Comparative transcriptome and DNA methylation analysis in temperature-sensitive genic male sterile wheat BS366

Background

Known as the prerequisite component for the heterosis breeding system, the male sterile line determines the hybrid yield and seed purity. Therefore, a deep understanding of the mechanism and gene network that leads to male sterility is crucial. BS366, a temperature-sensitive genic male sterile (TGMS) line, is male sterile under cold conditions (12 °C with 12 h of daylight) but fertile under normal temperature (20 °C with 12 h of daylight).

Results

During meiosis, BS366 was defective in forming tetrads and dyads due to the abnormal cell plate. During pollen development, unusual vacuolated pollen that could not accumulate starch grains at the binucleate stage was also observed. Transcriptome analysis revealed that genes involved in the meiotic process, such as sister chromatid segregation and microtubule-based movement, were repressed, while genes involved in DNA and histone methylation were induced in BS366 under cold conditions. MethylRAD was used for reduced DNA methylation sequencing of BS366 spikes under both cold and control conditions. The differentially methylated sites (DMSs) located in the gene region were mainly involved in carbohydrate and fatty acid metabolism, lipid metabolism, and transport. Differentially expressed and methylated genes were mainly involved in cell division.

Conclusions

These results indicated that the methylation of genes involved in carbon metabolism or fatty acid metabolism might contribute to male sterility in BS366 spikes, providing novel insight into the molecular mechanism of wheat male sterility.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08163-3.

Comprehensive analysis of formin gene family highlights candidate genes related to pollen cytoskeleton and male fertility in wheat (Triticum aestivum L.)

Background

Formin, a highly conserved multi-domain protein, interacts with microfilaments and microtubules. Although specifically expressed formin genes in anthers are potentially significant in research on male sterility and hybrid wheat breeding, similar reports in wheat, especially in thermo-sensitive genic male sterile (TGMS) wheat, remain elusive.

Results

Herein, we systematically characterized the formin genes in TGMS wheat line BS366 named TaFormins (TaFHs) and predicted their functions in inducing stress response. In total, 25 TaFH genes were uncovered, majorly localized in 2A, 2B, and 2D chromosomes. According to the neighbor-joining (NJ) method, all TaFH proteins from wheat and other plants clustered in 6 sub-groups (A-F). The modeled 3D structures of TaFH1-A/B, TaFH2-A/B, TaFH3-A/B and TaFH3-B/D were validated. And different numbers of stress and hormone-responsive regulatory elements in their 1500 base pair promoter regions were contained in the TaFH genes copies. TaFHs had specific temporal and spatial expression characteristics, whereby TaFH1, TaFH4, and TaFH5 were expressed highly in the stamen of BS366. Besides, the accumulation of TaFHs was remarkably lower in a low-temperature sterile condition (Nanyang) than fertile condition (Beijing), particularly at the early stamen development stage. The pollen cytoskeleton of BS366 was abnormal in the three stages under sterile and fertile environments. Furthermore, under different stress levels, TaFHs expression could be induced by drought, salt, abscisic acid (ABA), salicylic acid (SA), methyl jasmonate (MeJA), indole-3-acetic acid (IAA), polyethylene glycol (PEG), and low temperature. Some miRNAs, including miR167, miR1120, and miR172, interacts with TaFH genes; thus, we constructed an interaction network between microRNAs, TaFHs, phytohormone responses, and distribution of cytoskeleton to reveal the regulatory association between upstream genes of TaFH family members and sterile.

Conclusions

Collectively, this comprehensive analysis provides novel insights into TaFHs and miRNA resources for wheat breeding. These findings are, therefore, valuable in understanding the mechanism of TGMS fertility conversion in wheat.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07878-7.

Genome-wide identification and transcriptional characterization of DNA methyltransferases conferring temperature-sensitive male sterility in wheat

Background

DNA methyltransferase (DMT) genes contribute to plant stress responses and development by de novo establishment and subsequent maintenance of DNA methylation during replication. The photoperiod and/or temperature-sensitive genic male sterile (P/TGMS) lines play an important role in hybrid seed production of wheat. However, only a few studies have reported on the effect of DMT genes on temperature-sensitive male sterility of wheat. Although DMT genes have been investigated in some plant species, the identification and analysis of DMT genes in wheat (Triticum aestivum L.) based on genome-wide levels have not been reported.

Results

In this study, a detailed overview of phylogeny of 52 wheat DMT (TaDMT) genes was presented. Homoeolog retention for TaDMT genes was significantly above the average retention rate for whole-wheat genes, indicating the functional importance of many DMT homoeologs. We found that the strikingly high number of TaDMT genes resulted mainly from the significant expansion of the TaDRM subfamily. Intriguingly, all 5 paralogs belonged to the wheat DRM subfamily, and we speculated that tandem duplications might play a crucial role in the TaDRM subfamily expansion. Through the transcriptional analysis of TaDMT genes in a TGMS line BS366 and its hybrids with the other six fertile lines under sterile and fertile conditions, we concluded that TaCMT-D2, TaMET1-B1, and TaDRM-U6 might be involved in male sterility in BS366. Furthermore, a correlation analysis showed that TaMET1-B1 might negatively regulate the expression of TaRAFTIN1A, an important gene for pollen development, so we speculated regarding an epigenetic regulatory mechanism underlying the male sterility of BS366 via the interaction between TaMET1-B1 and TaRAFTIN1A.

Conclusions

Our findings presented a detailed phylogenic overview of the DMT genes and could provide novel insights into the effects of DMT genes on TGMS wheat.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07600-7.

Effectiveness and safety of electroacupuncture in treating Parkinson disease: A protocol for systematic review and meta-analyses

BACKGROUND

Parkinson disease (PD) is an Extrapyramidal Disease mainly characterized by static tremor, myotonia, bradykinesia and postural gait disorder. As China's population ages, the number of people suffering from PD is increasing. Since there are many side effects of western medicine for Parkinson's patients, and the high price of the drugs make it difficult for many patients to adhere to treat. At present, many clinical studies have shown that electroacupuncture is effective in treating PD. Therefore, this systematic review aims to explore the effectiveness and safety of electroacupuncture in the treatment of PD.

METHODS

Comprehensive search of PubMed, Embase, Medline, Cochrane Database of Systematic Reviews, Chinese Biomedical Literatures Database, China National Knowledge Infrastructure, Chinese Scientific Journal Database, Wang Fang Database from inception to February 2021, the literature selected is not restricted by language. In addition, we will search for unpublished studies and the references that were originally included in the literature manually. There were two reviewers screened the data and cross-checked the information individually, the quality of the literature was assessed by reviewers independently. The outcomes of interest include:the scale of Unifified PD Rating Scales, the Webster scale, the Quality of Life Questionnaire, total effective rate, recurrence rate, adverse events. The laboratory inspection indicators include:the content of lipid peroxidase, Superoxide dismutase activity in plasma and erythrocyte. The relevant randomized controlled trials will be included in this study. And we will evaluate the quality of the selected literature according to the Cochrane Handbook. Meta-analysis will be performed using RevMan 5.4.0 software. The heterogeneity test will be implemented in the included literature, the tests' thresholds will be P < .1 and I2 > 50%. We will use either fixed effects model or random effects model according to the size of heterogeneity.

RESULTS

The results of this systematic review will provide a comprehensive evidence for the clinical treatment of PD, and we will report this result soon.

CONCLUSION

This paper will explore whether or not electroacupuncture can be used as a non-drug therapy for PD.

ETHICS AND DISSEMINATION

Ethical approval is not required for this paper, our plan will be published in the journal.

TRIAL REGISTRATION NUMBER

INPLASY202120031.

Genomic identification and characterization of MYC family genes in wheat (Triticum aestivum L.)

Background

MYC transcriptional factors are members of the bHLH (basic helix-loop-helix) superfamily, and play important roles in plant growth and development. Recent studies have revealed that some MYCs are involved in the crosstalk between Jasmonic acid regulatory pathway and light signaling in Arabidopsis, but such kinds of studies are rare in wheat, especially in photo-thermo-sensitive genic male sterile (PTGMS) wheat line.

Results

27 non-redundant MYC gene copies, which belonged to 11 TaMYC genes, were identified in the whole genome of wheat (Chinese Spring). These gene copies were distributed on 13 different chromosomes, respectively. Based on the results of phylogenetic analysis, 27 TaMYC gene copies were clustered into group I, group III, and group IV. The identified TaMYC genes copies contained different numbers of light, stress, and hormone-responsive regulatory elements in their 1500 base pair promoter regions. Besides, we found that TaMYC3 was expressed highly in stem, TaMYC5 and TaMYC9 were expressed specially in glume, and the rest of TaMYC genes were expressed in all tissues (root, stem, leaf, pistil, stamen, and glume) of the PTGMS line BS366. Moreover, we found that TaMYC3, TaMYC7, TaMYC9, and TaMYC10 were highly sensitive to methyl jasmonate (MeJA), and other TaMYC genes responded at different levels. Furthermore, we confirmed the expression profiles of TaMYC family members under different light quality and plant hormone stimuli, and abiotic stresses. Finally, we predicted the wheat microRNAs that could interact with TaMYC family members, and built up a network to show their integrative relationships.

Conclusions

This study analyzed the size and composition of the MYC gene family in wheat, and investigated stress-responsive and light quality induced expression profiles of each TaMYC gene in the PTGMS wheat line BS366. In conclusion, we obtained lots of important information of TaMYC family, and the results of this study was supposed to contribute novel insights and gene and microRNA resources for wheat breeding, especially for the improvement of PTGMS wheat lines.

Genome-wide identification and analysis of the COI gene family in wheat (Triticum aestivum L.)

Background

COI (CORONATINE INSENSITIVE), an F-box component of the Skp1-Cullin-F-box protein (SCF^COI1) ubiquitin E3 ligase, plays important roles in the regulation of plant growth and development. Recent studies have shown that COIs are involved in pollen fertility. In this study, we identified and characterized COI genes in the wheat genome and analyzed expression patterns under abiotic stress.

Results

A total of 18 COI candidate sequences for 8 members of COI gene family were isolated in wheat (Triticum aestivum L.). Phylogenetic and structural analyses showed that these COI genes could be divided into seven distinct subfamilies. The COI genes showed high expression in stamens and glumes. The qRT-PCR results revealed that wheat COIs were involved in several abiotic stress responses and anther/glume dehiscence in the photoperiod-temperature sensitive genic male sterile (PTGMS) wheat line BS366.

Conclusions

The structural characteristics and expression patterns of the COI gene family in wheat as well as the stress-responsive and differential tissue-specific expression profiles of each TaCOI gene were examined in PTGMS wheat line BS366. In addition, we examined SA- and MeJA-induced gene expression in the wheat anther and glume to investigate the role of COI in the JA signaling pathway, involved in the regulation of abnormal anther dehiscence in the PTGMS wheat line. The results of this study contribute novel and detailed information about the TaCOI gene family in wheat and could be used as a benchmark for future studies of the molecular mechanisms of PTGMS in other crops.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5116-9) contains supplementary material, which is available to authorized users.

Transcriptome analysis of wheat seedling and spike tissues in the hybrid Jingmai 8 uncovered genes involved in heterosis

Transcriptome analysis was carried out for wheat seedlings and spikes from hybrid Jingmai 8 and both inbred lines to unravel mechanisms underlying heterosis. Heterosis, known as one of the most successful strategies for increasing crop yield, has been widely exploited in plant breeding systems. Despite its great importance, the molecular mechanism underlying heterosis remains elusive. In the present study, RNA sequencing (RNA-seq) was performed on the seedling and spike tissues of the wheat (Triticum aestivum) hybrid Jingmai 8 (JM8) and its homozygous parents to unravel the underlying mechanisms of wheat heterosis. In total, 1686 and 2334 genes were identified as differentially expressed genes (DEGs) between the hybrid and the two inbred lines in seedling and spike tissues, respectively. Gene Ontology analysis revealed that DEGs from seedling tissues were significantly enriched in processes involved in photosynthesis and carbon fixation, and the majority of these DEGs expressed at a higher level in JM8 compared to both inbred lines. In addition, cell wall biogenesis and protein biosynthesis-related pathways were also significantly represented. These results confirmed that a combination of different pathways could contribute to heterosis. The DEGs between the hybrid and the two inbred progenitors from the spike tissues were significantly enriched in biological processes related to transcription, RNA biosynthesis and molecular function categories related to transcription factor activities. Furthermore, transcription factors such as NAC, ERF, and TIF-IIA were highly expressed in the hybrid JM8. These results may provide valuable insights into the molecular mechanisms underlying wheat heterosis.

Uncovering Male Fertility Transition Responsive miRNA in a Wheat Photo-Thermosensitive Genic Male Sterile Line by Deep Sequencing and Degradome Analysis

MicroRNAs (miRNAs) are endogenous small RNAs which play important negative regulatory roles at both the transcriptional and post-transcriptional levels in plants. Wheat is the most commonly cultivated plant species worldwide. In this study, RNA-seq analysis was used to examine the expression profiles of miRNA in the spikelets of photo-thermosenisitive genic male sterile (PTGMS) wheat line BS366 during male fertility transition. Through mapping on their corresponding precursors, 917-7,762 novel miRNAs were found in six libraries. Six novel miRNAs were selected for examination of their secondary structures and confirmation by stem-loop RT-PCR. In a differential expression analysis, 20, 22, and 58 known miRNAs exhibited significant differential expression between developmental stages 1 (secondary sporogenous cells had formed), 2 (all cells layers were present and mitosis had ceased), and 3 (meiotic division stage), respectively, of fertile and sterile plants. Some of these differential expressed miRNAs, such as tae-miR156, tae-miR164, tae-miR171, and tae-miR172, were shown to be associated with their targets. These targets were previously reported to be related to pollen development and/or male sterility, indicating that these miRNAs and their targets may be involved in the regulation of male fertility transition in the PTGMS wheat line BS366. Furthermore, target genes of miRNA cleavage sites were validated by degradome sequencing. In this study, a possible signal model for the miRNA-mediated signaling pathway during the process of male fertility transition in the PTGMS wheat line BS366 was developed. This study provides a new perspective for understanding the roles of miRNAs in male fertility in PTGMS lines of wheat.

Molecular characterization of novel TaNAC genes in wheat and overexpression of TaNAC2a confers drought tolerance in tobacco

Plant-specific NAC (NAM/ATAF/CUC) transcription factors (TFs) have been reported to play a role in diverse stress responses and developmental processes. We show here that six new genes encoding NAC TFs in wheat (Triticum aestivum) were identified (named as TaNAC2a, TaNAC4a, TaNAC6, TaNAC7, TaNAC13 and TaNTL5, respectively), and we classified them into three groups: stress-related NACs, development-related NACs and NTLs (membrane-associated TFs belonging to NAC) by phylogenetic analysis. All TaNACs were induced by one or several kinds of stress treatments including dehydration, salinity and low temperature, whereas different genes showed different expression levels. All these TaNACs, except TaNAC7, were proven to have transcriptional activation activity in the yeast strain AH109 by transactivation analysis. Furthermore, subcellular localization analysis revealed that four TaNAC:GFP (green fluorescent protein) fusion proteins were localized in the nucleus, TaNAC2a:GFP mainly located in the nucleus and the plasma membrane, TaNTL5:GFP was associated with the membrane, while truncated TaNTL5(ΔTM):GFP (lacking the transmembrane motif) was detected exclusively in the nucleus. Semi-quantitative reverse transcription polymerase chain reaction analysis demonstrated that five genes exhibited organ-specific expression. Transgenic tobacco plants overexpressing TaNAC2a showed higher fresh weight and dry weight than non-transgenic plants under drought condition, which indicated that the transgene improved tobacco tolerance to drought treatment. Together, these results provided a preliminary characterization of six TaNACs, which possessed a potential role in improving stress tolerance and the regulation of development in wheat, and suggested that TaNAC2a was potentially useful for engineering drought tolerant plants.

[Tweed-Merrifield analysis for Chinese Shangdong adults]

OBJECTIVE:This study was to establish cephalometric normals for Shangdong Chinese based on the Tweed-Merrifield analysis. MEHTODS: Lateral cephalograms of 80 young adults(40 female and 40 male) with normal occlusions were selected.The ages was 18-24. RESULTS: To establish cephalometric normals for Shangdong Chinese based on the Tweed-Merrifield analysis,and discover FMA female>male,AFH,PFH,IND(P/A) female>male. CONCLUSION: These normals will be used to orthodontic diagnosis and treatment planning for Shangdong adult patients.

[Discharge patterns of respiratory related neurones in the medial areas of nucleus retrofacialis of medulla]

Experiments were performed on rabbits and SD rats, both anesthetized with urethane (1.0 g/kg, i.v. or i.p.). Discharges of phrenic nerve and the diaphragmatic muscle electric activities were monitored. Discharge patterns of the respiration-related neurons (RRNs) in the medial area of nucleus retrofacialis (mNRF) were recorded and analyzed. Among the 249 RRNs recorded in the mNRF of the rabbits, 118 were inspiratory (I, 47.4%), 91 expiratory (E, 36.5%), and 40 phase-spanning (PS, 16.1%). Both I and E neurons could be further subdivided into 4 subtypes, the PS neurons into E-I and I-E type. In the 153 RRNs recorded in rats, 68 were I (44.5%), 55 E (35.9%), 30 PS (19.6%). It was found that a group of E-I PS neurons that fire preceding phrenic nerve respiratory activity are located in the mNRF, which was believed to be important in the generation of the basic respiratory rhythm.

Timed dose-response relationship of depressive action of ouabain on toad heart contraction in vitro

Timed dose-response relationship (TDRR) of depressive action of ouabain (Oua) 0.01-30 mmol.L-1 on toad heart contraction in vitro was studied by simultaneous recordings of mechanical tension and electrocardiography. It was found that the inhibition of contraction tension, the latency, the half equilibrium time of depression, and the cardioplegia time (CPT) were all concentration-dependent (P < 0.01). The EC50 +/- L95 of Oua was 35 +/- 8 mumol.L-1, in which L95 is the average 95% confidence limit. The TDRR data of latency or CPT were fitted to the hyperbolic 4-parameter model II weighted with the square of SE inversely: Y = 25.9492(7.2757)/(1nX + 23.5906)(6.2757) + 72.7732 for latency and Y = 20637.37/(1nX + 3.0947)(3.5907) + 196.7069 for CPT. It was concluded that the hyperbolic type of TDRR was present in Oua depressive action on the toad heart contraction in vitro.

Effect of blocking medial area of nucleus retrofacialis on respiratory rhythm

Experiments were performed on anaesthetized, vagotomized rabbits. Respiratory movement and phrenic rhythmical discharge were reversibly abolished by the symmetrical injection of 1% procaine into the medial area of the nucleus retrofacialis (mNRF). Blocking other areas of the medulla had no obvious effect on respiratory rhythm, with the exception of the rostral portion of the ventral respiratory group (VRG), which overlaps with the mNRF. When the mNRF was blocked, most inspiratory and expiratory neurons recorded in the VRG and DRG (dorsal respiratory group) gradually started to fire continuously, and no longer exhibited respiratory rhythm. A minority of respiratory neurons was inactivated during apnea. Stimulation of the caudal portion of the DRG and VRG evoked only a short cluster of phrenic discharges instead of rhythmical firing, indicating that the respiratory neurons situated in these areas cannot generate rhythmic activity by themselves. This suggests that the mNRF plays an important role in the genesis and maintenance of basic respiratory rhythm.

[Role of the medial region of nucleus retrofacialis of the rabbit in the generation of respiratory rhythm]

The medulla of rabbits were exposed from ventral surface. When 1% procaine (0.3-1.0 microliters) was injected bilaterally through a micropipette into the medial region of nucleus retrofacialis (mNRF), the respiratory movement and phrenic rhythmical discharge could be reversibly abolished in all of 20 rabbits tested. The area related is very limited, about 1.0 x 1.0 x 1.0mm. Histological examination has shown that the effective injected area is mNRF. Discharge patterns of the respiratory-related neurons (RRNs) in mNRF of the rabbit were analyzed. The result showed that there were many E and E-I PS neurones in the mNRF. Blockade of mNRF caused continuous firing of most inspiratory and expiratory neurons recorded in the VRG and DRG and abolishment of respiratory rhythm. The minority of respiratory neurons were inactivated during apnea. Stimulation of the caudal portion of VRG and DRG during apnea could evoke only a short cluster of phrenic discharges instead of rhythmical firing, indicating that respiratory neurons located in these areas can not generate rhythmic activity themselves. The results suggest that an important area of the respiratory rhythm generators may be located in the medial region of nucleus retrofacialis.