RESUMEN
Microbial inocula are considered a promising and effective alternative solution to the use of chemical fertilizers to support plant growth and productivity since they play a key role in the availability and uptake of nutrients. Here, the effect of a beneficial of a fungal root endophyte, Fusarium solani strain K (FsK), on nutrient acquisition efficiency of the legume Lotus japonicus was studied, and putative mode-of-action of the endophyte at a molecular level was determined. Plant colonization with the endophyte resulted in increased shoot and root fresh weight under Fe deficiency compared to control nutrient conditions. Plant inoculation with FsK was associated with a significant increase in macro- and micronutrient concentration in leaves at an early stage of endophyte inoculation and a replenishment of Fe content under prolonged iron starvation. The mechanistic basis of the plant growth promotion capabilities of the endophyte is exerted at the transcriptional level since we recorded changes in the expression levels of genes related to iron uptake in FsK-colonized plants under stress conditions compared to uninoculated plants. In addition, the observed changes in the ethylene biosynthesis-related genes suggest a possible implication of ethylene in the mode of action used by FsK to enhance plant response to nutrient stress conditions. Finally, we demonstrated that the endophyte possesses a reductive high-affinity Fe uptake system and identified a ferric reductase that was induced in planta under Fe deficiency conditions, indicating that this fungal Fe homeostasis mechanism may result in a benefit in nutrient acquisition for the plant as well.
Asunto(s)
Endófitos , Fusarium , Regulación de la Expresión Génica de las Plantas , Hierro , Lotus , Raíces de Plantas , Endófitos/fisiología , Endófitos/metabolismo , Hierro/metabolismo , Lotus/microbiología , Lotus/metabolismo , Lotus/genética , Fusarium/fisiología , Raíces de Plantas/microbiología , Raíces de Plantas/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Etilenos/metabolismo , FMN Reductasa/metabolismo , FMN Reductasa/genética , Nutrientes/metabolismo , Brotes de la Planta/metabolismo , Brotes de la Planta/microbiologíaRESUMEN
Maturity and drying treatment are important factors affecting the processing characteristics of lotus seeds and its starch. This study aimed to investigate the effect of maturity (from low to high-M-1, M-2, M-3, M-4) on far-infrared drying kinetics of lotus seeds, and on the variation of structure, gelation and digestive properties of lotus seed starch (LSS) before and after drying. As the maturity increased, the drying time reduced from 5.8 to 1.0 h. The reduction of drying time was correlated with the decrease of initial moisture content, the increase of water freedom and the destruction of tissue structure during ripening. The increased maturity and drying process altered the multiscale structure of LSS, including an increase in amylose content, disruption of the short-range structure, and a decrease in relative crystallinity and molecular weight. The viscosity, pasting temperature and enthalpy of LSS decreased during ripening, and drying treatment caused the further decrease. The digestibility of LSS increased during ripening and drying. Lotus seeds at M-4 would be optimal for obtaining shorter drying time, lower pasting temperature and enthalpy, and higher digestibility. This study provided theoretical guidance for achieving effective drying process and screening LSS with suitable processing properties through maturity sorting.
Asunto(s)
Lotus , Semillas , Almidón , Semillas/química , Lotus/química , Almidón/química , Desecación/métodos , Viscosidad , Amilosa/química , Peso Molecular , Digestión , Geles/química , Agua/química , Temperatura , Estructura MolecularRESUMEN
Polyphenol oxidase (PPO) plays a key role in the enzymatic browning process, and this study employed Gaussian-accelerated molecular dynamics (GaMD) simulations to investigate the catalytic efficiency mechanisms of lotus root PPO with different substrates, including catechin, epicatechin, and chlorogenic acid, as well as the inhibitor oxalic acid. Key findings reveal significant conformational changes in PPO that correlate with its enzymatic activity. Upon substrate binding, the alpha-helix in the Q53-D63 region near the copper ion extends, likely stabilizing the active site and enhancing catalysis. In contrast, this helix is disrupted in the presence of the inhibitor, resulting in a decrease in enzymatic efficiency. Additionally, the F350-V378 region, which covers the substrate-binding site, forms an alpha-helix upon substrate binding, further stabilizing the substrate and promoting catalytic function. However, this alpha-helix does not form when the inhibitor is bound, destabilizing the binding site and contributing to inhibition. These findings offer new insights into the substrate-specific and inhibitor-induced structural dynamics of lotus root PPO, providing valuable information for enhancing food processing and preservation techniques.
Asunto(s)
Catecol Oxidasa , Lotus , Simulación de Dinámica Molecular , Raíces de Plantas , Lotus/enzimología , Catecol Oxidasa/metabolismo , Catecol Oxidasa/química , Raíces de Plantas/enzimología , Especificidad por Sustrato , Cadenas de Markov , Dominio Catalítico , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Catequina/química , Catequina/metabolismo , Sitios de Unión , Distribución NormalRESUMEN
Plant architecture is an important agronomic trait to determine the biomass and sward structure of forage grass. The IGT family plays a pivotal role in plant gravitropism, encompassing both the gravitropic response and the modulation of plant architecture. We have previously shown that LjLAZY3, one of the IGT genes, plays a distinct role in root gravitropism in L. japonicus. However, the function of LAZY proteins on shoot gravitropism in this species is poorly understood. In this study, we identified nine IGT genes in the L. japonicus genome, which have been categorized into four clades based on the phylogenetic relationships of IGT proteins from 18 legumes: LAZY1, NGR (NEGATIVE GRAVITROPIC RESPONSE OF ROOTS), IGT-LIKE, and TAC1. We found that LAZY genes in the first three clades have demonstrated distinct role for modulating plant gravitropism in L. japonicus with specific impacts as follows. Mutation of the LAZY1 gene, LjLAZY1, defected the gravitropic response of hypocotyl without impacting the main stem's branch angle. In contrast, the overexpression of the NGR gene, LjLAZY3, substantially modulated the shoot's gravitropism, leading to narrower lateral branch angles. Additionally, it enhanced the shoots' gravitropic response. The overexpression of another NGR gene, LjLAZY4, specifically reduced the main stem's branch angle and decreased plant stature without affecting the shoot gravitropic response. The phenotype of IGT-LIKE gene LjLAZY2 overexpression is identical to that of LjLAZY4. While overexpression of the IGT-LIKE gene LjLAZY5 did not induce any observable changes in branch angle, plant height, or gravitropic response. Furthermore, the LjLAZYs were selectively interacted with different BRXL and RLD proteins, which should the important factor to determine their different functions in controlling organ architecture in L. japonicus. Our results deepen understanding of the LjLAZY family and its potential for plant architecture improvement in L. japonicus.
Asunto(s)
Gravitropismo , Lotus , Brotes de la Planta , Gravitropismo/genética , Gravitropismo/fisiología , Brotes de la Planta/genética , Brotes de la Planta/fisiología , Brotes de la Planta/crecimiento & desarrollo , Lotus/genética , Lotus/fisiología , Lotus/crecimiento & desarrollo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Filogenia , Genes de Plantas , Regulación de la Expresión Génica de las PlantasRESUMEN
The interaction between polyphenols and starch is an important factor affecting the structure and function of starch. Here, the impact of chlorogenic acid on the multi-scale structure and digestive properties of lotus seed starch under autoclaving treatment were evaluated in this study. The results showed that lotus seed starch granules were destroyed under autoclaving treatment, and chlorogenic acid promoted the formation of loose gel structure of lotus seed starch. In particular, the long- and short-range ordered structure of lotus seed starch-chlorogenic acid complexes were reduced compared with lotus seed starch under autoclaving treatment. The relative crystallinity of A-LS-CA complexes decreased from 23.4 % to 20.3 %, the value of R1047/1022 reduced from 0.87 to 0.80, and the proportion of amorphous region increased from 10.26 % to 13.85 %. In addition, thermal stability, storage modulus and loss modulus of lotus seed starch-chlorogenic acid complexes were reduced, indicating that the viscoelasticity of lotus seed starch gel was weakened with the addition of chlorogenic acid. It is remarkable that chlorogenic acid increased the proportion of resistant starch from 58.25 ± 1.43 % to 63.85 ± 0.96 % compared with lotus seed starch under autoclaving treatment. Here, the research results provided a theoretical guidance for the development of functional foods containing lotus seed starch.
Asunto(s)
Ácido Clorogénico , Lotus , Semillas , Almidón , Ácido Clorogénico/química , Ácido Clorogénico/farmacología , Semillas/química , Almidón/química , Lotus/químicaRESUMEN
Chitin, an N-acetyl-D-glucosamine polymer, has multiple functions in living organisms, including the induction of disease resistance and growth promotion in plants. In addition, chitin oligosaccharides (COs) are used as the backbone of the signaling molecule Nod factor secreted by soil bacteria rhizobia to establish a mutual symbiosis with leguminous plants. Nod factor perception triggers host plant responses for rhizobial symbiosis. In this study, the effects of chitins on rhizobial symbiosis were examined in the leguminous plants Lotus japonicus and soybean. Chitin nanofiber (CNF), retained with polymeric structures, and COs elicited calcium spiking in L. japonicus roots expressing a nuclear-localized cameleon reporter. Shoot growth and symbiotic nitrogen fixation were significantly increased by CNF but not COs in L.japonicus and soybean. However, treatments with chitin and cellulose nanofiber, structurally similar polymers to CNF, did not affect shoot growth and nitrogen fixation in L.japonicus. Transcriptome analysis also supported the specific effects of CNF on rhizobial symbiosis in L.japonicus. Although chitins comprise the same monosaccharides and nanofibers share similar physical properties, only CNF can promote rhizobial nitrogen fixation in leguminous plants. Taking the advantages on physical properties, CNF could be a promising material for improving legume yield by enhancing rhizobial symbiosis.
Asunto(s)
Quitina , Lotus , Nanofibras , Fijación del Nitrógeno , Rhizobium , Simbiosis , Lotus/microbiología , Quitina/química , Quitina/farmacología , Quitina/metabolismo , Nanofibras/química , Rhizobium/fisiología , Raíces de Plantas/microbiología , Raíces de Plantas/efectos de los fármacos , Oligosacáridos/farmacología , Oligosacáridos/química , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glycine max/microbiología , Glycine max/efectos de los fármacos , Glycine max/crecimiento & desarrolloRESUMEN
BACKGROUND: Postharvest quality deterioration poses a significant challenge to the commercial value of fresh lotus seeds. Low temperature storage is widely employed as the primary method for preserving postharvest lotus seeds during storage and transportation. RESULTS: This approach effectively extends the storage life of lotus seeds, resulting in distinct physiological changes compared to room temperature storage, including a notable reduction in starch, protein, H2O2, and MDA content. Here, we conducted RNA-sequencing to generate global transcriptome profiles of postharvest lotus seeds stored under room or low temperature conditions. Principal component analysis (PCA) revealed that gene expression in postharvest lotus seeds demonstrated less variability during low temperature storage in comparison to room temperature storage. A total of 14,547 differentially expressed genes (DEGs) associated with various biological processes such as starch and sucrose metabolism, energy metabolism, and plant hormone signaling response were identified. Notably, the expression levels of DEGs involved in ABA signaling were significantly suppressed in contrast to room temperature storage. Additionally, nine weighted gene co-expression network analysis (WGCNA)-based gene molecular modules were identified, providing insights into the co-expression relationship of genes during postharvest storage. CONCLUSION: Our findings illuminate transcriptional differences in postharvest lotus seeds between room and low temperature storage, offering crucial insights into the molecular mechanisms of low temperature preservation in lotus seeds.
Asunto(s)
Frío , Semillas , Transcriptoma , Semillas/genética , Lotus/genética , Lotus/fisiología , Lotus/metabolismo , Regulación de la Expresión Génica de las Plantas , Perfilación de la Expresión GénicaRESUMEN
Boiled lotus rhizome discs (BLRDs), as common processed products of lotus rhizome, have gained increasing attention from consumers and food manufacturers. However, the blue pigment formed during boiling affects its appearance and reduces the appetite of BLRDs. In this study, the effects of polyphenols and iron contents on blue pigment formation in BLRDs in different regions and months were investigated. Results revealed that blue variation was more serious in March and April of the second year in Wuhan, and polyphenols and iron contents in these two months were significantly higher than those in other months. Then, UPLC and UV-Vis analysis showed that polyphenols causing the formation of blue pigment in BLRDs were L-dopa, gallocatechin, catechin, epigallocatechin, chlorogenic acid and epicatechin, among which L-dopa (52.450 mg/100 g in fresh lotus rhizome (FLR)) and gallocatechin (36.210 mg/100 g in FLR) possessed the greatest effect. Moreover, the ESI-Q-TOF-MS analysis of L-dopa-iron chelate and gallocatechin-iron chelate suggested that the blue pigment of BLRDs was mainly in the form of bis-complexes under boiling conditions. The study on formation mechanism of blue pigment in BLRDs can provide a reference for lotus rhizome processing.
Asunto(s)
Hierro , Polifenoles , Rizoma , Rizoma/química , Polifenoles/química , Polifenoles/análisis , Hierro/química , Quelantes del Hierro/química , Pigmentos Biológicos/química , Catequina/química , Catequina/análogos & derivados , Catequina/análisis , Levodopa/química , Lotus/química , Cromatografía Líquida de Alta Presión , Culinaria , Calor , Ácido Clorogénico/química , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Skin wounds, prevalent and fraught with complications, significantly impact individuals and society. Wound healing encounters numerous obstacles, such as excessive reactive oxygen species (ROS) production and impaired angiogenesis, thus promoting the development of chronic wound. Traditional clinical interventions like hemostasis, debridement, and surgery face considerable challenges, including the risk of secondary infections. While therapies designed to scavenge excess ROS and enhance proangiogenic properties have shown effectiveness in wound healing, their clinical adoption is hindered by high costs, complex manufacturing processes, and the potential for allergic reactions. Lotus root, distinguished by its natural micro and macro porous architecture, exhibits significant promise as a tissue engineering scaffold. This study introduced a novel scaffold based on hybridization of lotus root-inspired and Gelatin Methacryloyl (GelMA), verified with satisfactory physicochemical properties, biocompatibility, antioxidative capabilities and proangiogenic abilities. In vivo tests employing a full-thickness wound model revealed that these scaffolds notably enhanced micro vessel formation and collagen remodeling within the wound bed, thus accelerating the healing process. Given the straightforward accessibility of lotus roots and the cost-effective production of the scaffolds, the novel scaffolds with ROS scavenging, pro-angiogenesis and re-epithelialization abilities are anticipated to have clinical applicability for various chronic wounds.
Asunto(s)
Lotus , Neovascularización Fisiológica , Raíces de Plantas , Especies Reactivas de Oxígeno , Andamios del Tejido , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Andamios del Tejido/química , Neovascularización Fisiológica/efectos de los fármacos , Raíces de Plantas/química , Animales , Lotus/química , Gelatina/química , Ratones , Repitelización/efectos de los fármacos , Humanos , Análisis Costo-Beneficio , Depuradores de Radicales Libres/farmacología , Depuradores de Radicales Libres/química , Masculino , AngiogénesisRESUMEN
Lotus (Nelumbo nucifera), belonging to the family of Nelumbonaceae, is a beautiful aquatic perennial plant. It has been used as an ancient horticulture plant and famous agricultural crop for thousands of years. Modern phytochemical and pharmacological experiments have proved that polysaccharide is one of the most pivotal bioactive constituents of lotus. Hence, the systematic review covering the fundamental research advances and developing prospects of N. nucifera polysaccharides (NNPs) is an urgent demand to provide theoretical basis for their further research and application. The present review summarizes current emerging research progresses on the polysaccharides isolated from lotus, and it focuses on advanced extraction and purification methods, unique structural features, engaging biological activities, potential molecular mechanisms, as well as the relationship of structure and activity of NNPs. This review sheds light on the potential values of NNPs in affording functionally bioactive agents in food industry or therapeutically effective medicines for health care. In addition, this review will provide valuable insights for further commercial product development and promising industrial application of NNPs in both of the fundamental research communities and food or pharmaceutical industries in future.
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Polisacáridos , Polisacáridos/química , Polisacáridos/farmacología , Polisacáridos/aislamiento & purificación , Humanos , Lotus/química , Animales , Extractos Vegetales/química , Extractos Vegetales/farmacología , Relación Estructura-ActividadRESUMEN
Symbiotic nitrogen fixation within nitrogen-fixing clade (NFC) plants is thought to have arisen from a single gain followed by massive losses in the genomes of ancestral non-nodulating plants. However, molecular evidence supporting this model is limited. Here, we confirm through bioinformatic analysis that NODULES WITH ACTIVATED DEFENSE1 (NAD1) is present only in NFC plants and is thus an NFC-specific gene. Moreover, NAD1 was specifically expressed in nodules. We identified three conserved nodulation-associated cis-regulatory elements (NACE1-3) in the promoter of LjNAD1 from Lotus japonicus that are required for its nodule specific expression. A survey of NFC plants revealed that NACE1 and NACE2 are specific to the Fabales and Papilionoideae, respectively, while NACE3 is present in all NFC plants. Moreover, we found that nodule inception (NIN) directly binds to all three NACEs to activate NAD1 expression. Mutation of L. japonicus LjNAD1 resulted in the formation of abnormal symbiosomes with enlarged symbiosome space and frequent breakdown of bacteroids in nodules, resembling phenotypes reported for Medicago truncatula Mtnad1 and Mtnin mutants. These data point to NIN-NAD1 as an important module regulating rhizobial accommodation in nodules. The regulation of NAD1 by NIN in the NFC ancestor represent an important evolutionary adaptation for nodulation.
Asunto(s)
Regulación de la Expresión Génica de las Plantas , Lotus , Proteínas de Plantas , Nodulación de la Raíz de la Planta , Nódulos de las Raíces de las Plantas , Simbiosis , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Lotus/genética , Lotus/microbiología , Lotus/metabolismo , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/microbiología , Nodulación de la Raíz de la Planta/genética , Simbiosis/genética , Fijación del Nitrógeno/genética , Medicago truncatula/genética , Medicago truncatula/microbiología , Medicago truncatula/metabolismo , Regiones Promotoras Genéticas/genética , Mutación/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Secuencia ConservadaRESUMEN
Lotus seed starch holds vast potential for utilization across various industries, with its content and structure directly influencing the commercial value of lotus seeds. However, there has been limited information available on the molecular mechanisms underlying lotus seed starch biosynthesis. In this study, three starch branching enzyme homologs were identified in the lotus genome, designated as NnSBE1 to NnSBE3, which possess conserved CBM_48 and α_Aamy domains. Among them, NnSBE1 exhibited predominant expression, with abundant transcript levels observed in lotus seeds and flower-related organs. Expression of NnSBE1 remained consistently up-regulated in lotus cotyledons from 6 to 21 days after pollination. Additionally, a C2H2-type finger protein encoding gene, NnLOL1, co-expressed with NnSBE1 in lotus cotyledons. As a seed-predominantly expressed transcription factor, NnLOL1 was confirmed to activate NnSBE1 expression. Transient overexpression of NnSBE1 in lotus cotyledons resulted in a significant increase in both amylopectin and total starch content compared to the control. Furthermore, multiple variation sites within the NnSBE1 gene gave rise to diverse haplotypes between seed-lotus and other lotus varieties. These findings contribute to our understanding of the regulation mechanisms involved in lotus seed starch biosynthesis, offering valuable theoretical insights for the genetic improvement of lotus seed starch by molecular breeding strategies.
Asunto(s)
Enzima Ramificadora de 1,4-alfa-Glucano , Regulación de la Expresión Génica de las Plantas , Lotus , Proteínas de Plantas , Semillas , Almidón , Lotus/genética , Lotus/enzimología , Semillas/genética , Almidón/biosíntesis , Almidón/metabolismo , Enzima Ramificadora de 1,4-alfa-Glucano/genética , Enzima Ramificadora de 1,4-alfa-Glucano/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cotiledón/genética , Cotiledón/enzimología , FilogeniaRESUMEN
Fusarium commune is the main pathogen of lotus rhizome rot, which causes the wilt of many plants. Histone acetyltransferase plays a critical part in the growth and virulence of fungi. In the present study, we identified an FcElp3 in F. commune homologous to histone acetyltransferase Elp3. We further constructed a mutant strain of F. commune to determine the function of FcElp3 in fungal growth and pathogenicity. The results showed that the deletion of FcElp3 resulted in reduced mycelial growth and sporulation. Compared with the wild type, the ΔFcElp3 strain showed more tolerance to osmotic stress and cell wall stress responses but was highly sensitive to oxidative stress. The subcellular localization results indicated that FcElp3 was distributed in both the cytoplasm and nucleus. Western blotting showed that FcElp3 was important for acetylation of H3K14 and H4K8. RNA sequencing analysis showed significant transcriptional changes in the ΔFcElp3 mutant, with 3,098 genes upregulated and 5,770 genes downregulated. Peroxisome was the most significantly enriched metabolic pathway for downregulated genes. This led to a significant decrease in the expression of the core transcription factor Fcap1 involved in the oxidative stress response. Pathogenicity tests revealed that the ΔFcElp3 mutant's pathogenicity on lotus was significantly decreased. Together, these findings clearly demonstrated that FcElp3 was involved in fungal growth, development, stress response, and pathogenicity via the direct regulation of multiple target genes.
Asunto(s)
Proteínas Fúngicas , Fusarium , Histona Acetiltransferasas , Lotus , Enfermedades de las Plantas , Lotus/microbiología , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Fusarium/genética , Fusarium/patogenicidad , Fusarium/enzimología , Fusarium/fisiología , Enfermedades de las Plantas/microbiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Acetilación , Rizoma/microbiología , Estrés Oxidativo , Regulación Fúngica de la Expresión Génica , Virulencia , Histonas/metabolismo , Histonas/genética , Presión OsmóticaRESUMEN
Human mitochondria contain a molybdoprotein capable of reducing amidoximes using cytochrome b5/cytochrome b5 reductase (Cb/CbR). This 'amidoxime reducing component' (ARC) also reduces nitrite to nitric oxide (NO). In the plant kingdom, distinct functions have been suggested for ARCs. Thus, the single ARC of Chlamydomonas reinhardtii (crARC) reduces nitrite to NO by taking electrons from nitrate reductase (NR). Therefore, it was proposed that a dual NR/crARC system can generate NO under physiological conditions and the crARC was renamed to 'NO-forming nitrite reductase' (NOFNiR). In contrast to this, the two ARC enzymes from Arabidopsis thaliana were not found to produce NO in vitro at physiological nitrite concentrations, suggesting a different, as yet unknown, function in vascular plants. Here, we have investigated the two ARCs of Lotus japonicus (LjARCs) to shed light on this controversy and to examine, for the first time, the distribution of ARCs in plant tissues. The LjARCs are localized in the cytosol and their activities and catalytic efficiencies, which are much higher than those of A. thaliana, are consistent with a role as NOFNiR. LjARCs are prone to S-nitrosylation in vitro by S-nitrosoglutathione and this post-translational modification drastically inhibits their activities. The enzymes are mainly expressed in flowers, seeds and pods, but are absent in nodules. LjARCs are active with NR and Cb/CbR as electron-transferring systems. However, the LjNR mRNA levels in seeds and pods are negligible, whereas our proteomic analyses show that pods contain the two ARCs, Cb and CbR. We conclude that LjARCs may play a role as NOFNiR by receiving electrons from the Cb/CbR system but do not act in combination with NR.
Asunto(s)
Lotus , Óxido Nítrico , Nitrito Reductasas , Proteínas de Plantas , Lotus/genética , Lotus/enzimología , Lotus/metabolismo , Óxido Nítrico/metabolismo , Nitrito Reductasas/metabolismo , Nitrito Reductasas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Nitritos/metabolismo , Oxidación-ReducciónRESUMEN
BACKGROUND: Drought stress affects plant growth and development. DREB proteins play important roles in modulating plant growth, development, and stress responses, particularly under drought stress. To study the function of DREB transcription factors (TFs), we screened key DREB-regulating TFs for drought in Lotus japonicus. RESULTS: Forty-two DREB TFs were identified, and phylogenetic analysis of proteins from L. japonicus classified them into five subfamilies (A1, A2, A4, A5, A6). The gene motif composition of the proteins is conserved within the same subfamily. Based on the cis-acting regulatory element analysis, we identified many growth-, hormone-, and stress-responsive elements within the promoter regions of DREB. We further analyzed the expression pattern of four genes in the A2 subfamily in response to drought stress. We found that the expression of most of the LjDREB A2 subfamily genes, especially LjDREB2B, was induced by drought stress. We further generated LjDREB2B overexpression transgenic Arabidopsis plants. Under drought stress, the growth of wild-type (WT) and overexpressing LjDREB2B (OE) Arabidopsis lines was inhibited; however, OE plants showed better growth. The malondialdehyde content of LjDREB2B overexpressing lines was lower than that of the WT plants, whereas the proline content and antioxidant enzyme activities in the OE lines were significantly higher than those in the WT plants. Furthermore, after drought stress, the expression levels of AtP5CS1, AtP5CS2, AtRD29A, and AtRD29B in the OE lines were significantly higher than those in the WT plants. CONCLUSIONS: Our results facilitate further functional analysis of L. japonicus DREB. LjDREB2B overexpression improves drought tolerance in transgenic Arabidopsis. These results indicate that DREB holds great potential for the genetic improvement of drought tolerance in L. japonicus.
Asunto(s)
Resistencia a la Sequía , Lotus , Proteínas de Plantas , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/fisiología , Resistencia a la Sequía/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Lotus/genética , Lotus/fisiología , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Estrés Fisiológico/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Legumes acquire nitrogen-fixing ability by forming root nodules. Transferring this capability to more crops could reduce our reliance on nitrogen fertilizers, thereby decreasing environmental pollution and agricultural production costs. Nodule organogenesis is complex, and a comprehensive transcriptomic atlas is crucial for understanding the underlying molecular events. Here, we utilized spatial transcriptomics to investigate the development of nodules in the model legume, Lotus japonicus. Our investigation has identified the developmental trajectories of two critical regions within the nodule: the infection zone and peripheral tissues. We reveal the underlying biological processes and provide gene sets to achieve symbiosis and material exchange, two essential aspects of nodulation. Among the candidate regulatory genes, we illustrate that LjNLP3, a transcription factor belonging to the NIN-LIKE PROTEIN family, orchestrates the transition of nodules from the differentiation to maturation. In summary, our research advances our understanding of nodule organogenesis and provides valuable data for developing symbiotic nitrogen-fixing crops.
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Regulación de la Expresión Génica de las Plantas , Lotus , Fijación del Nitrógeno , Proteínas de Plantas , Nódulos de las Raíces de las Plantas , Transcriptoma , Lotus/genética , Lotus/metabolismo , Lotus/crecimiento & desarrollo , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fijación del Nitrógeno/genética , Simbiosis/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Nodulación de la Raíz de la Planta/genética , Perfilación de la Expresión Génica , Análisis Espacio-Temporal , Organogénesis de las Plantas/genética , Organogénesis/genéticaRESUMEN
This study aimed to identify and quantify the primary components in lotus leaf and to explore the hypolipidemic components through spectral-effect relationships and chemometric methods. Utilizing a data-dependent acquisition-diagnostic fragment ion/characteristic neutral loss screening strategy (DFI-NLS), a reliable HPLC-Q-TOF-MS analysis was conducted, identifying 77 compounds, including 36 flavonoids, 21 alkaloids, 3 terpenoids, 11 organic acids, 4 phenols, 1 lignin and 1 unsaturated hydrocarbon. A straightforward HPLC-DAD method was developed for the simultaneous determination of seven major components in lotus leaf, and quercetin-3-O-glucuronide (Q3GA) was identified as the most abundant component. The HPLC fingerprints of 36 lotus leaf sample batches were assessed using chemometric approaches such as principal component analysis and hierarchical cluster analysis. The hypolipidemic effect of these samples was analyzed by measuring total cholesterol (TC) and total triglycerides (TG) levels in palmitic acid (PA) and oleic acid (OA)-induced lipid modeling in HepG-2 cells, employing partial least squares regression and grey relation analysis to investigate the spectral-effect relationship of the lotus leaf. The in vivo hypolipidemic effect of these compounds was assessed using an egg yolk powder-induced high-fat zebrafish model. The findings indicated that peak No.11 (Q3GA) in the chemical fingerprint was significantly associated with hypolipidemic activity, suggesting it as a potential hypolipidemic compound in lotus leaf. In summary, this study facilitates the exploration of the phytochemical compounds and their bioactive properties in the lotus leaf.
Asunto(s)
Hipolipemiantes , Lotus , Fitoquímicos , Hojas de la Planta , Pez Cebra , Cromatografía Líquida de Alta Presión/métodos , Hojas de la Planta/química , Hipolipemiantes/análisis , Hipolipemiantes/farmacología , Hipolipemiantes/química , Animales , Lotus/química , Fitoquímicos/análisis , Fitoquímicos/farmacología , Fitoquímicos/química , Humanos , Células Hep G2 , Extractos Vegetales/farmacología , Extractos Vegetales/química , Triglicéridos/análisis , Flavonoides/análisis , Flavonoides/farmacología , Quercetina/análogos & derivados , Quercetina/análisis , Quercetina/farmacología , Colesterol/análisis , Espectrometría de Masas/métodos , Alcaloides/análisis , Alcaloides/farmacologíaRESUMEN
Lotus rhizome powder (LRP) tends to lump during hot-water rehydration, adversely affecting its edible quality. By utilizing a restricted swelling treatment (ST), where LRP was swollen at a temperature slightly below its onset gelatinization temperature (To), the lumping rate could be substantially reduced from 30.95% to 6.39%. This treatment induced an ordered-disordered structural transition of LRP without compromising its granule morphology and water dispersibility. This transition led to significant increases in thermal transition temperatures and a notable delay in peak pasting time by 86.6 s. These changes effectively delayed the formation of a gelatinous skin surrounding the dry granules, allowing them sufficient time to absorb water and paste completely, thereby preventing lumping. The prevention of lumping was beneficial for obtaining desired viscoelasticity of LRP paste. Conversely, ST treatments conducted at temperatures markedly deviating from To resulted in significantly higher lumping rates, underscoring the importance of carefully controlling the ST temperature.
Asunto(s)
Calor , Lotus , Polvos , Rizoma , Agua , Rizoma/química , Polvos/química , Lotus/química , Agua/química , Manipulación de AlimentosRESUMEN
Host plants benefit from legume root nodule symbiosis with nitrogen-fixing bacteria under nitrogen-limiting conditions. In this interaction, the hosts must regulate nodule numbers and distribution patterns to control the degree of symbiosis and maintain root growth functions. The host response to symbiotic bacteria occurs discontinuously but repeatedly at the region behind the tip of the growing roots. Here, live-imaging and transcriptome analyses revealed oscillating host gene expression with approximately 6-hour intervals upon bacterial inoculation. Cytokinin response also exhibited a similar oscillation pattern. Cytokinin signaling is crucial to maintaining the periodicity, as observed in cytokinin receptor mutants displaying altered infection foci distribution. This periodic regulation influences the size of the root region responsive to bacteria, as well as the nodulation process progression.
Asunto(s)
Citocininas , Regulación de la Expresión Génica de las Plantas , Interacciones Microbiota-Huesped , Lotus , Mesorhizobium , Nodulación de la Raíz de la Planta , Nódulos de las Raíces de las Plantas , Simbiosis , Citocininas/metabolismo , Perfilación de la Expresión Génica , Lotus/genética , Lotus/crecimiento & desarrollo , Lotus/metabolismo , Mutación , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Nódulos de las Raíces de las Plantas/microbiología , Transducción de Señal , Mesorhizobium/genética , Mesorhizobium/fisiologíaRESUMEN
The symbiosis between Mesorhizobium japonicum R7A and Lotus japonicus Gifu is an important model system for investigating the role of bacterial exopolysaccharides (EPS) in plant-microbe interactions. Previously, we showed that R7A exoB mutants that are affected at an early stage of EPS synthesis and in lipopolysaccharide (LPS) synthesis induce effective nodules on L. japonicus Gifu after a delay, whereas exoU mutants affected in the biosynthesis of the EPS side chain induce small uninfected nodule primordia and are impaired in infection. The presence of a halo around the exoU mutant when grown on Calcofluor-containing media suggested the mutant secreted a truncated version of R7A EPS. A nonpolar ΔexoA mutant defective in the addition of the first glucose residue to the EPS backbone was also severely impaired symbiotically. Here, we used a suppressor screen to show that the severe symbiotic phenotype of the exoU mutant was due to the secretion of an acetylated pentasaccharide, as both monomers and oligomers, by the same Wzx/Wzy system that transports wild-type exopolysaccharide. We also present evidence that the ΔexoA mutant secretes an oligosaccharide by the same transport system, contributing to its symbiotic phenotype. In contrast, ΔexoYF and polar exoA and exoL mutants have a similar phenotype to exoB mutants, forming effective nodules after a delay. These studies provide substantial evidence that secreted incompatible EPS is perceived by the plant, leading to abrogation of the infection process. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.