Response surface methodology mediated optimization of phytosulfokine and plant growth regulators for enhanced protoplast division, callus induction, and somatic embryogenesis in Angelica Gigas Nakai.

BACKGROUND: Angelica Gigas (Purple parsnip) is an important medicinal plant that is cultivated and utilized in Korea, Japan, and China. It contains bioactive substances especially coumarins with anti-inflammatory, anti-platelet aggregation, anti-cancer, anti-diabetic, antimicrobial, anti-obesity, anti-oxidant, immunomodulatory, and neuroprotective properties. This medicinal crop can be genetically improved, and the metabolites can be obtained by embryonic stem cells. In this context, we established the protoplast-to-plant regeneration methodology in Angelica gigas. RESULTS: In the present investigation, we isolated the protoplast from the embryogenic callus by applying methods that we have developed earlier and established protoplast cultures using Murashige and Skoog (MS) liquid medium and by embedding the protoplast in thin alginate layer (TAL) methods. We supplemented the culture medium with growth regulators namely 2,4-dichlorophenoxyaceticacid (2,4-D, 0, 0.75, 1.5 mg L- 1), kinetin (KN, 0, 0.5, and 1.0 mg L- 1) and phytosulfokine (PSK, 0, 50, 100 nM) to induce protoplast division, microcolony formation, and embryogenic callus regeneration. We applied central composite design (CCD) and response surface methodology (RSM) for the optimization of 2,4-D, KN, and PSK levels during protoplast division, micro-callus formation, and induction of embryogenic callus stages. The results revealed that 0.04 mg L- 1 2,4-D + 0.5 mg L- 1 KN + 2 nM PSK, 0.5 mg L- 1 2,4-D + 0.9 mg L- 1 KN and 90 nM PSK, and 1.5 mg L- 1 2,4-D and 1 mg L- 1 KN were optimum for protoplast division, micro-callus formation and induction embryogenic callus. MS basal semi-solid medium without growth regulators was good for the development of embryos and plant regeneration. CONCLUSIONS: This study demonstrated successful protoplast culture, protoplast division, micro-callus formation, induction embryogenic callus, somatic embryogenesis, and plant regeneration in A. gigas. The methodologies developed here are quite useful for the genetic improvement of this important medicinal plant.

Exploring the Seasonal Dynamics and Molecular Mechanism of Wood Formation in Gymnosperm Trees.

Forests, comprising 31% of the Earth's surface, play pivotal roles in regulating the carbon, water, and energy cycles. Despite being far less diverse than angiosperms, gymnosperms account for over 50% of the global woody biomass production. To sustain growth and development, gymnosperms have evolved the capacity to sense and respond to cyclical environmental signals, such as changes in photoperiod and seasonal temperature, which initiate growth (spring and summer) and dormancy (fall and winter). Cambium, the lateral meristem responsible for wood formation, is reactivated through a complex interplay among hormonal, genetic, and epigenetic factors. Temperature signals perceived in early spring induce the synthesis of several phytohormones, including auxins, cytokinins, and gibberellins, which in turn reactivate cambium cells. Additionally, microRNA-mediated genetic and epigenetic pathways modulate cambial function. As a result, the cambium becomes active during the summer, resulting in active secondary xylem (i.e., wood) production, and starts to become inactive in autumn. This review summarizes and discusses recent findings regarding the climatic, hormonal, genetic, and epigenetic regulation of wood formation in gymnosperm trees (i.e., conifers) in response to seasonal changes.

Efficient knockout of the phytoene desaturase gene in a hybrid poplar (Populus alba × Populus glandulosa) using the CRISPR/Cas9 system with a single gRNA.

The CRISPR/Cas9 system has been used for genome editing in several plant species; however, there are few reports on its use in trees. Here, CRISPR/Cas9 was used to mutate a target gene in Populus alba × Populus glandulosa hybrid poplars. The hybrid poplar is routinely used in molecular biological studies due to the well-established Agrobacterium-mediated transformation method. A single guide RNA (sgRNA) with reported high mutation efficiency in other popular species was designed with a protospacer adjacent motif sequence for the phytoene desaturase 1 (PagPDS1) gene. The pHSE/Cas9-PagPDS1 sgRNA vector was delivered into hybrid poplar cells using Agrobacterium-mediated transformation. The transgenic plants were propagated and classified them into three groups according to their phenotypes. Among a total of 110 lines of transgenic hybrid poplars, 82 lines showed either an albino or a pale green phenotype, indicating around 74.5% phenotypic mutation efficiency of the PagPDS1 gene. The albino phenotypes were observed when the CRISPR/Cas9-mediated mutations in both PagPDS1 alleles in the transgenic plants. There was no off-target modification of the PagPDS2 gene, which has a potential sgRNA target sequence with two mismatches. The results confirmed that the sgRNA can specifically edit PagPDS1 rather than PagPDS2, indicating that CRISPR/Cas9-mediated genome editing can effectively induce target mutations in the hybrid poplar. This technique will be useful to improve tree quality in hybrid poplars (P. alba × P. glandulosa); for example, by enhancing biomass or stress tolerance.

Human Milk Oligosaccharide 2'-Fucosyllactose Induces Neuroprotection from Intracerebral Hemorrhage Stroke.

Intracerebral hemorrhage (ICH) occurs when brain blood vessels rupture, causing inflammation and cell death. 2-Fucosyllactose (2FL), a human milk oligosaccharide, has potent antiapoptotic and anti-inflammatory effects. The purpose of this study was to examine the protective effect of 2FL in cellular and rodent models of ICH. Hemin was added to a primary rat cortical neuronal and BV2 microglia coculture to simulate ICH in vitro. IBA1 and MAP2 immunoreactivities were used to determine inflammation and neuronal survival. Hemin significantly increased IBA1, while it reduced MAP2 immunoreactivity. 2FL significantly antagonized both responses. The protective effect of 2FL was next examined in a rat ICH model. Intracerebral administration of type VII collagenase reduced open-field locomotor activity. Early post-treatment with 2FL significantly improved locomotor activity. Brain tissues were collected for immunohistochemistry and qRT-PCR analysis. 2FL reduced IBA1 and CD4 immunoreactivity in the lesioned striatum. 2FL downregulated the expression of ER stress markers (PERK and CHOP), while it upregulated M2 macrophage markers (CD206 and TGFß) in the lesioned brain. Taken together, our data support that 2FL has a neuroprotective effect against ICH through the inhibition of neuroinflammation and ER stress. 2FL may have clinical implications for the treatment of ICH.

CRISPR-Knockout of CSE Gene Improves Saccharification Efficiency by Reducing Lignin Content in Hybrid Poplar.

Caffeoyl shikimate esterase (CSE) has been shown to play an important role in lignin biosynthesis in plants and is, therefore, a promising target for generating improved lignocellulosic biomass crops for sustainable biofuel production. Populus spp. has two CSE genes (CSE1 and CSE2) and, thus, the hybrid poplar (Populus alba × P. glandulosa) investigated in this study has four CSE genes. Here, we present transgenic hybrid poplars with knockouts of each CSE gene achieved by CRISPR/Cas9. To knockout the CSE genes of the hybrid poplar, we designed three single guide RNAs (sg1-sg3), and produced three different transgenic poplars with either CSE1 (CSE1-sg2), CSE2 (CSE2-sg3), or both genes (CSE1/2-sg1) mutated. CSE1-sg2 and CSE2-sg3 poplars showed up to 29.1% reduction in lignin deposition with irregularly shaped xylem vessels. However, CSE1-sg2 and CSE2-sg3 poplars were morphologically indistinguishable from WT and showed no significant differences in growth in a long-term living modified organism (LMO) field-test covering four seasons. Gene expression analysis revealed that many lignin biosynthetic genes were downregulated in CSE1-sg2 and CSE2-sg3 poplars. Indeed, the CSE1-sg2 and CSE2-sg3 poplars had up to 25% higher saccharification efficiency than the WT control. Our results demonstrate that precise editing of CSE by CRISPR/Cas9 technology can improve lignocellulosic biomass without a growth penalty.

Overexpression of a Poplar RING-H2 Zinc Finger, Ptxerico, Confers Enhanced Drought Tolerance via Reduced Water Loss and Ion Leakage in Populus.

Drought stress is one of the major environmental problems in the growth of crops and woody perennials, but it is getting worse due to the global climate crisis. XERICO, a RING (Really Interesting New Gene) zinc-finger E3 ubiquitin ligase, has been shown to be a positive regulator of drought tolerance in plants through the control of abscisic acid (ABA) homeostasis. We characterized a poplar (Populus trichocarpa) RING protein family and identified the closest homolog of XERICO called PtXERICO. Expression of PtXERICO is induced by both salt and drought stress, and by ABA treatment in poplars. Overexpression of PtXERICO in Arabidopsis confers salt and ABA hypersensitivity in young seedlings, and enhances drought tolerance by decreasing transpirational water loss. Consistently, transgenic hybrid poplars overexpressing PtXERICO demonstrate enhanced drought tolerance with reduced transpirational water loss and ion leakage. Subsequent upregulation of genes involved in the ABA homeostasis and drought response was confirmed in both transgenic Arabidopsis and poplars. Taken together, our results suggest that PtXERICO will serve as a focal point to improve drought tolerance of woody perennials.

DPP-4 inhibitors sitagliptin and PF-00734,200 mitigate dopaminergic neurodegeneration, neuroinflammation and behavioral impairment in the rat 6-OHDA model of Parkinson's disease.

Epidemiological studies report an elevated risk of Parkinson's disease (PD) in patients with type 2 diabetes mellitus (T2DM) that is mitigated in those prescribed dipeptidyl peptidase 4 (DPP-4) inhibitors. With an objective to characterize clinically translatable doses of DPP-4 inhibitors (gliptins) in a well-characterized PD rodent model, sitagliptin, PF-00734,200 or vehicle were orally administered to rats initiated either 7-days before or 7-days after unilateral medial forebrain bundle 6-hydroxydopamine (6-OHDA) lesioning. Measures of dopaminergic cell viability, dopamine content, neuroinflammation and neurogenesis were evaluated thereafter in ipsi- and contralateral brain. Plasma and brain incretin and DPP-4 activity levels were quantified. Furthermore, brain incretin receptor levels were age-dependently evaluated in rodents, in 6-OHDA challenged animals and human subjects with/without PD. Cellular studies evaluated neurotrophic/neuroprotective actions of combined incretin administration. Pre-treatment with oral sitagliptin or PF-00734,200 reduced methamphetamine (meth)-induced rotation post-lesioning and dopaminergic degeneration in lesioned substantia nigra pars compacta (SNc) and striatum. Direct intracerebroventricular gliptin administration lacked neuroprotective actions, indicating that systemic incretin-mediated mechanisms underpin gliptin-induced favorable brain effects. Post-treatment with a threefold higher oral gliptin dose, likewise, mitigated meth-induced rotation, dopaminergic neurodegeneration and neuroinflammation, and augmented neurogenesis. These gliptin-induced actions associated with 70-80% plasma and 20-30% brain DPP-4 inhibition, and elevated plasma and brain incretin levels. Brain incretin receptor protein levels were age-dependently maintained in rodents, preserved in rats challenged with 6-OHDA, and in humans with PD. Combined GLP-1 and GIP receptor activation in neuronal cultures resulted in neurotrophic/neuroprotective actions superior to single agonists alone. In conclusion, these studies support further evaluation of the repurposing of clinically approved gliptins as a treatment strategy for PD.

Sitagliptin elevates plasma and CSF incretin levels following oral administration to nonhuman primates: relevance for neurodegenerative disorders.

The endogenous incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) possess neurotrophic, neuroprotective, and anti-neuroinflammatory actions. The dipeptidyl peptidase 4 (DPP-4) inhibitor sitagliptin reduces degradation of endogenous GLP-1 and GIP, and, thereby, extends the circulation of these protective peptides. The current nonhuman primate (NHP) study evaluates whether human translational sitagliptin doses can elevate systemic and central nervous system (CNS) levels of GLP-1/GIP in naive, non-lesioned NHPs, in line with our prior rodent studies that demonstrated sitagliptin efficacy in preclinical models of Parkinson's disease (PD). PD is an age-associated neurodegenerative disorder whose current treatment is inadequate. Repositioning of the well-tolerated and efficacious diabetes drug sitagliptin provides a rapid approach to add to the therapeutic armamentarium for PD. The pharmacokinetics and pharmacodynamics of 3 oral sitagliptin doses (5, 20, and 100 mg/kg), equivalent to the routine clinical dose, a tolerated higher clinical dose and a maximal dose in monkey, were evaluated. Peak plasma sitagliptin levels were aligned both with prior reports in humans administered equivalent doses and with those in rodents demonstrating reduction of PD associated neurodegeneration. Although CNS uptake of sitagliptin was low (cerebrospinal fluid (CSF)/plasma ratio 0.01), both plasma and CSF concentrations of GLP-1/GIP were elevated in line with efficacy in prior rodent PD studies. Additional cellular studies evaluating human SH-SY5Y and primary rat ventral mesencephalic cultures challenged with 6-hydroxydopamine, established cellular models of PD, demonstrated that joint treatment with GLP-1 + GIP mitigated cell death, particularly when combined with DPP-4 inhibition to maintain incretin levels. In conclusion, this study provides a supportive translational step towards the clinical evaluation of sitagliptin in PD and other neurodegenerative disorders for which aging, similarly, is the greatest risk factor.

The role of α-defensin-1 and related signal transduction mechanisms in the production of IL-6, IL-8 and MMPs in rheumatoid fibroblast-like synoviocytes.

OBJECTIVES: To investigate the effect of α-defensin-1 on the expression of IL-6, IL-8 and MMPs as well as the signal transduction mechanisms responsible for their expression in RA fibroblast-like synoviocytes (FLS). METHODS: The concentrations of α-defensin-1 in SF were measured by ELISA. In RA FLS, mRNA expression of IL-6, IL-8 and MMPs and activation of signalling molecules were examined by real-time PCR, western blotting and electrophoretic mobility shift assay. RESULTS: Concentrations of SF α-defensin-1 were significantly increased in RA patients compared with OA patients. The levels of mRNA expression of IL-6, IL-8, MMP-1 and MMP-3 were significantly increased in RA FLS treated with α-defensin-1 compared with controls. Furthermore, α-defensin-1 activated JNK and ERK in RA FLS, respectively. Treatment of RA FLS with ERK or JNK inhibitors prior to α-defensin-1 treatment resulted in reduced expression of IL-6, IL-8, MMP-1, and MMP-3 compared with controls. Remarkably, treatment of RA FLS with an ERK inhibitor prior to α-defensin-1 stimulation significantly reduced production of IL-6 and MMP-1 by approximately 71% and 98% compared with controls, respectively. The JNK inhibitor significantly suppressed α-defensin-1-induced MMP-1 production by approximately 73% compared with controls. Finally, there was a significant induction of NF-κB DNA binding activity in response to α-defensin-1. CONCLUSION: Our results suggest that α-defensin-1 may play a role in RA pathogenesis by regulating the production of MMPs as well as IL-6 and IL-8. These processes were dependent on the regulation of the JNK and/or ERK and NF-κB pathways.

CIP2A facilitates apoptotic resistance of fibroblast-like synoviocytes in rheumatoid arthritis independent of c-Myc expression.

The aim of this study is to investigate the effects of CIP2A (Cancerous inhibitor of protein phosphatase 2A) on the apoptosis of RA FLS. Proliferation and apoptotic activity of RA FLS following treatment with CIP2A siRNA or control siRNA were analyzed using MTT assays and Cell Death Detection kit. RA FLS was treated with CIP2A siRNA or control siRNA in 3-, 6-, and 9-day intervals for a Western blot analysis to determine C-Myc expression. To evaluate the signal transduction pathways engaged in apoptosis, caspase-3 activity, caspase-9 activity, PARP, and phosphorylation of the Akt kinase were analyzed by Western blot. Cell viability of RA FLS was significantly lower in the CIP2A siRNA-treated group compared with the control after 7 days (p = 0.022). Apoptosis of RA FLS was significantly higher in the CIP2A siRNA-treated group compared with the control when incubated for 3, 6, and 9 days (p = 0.029, p = 0.021, p = 0.043, respectively). C-Myc expression did not change with the different incubation periods. CIP2A siRNA-treated FLS expressed higher level of activated caspase-3, caspase-9, and PARP (p = 0.014, p = 0.020, p = 0.021, respectively) and lower level of phosphorylated Akt (p = 0.001) compared with those treated with the control siRNA. Our data show that CIP2A expression in RA FLS is an important mediator of dysfunctional apoptosis independent of c-Myc stabilization. Expression of CIP2A may contribute to apoptotic resistance of RA FLS through the activation of Akt and deactivation of caspase-3, caspase-9, and PARP. Inhibition of CIP2A may therefore constitute a novel, promising therapeutic target in RA.

Neuronal Responses in the Globus Pallidus during Subthalamic Nucleus Electrical Stimulation in Normal and Parkinson's Disease Model Rats.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has been widely used as a treatment for the movement disturbances caused by Parkinson's disease (PD). Despite successful application of DBS, its mechanism of therapeutic effect is not clearly understood. Because PD results from the degeneration of dopamine neurons that affect the basal ganglia (BG) network, investigation of neuronal responses of BG neurons during STN DBS can provide informative insights for the understanding of the mechanism of therapeutic effect. However, it is difficult to observe neuronal activity during DBS because of large stimulation artifacts. Here, we report the observation of neuronal activities of the globus pallidus (GP) in normal and PD model rats during electrical stimulation of the STN. A custom artifact removal technique was devised to enable monitoring of neural activity during stimulation. We investigated how GP neurons responded to STN stimulation at various stimulation frequencies (10, 50, 90 and 130 Hz). It was observed that activities of GP neurons were modulated by stimulation frequency of the STN and significantly inhibited by high frequency stimulation above 50 Hz. These findings suggest that GP neuronal activity is effectively modulated by STN stimulation and strongly dependent on the frequency of stimulation.

Chromosome-level genome assembly of the Asian aspen Populus davidiana Dode.

The genome of Populus davidiana, a keystone aspen species, has been sequenced to improve our understanding of the evolutionary and functional genomics of the Populus genus. The Hi-C scaffolding genome assembly resulted in a 408.1 Mb genome with 19 pseudochromosomes. The BUSCO assessment revealed that 98.3% of the genome matched the embryophytes dataset. A total of 31,862 protein-coding sequences were predicted, of which 31,619 were functionally annotated. The assembled genome was composed of 44.9% transposable elements. These findings provide new knowledge about the characteristics of the P. davidiana genome and will facilitate comparative genomics and evolutionary research on the genus Populus.

Draft Genome Sequence for the Symbiotic Pine Mushroom Tricholoma matsutake.

We report the high-quality genome sequence of Tricholoma matsutake strain 2001, which was isolated from a mushroom fruiting body in South Korea. The genome has 80 contigs, a size of 162.6 Mb, and an N50 value of 5,103,859 bp and will provide insight into the symbiotic association between T. matsutake and Pinus densiflora.

Prosaposin PS18 reduces dopaminergic neurodegeneration in a 6-hydroxydopamine rat model of Parkinson's disease.

Saposin and its precursor prosaposin are endogenous proteins with neurotrophic and anti-apoptotic properties. Prosaposin or its analog prosaposin-derived 18-mer peptide (PS18) reduced neuronal damage in hippocampus and apoptosis in stroke brain. Its role in Parkinson's disease (PD) has not been well characterized. This study aimed to examine the physiological role of PS18 in 6-hydroxydopamine (6-OHDA) cellular and animal models of PD. We found that PS18 significantly antagonized 6-OHDA -mediated dopaminergic neuronal loss and TUNEL in rat primary dopaminergic neuronal culture. In SH-SY5Y cells overexpressing the secreted ER calcium-monitoring proteins, we found that PS18 significantly reduced thapsigargin and 6-OHDA-mediated ER stress. The expression of prosaposin and the protective effect of PS18 were next examined in hemiparkinsonian rats. 6-OHDA was unilaterally administered to striatum. The expression of prosaposin was transiently upregulated in striatum on D3 (day 3) after lesioning and returned below the basal level on D29. The 6-OHDA-lesioned rats developed bradykinesia and an increase in methamphetamine-mediated rotation, which was antagonized by PS18. Brain tissues were collected for Western blot, immunohistochemistry, and qRTPCR analysis. Tyrosine hydroxylase immunoreactivity was significantly reduced while the expressions of PERK, ATF6, CHOP, and BiP were upregulated in the lesioned nigra; these responses were significantly antagonized by PS18. Taken together, our data support that PS18 is neuroprotective in cellular and animal models of PD. The mechanisms of protection may involve anti-ER stress.

Herbal formula PM012 induces neuroprotection in stroke brain.

Stroke is a major cause of long-term disability world-wide. Limited pharmacological therapy has been used in stroke patients. Previous studies indicated that herb formula PM012 is neuroprotective against neurotoxin trimethyltin in rat brain, and improved learning and memory in animal models of Alzheimer's disease. Its action in stroke has not been reported. This study aims to determine PM012-mediated neural protection in cellular and animal models of stroke. Glutamate-mediated neuronal loss and apoptosis were examined in rat primary cortical neuronal cultures. Cultured cells were overexpressed with a Ca++ probe (gCaMP5) by AAV1 and were used to examine Ca++ influx (Ca++i). Adult rats received PM012 before transient middle cerebral artery occlusion (MCAo). Brain tissues were collected for infarction and qRTPCR analysis. In rat primary cortical neuronal cultures, PM012 significantly antagonized glutamate-mediated TUNEL and neuronal loss, as well as NMDA-mediated Ca++i. PM012 significantly reduced brain infarction and improved locomotor activity in stroke rats. PM012 attenuated the expression of IBA1, IL6, and CD86, while upregulated CD206 in the infarcted cortex. ATF6, Bip, CHOP, IRE1, and PERK were significantly down-regulated by PM012. Using HPLC, two potential bioactive molecules, paeoniflorin and 5-hydroxymethylfurfural, were identified in the PM012 extract. Taken together, our data suggest that PM012 is neuroprotective against stroke. The mechanisms of action involve inhibition of Ca++i, inflammation, and apoptosis.

CIP2A expression is associated with synovial hyperplasia and invasive function of fibroblast-like synoviocytes in rheumatoid arthritis.

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein that leads to cellular proliferation in cancer cells. We aim to investigate CIP2A expression in fibroblast-like synoviocytes (FLS) and its association with the histopathological grade of synovitis and the invasive function of FLS in rheumatoid arthritis (RA). CIP2A protein expression was measured in 8 RA FLS and 8 OA FLS using Western blot analysis. CIP2A mRNA expression from 19 RA FLS and 7 OA FLS was measured using real-time PCR. Synovitis score of RA FLS-matched synovial tissues was semiquantitatively measured by two independent pathologists. An in vitro cell invasion assay was performed using RA FLS treated with CIP2A small interfering RNA (siRNA) or with control vector. Western blot analysis showed that CIP2A is more frequently overexpressed in RA FLS compared with OA FLS. CIP2A mRNA expression was higher in RA FLS compared with those in OA FLS, but did not reach statistical significance (P = 0.076). In RA, total synovitis score was strongly correlated with FLS CIP2A mRNA expression (rs = 0.849, P = 0.043). TNF-α treatment induced a robust increase in the invasive function of control FLS (P = 0.0021), but no significant effect was observed in CIP2A siRNA-treated FLS. Our data demonstrate that CIP2A expression is closely associated with the histopathological score of synovitis and invasive function of FLS in RA. These results suggest that CIP2A may play a critical role in the destructive process in RA and warrant further investigation of CIP2A as a therapeutic target.

Current Understanding of the Genetics and Molecular Mechanisms Regulating Wood Formation in Plants.

Unlike herbaceous plants, woody plants undergo volumetric growth (a.k.a. secondary growth) through wood formation, during which the secondary xylem (i.e., wood) differentiates from the vascular cambium. Wood is the most abundant biomass on Earth and, by absorbing atmospheric carbon dioxide, functions as one of the largest carbon sinks. As a sustainable and eco-friendly energy source, lignocellulosic biomass can help address environmental pollution and the global climate crisis. Studies of Arabidopsis and poplar as model plants using various emerging research tools show that the formation and proliferation of the vascular cambium and the differentiation of xylem cells require the modulation of multiple signals, including plant hormones, transcription factors, and signaling peptides. In this review, we summarize the latest knowledge on the molecular mechanism of wood formation, one of the most important biological processes on Earth.

Knockdown of PagSAP11 Confers Drought Resistance and Promotes Lateral Shoot Growth in Hybrid Poplar (Populus alba × Populus tremula var. glandulosa).

Plants have evolved defense mechanisms to overcome unfavorable climatic conditions. The growth and development of plants are regulated in response to environmental stress. In this study, we investigated the molecular and physiological characteristics of a novel gene PagSAP11 in hybrid poplar (Populus alba × Populus tremula var. glandulosa) under drought stress. PagSAP11, a stress-associated protein (SAP) family gene, encodes a putative protein containing an A20 and AN1 zinc-finger domain at its N- and C-termini, respectively. Knockdown of PagSAP11 transgenic poplars (SAP11-Ri) enhanced their tolerance to drought stress compared with wild type plants. Moreover, the RNAi lines showed increased branching of lateral shoots that led to a gain in fresh weight, even when grown in the living modified organism (LMO) field. In SAP11-Ri transgenic plants, the expression levels of genes involved in axillary bud outgrowth and cell proliferation such as DML10, CYP707A and RAX were increased while the DRM gene which involved in bud dormancy was down-regulated. Taken together, these results indicate that PagSAP11 represents a promising candidate gene for engineering trees with improved stress tolerance and growth during unfavorable conditions.

Chromosome-level genome assembly of the fully mycoheterotrophic orchid Gastrodia elata.

Gastrodia elata, an obligate mycoheterotrophic orchid, requires complete carbon and mineral nutrient supplementation from mycorrhizal fungi during its entire life cycle. Although full mycoheterotrophy occurs most often in the Orchidaceae family, no chromosome-level reference genome from this group has been assembled to date. Here, we report a high-quality chromosome-level genome assembly of G. elata, using Illumina and PacBio sequencing methods with Hi-C technique. The assembled genome size was found to be 1045 Mb, with an N50 of 50.6 Mb and 488 scaffolds. A total of 935 complete (64.9%) matches to the 1440 embryophyte Benchmarking Universal Single-Copy Orthologs were identified in this genome assembly. Hi-C scaffolding of the assembled genome resulted in 18 pseudochromosomes, 1008 Mb in size and containing 96.5% of the scaffolds. A total of 18,844 protein-coding sequences (CDSs) were predicted in the G. elata genome, of which 15,619 CDSs (82.89%) were functionally annotated. In addition, 74.92% of the assembled genome was found to be composed of transposable elements. Phylogenetic analysis indicated a significant contraction of genes involved in various biosynthetic processes and cellular components and an expansion of genes for novel metabolic processes and mycorrhizal association. This result suggests an evolutionary adaptation of G. elata to a mycoheterotrophic lifestyle. In summary, the genomic resources generated in this study will provide a valuable reference genome for investigating the molecular mechanisms of G. elata biological functions. Furthermore, the complete G. elata genome will greatly improve our understanding of the genetics of Orchidaceae and its mycoheterotrophic evolution.

Extracellular high-mobility group box 1 is increased in patients with Behçet's disease with intestinal involvement.

High-mobility group box 1 (HMGB1) protein has been demonstrated to play an important role in chronic inflammatory diseases including rheumatoid arthritis, and systemic lupus erythematosus. This study investigated the association between extracellular HMGB1 expression and disease activity, and clinical features of Behçet's disease (BD). Extracellular HMGB1 expression in the sera of 42 BD patients was measured and was compared to that of 22 age- and sex-matched healthy controls. HMGB1 expression was significantly increased in BD patients compared to healthy controls (78.70 ± 20.22 vs 10.79 ± 1.90 ng/mL, P = 0.002). In addition, HMGB1 expression was significantly elevated in BD patients with intestinal involvement compared to those without (179.61 ± 67.95 vs 61.89 ± 19.81 ng/mL, P = 0.04). No significant association was observed between HMGB1 concentration and other clinical manifestations, or disease activity. It is suggested that extracellular HMGB1 may play an important role in the pathogenesis of BD.