This study explores interactions between six chlorogenic acid (CGA) isomers and casein, milk's functional protein. Covalent binding via phenolic hydroxyls markedly suppressed protein carbonylation, a hallmark of processing-induced protein oxidation, lowering basal carbonyl content from 1.3 to 0.1-0.8 nmol mg-1 protein (≈40-90% reduction; p < 0.05). Although native casein contained fewer carbonyls than typically reported for oxidatively stressed or heavily processed casein, CGA conjugation still triggered a conformational shift from α-helix to β-turn. Polyphenol modification reduced particle size from 4900 nm to 250-374 nm, while isochlorogenic acid A elevated zeta potential from -26.03 mV to -18.7 mV. Functionally, DPPH radical scavenging capacity increased 2.1-fold and emulsion stability improved by 37.00%. Results demonstrate that CGA isomers remodel casein through covalent crosslinking and hydrophobic interactions, enhancing thermal stability, antioxidant capacity, and emulsifying properties, while the gastrointestinal fate and safety of these CQA-casein conjugates require further investigation before use in real food products.

Coal mining-induced subsidence disrupt soil ecosystems and diminishes agricultural productivity, requiring effective remediation strategies. While both lignite derived humic acid and microbial inoculants have individually shown potential to improve soil properties, the combined application of humic-microbial amendment (CHA), remains underexplored, especially with reduced inorganic fertilizer input. This study evaluated the efficacy of CHA in remediating subsidence-affected soil and promoting the growth of Brassica chinensis L. (pakchoi), focusing on soil-plant-microbe interactions. Results (P < 0.05) showed that CHA allowed a 50% reduction in inorganic fertilizer usage. The optimal CHA treatment (IFHA) increased soil urease and sucrase activities by 14.84% and 67.46%, respectively, promoted nitrogen and phosphorus uptake in pakchoi, and raised biomass yield by 87.6%. Additionally, protein and soluble sugar contents increased by 22.06-79.94% compared to the control. Microbial analysis revealed that CHA had minimal effect on bacterial abundance but altered the fungal community. Dominant phyla included Ascomycota (with beneficial Penicillium, enhance nitrogen mineralization) and Mortierellomycota (supporting soil nutrient transformation), as well as Streptomyces, a genus involved in carbon cycling. These microbial shifts correlated with improved soil nutrients availability and crop performance, helping mitigated mining-related degradation. Our findings suggest that CHA provides a promising approach for the sustainable remediation of coal mine subsidence soil and offers potential applications for other mining-impacted soils.

We generated triploid hybrids of I. trifida and I. tabascana, providing insights into sweetpotato evolution and bridge germplasm for genetic improvement. Sweetpotato [Ipomoea batatas (L.) Lam.] (2n = 6x = 90) is an important root crop whose genomic polyploidisation process remains incompletely understood and highly complex. Its wild relatives are favoured for the study of genome formation, polyploidy processes and genetic improvement in sweetpotato. In this study, we obtained two triploid hybrids via reciprocal crosses between the closest diploid (I. trifida, 2n = 2x = 30) and the closer tetraploid (I. tabascana, 2n = 4x = 60) wild relatives of sweetpotato. To verify the authenticity of these two hybrids, molecular marker analysis, flow cytometry analysis, chromosome counting, morphological characterisation, pollen viability testing and meiotic observation were performed. Through InDel marker analysis, nine primer pairs consistently amplified parent-specific bands in the hybrids. Ploidy characterisation showed that both hybrids were triploid with 45 chromosomes. Morphologically, the two hybrids inherited many traits from both parents whilst producing some variation, such as both round and pentagonal corollas and purple stigmas with two or three lobes. Some pollen grains from the hybrids were fertile. The hybrids showed many abnormalities during meiosis, such as lagging chromosomes and uneven chromosome distribution. The triploid hybrids produced in this study can be used to infer early triploid genomic events during the origin and evolution of sweetpotato and to develop bridge germplasm for its genetic improvement.

The development of sweetpotato storage roots (SRs) is governed by a complex genetic network that is crucial for breeding, yet its mechanisms remain unclear. This study characterized morphological, physiological, and whole-transcriptome dynamics during SR development. We found SR formation involves active meristematic activity, cell division, and coordinated phytohormone regulation. Through the whole transcriptome sequencing, a total of 30,759 mRNAs, 1545 microRNAs (miRNAs), 16,494 long non-coding RNAs (lncRNAs), and 1418 circular RNAs (circRNAs) were identified in association with SR development, including 14,306 differentially expressed (DE) mRNAs, 378 DEmiRNAs, 7340 DElncRNAs, and 56 DEcircRNAs. We constructed the first competing endogenous RNA (ceRNA) network associated with SR development. Through weighted gene co-expression network analysis (WGCNA), key genes involved in multiple metabolic and signaling pathways were identified, including starch/sucrose metabolism, phenylpropanoid biosynthesis, mitogen-activated protein kinase (MAPK) signaling, plant hormone signal transduction, glycerophospholipid metabolism, photosynthesis, and alpha-linolenic acid metabolism. Furthermore, the inclusion of interacting non-coding RNAs substantially expands the potential regulatory network of SRs. Our findings provide novel insights into SR development mechanisms and identify potential genetic targets for improving yield and quality through molecular breeding.

Sweetpotato (Ipomoea batatas (L.) Lam.) is an important multifunctional crop with great value in food supply, industrial processing and bioenergy utilization. Crude protein content (CPC) is a core target trait for sweetpotato quality breeding. To dissect the genetic basis of CPC and identify key candidate genes, we used an F1 population of 212 individuals. CPC was measured by near-infrared reflectance spectroscopy (NIRS) in 2020 and 2021, and QTL mapping was performed using a high-density SNP genetic linkage map. Candidate genes were explored via a genome-wide association study (GWAS), multiple-database functional annotation, and quantitative real-time PCR (qPCR) validation. The results showed that: (1) CPC in the population exhibited a continuous normal distribution with high inter-year stability, and phenotypic variation was mainly controlled by genetic factors; (2) one stable minor-effect QTL for CPC, qCPC09-1, was mapped to Chr09: 7906895-8614924 bp, explaining 5.7% of phenotypic variation; (3) GWAS detected no significant SNP loci, suggesting that CPC is regulated by multiple minor-effect genes; (4) genes within the qCPC09-1 interval were significantly enriched in three protein synthesis-related KEGG pathways: ribosome, nitrogen metabolism and ubiquinone and other terpenoid-quinone biosynthesis; (5) qPCR verified that itf09g13420 and itf09g13230 were upregulated in the low-CPC parent Yushu 10 and negatively correlated with CPC, while itf09g13550 was upregulated in the high-CPC parent Xin 24 and positively correlated with CPC. These three genes exhibited expression patterns highly consistent with phenotypic differences. This study provides a theoretical basis and technical support for molecular marker-assisted breeding and elite germplasm innovation in sweetpotato.

Starch, a key biological macromolecule accounting for 50-80% of dry weight in sweetpotato (Ipomoea batatas [L.] Lam.) storage roots, underpins food and industrial applications. However, sweetpotato starch characterization is limited by local-sectioning approaches that fail to capture the whole-root granule dynamics. Here, we established a new morphological observation system covering three key root regions based on two representative cultivars: Okinawa 100 (V100), and Yanshu25 (Y25). It was effective and convenient for in situ starch observation and analysis in sweetpotato roots. The whole-root in situ microscopy, starch physicochemical profiling, and transcriptomic correlation were integrated to resolve starch dynamics in Y25 and V100. We identified widespread simple starch granules (SSGs)-compound starch granule (CSG) coexistence across the whole root tissues, with Y25 exhibiting programmed CSG fragmentation driven by ARCs/FtsZ-mediated amyloplast envelope destabilization and concomitant AMY/BMY upregulation. Y25 had a higher amylose content and a higher proportion of medium/long chains, but the average degree of polymerization was slightly lower. Transcriptomic analyses revealed that the differentially expressed genes were annotated in pathways of carbohydrate metabolism, and the differentially expressed genes in the starch metabolism pathway were analyzed. Weighted gene co-expression network analysis further identified the hub genes from different modules and analyzed the co-expression networks. This work will not only advance the understanding of starch granule assembly and remodeling in sweetpotato, but also provide a robust methodological and transcriptome-guided framework for starch-focused germplasm screening and quality improvement.

Abstract Background The development of sustainable agriculture requires the creation of efficient biostimulants that enhance crop yield and nutritional quality while minimizing environmental impact. Biomass-derived carbon dots, with their unique physicochemical properties and low toxicity, have emerged as promising candidates. Results This study synthesized ligustrum lucidum carbon dots (LL-CDs) and evaluated their biological effects on vegetable sweetpotato over short-term periods (7 and 14 days). Foliar application of LL-CDs significantly promoted plant growth, biomass accumulation, photosynthetic efficiency, nutrient uptake, and antioxidant capacity. Transcriptomic and metabolomic analyses indicated that LL-CDs treatment synergistically upregulated photosynthesis-related pathways, including light capture, electron transport, and carbon fixation, and increased the accumulation of bioactive compounds. Additionally, LL-CDs improved soil nutrient availability and positively influenced the rhizosphere microbial community structure. Conclusions These preliminary results suggest that LL-CDs have the potential to be developed as agricultural nanomaterials, providing initial theoretical support and technical reference for the development of novel biostimulants.

Sweet potato (Ipomoea batatas) is a globally important autohexaploid root and tuber crop. Fusarium root rot threatens its entire growth, harvest, and storage period, thereby reducing yield and quality. Therefore, a deeper understanding of Fusarium pathogenicity and sweet potato defense is urgently required. Here, two single nucleotide polymorphisms are identified within the promoter region of the I. batatas CHY zinc-finger and ring protein1 (IbCHYR1) gene that encode an E3 ubiquitin ligase linked to root rot resistance. In susceptible varieties, the high dosage allele Pro::IbCHYR1Hap1 leads to increased expression of IbCHYR1. Overexpression of IbCHYR1 increases susceptibility to root rot and Fusarium wilt. IbCHYR1 interacts with the I. batatas CCCH-type zinc-finger protein (IbZnFR) to promote its degradation. IbZnFR confers resistance to root rot and Fusarium wilt and improves yield by more than 10%. The high dosage Pro::IbZnFRHap2 allele is associated with resistance to root rot disease. Moreover, FfRlpA2, a conserved Fusarium effector, is identified as a protease inhibitor that stabilizes and hijacks IbCHYR1 to degrade IbZnFR, thereby inhibiting multiple defense pathways. These findings provide insights into Fusarium pathogenicity and a genetic basis for root rot research and improvement of disease-resistant sweet potato varieties.

Sweet potato (Ipomoea batatas (L.) Lam.), as an important crop, is rich in polyphenols, vitamins, minerals, and other nutrients in its roots and leaves and is gradually gaining popularity. The use of endophytic bacteria to improve the quality of sweet potato can protect the environment and effectively promote the sustainable development of the sweet potato industry. In this study, 12 strains of endophytic bacteria were isolated from sweet potato. Through nitrogen fixation, phosphorus solubilization, indoleacetic acid production, siderophore production, ACC deaminase production, and carboxymethyl cellulose production, three strains with multiple biological activities were screened out. Among them, MEPW12 had the most plant growth-promoting functions. In addition, MEPW12 promoted host chlorophyll accumulation and inhibited pathogen growth and colonization in sweet potato roots and can utilize various carbon sources and salts for growth. It can also grow in extreme environments of high salt and weak acid. MEPW12 was identified as Bacillus amyloliquefaciens with a genome size of 3,928,046 bp and a GC content of 46.59%. After the annotation of multiple databases, it was found that MEPW12 had multiple enzymatic activities and metabolic potential. Comparative genomics and pan-genomics analyses revealed that other Bacillus sp. strains of MEPW12 have similar functions. However, due to adaptation to different growth environments, there are still genomic differences and changes. Inoculation with MEPW12 induced the high expression of IbGH3.10, IbERF1, and other genes, thereby promoting the growth of sweet potatoes. Bacillus amyloliquefaciens strain MEPW12 is a sweet potato endophyte with multiple growth-promoting functions, which can promote the growth of sweet potato seedlings. This study provides new microbial resources for developing microbial agents and improving the quality of sweet potatoes.

Sweetpotato is a typical "potassium(K+)-favoring" crop, and K+ deficiency can lead to slow growth, reduced photosynthetic capacity, and lower yield. Genome-wide association study (GWAS) has been widely used in the identification of plant resistance genes; however, there are limited reports on the discovery of low K+ tolerance genes in sweetpotato. In this study, we conducted a GWAS involving 213 sweetpotato cultivars and identified that IbHSP18.0 was significantly associated with low K+ tolerance. We cloned IbHSP18.0, constructed an overexpression vector, and expressed it in situ in sweetpotato to obtain transgenic seedlings. The experimental results demonstrated that transgenic sweetpotato plants overexpressing IbHSP18.0 exhibited longer shoots, more leaves, higher photosynthesis rates, more abundant roots, as well as higher biomass and K+ accumulation under low K+ stress conditions. These improvements were correlated with elevated activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with the effective removal of excess hydrogen peroxide (H2O2) and malondialdehyde (MDA). Additionally, the expression of IbHSP18.0 in sweetpotato induced the expression of K+ channels (IbAKT1-1, IbAKT1-3, and IbKC1-1) and high-affinity K+ transporter IbHAK5 within roots. In conclusion, our findings suggest that IbHSP18.0 plays a crucial role in enhancing the tolerance of sweetpotato to low K+ stress by strengthening the antioxidant defense mechanisms and positively regulating the expression of genes involved in K+ absorption and transport.

To uncover the variation patterns of the nutritional components in sweetpotato storage roots during long-term storage comprehensively, the general nutrients, phytochemicals, and starch properties of nine sweetpotato varieties with different flesh colors were quantified and analyzed by chemical and physical techniques. During the storage, the starch content decreased firstly and then increased, with sugar content the opposite. The crude protein content and the total dietary fiber content both increased continuously. The β-carotene content decreased or kept constant, while the anthocyanin content showed different variation patterns in the three purple-fleshed varieties. The four types of polyphenols and two types of flavonoids showed no obvious content changes during the storage. The amylose contents of all varieties showed various patterns, while the crystallinity was C-type. The proportion of small-sized starch granules reduced, and the combined proportion of medium-sized and large-sized granules increased. New correlations among the nutritional parameters for each variety were revealed for the first time. Principal component analysis indicated that the orange-fleshed varieties were distinguished from other varieties. Finally, the most storage-resistant variety ZZ3 and the suitable variety for each quality trait was selected. This study provides not only theoretical basis for comprehensive understanding of the nutrient’s variations in sweetpotato storage roots during long-term storage, but also guidelines for evaluation of nutritional quality of sweetpotato roots during storage and improvement of storage methods.

The National Sweetpotato Genebank in Vitro (Xuzhou, China) recently collected 1183 sweetpotato accessions, including potential duplicates. To assess genetic diversity and identify redundant accessions, we conducted comprehensive analyses using seven SSR (Simple Sequence Repeat) marker pairs coupled with agronomic trait evaluation. These markers demonstrated high polymorphism, with an average PIC (Polymorphic Information Content) value of 0.7821. Genetic distance-based clustering revealed the genetic similarity among accessions originating from the same geographic regions. Molecular analysis identified 543 duplicates (each sharing zero genetic distance with at least one counterpart) among the 1183 accessions, while 640 accessions were confirmed as genetically unique. Further classification of the 543 duplicates resulted in 130 distinct genetic groups based on zero genetic distance. Subsequent phenotypic characterization, including evaluations of skin color, flesh color, and aboveground morphological traits, revealed 190 additional unique accessions within these groups. Combining these with the initial 640 unique accessions yielded a final collection of 830 genetically distinct germplasm resources. This study significantly enhances germplasm identification efficiency for conservation purposes, provides valuable insights into the genetic diversity and geographical distribution patterns of sweetpotato germplasm, and underscores the importance of targeted collection efforts in regions exhibiting high genetic diversity.

Leaf color mutants are valuable resources for studying photosynthesis, pigment metabolism, and gene regulatory networks in plants. In this study, a naturally occurring sweetpotato albino mutant exhibiting a stable white-leaf phenotype across developmental stages was identified and compared with its green-leaf wild type to elucidate the molecular mechanisms underlying albinism. The mutant showed a dramatic 98.8% reduction in total chlorophyll content and a markedly decreased Fv/Fm value (0.59), indicating severe impairment of PSII efficiency. Integrated transcriptomic analysis identified 3520 differentially expressed genes (DEGs), while metabolomic profiling revealed 270 differentially accumulated metabolites (DAMs). Genes involved in chlorophyll and carotenoid biosynthesis, chloroplast development, and photosynthetic electron transport were strongly repressed, including key regulators such as GLK1, PORA, and PORB. Metabolomic alterations were mainly enriched in flavonoids, phenylpropanoids, and amino acid-derived pathways, reflecting broad reprogramming of both primary and secondary metabolism. These changes were accompanied by severely disrupted chloroplast ultrastructure, suggesting a primary defect in plastid development. Collectively, the integrated multi-omics evidence provides a comprehensive understanding of the coordinated transcriptional and metabolic alterations driving the albino phenotype in sweetpotato and establishes this mutant as a potential model for studying the interplay between chloroplast biogenesis, photosynthesis, and secondary metabolism.

[Objective]The purpose of this study was to analyze the quantitative trait loci(QTLs)related to stem nematode resistance in sweetpotato(Ipomoea batatas(L.)Lam.),lay a foundation for the fine mapping,cloning,and functional analysis of stem nematode resistance genes in sweetpotato.It also aimed to provide support for the study of the genetic mechanisms of stem nematode resistance,as well as the breeding of resistant varieties in sweetpotato.[Method]An F1 population of 212 progenies derived from a cross between the highly resistant cultivar Yushu 10 and the susceptible line Xin 24 was used.In this study,field-based natural infection assays were conducted to evaluate stem nematode resistance.QTL mapping was performed using composite interval mapping(CIM),and candidate genes within QTL confidence intervals were predicted.Additionally,genome-wide association studies(GWAS)were carried out using the rMVP software(a memory-efficient,visualization-enhanced,and parallel-accelerated R package).For further validation,the resistant cultivar Zhenghong 22 was artificially inoculated with D.destructor,and samples were collected at different post-inoculation time points.The expression patterns of five candidate genes(itf02g19880,itf02g20080,itf02g20100,itf13g18480 and itf13g18550)were analyzed via qRT-PCR.[Result]Three QTLs(qSNR02-1,qSNR02-2,and qSNR13-1)were identified,distributed on chromosomes 2 and 13.The phenotypic contribution rate of the individual QTL related to stem nematode resistance ranged from 9.6％to 11.7％.GWAS revealed one significantly associated locus with stem nematode resistance on chromosome 6.Based on the genomic annotation information,36 candidate genes related to stem nematode resistance were predicted within the QTL confidence intervals,including members of the ABC transporter family,multidrug and toxic compound extrusion(MATE)efflux proteins,E3 ubiquitin ligases,and glutathione S-transferases,which are involved in defense mechanisms,post-translational modification,and stress response.qRT-PCR results showed that the expression patterns of the five candidate genes were significantly different.The expression level of itf02g20100 reached a peak at 3 days after inoculation,which was 6.2 times that of the control;the expression level of itf02g19880 increased sharply and reached the highest level at 0.5 days after inoculation,which was 43.2 times that of the control;the expression patterns of itf13g18480 and itf13g18550 were similar,and both reached a peak at 7 days after inoculation.This indicates that different candidate genes may play different regulatory roles in the defense response after Ditylenchus destructor infection.[Conclusion]Three QTLs related to stem nematode resistance in sweetpotato were identified,and 36 related candidate genes were screened out,which can be used for the subsequent cloning and functional study of genes related to stem nematode resistance in sweetpotato.

The sweetpotato (Ipomoea batatas [L.] Lam) is a globally significant crop, valued for its nutritional and economic importance. The tuberous roots of the sweetpotato are rich in carotenoids, which contribute to their vibrant colors and health benefits. This study focuses on three elite fresh-consumption sweetpotato cultivars: “Kokei No. 14,” “Xinxiang,” and “Zheshu81” with distinct flesh colors. To elucidate the metabolic pathways and genetic mechanisms underlying carotenoid biosynthesis in the sweetpotato, 20 types of carotenoids were quantified using targeted metabolomic analyses, and the key genes involved in carotenoid synthesis were identified with transcriptomic analyses. The results revealed significant differences in carotenoid content and composition among the cultivars, with “Zheshu81” exhibiting the highest carotenoid levels. Weighted gene co-expression network analysis further highlighted key regulatory genes and transcription factors influencing carotenoid accumulation. This study identifies key transcriptional regulators associated with carotenoid accumulation, sheds light on sweetpotato carotenoid biosynthesis mechanisms, and lays a foundation for breeding to improve its nutritional quality and flesh color.

The lack of genomic and genetic research on wild sweetpotato species has hindered the advancement of sweetpotato variety development through modern crop improvement techniques. To facilitate the use of genomic and genetic approaches in sweetpotato variety development, we conducted a comprehensive assessment of the genome size and ploidy of six closely related wild sweetpotato species using flow cytometry and chromosome counting. Additionally, we acquired insights into their genomic characteristics through high-throughput sequencing. Based on the 17-mer frequency distribution, the genome sizes of these species ranged from 518.47 Mb to 1,505.04 Mb. Notably, most diploid species exhibited genome sizes of approximately 500 Mb, with the diploid wild species I. purpurea standing out as having a significantly larger genome size compared to other diploid species. A substantial proportion of repeats (ranging from 57.47 to 81.07

Introduction Sweetpotato (Ipomoea batatas (L.) Lam.) is a genetically intricate hexaploid crop. The purple-fleshed variety, enriched with anthocyanin pigments, is an outstanding source for creating high-value functional products. Previous research on anthocyanin biosynthesis has primarily focused on the above-ground plant parts at the transcriptional level. However, the regulatory mechanisms underlying anthocyanin accumulation in underground tuberous roots of sweetpotato remain largely unexplored. Objectives This study aimed to elucidate the post-transcriptional and post-translational mechanisms of Ib-miR2111 and its target gene IbKFB in anthocyanin synthesis in sweetpotato. Methods Genetic manipulation techniques were used to validate the function of Ib-miR2111 and IbKFB in anthocyanin biosynthesis in sweetpotato. To investigate how IbKFB works, a series of protein interaction assays, including yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), GST pull-down, co-immunoprecipitation (Co-IP), and ubiquitination, were conducted. Additionally, the impact of anthocyanin extracts from the genetically modified sweetpotato lines on inflammatory cells morphology, cytokine expression, and cell proliferation were evaluated using in vitro assays. Results Purple-fleshed sweetpotato (PFSP) varieties exhibited elevated Ib-miR2111 expression compared to white-fleshed sweetpotato (WFSP) varieties, with an inverse expression pattern in IbKFB. Genetic manipulations, including overexpression, CRISPR/Cas9 knockouts, and targeted mutations, confirmed their critical roles in anthocyanin modulation. Furthermore, IbKFB’s interactions and ubiquitination with phenylalanine ammonia-lyase 1 (IbPAL1) and glyceraldehyde-3-phosphate dehydrogenase 1 (IbGAPCp1) were elucidated, revealing intricate regulatory mechanisms. Enhanced anthocyanin content showed significant effects on inflammatory cell morphology, cytokine expression, and cell proliferation. Conclusion This study provides new insights into the regulatory mechanisms of Ib-miR2111 and IbKFB in anthocyanin biosynthesis and suggests potential health benefits of anthocyanin-rich sweetpotatoes.

The origin of hexaploid sweetpotato [Ipomoea batatas (L.) Lam.] remains controversial. Comparative karyotype analysis is particularly useful in determining species relationships and the origin of polyploid species. In previous study, we developed a set of oligo probes and identified all chromosomes of Ipomoea nil, a model diploid Ipomoea species. Here, we found that this set of oligo probes could be used to identify all chromosomes of sweetpotato and its wild relatives with different ploidy. Karyotypes based on individually identified chromosomes were established and the number and position of 5S and 35S rDNA loci were determined for these Ipomoea species. Comparison of their karyotypes revealed distinct variations in the karyotypic parameters. Karyological relationships among these species were revealed by principal coordinate analysis (PCoA) based on six quantitative parameters (x, 2n, TCL, MCA, CVCL and CVCI). These results show that I. trifida is the most closely related diploid species to sweetpotato, and other diploid species could be excluded from consideration as its possible diploid ancestor. In addition, our study also provides cytogenetic evidence for the segmental allopolyploid hypothesis of sweetpotato origin.

Phosphatidylserine (PS) is an important lipid signaling required for plant growth regulation and salt stress adaptation. However, how PS positively regulate plant salt tolerance is still largely unknown. In this study, IbPSS1-overexpressed sweetpotato plants that exhibited overproduction of PS was employed to explore the mechanisms underlying the PS stimulation of plant salt tolerance. The results revealed that the IbPSS1-overexpressed sweetpotato accumulated less Na+ in the stem and leaf tissues compared with the wild type plants. Proteomic profile of roots showed that lignin synthesis-related proteins over-accumulated in IbPSS1-overexpressed sweetpotato. Correspondingly, the lignin content was enhanced but the influx of Na+ into the stele was significantly blocked in IbPSS1-overexpressed sweetpotato. The results further revealed that ethylene synthesis and signaling related genes were upregulated in IbPSS1-overexpressed sweetpotato. Ethylene imaging experiment revealed the enhancement of ethylene mainly localized in the root stele. Inhibition of ethylene synthesis completely reversed the PS-overproduction induced lignin synthesis and Na+ influx pattern in stele tissues. Taken together, our findings demonstrate a mechanism by which PS regulates ethylene signaling and lignin synthesis in the root stele, thus helping sweetpotato plants to block the loading of Na+ into the xylem and to minimize the accumulation of Na+ in the shoots.\

AbstractEast Asia is an important region of sweetpotato production and consumption. To promote exchange among scientists studying sweetpotato in East Asia, the Trilateral Research Association of Sweetpotato (TRAS) was established in 2004 by sweetpotato scientists from China, South Korea, and Japan. The TRASgenome sequencing consortium was formally launched in 2014 and established a haploid-resolved and chromosome-scale de novo assembly of autohexaploid sweetpotato genome sequences. Before constructing the genome, we created chromosome-scale genome sequences in Ipomoea trifida using a highly homozygous accession, ‘Mx23Hm’, with PacBio RSII and Hi-C reads. Haploid-resolved genomeassembly was performed for the sweetpotato (I. batatas) cultivar ‘Xushu 18’ by hybrid assembly with Illumina paired-end (PE) and mate-pair (MP) reads, 10X genomics reads, and PacBio RSII reads. Then, 90 chromosome-scale pseudomolecules were generated by aligning the scaffolds onto a sweetpotato linkage map. In total, 34,386 and 175,633 genes were identified on the assembled nucleic genomesof I. trifida and sweetpotato, respectively. The assembled genome sequences have been used for genetic and RNA-Seq analysis for agronomically important traits. The assembled genome sequences are expected to continue to contribute to genetic and genomic analysis and promote sweetpotato breeding.