Fleshy Roots Research Articles

Standardization of vacuum frying techniques for the development of low-fat beetroot finger chips

Beetroot (Beta vulgaris L. ssp), is a popular root crop grown for its fleshy roots and is a nutritious and mostly consumed fresh vegetable. It is a perishable product of just two to three days after the mature stage. The beetroot can be used for the preparation of value-added products like juice, dehydrated powder, soup mix, chips, etc. The chips out-turn of beetroot finger chips under vacuum frying was about 20 %. The vacuum-fried beetroot finger chips with corn powder coating absorbed relatively less frying oil (16.79 %) when compared to those without corn powder coating chips (18.25 %). The tristimulus color of vacuum-fried beetroot finger chips with corn powder coating chips were improved. Among the vacuum-fried chips prepared under various combinations of vacuum (constant 640 mm Hg), frying temperature (3 levels), and frying duration (3 levels), it was found that the beetroot finger chips prepared with corn coating at 110 °C frying temperature for 15 minutes frying time were the best in terms of all quality parameters. The beetroot finger chip manufacturing cost was determined to be Rs. 235 per kg, and the benefit-cost ratio of production was found to be 1:1.70.

A novel SNP within the Rsa10025320 gene is highly associated with hollowness in red-skinned radish fleshy roots.

Hollowness is a physiological disorder that frequently occurs during the growth and postharvest storage phases of fleshy radish roots, significantly diminishing quality, yield, and marketability. However, the molecular mechanism for hollowness remains elusive. To identify the QTLs and potential candidate genes for hollowness tolerance in radish, F2 and BC1 populations were constructed from hollowness-tolerant radish (C16) and hollowness-sensitive radish (C17) in the present study. Genetic analysis indicated that hollowness tolerance may be governed by two independent recessive genes. By employing bulked segregant analysis sequencing (BSA-seq), two significant candidate genomic intervals were pinpointed on chromosomes R04 (960kb, 6.48-7.44Mb) and R05 (600kb, 31.44-32.04Mb), which together harbor 107 annotated genes. Transcriptomic sequencing revealed that the downregulated differentially expressed genes (DEGs) were significantly enriched in biological processes related to cell death and the response to water stress, whereas the upregulated DEGs were significantly associated with the chitin catabolic process and the cell wall macromolecule metabolic process. A total of 46 intersecting genes were identified among these DEGs within the genomic intervals of interest. One gene with high expression (Rsa10025345) and two with low expression (Rsa10025320 and Rsa10018106) were detected in the tolerant variety C16. Furthermore, a SNP within Rsa10025320 resulting in an amino acid change (A188E) was characterized through sequence variation observed in both BSA-seq and RNA-seq data and further developed as a derived cleaved amplified polymorphic sequence (dCAPS) marker. Our study reveals potential target genes for tolerance to hollowness and paves the way for marker-assisted breeding of hollowness tolerance in red-skinned radishes.

Hydrogen sulfide alleviates cadmium stress in germinating carrot seeds by promoting the accumulation of proline

Carrot (Daucus carota L.), a widely cultivated economically vegetable from the Apiaceae family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H2S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of L-cysteine desulfhydrase and D-cysteine desulfhydrase, along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H2S accumulation. Moreover, NaHS treatment triggered the expression of pyrroline-5-carboxylate synthase and pyrroline-5-carboxylate reductase and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H2S, suggesting that H2S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd2+ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H2S in plants responding to Cd stress.

Comparative transcriptome analysis reveals transcriptional regulation of anthocyanin biosynthesis in purple radish (Raphanus sativus L.)

Radish exhibits significant variation in color, particularly in sprouts, leaves, petals, fleshy roots, and other tissues, displaying a range of hues such as green, white, red, purple, and black. Although extensive research has been conducted on the color variation of radish, the underlying mechanism behind the variation in radish flower color remains unclear. To date, there is a lack of comprehensive research investigating the variation mechanism of radish sprouts, leaves, fleshy roots, and flower organs. This study aims to address this gap by utilizing transcriptome sequencing to acquire transcriptome data for white and purple radish flowers. Additionally, the published transcriptome data of sprouts, leaves, and fleshy roots were incorporated to conduct a systematic analysis of the regulatory mechanisms underlying anthocyanin biosynthesis in these four radish tissues. The comparative transcriptome analysis revealed differential expression of the anthocyanin biosynthetic pathway genes DFR, UGT78D2, TT12 and CPC in the four radish tissues. Additionally, the WGCNA results identified RsDFR.9c and RsUGT78D2.2c as hub genes responsible for regulating anthocyanin biosynthesis. By integrating the findings from the comparative transcriptome analysis, WGCNA, and anthocyanin biosynthetic pathway-related gene expression patterns, it is hypothesized that genes RsDFR.9c and RsUGT78D2.2c may serve as pivotal regulators of anthocyanins in the four radish tissues. Furthermore, the tissue-specific expression of the four copies of RsPAP1 is deemed crucial in governing anthocyanin synthesis and accumulation. Our results provide new insights into the molecular mechanism of anthocyanin biosynthesis and accumulation in different tissues of radish.

Effects of Salt Water on Growth and Quality of Raphanus sativus L. and Physiological Responses against Salt Stress

To determine the optimal salinity of irrigation water for fruit radish cultivated in peat, five levels of salinized water were used to evaluate their effect on the growth and quality of fruit radish (Raphanus sativus L.). Results showed that with an increase in salinity, the leaf growth was somehow inhibited, but the fleshy root growth increased, and quality improved with more soluble solids, sugar, protein, and Vitamin C substances in fleshy roots. With an increase in water salinity up to 4.2 dS/m, the weight of fleshy roots increased by 51.10% with a high increment in the root/shoot ratio. With the same salt concentration, the content of soluble solids in both root peal and pulp was the highest and improved by 11.06% and 6.70%, respectively. The soluble sugar content was the highest in root peals with the 4.2 dS/m treatment and in fleshy roots with the 7.4 dS/m treatment, with a 55.85% and 32.30% increase, respectively. The content of both soluble protein and vitamin C with the 4.2 dS/m treatment increased by 11.99% and 113.36%, respectively. Strong evidence derived from the study has indicated that 4.2 dS/m salinized irrigation water is optimal for growing ‘ice-cream’ fruit radishes and maintaining ultimate root weight and quality.

Pigmented radish (Raphanus sativus): Genetic variability, heritability and interrelationships of total phenolics, anthocyanins and antioxidant activity

Radish (Raphanus sativus L.) is an important salad vegetable grown and consumed throughout the world for fleshy roots which has numerous categories– varying in root colour, size, shape and flavour. The uses of coloured radishes in the salads and their anthocyanins as colourants are gaining popularity because of the colour characteristics, health benefits as well as antioxidant activities. However, information on the genetic variability, heritability and inter-relationship of total phenolics, anthocyanins and antioxidant activities in pigmented radish is very limited, but pre-requisite to initiate breeding programme; and therefore investigated in the present study. Radish genotypes were significantly diverse for all the antioxidants; differed by 4.98-fold for total phenolics, 36.16-fold for anthocyanins content, 4.96-fold for FRAP activity and 4.03-fold for CUPRAC activity; and the genotypes accounted for >97% of total variations. The meager differences between phenotypic and genotypic coefficient of variation reveals the greater role of genotypes and lesser influence of the environment on the biosynthesis and accumulation of antioxidants. Significantly positive correlations along with higher magnitude for anthocyanins content, total phenolics, FRAP activity and CUPRAC activity (r= 0.823 to 0.964) could be used as indirect selection criteria for improving levels of antioxidant compounds. The estimates of heritability and genetic advance indicate the role of additive and non-additive genes for biosynthesis of antioxidants and root development, respectively; therefore, recurrent selection would be the best breeding approach to improve both the traits simultaneously in coloured radish.

RsRbohD1 Plays a Significant Role in ROS Production during Radish Pithiness Development.

Pithiness is one of the physiological diseases of radishes, which is accompanied by the accumulation of reactive oxygen species (ROS) during the sponging of parenchyma tissue in the fleshy roots. A respiratory burst oxidase homolog (Rboh, also known as NADPH oxidase) is a key enzyme that catalyzes the production of ROS in plants. To understand the role of Rboh genes in radish pithiness, herein, 10 RsRboh gene families were identified in the genome of Raphanus sativus using Blastp and Hmmer searching methods and were subjected to basic functional analyses such as phylogenetic tree construction, chromosomal localization, conserved structural domain analysis, and promoter element prediction. The expression profiles of RsRbohs in five stages (Pithiness grade = 0, 1, 2, 3, 4, respectively) of radish pithiness were analyzed. The results showed that 10 RsRbohs expressed different levels during the development of radish pithiness. Except for RsRbohB and RsRbohE, the expression of other members increased and reached the peak at the P2 (Pithiness grade = 2) stage, among which RsRbohD1 showed the highest transcripts. Then, the expression of 40 genes related to RsRbohD1 and pithiness were analyzed. These results can provide a theoretical basis for improving pithiness tolerance in radishes.

Morphological, cytological, physiological, and molecular evidence to explain how underground fleshy roots expand in herbaceous peony (Paeonia lactiflora Pall.)

The fleshy roots of herbaceous peonies serve as vital storage organs and are the primary source material for Chinese herbal medicine. Moreover, in certain cultivars, these roots can be propagated by root cuttings. However, the specific mechanisms governing the expansion and development of fleshy roots in herbaceous peonies currently remain unclear. To elucidate patterns of changes during the enlargement and development of herbaceous peony fleshy roots, this study assessed fleshy roots in six growth and development periods (P1–P6). By integrating environmental monitoring data, morphological, cytological, physiological and biochemical, as well as molecular characteristics across these developmental periods were compared. Both precipitation and temperature influenced the development of fleshy roots. The fastest enlargement of fleshy roots occurred under the following growth conditions: daily average precipitation = 5.6 mm; monthly average air temperature = 25.6°C; monthly average soil temperature = 26.3°C. Phloem and xylem, produced by the activity of vascular cambium, are important components of fleshy roots. Secondary xylem thickness consistently increased across the six developmental periods, resulting in the radial expansion of fleshy roots. When average monthly air and soil temperatures were about 26°C, starch accumulated gradually in fleshy roots, and carbohydrates were mostly starch-based. However, when the average monthly air and soil temperatures decreased to about 11.0°C, soluble sugar content increased. Endogenous hormones such as IAA, ZR, GA3, MeJA, and ABA played regulatory roles throughout the development of fleshy roots, and their levels and dynamic equilibrium were correlated with expansion rate. Elevated IAA and ZR content, and stabilized IAA/ABA and MeJA/ABA ratios, favored fleshy root expansion. Trends in the expression of three genes that play key roles in the expansion of fleshy roots (PlEXLB3, PlAUX1 and PlWRKY13) were consistent with morphological and physiological data, but PlHXK1 and PlIPT3 also play important roles. These findings lay a foundation for studying, in greater depth, the regulatory mechanisms governing the enlargement of herbaceous peony fleshy roots, and offer practical advice pertaining to field cultivation and management practices of this ornamental plant.

Optimized Fertilizer–Water Management Improves Carrot Quality and Soil Nutrition and Reduces Greenhouse Gas Emissions on the North China Plain

In order to improve carrot quality and soil nutrition and reduce the environmental pollution caused by intensive carrot production, more comprehensive combined water–fertilizer management strategies are necessary. This study hypothesizes that optimal management of water and fertilizer can improve carrot yield and quality and reduce greenhouse gas emissions and soil nutrient residues. Thus, coordinated water–fertilizer management strategies were tested for carrot production on the North China Plain over two consecutive growing seasons. Four treatments were tested: local standard fertilization and irrigation practices (FNP); optimized irrigation and chemical nitrogen, phosphorus, and potassium fertilizer (OPT); OPT treatment with partial replacement of chemical fertilizer with peanut shell (PS); and OPT treatment with partial replacement of chemical fertilizer with mushroom residue (M). Compared to the FNP treatment, there were statistically significant increases in soluble sugars (12–27%) and free amino acids (14–26%), and decreases in the nitrate content (7–17%) of fleshy root in the OPT, PS, and M treatments. In autumn carrots, the OPT and M treatments decreased yield, whereas PS increased yield; spring carrot yield was significantly decreased in the OPT, PS, and M groups compared to the FNP group. There were no significant effects of the treatment group on carrot growth rates, nutrient accumulation, or nutrient distribution. However, the OPT, PS, and M treatments were associated with significantly increased partial productivity of phosphate fertilizer (233–363%), reduced residual levels of nitrate and available phosphorus in the top 80 cm of soil, and decreased greenhouse gas emissions by 8–18% compared to the FNP treatment. These results highlight the effectiveness of partial organic fertilizer substitution and integrated water–fertilizer management to produce high-quality carrots with minimal environmental damage.

Genome-wide identification of long non-coding RNAs and their potential functions in radish response to salt stress.

Long non-coding RNAs (lncRNAs) are increasingly recognized as cis- and trans-acting regulators of protein-coding genes in plants, particularly in response to abiotic stressors. Among these stressors, high soil salinity poses a significant challenge to crop productivity. Radish (Raphanus sativus L.) is a prominent root vegetable crop that exhibits moderate susceptibility to salt stress, particularly during the seedling stage. Nevertheless, the precise regulatory mechanisms through which lncRNAs contribute to salt response in radish remain largely unexplored. In this study, we performed genome-wide identification of lncRNAs using strand-specific RNA sequencing on radish fleshy root samples subjected to varying time points of salinity treatment. A total of 7,709 novel lncRNAs were identified, with 363 of them displaying significant differential expression in response to salt application. Furthermore, through target gene prediction, 5,006 cis- and 5,983 trans-target genes were obtained for the differentially expressed lncRNAs. The predicted target genes of these salt-responsive lncRNAs exhibited strong associations with various plant defense mechanisms, including signal perception and transduction, transcription regulation, ion homeostasis, osmoregulation, reactive oxygen species scavenging, photosynthesis, phytohormone regulation, and kinase activity. Notably, this study represents the first comprehensive genome-wide analysis of salt-responsive lncRNAs in radish, to the best of our knowledge. These findings provide a basis for future functional analysis of lncRNAs implicated in the defense response of radish against high salinity, which will aid in further understanding the regulatory mechanisms underlying radish response to salt stress.

Complete genome sequence of the carrot black rot pathogen Alternaria radicina isolate CBR2

Black rot, caused by Alternaria radicina, seriously endangers carrots throughout the growing season, affecting both leaves and fleshy roots. In this study, we sequenced and assembled the genome of the A. radicina isolate CBR2. The genome was 34.6 Mb in size and consisted of 6 scaffolds. The sequence information provided in this genome will be used as a reference for further comparative genomics analysis of Alternaria species and will contribute to disease control in carrot production.

Asparagus (Asparagus officinalis L.) Root Distribution: Cultivar Differences in Mature Plantings

Annual plant growth patterns and seasonal conditions have both been shown to influence asparagus (Asparagus officinalis L.) root development over time. Root biomass and distribution changes in mature asparagus cultivars are herein illustrated and described. Asparagus root length density and biomass were estimated from soil cores using a systematic field sampling approach each spring. Soil cores (0.9 m deep) were divided into 0.15 m lengths and fleshy roots collected from the soil. Root length density and dry weights were determined and root distribution maps generated from collected data. As asparagus plantings matured, the sampling year had a significant influence on root development. Fleshy roots grew deeper into the soil each year but the majority of roots of Atlas, Guelph Millennium, and Jersey Giant were found in the upper 60 cm of the soil profile. For the three cultivars evaluated, minor differences in root length and root weight occurred. By Year 6, Atlas showed a decrease in root length and weight when compared to Guelph Millennium and Jersey Giant. While spear yield differences between the varieties were not significant, Atlas tended to produce more very large and large spears compared to Guelph Millennium and Jersey Giant. These results increase our understanding of asparagus root development.

Anatomy and Histochemistry of the Vegetative System of Brachystele guayanensis (Lindl.) Schltr. (Orchidaceae), a Potential Medicinal Species.

The orchid genus Brachystele Schltr. (Orchidoideae, Cranichideae, Spiranthinae) comprises 20 species distributed from Mexico to Argentina, with 10 species found in Brazil. Anatomical studies of Orchidoideae Lindl. have been scarce, and the anatomy and histochemistry of Brachystele are still largely unknown. In this study, we conducted a characterization of the vegetative organs of B. guayanensis (Lindl.) Schltr. using standard anatomical and histochemical microtechniques. In this study, we provide the first information about the anatomy and histochemistry of Brachystele. The studied species was observed to display anatomical characters commonly found in the vegetative organs of representatives of the Cranichideae tribe (e.g., uniseriate epidermis; homogeneous mesophyll with 6-11 layers; rhizomes with rings of fibers; vascular bundles in the form of "^" or "v"; fleshy roots with uniseriate velamen, simple trichomes, and spiranthosomes). Others can be interpreted as adaptive strategies conditioned by the environment and their terrestrial life form (e.g., cuticle thickness; amphistomatic leaves; roots with reduced velamen compared to the cortex (18-20 layers); and raphides). In this study, cataphylls, and the presence of spiranthosomes in leaves, including stomatal guard cells, as well as alkaloids in these structures, are anatomically described for the first time in Orchidaceae. The presence of hyphae and pelotons in the stem of B. guayanensis is described for the first time in Cranichideae. Histochemical tests confirmed the presence of lignin, proteins, and alkaloids, the lipidic nature of the cuticle, starch grains stored in spiranthosomes, and the composition of the raphides. Alkaloids were observed in abundance, particularly in the roots, suggesting a potential role in defense against pathogens and herbivores, as well as potential medicinal activities, as seen in phylogenetically related groups to Brachystele.

Synthesis of betanin by expression of the core betalain biosynthetic pathway in carrot

Betalain has received increased attention because of its high nutritional value and crucial physiological functions. Based on the elucidation of its core biosynthetic pathway, betalain can be produced in additional plants by metabolic engineering. Synthesis of betalain in carrot (Daucus carota L.) can improve its nutritional quality and economic value by extracting betalain from the fleshy root, non-edible part, and processing residue of carrot. In this study, two different constructs, namely, pYB:mCD (AomelOS, BvCYP76AD1S, and BvDODA1S) and pYB:CDD (BvCYP76AD1S, BvDODA1S, and MjcDOPA5GTS), were introduced into carrot for betanin synthesis by Agrobacterium-mediated transformation. Betanin can be synthetized in both transgenic calli, and pYB:mCD-transgenic callus can be used to produce betacyanin by suspension culture. However, pYB:mCD-transgenic seedlings can synthetize betanin only by tyrosine feeding. The pYB:CDD-transgenic lines can synthetize betanin in whole plants. The betanin content in fleshy root of pYB:CDD-transgenic carrot was (63.4 ± 9) μg ·g−1 fresh weight according to quantitative analysis. These betanin-producing carrot plant materials can be used to synthesize betanin for industrial application or consumption as dietary sources.

Lycopene ε-cyclase mediated transition of α-carotene and β-carotene metabolic flow in carrot fleshy root.

The accumulation of carotenoids, such as xanthophylls, lycopene, and carotenes, is responsible for the color of carrot (Daucus carota subsp. sativus) fleshy roots. The potential role of DcLCYE, encoding a lycopene ε-cyclase associated with carrot root color, was investigated using cultivars with orange and red roots. The expression of DcLCYE in red carrot varieties was significantly lower than that in orange carrots at the mature stage. Furthermore, red carrots accumulated larger amounts of lycopene and lower levels of α-carotene. Sequence comparison and prokaryotic expression analysis revealed that amino acid differences in red carrots did not affect the cyclization function of DcLCYE. Analysis of the catalytic activity of DcLCYE revealed that it mainly formed ε-carotene, while a side activity on α-carotene and γ-carotene was also observed. Comparative analysis of the promoter region sequences indicated that differences in the promoter region may affect the transcription of DcLCYE. DcLCYE was overexpressed in the red carrot 'Benhongjinshi' under the control of the CaMV35S promoter. Lycopene in transgenic carrot roots was cyclized, resulting in the accumulation of higher levels of α-carotene and xanthophylls, while the β-carotene content was significantly decreased. The expression levels of other genes in the carotenoid pathway were simultaneously upregulated. Knockout of DcLCYE in the orange carrot 'Kurodagosun' by CRISPR/Cas9 technology resulted in a decrease in the α-carotene and xanthophyll contents. The relative expression levels of DcPSY1, DcPSY2, and DcCHXE were sharply increased in DcLCYE knockout mutants. The results of this study provide insights into the function of DcLCYE in carrots, which could serve as a basis for creating colorful carrot germplasms.

Telomere-to-telomere carrot (Daucus carota) genome assembly reveals carotenoid characteristics.

Carrot (Daucus carota) is an Apiaceae plant with multi-colored fleshy roots that provides a model system for carotenoid research. In this study, we assembled a 430.40Mb high-quality gapless genome to the telomere-to-telomere (T2T) level of "Kurodagosun" carrot. In total, 36 268 genes were identified and 34 961 of them were functionally annotated. The proportion of repeat sequences in the genome was 55.3%, mainly long terminal repeats. Depending on the coverage of the repeats, 14 telomeres and 9 centromeric regions on the chromosomes were predicted. A phylogenetic analysis showed that carrots evolved early in the family Apiaceae. Based on the T2T genome, we reconstructed the carotenoid metabolic pathway and identified the structural genes that regulate carotenoid biosynthesis. Among the 65 genes that were screened, 9 were newly identified. Additionally, some gene sequences overlapped with transposons, suggesting replication and functional differentiation of carotenoid-related genes during carrot evolution. Given that some gene copies were barely expressed during development, they might be functionally redundant. Comparison of 24 cytochrome P450 genes associated with carotenoid biosynthesis revealed the tandem or proximal duplication resulting in expansion of CYP gene family. These results provided molecular information for carrot carotenoid accumulation and contributed to a new genetic resource.

Comparative and phylogenetic analysis of the complete chloroplast genomes of six Polygonatum species (Asparagaceae)

Polygonatum Miller belongs to the tribe Polygonateae of Asparagaceae. The horizontal creeping fleshy roots of several species in this genus serve as traditional Chinese medicine. Previous studies have mainly reported the size and gene contents of the plastomes, with little information on the comparative analysis of the plastid genomes of this genus. Additionally, there are still some species whose chloroplast genome information has not been reported. In this study, the complete plastomes of six Polygonatum were sequenced and assembled, among them, the chloroplast genome of P. campanulatum was reported for the first time. Comparative and phylogenetic analyses were then conducted with the published plastomes of three related species. Results indicated that the whole plastome length of the Polygonatum species ranged from 154,564 bp (P. multiflorum) to 156,028 bp (P. stenophyllum) having a quadripartite structure of LSC and SSC separated by two IR regions. A total of 113 unique genes were detected in each of the species. Comparative analysis revealed that gene content and total GC content in these species were highly identical. No significant contraction or expansion was observed in the IR boundaries among all the species except P. sibiricum1, in which the rps19 gene was pseudogenized owing to incomplete duplication. Abundant long dispersed repeats and SSRs were detected in each genome. There were five remarkably variable regions and 14 positively selected genes were identified among Polygonatum and Heteropolygonatum. Phylogenetic results based on chloroplast genome strongly supported the placement of P. campanulatum with alternate leaves in sect. Verticillata, a group characterized by whorled leaves. Moreover, P. verticillatum and P. cyrtonema were displayed as paraphyletic. This study revealed that the characters of plastomes in Polygonatum and Heteropolygonatum maintained a high degree of similarity. Five highly variable regions were found to be potential specific DNA barcodes in Polygonatum. Phylogenetic results suggested that leaf arrangement was not suitable as a basis for delimitation of subgeneric groups in Polygonatum and the definitions of P. cyrtonema and P. verticillatum require further study.

Integration of mRNA and miRNA Analysis Reveals the Post-Transcriptional Regulation of Salt Stress Response in Hemerocallis fulva.

MicroRNAs (miRNAs) belong to non-coding small RNAs which have been shown to take a regulatory function at the posttranscriptional level in plant growth development and response to abiotic stress. Hemerocallis fulva is an herbaceous perennial plant with fleshy roots, wide distribution, and strong adaptability. However, salt stress is one of the most serious abiotic stresses to limit the growth and production of Hemerocallis fulva. To identify the miRNAs and their targets involved in the salt stress resistance, the salt-tolerant H. fulva with and without NaCl treatment were used as materials, and the expression differences of miRNAs-mRNAs related to salt-tolerance were explored and the cleavage sites between miRNAs and targets were also identified by using degradome sequencing technology. In this study, twenty and three significantly differential expression miRNAs (p-value < 0.05) were identified in the roots and leaves of H. fulva separately. Additionally, 12,691 and 1538 differentially expressed genes (DEGs) were also obtained, respectively, in roots and leaves. Moreover, 222 target genes of 61 family miRNAs were validated by degradome sequencing. Among the DE miRNAs, 29 pairs of miRNA targets displayed negatively correlated expression profiles. The qRT-PCR results also showed that the trends of miRNA and DEG expression were consistent with those of RNA-seq. A gene ontology (GO) enrichment analysis of these targets revealed that the calcium ion pathway, oxidative defense response, microtubule cytoskeleton organization, and DNA binding transcription factor responded to NaCl stress. Five miRNAs, miR156, miR160, miR393, miR166, and miR396, and several hub genes, squamosa promoter-binding-like protein (SPL), auxin response factor 12 (ARF), transport inhibitor response 1-like protein (TIR1), calmodulin-like proteins (CML), and growth-regulating factor 4 (GRF4), might play central roles in the regulation of NaCl-responsive genes. These results indicate that non-coding small RNAs and their target genes that are related to phytohormone signaling, Ca2+ signaling, and oxidative defense signaling pathways are involved in H. fulva's response to NaCl stress.

Age-dependent variations in bioactive compounds in the roots of Himalayan peony (Paeonia emodi Royle)

Himalayan peony (Paeonia emodi Royle) is a popular herbaceous plant known for its medicinal and therapeutic potential in indigenous and traditional systems of medicine. The fleshy roots of P. emodi are most frequently uses in uterine diseases, rheumatic pain, sciatica, muscle cramps, epilepsy, and nervous affection. Phytochemical compounds like phenolics, monoterpenes, triterpenes, steroids, and various organic acids are also present in the roots of P. emodi. In the present study, for the first time, the root age of P. emodi determined using growth rings and corresponding paeoniflorin, albiflorin, polyphenolics, and antioxidant content were evaluated. Based on the paraffin sectioning method, 1–7-year-old roots were identified, followed by quantification of bioactive compounds. The maximum content of gallic acid (79.15 ± 3.93 mg/100 g D.W.), naringin (158.82 ± 9.49 mg/100 g D.W.), chlorogenic acid (29.45 ± 2.60 mg/100 g D.W.), and p-hydroxybenzoic acid (37.69 ± 1.92 mg/100 g D.W.) were recorded from 5, 4, 6, and 7-year-old roots. The maximum content of catechin (176.82 ± 6.66 mg/100 g D.W.) and salicylic acid (24.15 ± 3.18 mg/100 g D.W.) were recorded from 3-year-old roots. The maximum content of paeoniflorin (20.51 ± 0.16 mg/g D.W.) and albiflorin (2.96 ± 0.65 mg/g D.W.) were recorded from 5 and 7-year-old roots, respectively. Maximum FRAP (12.75 ± 0.003 mg/g D.W.) and DPPH activity (18.67 ± 0.004 mg/g D.W.) were recorded in 6-year-old roots; while ABTS activity (13.54 ± 0.81 mg/g D.W.) was found maximum in 7-year-old roots. The Pearson correlation analysis showed that plant age demonstrated significant positive relationships (p < 0.01) with paeoniflorin, albiflorin, p-hydroxybenzoic acid, FRAP, and ABTS. The study showed that the amounts of bioactive compounds increased with the age of P. emodi. However, to harness and maintain the quality of raw materials in herbal or pharmaceutical industries, it is necessary to identify the material with the same age root of the target species for subsequent use.

Asparagus (Asparagus officinalis L.) Root Distribution Varies with Cultivar during Early Establishment Years

Soil type, crop management practices, annual plant growth patterns, and seasonal changes have all been shown to influence asparagus (Asparagus officinalis) roots. This study describes the changes in root growth that occur over the three establishment seasons of three asparagus cultivars. Starting one year after planting, asparagus root length density and biomass were estimated from soil cores (55 mm diam. × 0.2 m long) collected to 0.9 m at three locations adjacent to the row (0.15, 0.3, and 0.6 m from row center). Samples were collected each spring during the spear harvest period (late April to early May). Soil cores were divided into 0.15 m lengths and fleshy roots were collected for the soil, root length density determined, and dry weights measured. The year of sampling had a significant effect on root development and, as time progressed, fleshy asparagus roots grew deeper into the soil. There was no difference in fleshy root length or fresh weight between the three cultivars evaluated. However, root distribution patterns varied between the cultivars. Fleshy roots for the cultivars Atlas and Jersey Giant extended further from the crown and deeper in the soil when compared to Guelph Millennium. Results can be used to improve crop management practices and increase our understanding of the dynamic changes of root development that occur over time in asparagus.