyanobacterial strains using a 2-dimensional similarity plot with the negative logarithm of the e-values and protein length allowing accurate prediction of nitrogen fixation. The evaluation that almost all heterocystous strains are nitrogen fixer supports the accuracy of this method. Overall, 48% of the strains were predicted to be nitrogen-fixing with a mosaic distribution in non-heterocystous strains. Using the results as training data, nitrogen fixation was evaluated for a broader cyanobacterial lineage, including uncultured strains and metagenomes. Approximately 20% of 2,718 strains were evaluated to be nitrogen fixers, revealing a higher retention rate in Cyanobacteria phylum than other bacterial phyla. We also found a novel nif genes belonging to Group II and discussed the dynamic evolution process in cyanobacteria.

microbiology↗

bioRxiv2025

Dual Metabolic Compensation to Dietary Choline Deficiency by the Drosophila Hologenome

Coping with an unbalanced diet is critical in animals. However, the mechanisms that mitigate deficiencies of specific nutrients, such as choline, remain poorly understood. Choline is converted to phosphatidylcholine (PC), a major phospholipid. Using genetic, nutritional, and microbiome manipulation tools in Drosophila melanogaster, we identified two independent mechanisms that ameliorate the effects of choline deficiency. First, a strain of commensal bacteria synthesizes PC via choline-independent pathway and provides it to the host. Second, a host-derived phospholipid, {beta}-methylphosphatidylcholine ({beta}mPC), is generated from carnitine, which compensates choline deficiency as a functional analog of PC. Our findings reveal microbial and host metabolic processes that modulate dietary requirement for choline. This study also provides evidence that hologenomic coordination of metabolism enables animals to adapt to a micronutrient deficiency.

physiology↗

bioRxiv2025

Cellular and molecular fine mapping pinpoints new immunopathology of lupus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with an unknown etiology. To pinpoint new disease-relevant cell states and their molecular profiles, we performed an in-depth investigation of multimodal single-cell datasets comprising [~]2.1 million peripheral blood mononuclear cells from 346 donors. By resolving 123 fine-grained cell states across 27 cell types, we identified previously uncharacterized populations distinctively associated with clinical severity and treatment status, including GZMK+GZMH+HLA-DR+ effector memory CD8+ T cells (double-positive [DP] EMCD8) and FOXO1+ARHGAP15+ T cells. Through extensive statistical frameworks and multimodal approaches, we delineated their aberrant immune signaling networks, transcriptional regulators, key surface proteins, T cell receptor repertoires, and genetic/epigenetic landscapes, underscoring them as candidate drivers of SLE immunopathology. These findings provide new insights into therapeutic target discovery in SLE.

immunology↗

bioRxiv2025

From Lab to Industry: Awareness of the translational potential of Extracellular Vesicles by the ISEV Translation, Regulation and Advocacy Committee (ISEV-TRA).

Extracellular vesicles (EVs) are critical mediators of cellular communication, with significant potential for disease diagnosis, therapeutics, and other industrial applications. However, translating EV-based innovations into real-world products faces substantial challenges, particularly concerning regulatory frameworks and scientific gaps. To address these issues, the International Society for Extracellular Vesicles (ISEV) established the Translation, Regulation, and Advocacy Committee (ISEV-TRA) to create an environment that facilitates the translation of EV research into practical societal applications. This reporet presents the results of the first survey conducted by the ISEV-TRA, assessing the degree to which EVs have been translated into society applications, awareness of EV potential, and the current use of EVs across various industry sectors. Respondents included individuals from Academia, Industry, and dual affiliation (Academia-Industry), provided an initial perspective on EV research and its translational status. The survey highlights the growing interest in EV-based products, suggesting that there is an important wave of efforts to develop these products. Several spin-outs created by academic researchers are focusing on EV-based products, a key trend in the field, while large companies are showing increasing interest in EV-based technologies. The expectations and suggestions for the newly established ISEV-TRA underscore the need for a unified approach to accelerate the translation of EV-based technologies into practical applications. The ISEV-TRA is well-positioned to play a key role by providing essential resources, organizing workshops, and promoting interdisciplinary collaboration, ultimately driving the commercialization of EV-based innovations.

scientific communication and education↗

bioRxiv2025

Transient let-7/miR-98 reprograms primed pluripotency to induce naivehuman PSCs

Naive human pluripotent stem cells (hPSCs) are valuable for modeling early development and enabling regenerative applications, yet resetting from the primed state remains inefficient and mechanistically unclear. We identify an unexpected role for miR-98-5p, a let-7 family microRNA (miRNA) typically linked to differentiation, in promoting naive induction. Using a synthetic mRNA screen containing diverse miRNA-responsive elements, we uncovered miR-98-5p as a potent enhancer of resetting. Single-cell RNA sequencing and targeted perturbations show that miR-98-5p directly represses NR6A1 while transiently activating BMP2/4 signaling, triggering network transitions. These changes destabilize the primed gene-regulatory network and enable acquisition of a naive state. Leveraging this mechanism, we establish a feeder-free, miRNA-based, editing-free protocol that boosts resetting efficiency from <10% to [~]80%. To our knowledge, this is the first demonstration that a let-7 miRNA can drive naive induction by coupling direct target repression with activation of pro-naive signaling, suggesting a generalizable reprogramming principle of transient network destabilization.

developmental biology↗

bioRxiv2025

Modeling viral shedding and symptom outcomes in oseltamivir-treated experimental influenza infection

Influenza remains a global public health concern, and although the antiviral drug oseltamivir is widely used to treat infections, questions regarding its actual antiviral efficacy and clinical benefits remain. Here, we evaluated the effects of oseltamivir on viral shedding dynamics in the context of experimental influenza infection. We analyzed individual participant data, including viral load, time to symptom alleviation, and laboratory test measurements, obtained from three publicly available clinical trials involving experimental infections with influenza A and B viruses. We applied mathematical modeling and estimated parameters using a nonlinear mixed-effects model to capture viral infection dynamics. Our analysis revealed that, compared with placebo groups, the oseltamivir-treated groups tended to have lower values in terms of viral load area under the curve, duration of infection, peak viral titer, and time to peak; however, most of these differences were not significant; and no dose-dependent effects were observed. Moreover, there was no significant correlation between time to symptom alleviation and viral load. Some laboratory test parameters showed opposing correlations with symptom-related and viral load-related outcomes. These findings are consistent with distinct mechanisms underlying the symptom-alleviating effects of oseltamivir and its antiviral activity. Our findings suggest that the availability of individual-level data for public use is essential because it enables the evaluation of mechanisms in clinical trials and the development of more appropriate outcome measures.

microbiology↗

bioRxiv2025

Dietary amino acid manipulations in the common marmoset Callithrix jacchus impacts serum metabolites and FGF21 levels

Restricting dietary protein intake has metabolic and physiological benefits for animals. Rodent studies have identified the involvement of a hormone fibroblast growth factor 21 (FGF21), which is upregulated by sensing amino acid scarcity. However, to what extent this mechanism is conserved in primates remains elusive. Using common marmosets Callithrix jacchus as a non-human primate model, we demonstrate a protocol for protein restriction and dietary amino acid manipulation. Low protein diet induces a decrease in blood urea nitrogen, altered plasma amino acid profiles, and an increase in plasma FGF21. Supplementation of purified amino acids to the diet suppresses plasma features of protein restriction. Our data provide a dietary intervention technique in marmosets and an insight into the evolutionarily conserved mechanism of FGF21 induction during protein restriction.

physiology↗

bioRxiv2025

Differential O-Glc elongation on the specific EGF repeat within a ligand binding domain regulates NOTCH1 signaling

Three types of O-linked glycosylation - O-glucose, O-fucose, and O-N-acetylglucosamine - are crucial for the function of Notch receptors, which regulates critical cell fate determination processes in a wide variety of contexts. O-Glucose glycans are added to serine residues located between the first and second conserved cysteines within the epidermal growth factor (EGF) -like repeats in the Notch extracellular domain. Previously, O-glucose glycans were shown to be extended to a trisaccharide structure with two xyloses via an 1-3 linkage. Our recent studies, however, indicated that the O-glucose glycan on NOTCH1 EGF10 can be extended by hexose and Neu5Ac. Here, we demonstrated that this hexose- and Neu5Ac-extended glycan has a 3-sialyllactose-like structure synthesized by specific members of two isoenzyme families, B4GALT1 and ST3GAL4. Using mass spectrometry, we identified this modification exclusively on NOTCH1 EGF10 and NOTCH3 EGF9 (equivalent to NOTCH1 EGF10), with no detection in any other EGF domains in NOTCH1-3. Sequence comparison and mutagenesis experiments identified one amino acid at position -2 of the fourth cysteine in the EGF domain as crucial for the galactose elongation of O-glucose glycans. We further demonstrated that this site-specific elongation of O-glucose on NOTCH1 EGF10 significantly impact ligand binding and signal transduction of NOTCH1. Our findings contribute to the understanding of the intricate regulatory mechanisms of Notch receptor function mediated by distinct positions and structures of O-glycans. Significance StatementNotch, a signaling receptor critical for development, differentiation, and homeostasis in multicellular organisms, undergoes multiple post-translational glycan modifications to regulate its function. While O-glucose glycan elongation by xylose was previously known, we identified an O-glucose glycan extended by galactose and Neu5Ac on specific epidermal growth factor (EGF) -like repeats of certain Notch paralogs, NOTCH1 and NOTCH3. As far as we know, this structure has not been reported on any other proteins. We identify the enzymes involved in the biosynthesis of this glycan and demonstrate that modifications at a specific site on Notch direct receptor functions, including ligand binding and Notch signaling.

biochemistry↗

bioRxiv2024

Time- Space Resolved Fluorescence Spectroscopy in Live Chlamydomonas Cells under Light-Harvesting Regulation

We report here a technical advancement that enables time-resolved fluorescence spectroscopy in spatially resolved domains of a living cell at low temperatures. The technique is based on a combination of the self-developed cryo-confocal microscope system and the streak-camera technology. An instrumental response time of ca. 24 ps was achieved. This technique was applied to reveal the light-harvesting dynamics in local domains within single Chlamydomonas reinhardtii cells. Organisms performing oxygenic photosynthesis, like Chlamydomonas, have evolved a regulation mechanism called state transitions (ST), which maintains the excitation balance between PSI and PSII. ST relies on the shuttling of light-harvesting chlorophyll protein complex II (LHCII) between the two PSs. In the present experiment, cells were induced either to state1, where LHCII is bound to PSII, or state2, where LHCII moved and is bound to PSI. After the induction of ST, cells were immediately cooled to ca. 80 K, where PSI and PSII show clearly separated fluorescence emission bands, enabling the visualization of these components separately. Based on kinetic analyses of the time-resolved fluorescence spectra in both PSI-rich and PSII-rich local domains, we concluded that (1) the intracellular inhomogeneity in the PSII/PSI fluorescence ratio comes from that in the PSII/PSI stoichiometry, not from that in the antenna sizes of the PSs, and (2) the antenna size of PSI in state2 cells may larger in intact cells than that of the isolated PSI-LHCI-LHCII super-complex reported so far.

biophysics↗

bioRxiv2024

CqHKT1 and CqSOS1 mediate genotype-dependent Na+ exclusion under high salt stress in quinoa

Salinity threatens crop production worldwide, and salinized areas are steadily increasing. As most crops are sensitive to salt, there is a need to improve the salt tolerance of major crops and promote the cultivation of under-utilized salt-tolerant crops. Quinoa, a pseudocereal and leafy vegetable from the Andean region of South America, is highly salt-tolerant, thrives in marginal environments, and has excellent nutritional properties. Research has often focused on epidermal bladder cells, a feature of quinoa thought to contribute to salt tolerance; however recent evidence suggests that these cells are not directly involved. The salt tolerance mechanism in quinoa remains unclear. Here, we show genotype-dependent differences in Na+ and K+ accumulation mechanisms using representative 18 lines of three genotypes by focusing on young quinoa seedlings at a stage without epidermal bladder cells. High salinity (600 mM NaCl) did not affect the early growth of all three quinoa genotypes. Under high salinity, lowland quinoa lines accumulated the most Na+ in the aerial parts, whereas southern highland lines accumulated the least. By contrast, K+ accumulation was slightly reduced in the aerial parts but significantly decreased in roots of all the genotypes. Resequencing of 18 quinoa lines supports the notion that genotype determines aboveground Na+ uptake and gene expression in response to salt stress. Using virus-induced gene silencing, we further demonstrated that CqHKT1 and CqSOS1 mediate Na+ exclusion in quinoa. These findings provide insight into salt tolerance mechanisms, serving as a basis for improving crop production under salt stress.

plant biology↗