The leaves of Acer truncatum are rich in bioactive compounds such as flavonoids and chlorogenic acid, making them a promising resource for functional tea development. However, the impact of processing parameters on tea quality remains poorly understood. This study investigated the effect of particle size on the quality of A. truncatum leaf tea. A total of 144 compounds with relative contents above 100 mu g/g were identified, among which flavonoids were the most abundant. The leaves were ground into four particle sizes (5-, 10-, 20- and 30mesh) for subsequent analysis. Tea infusions were analyzed for several components, aroma, and taste using Enose and E-tongue. Among 301 volatile compounds, 12 were key odorants (OAV >= 1.0), with propanoic acid octyl ester, beta-damascenone, cyclohexanone and citral being major contributors. Artificial sensory evaluation awarded the 20-mesh sample the highest score; E-nose/E-tongue analyses confirmed its balanced flavor profile with fruity/floral aroma and umami-sweet taste. The 5-mesh sample gave higher yields of bioactive compounds (total flavonoids, chlorogenic acid, free amino acids, soluble sugars) across two brews. This study provides a scientific basis for optimizing A. truncatum tea processing.

The Aceraceae family has ecological, ornamental and economical importance in plants. However, the genetic variations, evolution, and domestication of Aceraceae species are not well understood. Pan-genomes provide a framework for capturing genetic diversity across a genus and for a comprehensive understanding of genomic variation during evolution. Here, we construct a graph-based pan-genome from 13 Aceraceae species, revealing evolutionary dynamics driven by long-terminal repeat retrotransposons. Sequencing of 134 cultivated Acer palmatum accessions identifies 2,160 single nucleotide polymorphisms associated with 10 fatty acid traits through genome wide association study. We further characterize 1,064,183 structural variation loci impacting fatty acid accumulation. By multi-omics analysis, we also identify ActKCS as a key candidate gene required for nervonic acid biosynthesis. Transgenic overexpression of ActKCS in Arabidopsis thaliana and Brassica napus enhances seed nervonic acid content, with increases ranging from 0.05

Acer truncatum is an economically important multipurpose tree in China due to its high values in ornamental, ecology, oil-production and medicine. The lack of reliable and stable in vitro regeneration system seriously restricts its breeding and industrial development. This study first presented a protocol for in vitro regeneration of A. truncatum via de novo shoot organogenesis from stem explants. The results showed that sterilization, basal medium, plant growth regulators and light condition significantly influenced shoot regeneration of A. truncatum . The best sterilization protocol for stem explants was 75% ethanol (30 s) + 0.1% HgCl 2 (10 min ), with a lowest contamination rate (4.74%). The highest callus induction rate (97.17%) was achieved when stem segments were cultured on WPM medium with 0.2 mg/L 2,4-D and 0.5 mg/L 6-BA in the dark for 15 days. The optimal shoot differentiation rate (10.51%) was obtained when callus was cultured on NN69 medium containing 0.5 mg/L CPPU. The rooting rate of adventitious shoots was achieved 85% by using NN69 medium with 0.25 mg/L IBA, and the rooted seedlings were transplanted into pots containing a mixture of peat, perlite and vermiculite (2:1:1, v:v:v), the survival rate was more than 80%. Histological analysis demonstrated the origin and development process of indirect shoot organogenesis, including callus formation, meristematic nodule formation and shoot differentiation. This study will be beneficial to the germplasm conservation, mass propagation and genetic improvement of A. truncatum .

Acer truncatum is an economically important multipurpose tree in China due to its high values in ornamental, ecology, oil-production and medicine. The lack of reliable and stable in vitro regeneration system seriously restricts its breeding and propagation. This study first presented a protocol for in vitro regeneration of A. truncatum via de novo shoot organogenesis from stem explants. The results showed that sterilization, basal medium, plant growth regulators and light condition significantly influenced shoot regeneration of A. truncatum. The best sterilization protocol for stem explants was 75

As the direct recipients of plant abscisic acid (ABA), pyrabactin resistance/pyrabactin resistance-like/regulatory component of ABA receptor proteins (PYR/PYL/RCAR; hereinafter called PYLs) play pivotal roles in plant coercive responses. However, the PYL genes in Acer palmatum have yet to be investigated. In this study, using a genome search method, we identified 14 A. palmatum PYL genes (ApPYLs) and clustered them into three clades based on the phylogenetic, gene structure, and conserved motif analyses. The ApPYLs were dispersed on eight chromosomes of A. palmatum; cis-acting element analysis indicated that the ApPYLs were involved in biological processes, including resistance, hormone regulation, and growth. Gene expression profiling of cold-treated A. palmatum plants revealed that ApPYL1 and ApPYL2 may be related to cold stress response. ApPYL1 and ApPYL2 interacted directly with ApMYB44, and the ApPYL1, ApPYL2, and ApMYB44 genes were found to enhance freezing tolerance in Arabidopsis. These findings illustrate that ApPYL1 and ApPYL2 respond to the cold signalling pathway by interacting with ApMYB44 and provide a reference for improving cold resistance of plants.

BACKGROUND:The accumulation of fatty acids in plants covers a wide range of functions in plant physiology and thereby affects adaptations and characteristics of species. As the famous woody oilseed crop, Acer truncatum accumulates unsaturated fatty acids and could serve as the model to understand the regulation and trait formation in oil-accumulation crops. Here, we performed Ribosome footprint profiling combing with a multi-omics strategy towards vital time points during seed development, and finally constructed systematic profiling from transcription to proteomes. Additionally, we characterized the small open reading frames (ORFs) and revealed that the translational efficiencies of focused genes were highly influenced by their sequence features.RESULTS:The comprehensive multi-omics analysis of lipid metabolism was conducted in A. truncatum. We applied the Ribo-seq and RNA-seq techniques, and the analyses of transcriptional and translational profiles of seeds collected at 85 and 115 DAF were compared. Key members of biosynthesis-related structural genes (LACS, FAD2, FAD3, and KCS) were characterized fully. More meaningfully, the regulators (MYB, ABI, bZIP, and Dof) were identified and revealed to affect lipid biosynthesis via post-translational regulations. The translational features results showed that translation efficiency tended to be lower for the genes with a translated uORF than for the genes with a non-translated uORF. They provide new insights into the global mechanisms underlying the developmental regulation of lipid metabolism.CONCLUSIONS:We performed Ribosome footprint profiling combing with a multi-omics strategy in A. truncatum seed development, which provides an example of the use of Ribosome footprint profiling in deciphering the complex regulation network and will be useful for elucidating the metabolism of A. truncatum seed oil and the regulatory mechanisms.

Low temperature is one of the most prominent environmental factors affecting plant growth. As a deciduous arboreal tree, Acer palmatum has considerable ornamental and economic value; however, the molecular mechanisms underlying cold stress regulation in this species have yet to be determined. In this study, we performed Illumina high-throughput sequencing of 18 libraries obtained from A. palmatum subjected to cold treatment and subsequently identified a differentially expressed R2R3-MYB family gene, ApMYB77, which was then cloned and functionally characterized. The expression of ApMYB77 was induced by cold and drought treatments, and overexpression in A. thaliana enhanced the freezing tolerance (− 9 °C for 6 h) of transgenic plants compared with that of wild-type plants. The survival rates of transgenic plants (89% and 92%) were significantly higher than the wild-type plants (52%). Moreover, the transcript abundances of CBF-dependent regulatory pathway genes (AtCBF1, AtCBF2, AtCBF3, AtCBF4, AtCOR6.6A, AtCOR15B, AtCOR78, AtCOR414, and AtKIN1) were found to be significantly up-regulated in the transgenic lines. Enhanced abscisic acid (ABA)-dependent drought tolerance in transgenic plants was a further consequence of the overexpression of ApMYB77 following treatment of 15% polyethylene glycol for 4 d, compared with that in wild-type plants. In contrast, the expressions of genes (AtANAC072, AtDREB2A, AtERD1, AtMYB2, AtRD20, and AtRD29A) positively regulated by ABA were activated. Overall, the findings of this study indicate that ApMYB77 confers both freezing and drought tolerances.

以江苏省农业科学院自主选育的鸡爪槭新品种金陵丹枫和金陵黄枫为研究对象,对其4月至7月观赏期叶片进行叶色对比观察,发现金陵丹枫新叶为亮红色,而后红色逐渐变淡,而金陵黄枫新叶为黄色,边缘呈浅珊瑚色,而后逐渐变为金黄色.比对金陵丹枫和金陵黄枫叶片中的叶绿素、类胡萝卜素、花青素和黄酮类物质含量,发现金陵丹枫亮红色叶片中各种色素含量均高于同时期的金陵黄枫金黄色叶片,且花青素和黄酮生物合成途径中一系列关键基因(ApPAL、ApCHS、ApCHI、ApF3H、ApF3′H、ApDFR和ApANS)的相对表达量在金陵丹枫叶片中上调.研究结果提示,这些色素含量的不同可能是导致金陵丹枫和金陵黄枫叶片呈色不同的主要原因.尤其是3种花青素(飞燕草素、矢车菊素和矢车菊半乳糖苷)在金陵丹枫亮红色叶片中的含量远高于金陵黄枫金黄色叶片,表明花青素在金陵丹枫叶片呈色中起到关键作用.

Background Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). The species is admired as a landscape plant with high developmental prospects and scientific research value. The A. truncatum chloroplast genome has recently been reported; however, the mitochondrial genome (mitogenome) is still unexplored. Results We characterized the A. truncatum mitogenome, which was assembled using reads from PacBio and Illumina sequencing platforms, performed a comparative analysis against different species of Acer . The circular mitogenome of A. truncatum has a length of 791,052 bp, with a base composition of 27.11% A, 27.21% T, 22.79% G, and 22.89% C. The A. truncatum mitogenome contains 62 genes, including 35 protein-coding genes, 23 tRNA genes and 4 rRNA genes. We also examined codon usage, sequence repeats, RNA editing and selective pressure in the A. truncatum mitogenome. To determine the evolutionary and taxonomic status of A. truncatum , we conducted a phylogenetic analysis based on the mitogenomes of A. truncatum and 25 other taxa. In addition, the gene migration from chloroplast and nuclear genomes to the mitogenome were analyzed. Finally, we developed a novel NAD1 intron indel marker for distinguishing several Acer species. Conclusions In this study, we assembled and annotated the mitogenome of A. truncatum , a woody oil-tree species producing nervonic acid. The results of our analyses provide comprehensive information on the A. truncatum mitogenome, which would facilitate evolutionary research and molecular barcoding in Acer .

BACKGROUND:Ornamental trees with seasonally-dependent leaf color, such as Acer palmatum, have gained worldwide popularity. Leaf color is a main determinant of the ornamental and economic value of A. palmatum. However, the molecular mechanisms responsible for leaf color changes remain unclear.RESULTS:We chose A. palmatum cultivars with yellow ('Jinling Huangfeng') and red ('Jinling Danfeng') leaves as the ideal material for studying the complex metabolic networks responsible for variations in leaf coloration. The 24 libraries obtained from four different time points in the growth of 'Jinling Huangfeng' and 'Jinling Danfeng' was subjected to Illumina high-throughput sequencing. We observed that the difference in cyanidin and delphinidin content is the primary reason behind the varying coloration of the leaves. Transcriptomic analyses revealed 225,684 unigenes, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of differentially expressed genes (DEGs) confirmed that they were involved in 'anthocyanin biosynthesis.' Eighteen structural genes involved in anthocyanin biosynthesis were thought to be related to anthocyanin accumulation, whereas 46 MYBs, 33 basic helix-loop-helixs (bHLHs), and 29 WD40s were presumed to be involved in regulating anthocyanin biosynthesis. Based on weighted gene co-expression network analysis (WGCNA), three candidate genes (ApRHOMBOID, ApMAPK, and ApUNE10) were screened in the significant association module with a correlation coefficient (r2) of 0.86.CONCLUSION:In this study, the leaf color changes of two A. palmatum genotypes were analyzed. These findings provide novel insights into variations in leaf coloration and suggest pathways for targeted genetic improvements in A. palmatum.

元宝枫是中国重要的木本油料树种,具有重要的观赏价值和药用价值.本研究对元宝枫种子发育过程中脂肪酸含量的动态变化以及油脂积累与可溶性糖积累和蛋白质积累之间的关系进行分析.结果表明,油体和蛋白体在元宝枫花后80 d时开始发育,且后期数量均大量增多,直至填满整个细胞.元宝枫种子发育过程中,油脂含量整体呈现"上升-下降-上升"的趋势,其中油酸和亚油酸是2种主要的脂肪酸,且积累模式大致相同;蛋白质含量在种子发育过程中不断增加,在花后210 d达到最大值(161.18 mg/g),且蛋白质积累与油脂积累呈显著正相关(P>0.05).本研究结果为元宝枫育种和栽培管理提供了重要理论依据.

[目的]通过对元宝枫外植体灭菌方法和培养基配方的筛选,建立元宝枫快速繁殖体系,为开展元宝枫优良种苗繁育推广研究奠定基础,并为元宝枫后期优良种苗的规模化生产提供理论与技术支撑.[方法]以元宝枫带芽茎段为外植体,研究不同消毒剂处理方法、不同基本培养基类型(1/2MS、MS、1/2NN69、NN69)以及不同浓度外源生长调节剂(IBA)对腋芽诱导、生根等过程的影响.[结果]元宝枫茎段在体积分数75％乙醇中处理30 s和0.1％HgCl2灭菌180 s时,成活率最高,但外植体不宜在9月前后采集.在NN69培养基中添加0.2 mg/L IBA时,腋芽诱导率最高(97.2％),且用时最短(10～15 d).在1/2 NN69中添加0.4 mg/L IBA时有利于生根,生根率可达87.8％.[结论]元宝枫带芽茎段适宜的灭菌方法为75％乙醇处理30 s,再以质量分数0.1％HgCl2处理180 s;腋芽诱导的适宜培养基为NN69+IBA(0.2 mg/L);适宜元宝枫茎段生根的培养基为1/2 NN69+IBA(0.4 mg/L).以泥炭、珍珠岩、蛭石体积比为7∶2∶1的混合基质为移栽基质时,试管苗移栽成活率可达95.0％.

TCP transcription factors are important regulators of plant growth and proliferation processes, such as leaf morphogenesis, petal growth and development, and shoot branching. Here, an RNA-seq analysis revealed that an Acer palmatum class II TCP transcription factor was differentially expressed in 'Jinlinghuangfeng' and the mutant 'Jinlinghuangyu,' which exhibit different expression level of microRNA 319 (miR319). We isolated and functionally characterized this gene, which is named ApTCP2. ApTCP2 expression was detected in the root, stem, and leaf and was strongest in the leaf. ApTCP2 is deposited in the nucleus and exhibits no transcriptional activation ability in yeast. The overexpression of ApTCP2 and ApmTCP2 (an mRNA sequence with synonymous changes from ApTCP2 that exhibits reduced sequence complementarity to miR319) in Arabidopsis jaw-D plants (which overexpress miR319) rescued the leaf defects in these plants. In Arabidopsis, ApTCP2 and ApmTCP2 affected the flowering period, and leaf senescence was accelerated by high expression of ApTCP2 and ApmTCP2. The transcript levels of key jasmonic acid (JA) biosynthesis genes (LIPOXYGENASE [AtLOXs]; AtLOX2, AtLOX3, and AtLOX4) were increased in the transgenic lines. Our results reveal that ApTCP2 plays multiple roles, including modulating leaf morphogenesis, affecting flowering and positively regulating leaf senescence, via miR319, and these effects are at least partially achieved by influencing JA biosynthesis.

鸡爪槭新品种金陵丹枫叶色绚烂,是优质的彩叶树种.以金陵丹枫带芽茎段为外植体,75％乙醇40 s+0.1％氯化汞20 min消毒效果最佳.以NN69为基本培养基,筛选获得最适宜的启动培养基为NN69+0.1 mg/L IBA,增殖培养基为NN69+0.4 mg/L KT+0.1 mg/L IBA,生根培养基为NN69+0.3 mg/LIBA.探讨了金陵丹枫不定芽对羧苄青霉素和潮霉素的敏感性,筛选获得羧苄青霉素的临界值为300～400 mg/L,潮霉素的临界值为2.5 mg/L.

Acer truncatum seeds are an excellent source of beneficial natural compounds, including high levels of unsaturated fatty acids (UFAs), that promote health. Recently, A. truncatum has emerged as an oil crop. Therefore, the transcriptomes of A. truncatum seeds at 70, 85, 100, 115, 145, 180 days after flowering (DAF) were analyzed to gain a better understanding of the transcriptional and translational regulation of seed development and oil biosynthesis. A total of 28,438 genes were identified, and 3069/2636, 3288/3438, 1319/2750, and 5724/5815 upregulated/downregulated genes were identified when comparing different samples with 85 DAF seeds. Sixteen lipid metabolism pathways with 754 differentially expressed genes (DEGs) were identified, including 34 DEGs associated with UFA biosynthesis. A phylogenetic analysis revealed that six putative fatty acid desaturase (FAD) genes clustered into five FAD groups. A quantitative real-time polymerase chain reaction analysis indicated that the temporal expression patterns of oil biosynthesis genes and transcription factors were largely similar to the RNA sequencing results. The results of this study will enhance the current understanding of oil metabolism in A. truncatum seeds and allow new methods of improving oil quality and seed yield in the future.

Quantitative real-time reverse transcriptase PCR (qRT-PCR) technology has been extensively used to estimate gene expression levels, and the selection of appropriate reference genes for qRT-PCR analysis is critically important for obtaining authentic normalized data. Acer palmatum is an important colorful leaf ornamental tree species, and reference genes suitable for normalization of the qRT-PCR data obtained from this species have not been investigated. In this study, the expression stability of ten candidate reference genes, namely, Actin3, Actin6, Actin9, EF1 alpha, PP2A, SAMDC, TIP41, TUB alpha, TUB beta and UBQ10, in two distinct tissues (leaves and roots) of A. palmatum under four different abiotic stress conditions (cold, heat, salt and drought) were investigated and assessed using three statistical methods (GeNorm, NormFinder and BestKeeper). The combinations of reference genes that showed stability in the different stressed samples differed. Specifically, Actin6, UBQ10 and Actin9 were the most stable reference genes in all the samples, and Actin3 and Actin6 wexre stably expressed in cold-stressed leaves and roots. Actin3, Actin6 and UBQ10 were identified as an appropriate combination of reference genes for the analysis of heat-stressed leaves and roots, whereas the combination of Actin9, UBQ10 and Actin6 was deemed the most suitable for the analysis of salt-stressed leaves and roots. Similarly, Actin6 and UBQ10 exhibited stable expression in drought-stressed leaves and roots. Furthermore, the expression levels of CBF, Cu/Zn-SOD and HsfA1 were estimated to determine the reliability of the reference genes assessed in this study. This study revealed stable reference genes in A. palmatum that might be used for the normalization of qRT-PCR data obtained under various abiotic stresses.

SUMMARYAcer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). However, the lack of a complete genome sequence has limited both basic and applied research on A. truncatum. We describe a high‐quality draft genome assembly comprising 633.28 Mb (contig N50 = 773.17 kb; scaffold N50 = 46.36 Mb) with at least 28 438 predicted genes. The genome underwent an ancient triplication, similar to the core eudicots, but there have been no recent whole‐genome duplication events. Acer yangbiense and A. truncatum are estimated to have diverged about 9.4 million years ago. A combined genomic, transcriptomic, metabonomic, and cell ultrastructural analysis provided new insights into the biosynthesis of very long‐chain monounsaturated fatty acids. In addition, three KCS genes were found that may contribute to regulating nervonic acid biosynthesis. The KCS paralogous gene family expanded to 28 members, with 10 genes clustered together and distributed in the 0.27‐Mb region of pseudochromosome 4. Our chromosome‐scale genomic characterization may facilitate the discovery of agronomically important genes and stimulate functional genetic research on A. truncatum. Furthermore, the data presented also offer important foundations from which to study the molecular mechanisms influencing the production of nervonic acids.

采用基因克隆的方法获得鸡爪槭金陵黄枫R2R3-MYB转录因子基因,经同源比对和生物信息学分析将其命名为ApMYB306.通过组织表达特性分析发现ApMYB306在茎中表达量最高,叶中表达量次之,根中表达量最低.在洋葱表皮细胞中瞬时表达分析结果显示ApMYB306蛋白定位于细胞核中.ApMYB306对于高温、低温、干旱和盐胁迫均有明显的响应,受胁迫诱导后表达量显著上升.冷冻处理后,转ApMYB306基因株系成活率较野生型升高.ApMYB306超表达拟南芥株系较野生型开花延迟,表明ApMYB306可能通过抑制拟南芥FT基因启动子的表达调控花期.

金陵红2019年通过了江苏省林木品种审定委员会审定. 1.特征特性.该品种为落叶乔木,枝条粗壮,生长势强.树皮灰褐色,较为平滑.一年生枝圆柱形,绿色,密被白色茸毛.单叶对生,叶片卵形,全缘,浅3裂或不分裂,基部圆形,叶片上表面绿色、下表面浅绿色,被白粉.叶柄绿色,长3～4厘米,被白色茸毛.花期3月下旬,伞房花序,花序着生于小枝顶端.幼果期翅果绿色,成熟期坚果黄褐色.10月下旬至11月上旬叶片颜色由深绿色变为暗红色,进而变成亮紫红色,12月下旬至翌年1月上旬落叶.抗逆性强,适应性广.

Acer truncatum, which is a new woody oil tree species, is an important ornamental and medicinal plant in China. To assess the genetic diversity and relationships of A. truncatum, we analyzed its complete chloroplast (cp) genome sequence. The A. truncatum cp genome comprises 156,492 bp, with the large single-copy, small single-copy, and inverted repeat (IR) regions consisting of 86,010, 18,050, and 26,216 bp, respectively. The A. truncatum cp genome contains 112 unique functional genes (i.e., 4 rRNA, 30 tRNA, and 78 protein-coding genes) as well as 78 simple sequence repeats, 9 forward repeats, 1 reverse repeat, 5 palindromic repeats, and 7 tandem repeats. We analyzed the expansion/contraction of the IR regions in the cp genomes of six Acer species. A comparison of these cp genomes indicated the noncoding regions were more diverse than the coding regions. A phylogenetic analysis revealed that A. truncatum is closely related to A. miaotaiense. Moreover, a novel ycf4-cemA indel marker was developed for distinguishing several Acer species (i.e., A. buergerianum, A. truncatum, A. henryi, A. negundo, A. ginnala, and A. tonkinense). The results of the current study provide valuable information for future evolutionary studies and the molecular barcoding of Acer species.