The Impact of Home Cardiac Rehabilitation on Quality of Life and Psychological Well-Being in Patients with Coronary Heart Disease: A Randomized Controlled Study.

BACKGROUND Percutaneous coronary intervention (PCI), a therapeutic approach to coronary heart disease, significantly alleviates symptoms of coronary heart disease (CHD) and substantially improves quality of life. This study aimed to investigate the effect of home cardiac rehabilitation (HCR) on patients after PCI. MATERIAL AND METHODS We randomly divided 106 patients after PCI into an Intervention group (n=52) and a Control group (n=53). Left ventricular ejection fraction (LVEF), blood pressure, blood glucose, and low-density lipoprotein were measured in both groups before hospital discharge and after 3 months of engaging in the intervention. Patients were assessed using the short-form health survey (SF-12) scale and Hospital Anxiety and Depression Scale (HADS) scale. RESULTS After 3 months of HCR intervention, SF-12 scores of patients in the Intervention group were significantly higher compared to patients in the Control group (physical component summary (PCS): 47.46±9.86 vs 43.28±8.21; and Mental Component Summary (MCS): 50.68±9.82 vs 48.26±9.69) (P.

Quantitative detection of the Ralstonia solanacearum species complex in soil by qPCR combined with a recombinant internal control strain.

IMPORTANCE: DNA-based detection and quantification of soil-borne pathogens, such as the Ralstonia solanacearum species complex (RSSC), plays a vital role in risk assessment, but meanwhile, precise quantification is difficult due to the poor purity and yield of the soil DNA retrieved. The internal sample process control (ISPC) strain RsPC we developed solved this problem and significantly improved the accuracy of quantification of RSSC in different soils. ISPC-based quantitative PCR detection is a method especially suitable for the quantitative detection of microbes in complex matrices (such as soil and sludge) containing various PCR inhibitors and for those not easy to lyse (like Gram-positive bacteria, fungi, and thick-wall cells like resting spores). In addition, the use of ISPC strains removes additional workload on the preparation of high-quality template DNA and facilitates the development of high-throughput quantitative detection techniques for soil microbes.

Identification and Characterization of the HbPP2C Gene Family and Its Expression in Response to Biotic and Abiotic Stresses in Rubber Tree.

Plant PP2C genes are crucial for various biological processes. To elucidate the potential functions of these genes in rubber tree (Hevea brasiliensis), we conducted a comprehensive analysis of these genes using bioinformatics methods. The 60 members of the PP2C family in rubber tree were identified and categorized into 13 subfamilies. The PP2C proteins were conserved across different plant species. The results revealed that the HbPP2C genes contained multiple elements responsive to phytohormones and stresses in their promoters, suggesting their involvement in these pathways. Expression analysis indicated that 40 HbPP2C genes exhibited the highest expression levels in branches and the lowest expression in latex. Additionally, the expression of A subfamily members significantly increased in response to abscisic acid, drought, and glyphosate treatments, whereas the expression of A, B, D, and F1 subfamily members notably increased under temperature stress conditions. Furthermore, the expression of A and F1 subfamily members was significantly upregulated upon powdery mildew infection, with the expression of the HbPP2C6 gene displaying a remarkable 33-fold increase. These findings suggest that different HbPP2C subgroups may have distinct roles in the regulation of phytohormones and the response to abiotic and biotic stresses in rubber tree. This study provides a valuable reference for further investigations into the functions of the HbPP2C gene family in rubber tree.

Genome-Wide Identification of MADS-Box Genes in Taraxacum kok-saghyz and Taraxacum mongolicum: Evolutionary Mechanisms, Conserved Functions and New Functions Related to Natural Rubber Yield Formation.

MADS-box transcription regulators play important roles in plant growth and development. However, very few MADS-box genes have been isolated in the genus Taraxacum, which consists of more than 3000 species. To explore their functions in the promising natural rubber (NR)-producing plant Taraxacum kok-saghyz (TKS), MADS-box genes were identified in the genome of TKS and the related species Taraxacum mongolicum (TM; non-NR-producing) via genome-wide screening. In total, 66 TkMADSs and 59 TmMADSs were identified in the TKS and TM genomes, respectively. From diploid TKS to triploid TM, the total number of MADS-box genes did not increase, but expansion occurred in specific subfamilies. Between the two genomes, a total of 11 duplications, which promoted the expansion of MADS-box genes, were identified in the two species. TkMADS and TmMADS were highly conserved, and showed good collinearity. Furthermore, most TkMADS genes exhibiting tissue-specific expression patterns, especially genes associated with the ABCDE model, were preferentially expressed in the flowers, suggesting their conserved and dominant functions in flower development in TKS. Moreover, by comparing the transcriptomes of different TKS lines, we identified 25 TkMADSs related to biomass formation and 4 TkMADSs related to NR content, which represented new targets for improving the NR yield of TKS.

Physiological and Transcriptomic Analyses Reveal the Effects of Carbon-Ion Beam on Taraxacum kok-saghyz Rodin Adventitious Buds.

Taraxacum kok-saghyz Rodin (TKS) has great potential as an alternative natural-rubber (NR)-producing crop. The germplasm innovation of TKS still faces great challenges due to its self-incompatibility. Carbon-ion beam (CIB) irradiation is a powerful and non-species-specific physical method for mutation creation. Thus far, the CIB has not been utilized in TKS. To better inform future mutation breeding for TKS by the CIB and provide a basis for dose-selection, adventitious buds, which not only can avoid high levels of heterozygosity, but also further improve breeding efficiency, were irradiated here, and the dynamic changes of the growth and physiologic parameters, as well as gene expression pattern were profiled, comprehensively. The results showed that the CIB (5-40 Gy) caused significant biological effects on TKS, exhibiting inhibitory effects on the fresh weight and the number of regenerated buds and roots. Then,15 Gy was chosen for further study after comprehensive consideration. CIB-15 Gy resulted in significant oxidative damages (hydroxyl radical (OH•) generation activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and malondialdehyde (MDA) content) and activated the antioxidant system (superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX)) of TKS. Based on RNA-seq analysis, the number of differentially expressed genes (DEGs) peaked at 2 h after CIB irradiation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that DNA-replication-/repair- (mainly up-regulated), cell-death- (mainly up-regulated), plant-hormone- (auxin and cytokinin, which are related to plant morphogenesis, were mainly down-regulated), and photosynthesis- (mainly down-regulated) related pathways were involved in the response to the CIB. Furthermore, CIB irradiation can also up-regulate the genes involved in NR metabolism, which provides an alternative strategy to elevate the NR production in TKS in the future. These findings are helpful to understand the radiation response mechanism and further guide the future mutation breeding for TKS by the CIB.

Single-cell transcriptomic analyses reveal cellular and molecular patterns of rubber tree response to early powdery mildew infection.

As a perennial woody plant, the rubber tree (Hevea brasiliensis) must adapt to various environmental challenges through gene expression in multiple cell types. It is still unclear how genes in this species are expressed at the cellular level and the precise mechanisms by which cells respond transcriptionally to environmental stimuli, especially in the case of pathogen infection. Here, we characterized the transcriptomes in Hevea leaves during early powdery mildew infection using single-cell RNA sequencing. We identified 10 cell types and constructed the first single-cell atlas of Hevea leaves. Distinct gene expression patterns of the cell clusters were observed under powdery mildew infection, which was especially significant in the epidermal cells. Most of the genes involved in host-pathogen interactions in epidermal cells exhibited a pattern of dramatically increased expression with increasing pseudotime. Interestingly, we found that the HbCNL2 gene, encoding a nucleotide-binding leucine-rich repeat protein, positively modulated the defence of rubber leaves against powdery mildew. Overexpression of the HbCNL2 gene triggered a typical cell death phenotype in tobacco leaves and a higher level of reactive oxygen species in the protoplasts of Hevea leaves. The HbCNL2 protein was located in the cytomembrane and nucleus, and its leucine-rich repeat domain interacted with the histidine kinase-like ATPase domain of the molecular chaperone HbHSP90 in the nucleus. Collectively, our results provide the first observation of the cellular and molecular responses of Hevea leaves to biotrophic pathogen infection and can guide the identification of disease-resistance genes in this important tree species.

Construction of the first high-density SNP genetic map and identification of QTLs for the natural rubber content in Taraxacum kok-saghyz Rodin.

BACKGROUND: Taraxacum kok-saghyz Rodin (TKS) is a promising commercial alternative natural rubber (NR) yielding plant. Cultivating TKS with a high NR content is an important breeding target, and developing molecular markers related to NR content can effectively accelerate the breeding process of TKS. RESULTS: To construct a high-density SNP genetic map and uncover genomic regions related to the NR content in TKS, an F1 mapping population of TKS was constructed by crossing two parents (l66 and X51) with significant differences in NR contents. The NR content of the F1 plants ranged from 0.30 to 15.14% and was distributed normally with a coefficient of variation of 47.61%, indicating quantitative trait inheritance. Then, employing whole-genome resequencing (WGR), a TKS genetic linkage map of 12,680 bin markers comprising 322,439 SNPs was generated. Based on the genetic map and NR content of the F1 population, six quantitative trait loci (QTLs) for NR content with LOD > 4.0 were identified on LG01/Chr01 and LG06/Chr06. Of them, the 2.17 Mb genomic region between qHRC-C6-1 and qHRC-C6-2 on ChrA06, with 65.62% PVE in total, was the major QTL region. In addition, the six QTLs have significant additive genetic effects on NR content and could be used to develop markers for marker-assisted selection (MAS) in TKS with a high NR content. CONCLUSION: This work constructed the first high-density TKS genetic map and identified the QTLs and genomic regions controlling the NR content, which provides useful information for fine mapping, map-based cloning, and MAS in TKS.

Prevention of catheter tip malposition with an ultrasound-guided finger-pressure method to block the internal jugular vein during PICC placement: a meta-analysis.

Introduction: Peripherally inserted central catheters (PICC) are a type of deep venipuncture, for which the catheter tip malposition rate is high. Aim: To examine the feasibility of preventing catheter tip malposition during PICC placement using an ultrasound-guided finger-pressure method to block the internal jugular vein. Material and methods: We conducted a double-blinded randomized controlled trial (RCT) at a tertiary public hospital in Hubei province, China. A total of 600 patients were recruited and randomly allocated to the ultrasound-guided finger compression method (UGFCM) and traditional partial head method (TPHM) group (n = 300/group). Incidence of catheter tip malposition was assessed as the primary outcome of the study. A systematic literature review and meta-analysis was performed. We searched MEDLINE, EMBASE, Cochrane Library, China-National Knowledge Infrastructure, and Chinese Biomedicine Database and performed publication bias and sensitivity analyses on 10 extracted studies. Results: There were no significant differences in baseline demographic and clinical characteristics between the two groups (p > 0.05). Overall incidence of catheter tip malposition was significantly lower in the UGFCM and TPHM group (1.67% vs. 10.3%) and particularly the incidence of malposition in the internal jugular vein (1% vs. 9%). In the meta-analysis of 10 eligible studies, with 1263 cases using the UGFCM method while 1261 adopted the TPHM method, the results showed that the incidence of catheter tip malposition was significantly lower in the group using the UGFCM method (OR = 0.17, 95% CI: 0.11-0.27, p < 0.01), which is in line with the results of our RCT study. Conclusions: This study may add valuable evidence on adopting the finger-pressure method for blocking neck veins to reduce the incidence of catheter tip malposition, particularly in the internal jugular vein.

HbMYB44, a Rubber Tree MYB Transcription Factor With Versatile Functions in Modulating Multiple Phytohormone Signaling and Abiotic Stress Responses.

The vital roles of R2R3-MYB transcription factors (TFs) in regulating stress response and phytohormone signaling have been thoroughly studied in numerous plant species, but the functions of these TFs in rubber tree are poorly understood. Rubber tree is the most important source of natural rubber but often suffers from various abiotic and biotic stresses that cause severe yield losses each year. In this study, we reported a novel MYB44 gene in rubber tree (named HbMYB44) and revealed its biological function. HbMYB44 was highly similar to AtMYB44 and clustered into subgroup 22. Transient expression indicated that HbMYB44 is a nuclear localized protein and displays transactivation activity at the C-terminus. HbMYB44 was ubiquitously expressed in rubber tree, and its expression was strongly induced by multiple phytohormones, drought stress, wounding, and H2O2 treatments. Furthermore, overexpression of HbMYB44 in Arabidopsis (OE) demonstrated that OE plants significantly enhanced stress tolerance, i.e., salt stress, osmotic stress, and drought stress. Additionally, HbMYB44 promoted recovery from root growth inhibition of OE plants caused by exogenous phytohormones (including abscisic acid, methyl jasmonic acid, gibberellic acid 3, and salicylic acid), but the opposite effect was present in response to ethephon. Interestingly, HbMYB44 increased the expression of its homologous genes and interacting protein-encoding genes in OE plants. Overall, HbMYB44 plays versatile functions in modulating multiple phytohormone signaling pathways and stress tolerance.

Involvement of Gut Microbiota in the Development of Psoriasis Vulgaris.

Objectives: Psoriasis is a common chronic recurrent dermatitis. Accumulating observations show gut microbiota dysbiosis in psoriasis. We intend to further investigate the relationship between intestinal microbiota and psoriasis development. Design: We first performed an epidemiological investigation on differences of gastrointestinal discomfort symptoms between patients with psoriasis and general population. Then variation of gut microbiota in patients with psoriasis (un)treated with acitretin plus narrow-band ultraviolet B (NB-UVB) was analyzed by 16S rRNA sequencing. We last compared recovery status and vital cytokines (lesion and intestine) of mouse psoriasiform models, which were transplanted with fecal microbiota from patients with psoriasis or healthy controls. Results: (1) About 85.5% of patients with psoriasis vs. 58.1% of healthy controls presented with at least one gastrointestinal symptom. The prevalence of investigated symptoms (e.g., abdominal distension and constipation) were significantly higher in patients, compared with controls (p < 0.05). Passing flatus and constipation were significantly correlated with psoriasis (p < 0.05 in both cases). (2) The abundance of Ruminococcaceae family, Coprococcus_1 genus, and Blautia genus were decreased with psoriasis improvement (p < 0.05, respectively), which had been demonstrated significantly increased in psoriasis. (3) Mice receiving psoriatic microbes transplantation showed delayed recovery of psoriasiform dermatitis and less reduction of interleukin (IL)-17A than those receiving healthy microbiota or blank control (p < 0.05 and p < 0.01, respectively). Conclusion: Multiple evidence we provided here preliminarily demonstrates the involvement of gut microbiota in the different degree of psoriasis activity. The strategy based on overall microbial communities is expected to be a promising supplementary for long-term management of psoriasis.

Characterization of fungal communities on shared bicycles in Southwest China.

BACKGROUND: The widespread use of shared bicycles has increased the demand and sanitary requirements for shared bicycles. Previous studies have identified potentially pathogenic bacteria on the surfaces of shared bicycles, but fungal communities have not been investigated. METHODS: We sampled shared-bicycle handles and saddles from five selected locations in a metropolis (Chengdu, China, n = 98) and used surrounding air deposition samples as controls (n = 12). Full-length ITS sequencing and multiple bioinformatic analyses were utilized to reveal fungal community structures and differences. RESULTS: Aspergillus was dominant on both the handles and saddles of shared bicycles, and Alternaria and Cladosporium were the most abundant families in the air samples. Significant differences in fungal community structures were found among the three groups. The handle samples contained higher abundances of Aureobasidium melanogenum and Filobasidium magnum than the saddle and air samples. The saddle samples had a higher abundance of Cladosporium tenuissimum than the other two sample types (P < 0·05). A higher abundance of fungal animal pathogens on shared-bicycle surfaces than in air by FUNGuild (P < 0·05). Moreover, the co-occurrence network of fungi on handles was more stable than that on saddles. CONCLUSION: There were more potential pathogens, including Aspergillus pseudoglaucus, Aureobasidium melanogenum, Kazachstania pintolopesii, Filobasidium magnum, Candida tropicalis, and Malassezia globose were found on shared bicycles than in air, suggesting that hands should not contact mucous membrane after cycling, especially in susceptible individuals, and hygiene management of shared bicycles should be given more attention by relevant organizations worldwide.

The nerve injuries attenuate the persistence of psoriatic lesions.

BACKGROUND: The involvement of the nerve in psoriasis development was suggested by sporadic case reports. OBJECTIVES: To provide multiple evidence for the nerve in psoriasis development with a retrospective case review, a literature review and a mouse-based experimental experiment. METHODS: Psoriatic patients who had concomitant nerve injuries and such cases from literatures were reviewed. And, on wild-type mouse level, unilateral denervation surgery was performed on the dorsal skin before and after the induction of psoriasiform dermatitis, respectively. Lesion visual scores were calculated, and biopsies were taken for hematoxylin-eosin (HE) staining, immunofluorescence analysis, and RNA sequencing & bioinformatics analysis before denervation surgery and the 2nd, 4th, 6th, 8th day after the surgery. RESULTS: All clinical cases (20/20) showed that local lesions under the control of injured nerves relieved spontaneously or even cleared/spared, and only about 1/3 experienced partial recurrence. Next, mouse psoriasiform experiments demonstrated that unilateral denervation prior to imiquimod application attenuated the enhancement of inflammatory reactions (e.g. adaptive immune response and Th17 cell differentiation pathway) and the induction of ipsilateral psoriasiform dermatitis. On the other hand, unilateral denervation after psoriasiform dermatitis induction promoted the regression of inflammatory reactions (e.g. T cell activation, TNF signaling, and Th17 cell differentiation pathway) and ipsilateral dermatitis recovery. CONCLUSION: Our study based on both retrospective clinical case review and wild-type mouse experiments provides multiple evidence for the involvement of the nerve in psoriasis development. Regulation of immune events, including TNF signaling and Th17 cell differentiation, may be the mechanisms of the nerve in psoriasis.

Identification and Characterization of a Potential Candidate Mlo Gene Conferring Susceptibility to Powdery Mildew in Rubber Tree.

Mildew resistance locus O (Mlo) gene was first found in barley as a powdery mildew susceptibility gene, and recessive mlo alleles confer durable resistance to barley powdery mildew. To identify candidate Mlo susceptibility genes in rubber tree, HbMlo12 was cloned from rubber tree clone CATAS7-33-97, which is susceptible to powdery mildew. Protein architecture analysis showed that HbMlo12 was a typical Mlo protein with seven transmembrane domains. Protein blast search in the Arabidopsis thaliana proteome database showed that HbMlo12 shared the highest similarity with AtMlo12, with 63% sequence identity. Furthermore, HbMlo12 together with the dicot powdery mildew susceptible Mlo proteins (including AtMlo2, AtMlo6, AtMlo12, tomato SlMlo1, pepper CaMlo2, pea PsMlo1, etc.) were grouped into clade V. Subcellular localization analysis in tobacco epidermal cells revealed that HbMlo12 was localized to the endoplasmic reticulum membrane. HbMlo12 was preferentially expressed in the flower and leaf of rubber tree. Moreover, its expression was significantly upregulated in response to powdery mildew inoculation. Application of exogenous ethephon caused a distinct increase in HbMlo12 expression. Additionally, HbMlo12 transcript was quickly induced by spraying salicylic acid and gibberellic acid and reached the maximum at 0.5 h after treatments. By contrast, HbMlo12 expression was downregulated by methyl jasmonate, abscisic acid, and drought stress treatments. There was no significant change in HbMlo12 expression after indole-3-acetic acid, H2O2, and wounding stimuli. Taken together, these results suggested that HbMlo12 might be a candidate Mlo gene conferring susceptibility to powdery mildew in rubber tree. The results of this study are vital in understanding Mlo gene evolution and developing new rubber tree varieties with powdery mildew resistance using reverse genetics.

[Efficacy of repetitive transcranial magnetic stimulation for alleviating clinical symptoms and suicidal ideation in elderly depressive patients: a randomized controlled trial].

OBJECTIVE: To assess the efficacy of repetitive transcranial magnetic stimulation (rTMS) for alleviating the clinical symptoms and suicidal ideation in elderly patients with depression. METHODS: A total of 178 elderly depressive patients with suicidal ideation were randomized into rTMS treatment group (n=80) and control group (n=98) and treated with rTMS or sham rTMS treatment for 4 weeks in addition to conventional therapy with medications. The 24-item Hamilton Depression Scales (HAMD) and Self-rating Idea of Suicide Scale (SIOSS) were used to assess the severity of depression and the risk of suicide at the baseline and after 2 and 4 weeks of treatment. The treatment response was defined as a 25% reduction in HAMD scores from baseline, and an early improvement as 20% reduction in HAMD scores after 2 weeks of treatment. RESULTS: The two groups of patients were comparable for baseline socio-demographic characteristics and baseline SIOSS and HAMD scores (P>0.05). After 2 and 4 weeks of treatment, both SIOSS and HAMD scores were improved in the two groups, but the patients in rTMS group showed a significantly faster score reduction. A significantly higher rate of early improvement at 2 weeks (52.5% vs 28.6%; χ2=10.569, P<0.01) and a higher response rate at 4 weeks (77.5% vs 53.1%; χ2=15.470, P<0.05) were observed in rTMS group. CONCLUSIONS: rTMS combined with medications can effectively improve sleep quality, cognitive impairment and somatization symptom and reduce suicidal ideation in elderly patients with depression.

Two members of TaRLK family confer powdery mildew resistance in common wheat.

BACKGROUND: Powdery mildew, caused by Blumeria graminearum f.sp. tritici (Bgt), is one of the most severe fungal diseases of wheat. The exploration and utilization of new gene resources is the most effective approach for the powdery mildew control. RESULTS: We report the cloning and functional analysis of two wheat LRR-RLKs from T. aestivum c.v. Prins- T. timopheevii introgression line IGV1-465, named TaRLK1 and TaRLK2, which play positive roles in regulating powdery mildew resistance in wheat. The two LRR-RLKs contain an ORF of 3,045 nucleotides, encoding a peptide of 1014 amino acids, with seven amino acids difference. Their predicted proteins possess a signal peptide, several LRRs, a trans-membrane domain, and a Ser/Thr protein kinase domain. In response to Bgt infection, the TaRLK1/2 expression is up-regulated in a developmental-stage-dependent manner. Single-cell transient over-expression and gene-silencing assays indicate that both genes positively regulate the resistance to mixed Bgt inoculums. Transgenic lines over-expressing TaRLK1 or TaRLK2 in a moderate powdery mildew susceptible wheat variety Yangmai 158 led to significantly enhanced powdery mildew resistance. Exogenous applied salicylic acid (SA) or hydrogen peroxide (H2O2) induced the expression of both genes, and H2O2 had a higher accumulation at the Bgt penetration sites in RLK over-expression transgenic plants, suggesting a possible involvement of SA and altered ROS homeostasis in the defense response to Bgt infection. The two LRR-RLKs are located in the long arm of wheat chromosome 2B, in which the powdery mildew resistance gene Pm6 is located, but in different regions. CONCLUSIONS: Two members of TaRLK family were cloned from IGV1-465. TaRLK1 and TaRLK2 contribute to powdery mildew resistance of wheat, providing new resistance gene resources for wheat breeding.

Molecular cloning and characterization of a Mlo gene in rubber tree (Hevea brasiliensis).

Mlo gene encodes a plant-specific seven-transmembrane domain protein involved in a variety of cellular processes. In this study, a novel Mlo gene from rubber tree (Hevea brasiliensis), designated HbMlo1, was cloned by RT-PCR in rubber tree. The ORF of HbMlo1 was 1551bp in length, encoding a putative protein of 516 amino acids. HbMlo1 was a typical Mlo protein with seven-transmembrane domain. Sequence comparison between HbMlo1 and other Mlo proteins demonstrated that HbMlo1 shared the highest similarity with the Cucumis melo CmMlo1 and Arabidopsis thaliana AtMlo1 with 75.1% and 71.3% sequence identity, respectively. Phylogenetic analysis revealed that HbMlo1, CmMlo1, AtMlo1, AtMlo13, and AtMlo15 formed into the phylogenetic clade II with 100% bootstrap support value. HbMlo1 transcript exhibited tissue specificity, and it was preferentially expressed in leaf. Furthermore, the amount of HbMlo1 transcript was significantly induced by various phytohormones (including ethephon, methyl jasmonate, salicylic acid, abscisic acid, indole-3-acetic acid, and gibberellic acid), H2O2, and wounding treatments. Under drought stress, HbMlo1 exhibited a complex pattern of regulation. However, HbMlo1 expression did not significantly change during powdery mildew infection. These results suggested that HbMlo1 might play a role in phytohormone signaling and abiotic stress response processes in rubber tree.

Molecular cloning and expression of a novel MYB transcription factor gene in rubber tree.

MYB family proteins regulate a variety of cellular processes in plants. Tapping panel dryness (TPD) in rubber tree (Hevea brasiliensis Muell. Arg.) affects latex biosynthesis and causes serious losses to rubber producers. In this study, a novel SANT/MYB transcription factor gene down-regulated in TPD rubber tree, named as HbSM1, was isolated from rubber tree. The complete HbSM1 open reading frame (ORF) was 948 bp in length. The deduced HbSM1 protein is 315 amino acids. HbSM1 belonged to 1RMYB subfamily with a single SANT domain. Sequence alignment revealed that HbSM1 had high homology with MYB members from Ricinus communis and Manihot esculenta, with 72 and 78 % identity, respectively. Moreover, HbSM1 shared 56 % identity with Glycine max GmMYB176. Phylogenetic analysis revealed that HbSM1, GmMYB176, rice OsMYBS2, and OsMYBS3 fell into the same cluster with 93 % bootstrap support value. Comparing expression among different tissues demonstrated that HbSM1 was ubiquitously expressed in all tissues, but it appeared to be preferentially expressed in leaf and latex. Furthermore, HbSM1 transcripts were significantly induced by various phytohormones (including gibberellic acid, ethephon, methyl jasmonate, salicylic acid, and abscisic acid) and wounding treatments. These results suggested that HbSM1 might play multiple roles in plant development via different phytohormones signaling pathways.

The function of Rad6 gene in Hevea brasiliensis extends beyond DNA repair.

The Rad6 gene of Saccharomyces cerevisiae encodes an ubiquitin-conjugating enzyme (E2) which is required for DNA repair, damage-induced mutagenesis, sporulation, etc. In this study, one Rad6 homolog, designated HbRad6, was cloned in rubber tree (Hevea brasiliensis). The putative protein sequence of HbRad6 contains 152 amino acids, a conserved UBC domain, and a conserved active-site cysteine in the UBC domain, which is required for E2 enzymes catalytic activity. HbRad6 shared high similarity with Rad6 from other species. It shared the highest similarity with rice OsRad6 and Arabidopsis thaliana AtUBC2 with 96.05% identical residues, and 63.16% sequence identity with yeast Rad6 (excluding the acidic tail). Comparing expression among different Hevea tissues demonstrated that HbRad6 was ubiquitously expressed in all tissues, but it revealed a preferential expression in the latex. Furthermore, HbRad6 expression was markedly induced by DNA-damaging agent H2O2, the latex stimulator ethephon (ET), and methyl jasmonate (MeJA), while NaCl and wounding treatments had relatively minor effect upon its expression. Genetic complementation experiment revealed that HbRad6 had minor effects on the complementation of the UV sensitivity of yeast rad6 null mutant, indicating that the Hevea Rad6 protein may partially suppress the UV sensitivity of the yeast rad6 mutant. These results suggested that HbRad6 was a multifunction gene involved in DNA damage repair, hormones and stress responses in rubber tree.

Molecular cloning, expression profiles and characterization of a novel translationally controlled tumor protein in rubber tree (Hevea brasiliensis).

The translationally controlled tumor protein (TCTP) is a multi-functioning protein that carries out vital roles in various life processes. In this study, a new TCTP gene, designated as HbTCTP1, was isolated in Hevea brasiliensis. The full-length complementary DNA (cDNA) of HbTCTP1 contained a maximum open reading frame (ORF) of 507base pair (bp) encoding 168 amino acids. The sequence comparison showed that the deduced HbTCTP1 indicated high identities to plant TCTP proteins, and clustered in the dicot cluster of plant TCTPs. Although HbTCTP1 and human TCTP proteins did not parallel in overall sequence similarity, they indicated highly similar 3D structures with a nearly identical spatial organization of α-helices, ß-sheets, and coil regions. Real time reverse-transcription PCR (RT-PCR) analyses showed that HbTCTP1 was expressed throughout different tissues and developmental stages of leaves. Besides being related to tapping panel dryness (TPD), the HbTCTP1 transcripts were regulated by various treatments, including drought, low temperature, high salt, ethrel (ET), wounding, H2O2, and methyl jasmonate (Me-JA) treatments. The recombinant HbTCTP1 fusion protein was shown to protect supercoiled plasmid DNA from damages induced by metal-catalyzed generation of reactive oxygen species. The (45)Ca(2+)-overlay assay showed that HbTCTP1 was a calcium-binding protein. Our results are greatly helpful in understanding the molecular characterization and expression profiles of HbTCTP1, and lay the foundation for further analyzing the function of HbTCTP1 in rubber tree.