The Small Auxin-Up RNA SAUR10 Is Involved in the Promotion of Seedling Growth in Rice.

Small auxin-up-regulated RNAs (SAURs) are genes rapidly activated in response to auxin hormones, significantly affecting plant growth and development. However, there is limited information available about the specific functions of SAURs in rice due to the presence of extensive redundant genes. In this study, we found that OsSAUR10 contains a conserved downstream element in its 3' untranslated region that causes its transcripts to be unstable, ultimately leading to the immediate degradation of the mRNA in rice. In our investigation, we discovered that OsSAUR10 is located in the plasma membrane, and its expression is regulated in a tissue-specific, developmental, and hormone-dependent manner. Additionally, we created ossaur10 mutants using the CRISPR/Cas9 method, which resulted in various developmental defects such as dwarfism, narrow internodes, reduced tillers, and lower yield. Moreover, histological observation comparing wild-type and two ossaur10 mutants revealed that OsSAUR10 was responsible for cell elongation. However, overexpression of OsSAUR10 resulted in similar phenotypes to the wild-type. Our research also indicated that OsSAUR10 plays a role in regulating the expression of two groups of genes involved in auxin biosynthesis (OsYUCCAs) and auxin polar transport (OsPINs) in rice. Thus, our findings suggest that OsSAUR10 acts as a positive plant growth regulator by contributing to auxin biosynthesis and polar transport.

Transcriptome Analysis Reveals Candidate Genes Involved in Gibberellin-Induced Fruit Development in Rosa roxburghii.

Gibberellins (GAs) play indispensable roles in the fruit development of horticultural plants. Unfortunately, the molecular basis behind GAs regulating fruit development in R. roxburghii remains obscure. Here, GA3 spraying to R. roxburghii 'Guinong 5' at full-bloom promoted fruit size and weight, prickle development, seed abortion, ascorbic acid accumulation, and reduction in total soluble sugar. RNA-Seq analysis was conducted to generate 45.75 Gb clean reads from GA3- and non-treated fruits at 120 days after pollination. We obtained 4275 unigenes belonging to differently expressed genes (DEGs). Gene ontology and the Kyoto Encyclopedia of Genes and Genomes displayed that carbon metabolism and oxidative phosphorylation were highly enriched. The increased critical genes of DEGs related to pentose phosphate, glycolysis/gluconeogenesis, and citrate cycle pathways might be essential for soluble sugar degradation. Analysis of DEGs implicated in ascorbate revealed the myoinositol pathway required to accumulate ascorbic acid. Finally, DEGs involved in endogenous phytohormones and transcription factors, including R2R3 MYB, bHLH, and WRKY, were determined. These findings indicated that GA3-trigged morphological alterations might be related to the primary metabolites, hormone signaling, and transcription factors, providing potential candidate genes that could be guided to enhance the fruit development of R. roxburghii in practical approaches.

Highly efficient Agrobacterium rhizogenes-mediated transformation for functional analysis in woodland strawberry.

BACKGROUND: The diploid woodland strawberry (Fragaria vesca) is an excellent model plant for investigating economically significant traits and several genetic resources within the Rosaceae family. Agrobacterium rhizogenes-mediated hairy root transformation is an alternative for exploring gene functions, especially the genes specifically expressed in roots. However, the hairy root transformation has not been established in strawberry. RESULTS: Here, we described an efficient and rapid hairy root transgenic system for strawberry using A. rhizogenes. Strain of A. rhizogenes MSU440 or C58C1 was the most suitable for hairy root transformation. The transformation efficiency was highest when tissues contained hypocotyls as explants. The optimal procedure involves A. rhizogenes at an optical density (OD600) of 0.7 for 10 min and co-cultivation duration for four days, achieving a transgenic efficiency of up to 71.43%. An auxin responsive promoter DR5ver2 carrying an enhanced green fluorescent protein (eGFP) marker was transformed by A. rhizogenes MSU440, thereby generating transgenic hairy roots capable of high eGFP expression in root tip and meristem of strawberry where auxin accumulated. Finally, this system was applied for functional analysis using jGCaMP7c, which could sense calcium signals. A significant upsurge in eGFP expression in the transgenic hairy roots was displayed after adding calcium chloride. The results suggested that this approach was feasible for studying specific promoters and could be a tool to analyze gene functions in the roots of strawberries. CONCLUSION: We established a rapid and efficient hairy root transformation in strawberry by optimizing parameters, which was adequate for promoter analysis and functional characterization of candidate genes in strawberry and other rosaceous plants.

Genome-wide identification and expression analyses of the pectate lyase (PL) gene family in Fragaria vesca.

BACKGROUND: Pectate lyase (PL, EC 4.2.2.2), as an endo-acting depolymerizing enzyme, cleaves α-1,4-glycosidic linkages in esterified pectin and involves a broad range of cell wall modifications. However, the knowledge concerning the genome-wide analysis of the PL gene family in Fragaria vesca has not been thoroughly elucidated. RESULTS: In this study, sixteen PLs members in F. vesca were identified based on a genome-wide investigation. Substantial divergences existed among FvePLs in gene duplication, cis-acting elements, and tissue expression patterns. Four clusters were classified according to phylogenetic analysis. FvePL6, 8 and 13 in cluster II significantly contributed to the significant expansions during evolution by comparing orthologous PL genes from Malus domestica, Solanum lycopersicum, Arabidopsis thaliana, and Fragaria×ananassa. The cis-acting elements implicated in the abscisic acid signaling pathway were abundant in the regions of FvePLs promoters. The RNA-seq data and in situ hybridization revealed that FvePL1, 4, and 7 exhibited maximum expression in fruits at twenty days after pollination, whereas FvePL8 and FvePL13 were preferentially and prominently expressed in mature anthers and pollens. Additionally, the co-expression networks displayed that FvePLs had tight correlations with transcription factors and genes implicated in plant development, abiotic/biotic stresses, ions/Ca2+, and hormones, suggesting the potential roles of FvePLs during strawberry development. Besides, histological observations suggested that FvePL1, 4 and 7 enhanced cell division and expansion of the cortex, thus negatively influencing fruit firmness. Finally, FvePL1-RNAi reduced leaf size, altered petal architectures, disrupted normal pollen development, and rendered partial male sterility. CONCLUSION: These results provide valuable information for characterizing the evolution, expansion, expression patterns and functional analysis, which help to understand the molecular mechanisms of the FvePLs in the development of strawberries.

A comprehensive view of metabolic responses to CYP98 perturbation in ancestral plants.

Cytochrome P450 monooxygenase 98 (CYP98) is a critical rate-limiting enzyme of the phenylpropanoid pathway. One of the end-product of the phenylpropanoid pathway is a lignin monomer, although the occurrence of lignin in bryophytes is controversial. Here we investigated the functions of PpCYP98 in Physcomitrium patens by transcriptome and metabolome analyses. We identified 5266 differentially expressed genes (DEGs) and 68 differentially abundant secondary metabolites between wild-type and ΔPpCYP98 gametophores. Of the identified metabolites, 23 phenolic acids were identified, with only one showing upregulation. Among the phenolic acids, 4-coumaroyl tartaric acid and chlorogenic acid showed significant decreases. Declines were also observed in coniferylaldehyde and coniferin, precursor substances and downstream products of the lignin monomer coniferyl alcohol, respectively. Thus, the pre-lignin synthesis pathway already exists in bryophytes, and PpCYP98 plays vital roles in this pathway. Besides, most flavonoids show significant reductions, including eriodyctiol, dihydroquecetin, and dihydromyricetin, whereas naringenin chalone and dihydrokaempferol were increased after PpCYP98 knockout. Therefore, the synthesis of flavonoids shares the core pathway with phenylpropanoids and mainly starts from caffeoyl-CoA, that is the compound of divergence between the two pathways in moss. PpCYP98 showed systemic effects on metabolisms, including carbohydrate, fatty acid, and hormonal signaling transductions, suggesting that PpCYP98 might indirectly regulate carbon influx allocation. Our results demonstrated roles of PpCYP98 were essential for the development of the early landing plant.

Identification and co-expression network analysis of plumule-preferentially expressed genes in Oryza sativa.

BACKGROUND: The seedling establishment is controlled by the programmed expression of sets of genes at the specific tissues of seed, abundance and environment. Plumule is an important part of the seed embryo and expresses the suits of genes to exert distinct functions during seed germination. Although rice genomic resources are available and developed rapidly, thousands of transcripts have not previously been located in the plumule of rice. OBJECTIVE: This study was performed to identify plumule-preferentially expressed (OsPluP) genes in rice and determine the expression profiles and functions of OsPluP genes. METHODS: We identified the OsPluP genes through Affymetrix microarray data. Meanwhile, qRT-PCR was performed to validate the expression pattern, also found that OsPluP genes were regulated by dark/light treatment. The cis-acting regulatory elements were analyzed in the promoters' regions of OsPluP genes. The T-DNA mutant of the OsPluP seed was used to reveal the function in seed germination. RESULTS: In this study, a genomic survey of OsPluP genes was performed, and we identified 88 OsPluP genes based on Affymetrix microarray data. The expression profiles of 88 OsPluP members in 24 representative tissues covering rice whole life cycle can be roughly classified into three major groups, suggesting functional divergence of OsPluP genes in seed germination. The microarray data, qRT-PCR, and promoter analysis results demonstrated that transcripts of more than half OsPluPs (54 genes) could be enhanced in the darkness and respond to phytohormone. Gene Ontology (GO)and Kyoto encyclopedia of genes and genomes (KEGG) analysis demonstrated that OsPluP and their co-expressed genes were highly enriched in fatty acid metabolism. Moreover, OsPluP82 T-DNA mutant seeds displayed short plumule length and storage lipid accumulation. CONCLUSION: This study would enable the functions of OsPluP genes during seed germination and contribute to the goal of molecular regulatory networks that lay the foundation for further studies of seedling growth.

Physcomitrium patens CAD1 has distinct roles in growth and resistance to biotic stress.

BACKGROUND: Physcomitrium patens provides an evolutionary link between green algae and vascular plants. Although the genome of P. patens includes orthologs of all the core lignin biosynthetic enzymes, the occurrence of lignin in moss is very controversial. Besides, little information is available about the lignin enzymes in moss to date. For example, cinnamyl alcohol dehydrogenase (CAD) is a crucial enzyme that catalyzes the last step of the lignin biosynthetic pathway, suggesting an ideal way to study the evolutionary process. By investigating the functions of CAD in evolution, this study will elucidate the evolutionary roles of lignin-like in the early stage of land colonization. RESULTS: CAD multigene family in P. patens is composed of four genes. The PpCADs contain a conserved glycine-rich domain to catalyze NADPH-dependent reduction to their corresponding alcohols, indicating that PpCADs have the potential to synthesize monolignols by bioinformatics analysis. Even though PpCAD1 could produce lignin in theory, no conventional monomer was detected in the cell wall or cytoplasm of PpCAD1_OE plants. However, the phenylpropanoids were promoted in PpCAD1_OE transformants to modify gametophore architecture and development, making the distribution of phyllids more scarcity and the moss colony more giant, possibly due to the enhanced expression of the AUX-IAA family. The transcripts of at least one gene encoding the enzyme in the lignin biosynthetic pathway were increased in PpCAD1_OE plants. In addition, the PpCAD1_OE gametophore inhibited the Botrytis cinerea assault mainly by enhanced phenylpropanoids in the cell wall instead of influencing transcripts of defense genes pathogenesis-related 10 (PR10) and nonexpresser of PR genes 1 (NPR1). Likewise, ectopic expression of PpCAD1 in Arabidopsis led to a significant increase in lignin content, exhibiting chunky roots, robust seedlings, advanced flowering, and efficient resistance against pathogens. CONCLUSION: PpCAD occurs in more than one copy, suggesting functional divergence in the ancestral plant. PpCAD1 catalyzes monolignol biosynthesis and has homologous functions with vascular plants. Despite no detected conventional monolignol, the increased phenylpropanoids in the PpCAD1_OE gametophore, possibly intermediate metabolites in the lignin pathway, had conserved functions during the evolution of terrestrial plants. The results inferred that the lignin enzyme of the early non-vascular plant played roles in stem elongation and resistance against pathogens of P. patens during the conquest of land.

RrTTG1 promotes fruit prickle development through an MBW complex in Rosa roxburghii.

Fruit prickles are widely distributed on the pericarp and exhibit polymorphic traits at different developmental stages. Although they are multicellular appendages that are well-known for helping plants defend against biotic and abiotic stresses, their origination and molecular mechanism are still less known. Here, we studied the origination and molecular mechanism of fruit prickles in Rosa roxburghii. Using morphological and histological observations, we found that the fruit prickle primordium of R. roxburghii originated from the ground meristem that underwent cell division to form flagelliform prickles, continued to enlarge, and finally lignified to form mature fruit prickles. We amplified a homolog of candidate gene TRANSPARENT TESTA GLABRA1 (TTG1) from R. roxburghii, named RrTTG1. RrTTG1 harbored four conserved WD-repeat domains and was exclusively nuclear-localized. Using qRT-PCR and in situ hybridization, we found that RrTTG1 was constitutively expressed and highly expressed during the initiation and cell expansion phases of fruit prickles. Ectopic expression analysis in Arabidopsis proved that RrTTG1 substantially enhanced the number of trichome and pigmentation production and inhibited root hair formation. Besides, RrTTG1 complemented the phenotypes of the ttg1 mutant in Arabidopsis, thus indicating that RrTTG1 played pleiotropic roles akin to AtTTG1. We demonstrated that the RrTTG1 only interacted with RrEGL3, a homolog of ENHANCER OF GLABRA3 (EGL3), via yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays. Briefly, RrTTG1 might positively regulate the initiation of fruit prickle primordium and cell enlargement by forming the RrTTG1-RrEGL3-RrGL1 complex in R. roxburghii. Therefore, our results help characterize the RrTTG1 in R. roxburghii and also elucidate the establishment of the prickles regulatory system in the Rosaceae plants.

Phylogenetic relationships and characterization of the complete chloroplast genome of Rosa sterilis.

Rosa sterilis is an economically and important fruit that is extensively grown in Southwestern China. In this study, we determined the complete chloroplast genome of R. sterilis using high-throughput Illumina sequencing. The chloroplast genome of R. sterilis is 156,561 bp in size, containing a large single-copy region (LSC)(85,701 bp), a small single-copy region (SSC) (18,746 bp), and a pair of inverted repeat (IR) regions (each one of 26,057 bp). The overall GC content of the chloroplast genome is 37.23%, while the corresponding values of GC contents of the LSC, SSC, and IR regions are 35.20%, 31.37%, and 42.70%, respectively. The chloroplast genome of R. sterilis contains 130 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The phylogenetic maximum-likelihood tree revealed that Rosa chinensis or Rosa chinensis var. spontanea is the closest related to R. sterilis in the phylogenetic relationship. This complete chloroplast genome can be further used for genomic studies, evolutionary analyses, and genetic engineering studies of the family Rosaceae.

Genome-wide analysis of LATERAL ORGAN BOUNDARIES DOMAIN-in Physcomitrella patens and stress responses.

BACKGROUND: LBDs, as the plant-specific gene family, play essential roles in lateral organ development, plant regeneration, as well as abiotic stress and pathogen response. However, the number and characteristic of LBD genes in Pyscomitrella patens were still obscure. OBJECTIVE: This study was performed to identify the LBD family gene in moss and to determine the expression profiles of LBDs under the abiotic and pathogen stress. METHODS: Complete genome sequences and transcriptomes of P. patens were downloaded from the Ensembl plant database. The hidden Markov model-based profile of the conserved LOB domain was submitted as a query to identify all potential LOB domain sequences with HMMER software. Expression profiles of PpLBDs were obtained based on the GEO public database and qRT-PCR analysis. RESULTS: In this study, a total of 31 LBDs were identified in the P. patens genome, divided into two classes based on the presence of the leucine zipper-like coiled-coil motif. A phylogenetic relationship was obtained between 31 proteins from P. patens and 43 proteins from the Arabidopsis thaliana genome, providing insights into their conserved and potential functions. Furthermore, the exon-intron organization of each PpLBD were analyzed. All PpLBD contain the conserved DNA binding motif (CX2CX6CX3C zinc finger-like motif), and were predicted to be located in cell nuclear. The 31 PpLBD genes were unevenly assigned to 18 out of 27 chromosomes based on the physical positions. Among these genes, PpLBD27 was not only remarkably highest expressed in desiccation, but also a susceptible gene to pathogens through jasmonic acid-mediated signaling pathway. Most of PpLBDs were up-regulated with the treatment of mannitol. These results showed they were differentially induced and their potential functions in the environmental stimulus of the early terrestrial colonizers. CONCLUSION: Despite significant differences in the life cycle in P. patens and flowering plants, their functions involved in abiotic and biotic stress-regulated by LBDs have been identified and appear to be conserved in the two lineages. These results provided a comprehensive analysis of PpLBDs and paved insights into studies aimed at a better understanding of PpLBDs.

Characterization of the Rosa roxburghii Tratt transcriptome and analysis of MYB genes.

Rosa roxburghii Tratt (Rosaceae) has a fruit that is flavorful, economically valuable, and highly nutritious, providing numerous health benefits. Myeloblastosis (MYB) proteins play key roles in the development and fruit quality of R. roxburghii. However, there is little available genomic and transcriptomic information for R. roxburghii. Here, a normalized cDNA library was constructed from five tissues, including the stem, leaf, flower, young fruit, and mature fruit, using the Illumina HiSeq 3000 platform. De novo assembly was performed, and 470.66 million clean reads were obtained. In total, 63,727 unigenes, with an average GC content of 42.08%, were discovered, 60,406 of which were annotated. In addition, 9,354 unigenes were assigned to Gene Ontology categories, and 20,202 unigenes were assigned to 25 Eukaryotic Ortholog Groups. Additionally, 19,508 unigenes were classified into 140 pathways of the Kyoto Encyclopedia of Genes and Genomes database. Based on the transcriptome, 163 unigenes associated with MYBs were detected. Among these genes, 75 genes were significantly expressed in the various tissues, including 10 R1 MYB, 42 R2R3 MYB, one R1R2R3 MYB, three R4 MYB and 19 atypical MYB-like proteins. The expression levels of the 12 MYB genes randomly selected for quantitative real-time PCR analysis corroborated the RNA sequencing results. A total of 37,545 microsatellites were detected, with an average expressed sequence tag-simple sequence repeat frequency of 0.59 (37,545/63,727). This transcriptome data improves our understanding of the role of MYB in R. roxburghii and will be valuable for identifying genes of interest.

GLABROUS1 from Rosa roxburghii Tratt regulates trichome formation by interacting with the GL3/EGL3 protein.

GLABROUS1 is an R2R3 MYB homolog that is essential for the initiation of trichome development. In this study, we used RACE to clone a full-length cDNA from Rosa roxburghii Tratt, termed RrGL1, which was 1013 bp, including an open reading frame of 792 bp that encoded 263 amino acids. In situ hybridization, corresponding with qRT-PCR results, revealed that RrGL1 transcripts were mainly expressed in petiole, leaf, and stem. RrGL1 expression levels at various fruit developmental stages in R. roxburghii were also evaluated. RrGL1 was highly expressed in young fruit, and the expression level decreased with fruit maturation. The overexpression of RrGL1 was able to functionally complemented the Arabidopsis thaliana gl1-/- mutant in trichome formation. RrGL1 was located in the cell nucleus with analysis of subcellular localization and physically interacted with A. thaliana GL3/EGL3 in the yeast two-hybrid assay, implying that RrGL1 might exert functions by forming a MYB-basic helix-loop-helix complex in trichome initiation. The formation of prickles in R. roxburghii is similar to that of Arabidopsis trichome. These results provided a foundation for further research on the molecular mechanisms underlying the formation and development of prickles that could assist and cultivate in the genetic engineering of prickle-free fruits.

The Salvia miltiorrhiza NAC transcription factor SmNAC1 enhances zinc content in transgenic Arabidopsis.

NAC transcription factors play important roles in plant biological processes, including plant development, environmental stress responses and element enrichment. A novel NAC transcription factor gene, designated SmNAC1, was isolated from Salvia miltiorrhiza. SmNAC1 was localized in the nucleus in onion protoplasts and exhibited transcriptional activation activities in yeast. In addition, the SmNAC1 protein could specifically bind to the cis-elements of the NAC proteins. SmNAC1 was expressed at a higher level in the leaves of S. miltiorrhiza, indicating that SmNAC1 might be involved in the transportation of zinc. To examine the function of SmNAC1, transgenic Arabidopsis plants overexpressing SmNAC1 were generated. Zinc content assays in the transgenic plants demonstrated that overexpressed SmNAC1 plants had enhanced tolerance to high zinc concentrations, and zinc was enriched in the shoot tissues. Our results demonstrate that SmNAC1 plays important roles in the response to zinc stress. Zinc was mainly enriched in the leaves of S. miltiorrhiza and the shoot tissues of transgenic Arabidopsis plants. SmNAC1 might participate in zinc transportation from the roots to the shoots, that constitutes a useful gene for improving zinc content in plants.

Erratum: Pro-inflammatory effects of a litchi protein extract in murine RAW264.7 macrophages.

[This corrects the article DOI: 10.1038/hortres.2016.17.].

Pro-inflammatory effects of a litchi protein extract in murine RAW264.7 macrophages.

It has been observed that the consumption of litchi often causes symptoms characterized by itching or sore throat, gum swelling, oral cavity ulcers and even fever and inflammation, which significantly impair the quality of life of a large population. Using the RAW264.7 cell line, a step-by-step strategy was used to screen for the components in litchi fruits that elicited adverse reactions. The adverse reaction fractions were identified by mass spectrometry and analyzed using the SMART program, and a sequence alignment of the homologous proteins was performed. MTT tests were used to determine the cytotoxicity of a litchi protein extract in RAW264.7 macrophages, and real-time PCR was applied to analyze the expression of inflammatory genes in the RAW264.7 cells treated with lipopolysaccharide or the litchi protein extract. The results showed that the litchi water-soluble protein extract could increase the production of the pro-inflammatory mediators IL-1ß, iNOS and COX-2, and the anti-inflammatory mediator HO-1 in the RAW264.7 cell line. The 14-3-3-like proteins GF14 lambda, GF14 omega and GF14 upsilon were likely the candidate proteins that caused the adverse effects.

A novel macromolecular extract screened from satsuma with pro-inflammatory effect.

Excessive consumption of horticultural fruit is a double-edged sword with both positive and negative effects. In Eastern countries, a large number of people have suffered from shang huo as a result of excessive consumption of "heating" foods, such as lychee, longan, mandarin orange, mango and civet durian. The present study adopted a step by step strategy screened the compositions with pro-inflammatory effect in satsuma fruits. The pro-inflammatory effects of all fractions were evaluated in RAW 264.7 cell lines by enzyme-linked immunosorbent assay (ELISA) and RT-PCR tests. The soluble water extract (SWE) from satsuma increased the production of prostaglandin E2 (PGE2) and promoted the expression level of cyclooxygenase-2 (COX-2) mRNA. SWE and high molecular weight molecules extracted from soluble water extract (HSWE) were respectively fractionated by dialysis bags and gel filtration chromatography. The macromolecular fraction named F1 was further obtained from HSWE, and could increase the production of inflammatory mediators. Finally F1 was resolved by SDS-PAGE and six proteins were identified by mass spectrometry. Compared with other detected proteins, polygalacturonase inhibitor (PGIP) and chitinase were the most likely candidate pro-inflammatory proteins according to molecular mass, and both of them were Citrus unshiu species. cDNA sequences of PGIP and chitinase were cloned and their functions were predicted as defensive proteins by SMART analysis. Excessive intake of these defensive proteins may result in adverse food reactions in human beings, such as shang huo and other immune responses.

Anti-inflammatory effect of auraptene extracted from trifoliate orange (Poncirus trifoliate) on LPS-stimulated RAW 264.7 cells.

Poncirus trifoliate is a traditional Chinese medicinal plant used for treating inflammation-related diseases for a long time and trifoliate orange contains abundant auraptene. The present study was to evaluate auraptene as a potential anti-inflammatory agent and investigate the mechanism of auraptene against prostaglandins E2 (PGE2) and cyclooxygenase-2 (COX-2) on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells by comparing it with aspirin as a positive control group. The methods of enzyme-linked immunosorbent assay, reverse transcriptive polymerase chain reaction, real-time PCR, and western-blotting were used in the study. The results showed that auraptene exhibited better biocompatibility and lower cytotoxicity. At the same time, it significantly inhibited the production of PGE2 on LPS-stimulated macrophage cells. The auraptene-treated group had a higher COX-2 mRNA expression but relatively lower COX-2 protein level which implied that auraptene suppressed the post-transcriptional expression of COX-2 protein but not the transcriptional process. Compared with aspirin, the lower cytotoxicity of auraptene can make it a potential source for medicine that can benefit patients who are suffering from chronic inflammatory diseases and need long-term medication.

Digital gene expression analysis of corky split vein caused by boron deficiency in 'Newhall' Navel Orange (Citrus sinensis Osbeck) for selecting differentially expressed genes related to vascular hypertrophy.

Corky split vein caused by boron (B) deficiency in 'Newhall' Navel Orange was studied in the present research. The boron-deficient citrus exhibited a symptom of corky split vein in mature leaves. Morphologic and anatomical surveys at four representative phases of corky split veins showed that the symptom was the result of vascular hypertrophy. Digital gene expression (DGE) analysis was performed based on the Illumina HiSeq™ 2000 platform, which was applied to analyze the gene expression profilings of corky split veins at four morphologic phases. Over 5.3 million clean reads per library were successfully mapped to the reference database and more than 22897 mapped genes per library were simultaneously obtained. Analysis of the differentially expressed genes (DEGs) revealed that the expressions of genes associated with cytokinin signal transduction, cell division, vascular development, lignin biosynthesis and photosynthesis in corky split veins were all affected. The expressions of WOL and ARR12 involved in the cytokinin signal transduction pathway were up-regulated at 1(st) phase of corky split vein development. Furthermore, the expressions of some cell cycle genes, CYCs and CDKB, and vascular development genes, WOX4 and VND7, were up-regulated at the following 2(nd) and 3(rd) phases. These findings indicated that the cytokinin signal transduction pathway may play a role in initiating symptom observed in our study.