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旨在为挖掘油料作物增产潜力、提升油料产能、保障国内食用植物油供给安全等政策制定提供参考，通过集中度和比较优势分析，研究了1979—2019年我国5种主要油料作物（花生、油菜、向日葵、芝麻和胡麻）的时空分布变化。结果显示：1979—2019年花生种植集中度呈减小趋势，油菜和胡麻集中度升高，向日葵和芝麻集中度则先降低后升高；2019年河南、山东、广东、辽宁、河北 5省花生综合优势指数大于1，其中河南为我国花生第一生产大省，综合优势指数从0.80增加至1.93；湖南、四川、湖北、贵州、安徽5省具有稳定的油菜生产综合优势，2019年川渝地区（四川和重庆）、湖北、湖南油菜籽产量居前三位；1979—2019年内蒙古和新疆向日葵综合优势指数分别为214~3.38和1.64~3.06，且在2019年它们分别是我国葵花籽生产第一、第二大主产地；河南、湖北两省一直是我国芝麻生产核心区域，综合优势指数分别为1.50~2.13和2.17~2.39；甘肃、宁夏、山西、内蒙古具有胡麻生产综合优势，2019年甘肃、内蒙古和宁夏胡麻籽产量居前三位。综上，当前河南、川渝地区、内蒙古、甘肃分别是我国花生（和芝麻）、油菜籽、葵花籽、胡麻籽等核心油料生产区域。To provide reference for exploring the potential for increasing oil crops yield, improving oil production, and ensuring the safety of domestic food and vegetable oil supply, the temporal and spatial changes of five major oil crops (peanut, rape, sunflower, sesame and flax) from 1979 to 2019 were studied through analysis of distribution concentration and comparative advantage. The results showed that from 1979 to 2019, the distribution concentration had a decreasing trend in peanut production, but an increase trend in rape and flax, while for sunflower and sesame the distribution concentration firstly decreased and then increased. In 2019, the comprehensive advantage indexes of peanut in Henan, Shandong, Guangdong, Liaoning, Hebei exceeded 1. Among them, Henan Province was the first producer of peanut in China, with the gradually increasing comprehensive advantage indexes from 0.80 to 193. Hunan, Sichuan, Hubei, Guizhou and Anhui had stable comprehensive advantages in rape production, and of them the Sichuan-Chongqing region, Hubei and Hunan ranked in the top three in rapeseed production. In 1979-2019, Inner Mongolia and Xinjiang displayed the comprehensive advantage in sunflower production with the index of 2.14-3.38 and 1.64-3.06, respectively. In 2019, they were the first and the second major sunflower seed production regions. Henan and Hubei were the two core regions of sesame production in China, with comprehensive advantage indexes ranging from 1.50 to 2.13 and 2.17 to 239, respectively. Gansu, Ningxia, Shanxi and Inner Mongolia showed comprehensive advantages in flax production, among which Gansu, Inner Mongolia and Ningxia ranked in the top three in flaxseed production in 2019. In summary, Henan, Sichuan-Chongqing, Inner Mongolia, and Gansu are currently the core oilseed production areas for peanut (and sesame seed), rapeseed, sunflower seed and flaxseed, respectively in China.

Peanut (Arachis hypogaea L.) is an oilseed crop grown worldwide. Flavonoids have profound benefits for plant growth and development because of their powerful antioxidant properties. Seed vigor is an important indicator of seed quality. However, how flavonoids impact seed vigor formation in large-seed peanuts is still poorly understood. Here, we profiled flavonoids, phytohormones, and transcriptomes of developing seeds of large-seed peanut varieties with low (ZP06) and high (H8107) seed vigor. A total of 165 flavonoids were identified, 51 of which were differentially accumulated in ZP06 and H8107. Lower levels of dihydromyricetin (0.28 times) and hesperetin-7-O-glucoside (0.26 times) were observed in ZP06 seeds than in H8107. All flavonoid biosynthesis structural genes were down-regulated in ZP06. The different hormone levels found in ZP06 and H8107 seeds could be associated with the expression of flavonoid biosynthesis genes via MYB and bHLH transcription factors. Dihydromyricetin could relate to ZP06′s poor seed vigor by impacting its seed antioxidant properties. Thus, the presence of flavonoids in large-seed peanuts could contribute to their physiological quality and germination potential through controlling the accumulation of reactive oxygen species to improve seed antioxidant properties. [ABSTRACT FROM AUTHOR]

Summary: N6‐methyladenosine (m6A) is the most abundant mRNA modification in eukaryotes and is an important regulator of gene expression as well as many other critical biological processes. However, the characteristics and functions of m6A in peanut (Arachis hypogea L.) resistance to bacterial wilt (BW) remain unknown.Here, we analyzed the dynamic of m6A during infection of resistant (H108) and susceptible (H107) peanut accessions with Ralstonia solanacearum (R. solanacearum), the causative agent of BW. Throughout the transcriptome, we identified 'URUAY' as a highly conserved motif for m6A in peanut. The majority of differential m6A located within the 3′ untranslated region (UTR) of the transcript, with fewer in the exons.Integrative analysis of RNA‐Seq and m6A methylomes suggests the correlation between m6A and gene expression in peanut R. solanacearum infection, and functional analysis reveals that m6A‐associated genes were related to plant‐pathogen interaction.Our experimental analysis suggests that AhALKBH15 is an m6A demethylase in peanut, leading to decreased m6A levels and upregulation of the resistance gene AhCQ2G6Y. The upregulation of AhCQ2G6Y expression appears to promote BW resistance in the H108 accession. [ABSTRACT FROM AUTHOR]

The article presents the development of an updated high-quality genome assembly of Arachis monticola, a wild peanut species. The previous genome assembly had low quality, but the use of long-read sequencing technologies allowed for a higher-quality assembly. The new assembly, called Amon2.0, has improved contiguity and completeness compared to the previous version. The genome assembly will contribute to further understanding the domestication and evolutionary histories of Arachis spp. and will be a valuable resource for functional genomics and molecular-assisted breeding in legume crops. [Extracted from the article]

Summary: Pod size is a key agronomic trait that greatly determines peanut yield, the regulatory genes and molecular mechanisms that controlling peanut pod size are still unclear. Here, we used quantitative trait locus analysis to identify a peanut pod size regulator, POD SIZE/WEIGHT1 (PSW1), and characterized the associated gene and protein. PSW1 encoded leucine‐rich repeat receptor‐like kinase (LRR–RLK) and positively regulated pod stemness. Mechanistically, this allele harbouring a 12‐bp insertion in the promoter and a point mutation in the coding region of PSW1 causing a serine‐to‐isoleucine (S618I) substitution substantially increased mRNA abundance and the binding affinity of PSW1 for BRASSINOSTEROID INSENSITIVE1‐ASSOCIATED RECEPTOR KINASE 1 (BAK1). Notably, PSW1HapII (super‐large pod allele of PSW1) expression led to up‐regulation of a positive regulator of pod stemness PLETHORA 1 (PLT1), thereby resulting in larger pod size. Moreover, overexpression of PSW1HapII increased seed/fruit size in multiple plant species. Our work thus discovers a conserved function of PSW1 that controls pod size and provides a valuable genetic resource for breeding high‐yield crops. [ABSTRACT FROM AUTHOR]

Peanuts are an economically important crop cultivated worldwide. However, several limitations restrained its productivity, including biotic/abiotic stresses. CRISPR/Cas9-based gene-editing technology holds a promising approach to developing new crops with improved agronomic and nutritional traits. Its application has been successful in many important crops. However, the application of this technology in peanut research is limited, probably due to the lack of suitable constructs and protocols. In this study, two different constructs were generated to induce insertion/deletion mutations in the targeted gene for a loss of function study. The first construct harbors the regular gRNA scaffold, while the second construct has the extended scaffold plus terminator. The designed gRNA targeting the coding sequence of the FAD2 genes was cloned into both constructs, and their functionality and efficiency were validated using the hairy root transformation system. Both constructs displayed insertions and deletions as the types of edits. The construct harboring the extended plus gRNA terminator showed a higher editing efficiency than the regular scaffold for monoallelic and biallelic mutations. These two constructs can be used for gene editing in peanuts and could provide tools for improving peanut lines for the benefit of peanut breeders, farmers, and industry. [ABSTRACT FROM AUTHOR]

Seed size/weight, a key domestication trait, is also an important selection target during peanut breeding. However, the mechanisms that regulate peanut seed development are unknown. We re-sequenced 12 RNA samples from developing seeds of two cultivated peanut accessions (Lines 8106 and 8107) and wild Arachis monticola at 15, 30, 45, and 60 days past flowering (DPF). Transcriptome analyses showed that ∼36,000 gene loci were expressed in each of the 12 RNA samples, with nearly half exhibiting moderate (2 ≤ FPKM < 10) expression levels. Of these genes, 12.2% (4,523) were specifically expressed during seed development, mainly at 15 DPF. Also, ∼12,000 genes showed significant differential expression at 30, 45, and/or 60 DPF within each of the three peanut accessions, accounting for 31.8–34.1% of the total expressed genes. Using a method that combined comprehensive transcriptome analysis and previously mapped QTLs, we identified several candidate genes that encode transcription factor TGA7, topless-related protein 2, IAA-amino acid hydrolase ILR1-like 5, and putative pentatricopeptide repeat-containing (PPR) protein. Based on sequence variations identified in these genes, SNP markers were developed and used to genotype both 30 peanut landraces and a genetic segregated population, implying that EVM0025654 encoding a PPR protein may be associated with the increased seed size/weight of the cultivated accessions in comparison with the allotetraploid wild peanut. Our results provide additional knowledge for the identification and functional research into candidate genes responsible for the seed size/weight phenotype in peanut. [ABSTRACT FROM AUTHOR]

Objective: Early leaf spot (ELS) caused by Cercospora arachidicola (Hori) is a serious foliar disease in peanut worldwide, which causes considerable reduction of yield. Identification of resistance genes is important for both conventional and molecular breeding. Few resistance genes have been identified and the mechanism of defense responses to this pathogen remains unknown. Results: We detected several genes involved in disease resistance to ELS through transcriptome analysis. Using RNA-seq technology, one hundred thirty-three differentially expressed genes (DEGs) were identified between resistant and susceptible lines. Among these DEGs, coiled coil-nucleotide binding-leucine rich repeat (NLR) type resistance genes were identified as duplicated R genes on the chromosome B2. Peanut phytoalexin deficient 4 (PAD4) regulator of effector-triggered immunity mediated by NLR resistance proteins and polyphenol oxidase (PPO) genes play important roles in early leaf spot resistance. Our study provides the useful information on plant response to C. arachidicola infection in peanut. The results suggest that a few major genes and several factors mediate the resistance to ELS disease, showing the characteristics of quantitative trait in defense responses. [ABSTRACT FROM AUTHOR]

Salvia leucantha (Lamiaceae) is an important horticultural plant with great ornamental and economic value. Here, we report the complete chloroplast genome of this species. The chloroplast genome was determined to be 151021 bp and the GC contents was 38.0%. The sequence includes a large single copy (LSC) region of 82,262 bp, a small single copy (SSC) region of 17,537 bp, and two separated inverted regions of 25,611 bp each. It contains 130 unique genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Based on the chloroplast genomes data of 26 species in Salvia, our result indicated that S. leucantha, S. tiliifolia, S. hispanica, and S. splendens formed one clade with Bootstrap = 100%. The four species belong to Salvia subgenus Calosphace, and S. leucantha was closely related to Salvia tiliifolia and Salvia hispanica. This result will facilitate population, genetic diversity and phylogenetic studies of S. leucantha. [ABSTRACT FROM AUTHOR]

Like many important crops, peanut is a polyploid that underwent polyploidization, evolution, and domestication. The wild allotetraploid peanut species Arachis monticola (A. monticola) is an important and unique link from the wild diploid species to cultivated tetraploid species in the Arachis lineage. However, little is known about A. monticola and its role in the evolution and domestication of this important crop. A fully annotated sequence of ≈2.6 Gb A. monticola genome and comparative genomics of the Arachis species is reported. Genomic reconstruction of 17 wild diploids from AA, BB, EE, KK, and CC groups and 30 tetraploids demonstrates a monophyletic origin of A and B subgenomes in allotetraploid peanuts. The wild and cultivated tetraploids undergo asymmetric subgenome evolution, including homoeologous exchanges, homoeolog expression bias, and structural variation (SV), leading to subgenome functional divergence during peanut domestication. Significantly, SV‐associated homoeologs tend to show expression bias and correlation with pod size increase from diploids to wild and cultivated tetraploids. Moreover, genomic analysis of disease resistance genes shows the unique alleles present in the wild peanut can be introduced into breeding programs to improve some resistance traits in the cultivated peanuts. These genomic resources are valuable for studying polyploid genome evolution, domestication, and improvement of peanut production and resistance. [ABSTRACT FROM AUTHOR]

Seed expansion in peanut is a complex biological process involving many gene regulatory pathways. MicroRNAs (miRNAs) play important regulatory roles in plant growth and development, but little is known about their functions during seed expansion, or how they contribute to seed expansion in different peanut lines. We examined seed miRNA expression patterns at 15 and 35 days after flowering (DAF) in two peanut eighth-generation recombinant inbred lines (RIL8); 8106, a mediumpod variety, and 8107, a super-pod variety. Using high-throughput sequencing, we identified 1,082 miRNAs in developing peanut seeds including 434 novel miRNAs. We identified 316 differentially expressed miRNAs by comparing expression levels between the two peanut lines. Interestingly, 24 miRNAs showed contrasting patterns of expression in the two RILs, and 149 miRNAs were expressed predominantly in only one RIL at 35 DAF. Also, potential target genes for some conserved and novel miRNAs were identified by degradome sequencing; target genes were predicted to be involved in auxin mediated signaling pathways and cell division. We validated the expression patterns of some representative miRNAs and 12 target genes by qPCR, and found negative correlations between the expression level of miRNAs and their targets. miR156e, miR159b, miR160a, miR164a, miR166b, miR168a, miR171n, miR172c- 5p, and miR319d and their corresponding target genes may play key roles in seed expansion in peanut. The results of our study also provide novel insights into the dynamic changes in miRNAs that occur during peanut seed development, and increase our understanding of miRNA function in seed expansion. [ABSTRACT FROM AUTHOR]

Metabolomics is an effective biotechnological tool that can be used to attain comprehensive information on metabolites. In this study, the profiles of metabolites produced by wheat seedlings in response to drought stress were investigated using an untargeted approach with ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to determine various physiological processes related to drought tolerance from the cross between drought-tolerant genotype (HX10) and drought-sensitive genotype (YN211). The current study results showed that under drought stress, HX10 exhibited higher growth indices than YN211. After drought stress treatment, a series of phenolics accumulated higher in HX10 than in YN211, whereas the amount of thymine, a pyrimidine, is almost 13 folds of that in YN211. These metabolites, as well as high levels of different amino acids, alkaloids, organic acids, and flavonoids in the drought treated HX10 could help to explain its strong drought-tolerant capacity. The current study explored the understanding of the mechanisms involved in the drought response of wheat seedling; these metabolome data could also be used for potential QTL or GWAS studies to identify locus (loci) or gene(s) associated with these metabolic traits for the crop improvement. [ABSTRACT FROM AUTHOR]

Growth-regulating factors (GRFs) are plant-specific transcription factors that perform important functions in plant growth and development. Herein, we identified and characterised 24 AhGRF genes in peanut (Arachis hypogaea). AhGRF family genes were divided into six classes with OLQ and WRC domains. Transcriptome expression profile showed that more AhGRF genes, such as AhGRF5a gene, were at higher expression during pod development in Arachis monticola than cultivated species, especially at the pod rapid-expansion stage. AhGRF5a and AhGRF5b genes expressed at higher levels in pods than roots, leaves and stems tissues, existing in the difference between Arachis monticola and H8107. Exogenous GA3 application can activate AhGRF5a and AhGRF5b genes and H8107 line showed more positive response than Arachis monticola species. These results imply that these two AhGRF genes may be active during the peanut pod development. [ABSTRACT FROM AUTHOR]

Arachis monticola (2n = 4x = 40) is the only allotetraploid wild peanut within the Arachis genus and section, with an AABB-type genome of ∼2.7 Gb in size. The AA-type subgenome is derived from diploid wild peanut Arachis duranensis , and the BB-type subgenome is derived from diploid wild peanut Arachis ipaensis. A. monticola is regarded either as the direct progenitor of the cultivated peanut or as an introgressive derivative between the cultivated peanut and wild species. The large polyploidy genome structure and enormous nearly identical regions of the genome make the assembly of chromosomal pseudomolecules very challenging. Here we report the first reference quality assembly of the A. monticola genome, using a series of advanced technologies. The final whole genome of A. monticola is ∼2.62 Gb and has a contig N50 and scaffold N50 of 106.66 Kb and 124.92 Mb, respectively. The vast majority (91.83%) of the assembled sequence was anchored onto the 20 pseudo-chromosomes, and 96.07% of assemblies were accurately separated into AA- and BB- subgenomes. We demonstrated efficiency of the current state of the strategy for de novo assembly of the highly complex allotetraploid species, wild peanut (A. monticola), based on whole-genome shotgun sequencing, single molecule real-time sequencing, high-throughput chromosome conformation capture technology, and BioNano optical genome maps. These combined technologies produced reference-quality genome of the allotetraploid wild peanut, which is valuable for understanding the peanut domestication and evolution within the Arachis genus and among legume crops. [ABSTRACT FROM AUTHOR]

Seed color is a key agronomic trait in crops such as peanut, where it is a vital indicator of both nutritional and commercial value. In recent years, peanuts with darker seed coats have gained market attention due to their high anthocyanin content. Here, we used bulk segregant analysis to identify the gene associated with the purplish-red coat trait and identified a novel gene encoding a basic/helix-loop-helix transcription factor, PURPLE RED SEED COAT1 (PSC1), which regulates the accumulation of anthocyanins in the seed coat. Specifically, we found that a 35-bp insertion in the PSC1 promoter increased the abundance of PSC1 mRNA. Transcriptomic and metabolomic analyses indicated that the purplish-red color of the seed coat was the result of decreased expression of anthocyanidin reductase (ANR), leading to increased accumulation of delphinidin, cyanidin, and pelargonidin derivatives. Further analysis revealed that PSC1 interacts with AhMYB7 to form a complex that specifically binds to the ANR promoter to suppress its expression, resulting in increased anthocyanin accumulation. Moreover, overexpression of PSC1 increased anthocyanin content in Arabidopsis thaliana and peanut callus. Our study reveals a new gene that controls seed coat color by regulating anthocyanin metabolism and provides a valuable genetic resource for breeding peanuts with a purplish-red seed coat., (© 2025 Institute of Botany, Chinese Academy of Sciences.)

Objective: The aim of this study was to understand the psychological insulin resistance status among Chinese patients with type 2 diabetes and investigate its associated factors in these patients., Methods: A multi-stage stratified random sampling was performed to randomly select patients with type 2 diabetes from the eastern, central, and western regions in Shandong Province, China, and 660 valid questionnaires were collected. Psychological insulin resistance was assessed by the scale of My Opinion on Insulin (MOI). Factors associated with psychological insulin resistance were examined in a binary logistic model., Results: Four-fifths of the patients with type 2 diabetes (82.1%) had psychological insulin resistance. Being female (OR = 1.770, 95% CI: 1.063-2.950, p < 0.05), having a monthly income of greater than 4,000 Renminbi (approximately $1,540) (OR = 0.444, 95% CI: 0.216-0.915, p < 0.05), living with type 2 diabetes for 11 years or more (OR = 0.387, 95% CI: 0.238-0.630, p < 0.05), self-rated poor health (OR = 1.706, 95% CI: 1.092-2.664, p < 0.05), and moderate discrimination against type 2 diabetes (OR = 1.924, 95% CI: 1.166-3.175, p < 0.05) were associated with psychological insulin resistance., Conclusions: The prevalence of psychological insulin resistance among Chinese patients with type 2 diabetes is relatively high. Approaches are needed to address the issue of psychological insulin resistance of type 2 diabetes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhang, Zhang, Wang, Fan, Ma, Song and Zhang.)

Salvia leucantha (Lamiaceae) is an important horticultural plant with great ornamental and economic value. Here, we report the complete chloroplast genome of this species. The chloroplast genome was determined to be 151021 bp and the GC contents was 38.0%. The sequence includes a large single copy (LSC) region of 82,262 bp, a small single copy (SSC) region of 17,537 bp, and two separated inverted regions of 25,611 bp each. It contains 130 unique genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Based on the chloroplast genomes data of 26 species in Salvia , our result indicated that S. leucantha , S. tiliifolia , S. hispanica, and S. splendens formed one clade with Bootstrap = 100%. The four species belong to Salvia subgenus Calosphace , and S. leucantha was closely related to Salvia tiliifolia and Salvia hispanica . This result will facilitate population, genetic diversity and phylogenetic studies of S. leucantha ., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Auxin response factors (ARFs) are transcription factors that regulate the expression of auxin response genes, and have important functions in plant growth and development. In this study, available genome data for peanut ( Arachis hypogaea L.) were used to identify AhARF genes. In total, 61 AhARFs and 23 AtARFs were divided into six groups (I-VI). Molecular structural analysis revealed that the protein members of AhARF contain at least two domains, the B3 domain and the Auxin-resp domain, and that some have a C-terminal dimerisation domain. Screening of the transcriptome data of 22 tissues of A. hypogaea cv. Tifrunner in a public database showed high expression levels of AhARF2 and AhARF6 . AhARF6 was expressed more highly in the stem and branch than in the root and leaf of the wild species Arachis monticola ( A. mon ) and cultivated species H103. After treatment with exogenous auxin (NAA), the expression of AhARF6 was inhibited, and this inhibition was greater in A. mon than in H103. The transcriptome map revealed that the expression of AhARF6 was higher in the larger pods of H8107 and ZP06 than in the medium pods of H103 and small pods of A. mon . Moreover, AhARF6 -5 was proven to be localised in the nucleus, consistent with the location of AtARF6 . These results suggest that AhARF6 may play an important role in pod development in peanut., Competing Interests: The authors declare that they have no competing interests., (© 2021 Li et al.)

Peanut ( Arachis hypogaea ) consists of two subspecies, hypogaea and fastigiata , and has been cultivated worldwide for hundreds of years. Here, 158 peanut accessions were selected to dissect the molecular footprint of agronomic traits related to domestication using specific-locus amplified fragment sequencing (SLAF-seq method). Then, a total of 17,338 high-quality single nucleotide polymorphisms (SNPs) in the whole peanut genome were revealed. Eleven agronomic traits in 158 peanut accessions were subsequently analyzed using genome-wide association studies (GWAS). Candidate genes responsible for corresponding traits were then analyzed in genomic regions surrounding the peak SNPs, and 1,429 genes were found within 200 kb windows centerd on GWAS-identified peak SNPs related to domestication. Highly differentiated genomic regions were observed between hypogaea and fastigiata accessions using F ST values and sequence diversity (π) ratios. Among the 1,429 genes, 662 were located on chromosome A3, suggesting the presence of major selective sweeps caused by artificial selection during long domestication. These findings provide a promising insight into the complicated genetic architecture of domestication-related traits in peanut, and reveal whole-genome SNP markers of beneficial candidate genes for marker-assisted selection (MAS) in future breeding programs.

Peanut seeds have a high oil content making them an important oil crop. During development and germination, seeds undergo complex dynamic and physiological changes. Changes in lipid metabolism and underlying mechanisms during seed development have been studied extensively by DNA and RNA sequencing; however, there are few studies on dynamic changes of proteomics during peanut seed development and germination. In this study, proteomic analyses were carried out 20, 40, 60, and 80 days after pollination and 5, 10, 20, and 30 days after germination using isobaric tags for relative and absolute quantitation (iTRAQ) technology to determine the protein profiles of lipid dynamics during peanut seed development and postgermination. A total of 5712 of 8505 proteins were identified, quantified, and divided into 23 functional groups, the largest of which was metabolism-related. Further analyses of the proteins and their pathways revealed initiation of fatty acid accumulation at early stages after flowering, while lipid degradation occurred largely through the lipoxygenase-dependent pathway. Protein expression patterns related to lipid accumulation and degradation were also verified at transcript levels using quantitative real-time polymerase chain reaction. The proteome profiles determined here will significantly enrich our understanding of the process of lipid accumulation and degradation and the dynamic changes in metabolic networks during peanut development.

Background: MicroRNAs (miRNAs) play critical roles in the processes of plant growth and development, but little is known of their functions during dehydration stress in wheat. Moreover, the mechanisms by which miRNAs confer different levels of dehydration stress tolerance in different wheat genotypes are unclear., Results: We examined miRNA expressions in two different wheat genotypes, Hanxuan10, which is drought-tolerant, and Zhengyin1, which is drought-susceptible. Using a deep-sequencing method, we identified 367 differentially expressed miRNAs (including 46 conserved miRNAs and 321 novel miRNAs) and compared their expression levels in the two genotypes. Among them, 233 miRNAs were upregulated and 10 were downregulated in both wheat genotypes after dehydration stress. Interestingly, 13 miRNAs exhibited opposite patterns of expression in the two wheat genotypes, downregulation in the drought-tolerant cultivar and upregulation in the drought-susceptible cultivar. We also identified 111 miRNAs that were expressed predominantly in only one or the other genotype after dehydration stress. We verified the expression patterns of a number of representative miRNAs using qPCR analysis and northern blot, which produced results consistent with those of the deep-sequencing method. Moreover, monitoring the expression levels of 10 target genes by qPCR analysis revealed negative correlations with the levels of their corresponding miRNAs., Conclusions: These results indicate that differentially expressed patterns of miRNAs between these two genotypes may play important roles in dehydration stress tolerance in wheat and may be a key factor in determining the levels of stress tolerance in different wheat genotypes.