Expression and localization of SWEETs in Populus and the effect of SWEET7 overexpression in secondary growth

2020 ◽  
Author(s):  
Li Zhang ◽  
Lijuan Wang ◽  
Jin Zhang ◽  
Cai Song ◽  
Yu Li ◽  
...  

Abstract In trees, wood formation needs carbon import from the photosynthetic source tissues. Sugar transporters play important roles in carbohydrate transport into wood-forming cells. SWEETs (Sugars Will Eventually be Exported Transporters) play essential roles in many physiological processes. However, the roles of this family in the growth and development of woody plants have not been systematically investigated. In this study, 27 SWEET genes were identified in the Populus trichocarpa genome. These SWEET genes were classified into four clades based on their phylogenetic relationships, gene structures, conserved motifs, and chromosomal locations. Representative SWEET members from each clade were selected for further studies. The PagSWEETs were localized to plasma membrane, vacuolar, endoplasmic reticulum (ER) or Golgi. Real-time quantitative PCR analysis showed that PagSWEETs have distinct expression patterns in various tissues, and PagSWEET5, 7, 10b, 10c, 15b, 17a, and 17c exhibited high expression levels in stems. PagSWEET7 is localized to the cytoplasmic membrane and specifically expressed in the phloem as detected by histochemical GUS assays. Xylem production and xylem sugar content were greater in developing wood of SWEET7 overexpression (OX) than Wild-type (WT) lines. Collectively, these results provide valuable information for further investigating functions of PagSWEET genes, and identify PagSWEET7 as a candidate gene for using biotechnology to modify the wood formation in poplar.

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 315
Author(s):  
Hanzeng Wang ◽  
Xue Leng ◽  
Xuemei Xu ◽  
Chenghao Li

The TIFY gene family is specific to land plants, exerting immense influence on plant growth and development as well as responses to biotic and abiotic stresses. Here, we identify 25 TIFY genes in the poplar (Populus trichocarpa) genome. Phylogenetic tree analysis revealed these PtrTIFY genes were divided into four subfamilies within two groups. Promoter cis-element analysis indicated most PtrTIFY genes possess stress- and phytohormone-related cis-elements. Quantitative real-time reverse transcription polymerase chain reaction (qRT–PCR) analysis showed that PtrTIFY genes displayed different expression patterns in roots under abscisic acid, methyl jasmonate, and salicylic acid treatments, and drought, heat, and cold stresses. The protein interaction network indicated that members of the PtrTIFY family may interact with COI1, MYC2/3, and NINJA. Our results provide important information and new insights into the evolution and functions of TIFY genes in P. trichocarpa.


Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 142
Author(s):  
Xiaowei Ma ◽  
Feng An ◽  
Lifeng Wang ◽  
Dong Guo ◽  
Guishui Xie ◽  
...  

The rubber tree (Hevea brasiliensis) is a widely cultivated crop in tropical acidic soil that is tolerant to high concentration of aluminum and the aluminum-activated malate transporter (ALMT) plays an important role in plant aluminum detoxification. However, the effects of ALMT on rubber tree aluminum tolerance, growth performance, and latex production are unclear. In this study, 17 HbALMT genes were identified from the genome of rubber trees. The physiological and biochemical characteristics, phylogenetic relationships, gene structures, conserved motifs, cis-elements of promoter, and expression patterns of the identified HbALMT genes were studied. Phylogenetic relationships indicated that these genes were divided into four clusters and genes in the same cluster have similar gene structures and conserved motifs. The promoters of HbALMT genes contain many cis-elements associated with biotic stress and abiotic stress. Quantitative real-time PCR analysis revealed HbALMTs showed various expression patterns in different tissues, indicating the functional diversity of HbALMT genes in different tissues of rubber trees. Transcriptome analysis and qRT-PCR assay showed that most of the HbALMT genes responded to aluminum stress, and among the 17 HbALMTs, HbALMT1, HbALMT2, HbALMT13, and HbALMT15 displayed higher expression levels in roots after two or five days of Al treatments, indicating their potential involvement in aluminum detoxification. Taken together, this study laid a foundation for further understanding the molecular evolution of the ALMT genes and their involvement in rubber tree aluminum adaption.


HortScience ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 614-619
Author(s):  
Cai-Hong Jia ◽  
Ju-Hua Liu ◽  
Zhi-Qiang Jin ◽  
Qiu-Ju Deng ◽  
Jian-Bin Zhang ◽  
...  

A full-length cDNA isolated from banana (Musa acuminata L. AAA group) fruit was named MaMDH, containing an open reading frame encoding 332 amino acids that represents the gene for cytoplasmic malic dehydrogenase (MDH). Sequence analysis showed that MaMDH shares high similarity with MDHs from castor bean (XP_002533463), tobacco (CAC12826), peach (AAL11502), and chickpeas (CAC10208). Real-time quantitative polymerase chain reaction (PCR) analysis of MaMDH spatial expression showed that it was expressed in all organs examined: roots, rhizomes, leaves, flowers, and fruits. The expression was the highest in flowers followed by the fruits and roots, whereas the rhizomes and leaves displayed the lowest expression levels. Real-time quantitative PCR revealed that MaMDH exhibited differential expression patterns in post-harvest banana fruits correlating with ethylene biosynthesis. In naturally ripened banana fruits, MaMDH expression was in accordance with ethylene biosynthesis. In accordance, for banana fruits treated with the ethylene analog 1-methylclopropene (1-MCP), MaMDH expression levels were inhibited and remained constant. After treatment with ethylene, MaMDH expression in banana fruits significantly increased with ethylene biosynthesis and peaked 3 days after harvest, which was 11 days earlier than that in naturally ripened banana fruits. These results suggest that MaMDH expression is induced by ethylene to regulate post-harvest banana fruits ripening.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7605
Author(s):  
Caili Li ◽  
Dongqiao Li ◽  
Hong Zhou ◽  
Jiang Li ◽  
Shanfa Lu

Salvia miltiorrhiza is one of the most commonly used traditional Chinese medicine materials. It contains important bioactive phenolic compounds, such as salvianolic acids, flavonoids and anthocyanins. Elucidation of phenolic compound biosynthesis and its regulatory mechanism is of great significance for S. miltiorrhiza quality improvement. Laccases (LACs) are multicopper-containing enzymes potentially involved in the polymerization of phenolic compounds. So far, little has been known about LAC genes in S. miltiorrhiza. Through systematic investigation of the whole genome sequence and transcriptomes of S. miltiorrhiza, we identified 65 full-length SmLAC genes (SmLAC1–SmLAC65). Phylogenetic analysis showed that 62 of the identified SmLACs clustered with LACs from Arabidopsis and Populus trichocarpa in seven clades (C1–C7), whereas the other three fell into one S. miltiorrhiza-specific clade (C8). All of the deduced SmLAC proteins contain four conserved signature sequences and three typical Cu-oxidase domains, and gene structures of most LACs from S. miltiorrhiza, Arabidopsis and P. trichocarpa were highly conserved, however SmLACs encoding C8 proteins showed distinct intron-exon structures. It suggests the conservation and diversity of plant LACs in gene structures. The majority of SmLACs exhibited tissue-specific expression patterns, indicates manifold functions of SmLACs played in S. miltiorrhiza. Analysis of high-throughput small RNA sequences and degradome data and experimental validation using the 5′ RACE method showed that 23 SmLACs were targets of Smi-miR397. Among them, three were also targeted by Smi-miR408. It suggests the significance of miR397 and miR408 in posttranscriptional regulation of SmLAC genes. Our results provide a foundation for further demonstrating the functions of SmLACs in the production of bioactive phenolic compounds in S. miltiorrhiza.


Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Xue Leng ◽  
Hanzeng Wang ◽  
Shuang Zhang ◽  
Chunpu Qu ◽  
Chuanping Yang ◽  
...  

Ascorbate peroxidase (APX) is a member of class I of the heme-containing peroxidase family. The enzyme plays important roles in scavenging reactive oxygen species for protection against oxidative damage and maintaining normal plant growth and development, as well as in biotic stress responses. In this study, we identified 11 APX genes in the Populus trichocarpa genome using bioinformatic methods. Phylogenetic analysis revealed that the PtrAPX proteins were classifiable into three clades and the members of each clade shared similar gene structures and motifs. The PtrAPX genes were distributed on six chromosomes and four segmental-duplicated gene pairs were identified. Promoter cis-elements analysis showed that the majority of PtrAPX genes contained a variety of phytohormone- and abiotic stress-related cis-elements. Tissue-specific expression profiles indicated that the PtrAPX genes primarily function in roots and leaves. Real-time quantitative PCR (RT-qPCR) analysis indicated that PtrAPX transcription was induced in response to drought, salinity, high ammonium concentration, and exogenous abscisic acid treatment. These results provide important information on the phylogenetic relationships and functions of the APX gene family in P. trichocarpa.


2010 ◽  
Vol 56 (4) ◽  
pp. 445-453 ◽  
Author(s):  
Zhengbing Guan ◽  
Guolin Cai ◽  
Junyong Sun ◽  
Jian Lu

Abstract Encoded by seven genes, angiopoietin-like (ANGPTL) family members structurally similar to the angiogenic regulating factor angiopoietin are known to possess biological activities in angiogenesis and metabolism. Here we reports for the first time the identification and expression analysis of all the seven members of bovine ANGPTL gene family, which were designated bANGPTL1 to bANGPTL7 in order. The seven bANGPTL genes consist of 4-9 exons, span 3800-43000 bp and are located on different chromosomes. The deduced amino acid sequences of the members all possess an N-terminal coiled-coil domain and a C-terminal fibrinogen-like domain, both characteristics of angiopoietins. Phylogenetic analysis showed that the 32 identified ANGPTL homologs from 9 species could be classified into two major groups. Real-time quantitative PCR (Q-PCR) analysis revealed that the bANGPTL family members have different expression patterns. This study will be helpful for investigation on the biological role of the bANGPTL family in this economically important species. Furthermore, it provides an insight into the molecular evolution of the emerging ANGPTL family.


Biomolecules ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 66 ◽  
Author(s):  
Ren-Fang Zeng ◽  
Jing-Jing Zhou ◽  
Sheng-Rui Liu ◽  
Zhi-Meng Gan ◽  
Jin-Zhi Zhang ◽  
...  

SQUAMOSA-promoter binding protein (SBP)-box genes encode a family of plant-specific transcription factors that play vital roles in plant growth and development. In this study, 15 SBP-box genes were identified and isolated from Citrus clementina (CclSBPs), where 10 of these genes were predicted to be putative targets of Citrus clementina microRNA156 (CclmiR156). The 15 CclSBP genes could be classified into six groups based on phylogenetic analysis, diverse intron–exon structure, and motif prediction, similar to the SQUAMOSA promoter binding protein-like (SPL) gene family of Populus trichocarpa and Arabidopsis thaliana. Furthermore, CclSBPs classified into a group/subgroup have similar gene structures and conserved motifs, implying their functional redundancy. Tissue-specific expression analysis of CclSBPs demonstrated their diversified expression patterns. To further explore the potential role of CclSBPs during floral inductive water deficits, the dynamic changes of the 15 CclSBPs were investigated during floral inductive water deficits, and the results showed that some CclSBPs were associated with floral induction. Among these genes, CclSBP6 was not homologous to the Arabidopsis SBP-box gene family, and CclSBP7 was regulated by being alternatively spliced. Therefore, CclSBP6 and CclSBP7 were genetically transformed in Arabidopsis. Overexpression of the two genes changed the flowering time of Arabidopsis.


2019 ◽  
Author(s):  
Xinghao Chen ◽  
Jun Zhang ◽  
Chao Zhang ◽  
Shijie Wang ◽  
Minsheng Yang

Malate dehydrogenase (MDH) is widely distributed in plants and animals, and plays an important role in many metabolic processes. However, there have been few studies on MDH genes in poplar. In this study, 16 MDH gene sequences were identified from the Populus trichocarpa genome and renamed according to their chromosomal locations. Based on phylogenetic analysis, the PtMDH genes were divided into five groups, and genes that grouped together all shared the same subcellular location and had similar sequence lengths, gene structures, and conserved motifs. Two pairs of tandem duplication events and three segmental duplication events involving five genes were identified from the 15 PtMDH genes located on the chromosomes. Each pair of genes had a Ka/Ks ratios <1, indicating that the MDH gene family of P. trichocarpa was purified during evolution. Based on the transcriptome data of P. trichocarpa under salt stress and qRT-PCR verification, the expression patterns of PtMDH genes under salt stress were analyzed. The results showed that most of the genes were upregulated under salt stress, indicating that they play a role in the response of poplar to salt stress. The PtmMDH1 gene can be used as an important salt-tolerant candidate gene for further investigations of molecular mechanisms. This study lays the foundation for functional analysis of MDH genes and genetic improvement in poplar.


2021 ◽  
Vol 22 (22) ◽  
pp. 12336
Author(s):  
Shuo Han ◽  
Zhiyin Jiao ◽  
Meng-Xue Niu ◽  
Xiao Yu ◽  
Mengbo Huang ◽  
...  

Gibberellic acid-stimulated Arabidopsis (GASA) proteins, as cysteine-rich peptides (CRPs), play roles in development and reproduction and biotic and abiotic stresses. Although the GASA gene family has been identified in plants, the knowledge about GASAs in Populus euphratica, the woody model plant for studying abiotic stress, remains limited. Here, we referenced the well-sequenced Populus trichocarpa genome, and identified the GASAs in the whole genome of P. euphratica and P. trichocarpa. 21 candidate genes in P. trichocarpa and 19 candidate genes in P. euphratica were identified and categorized into three subfamilies by phylogenetic analysis. Most GASAs with signal peptides were located extracellularly. The GASA genes in Populus have experienced multiple gene duplication events, especially in the subfamily A. The evolution of the subfamily A, with the largest number of members, can be attributed to whole-genome duplication (WGD) and tandem duplication (TD). Collinearity analysis showed that WGD genes played a leading role in the evolution of GASA genes subfamily B. The expression patterns of P. trichocarpa and P. euphratica were investigated using the PlantGenIE database and the real-time quantitative PCR (qRT-PCR), respectively. GASA genes in P. trichocarpa and P. euphratica were mainly expressed in young tissues and organs, and almost rarely expressed in mature leaves. GASA genes in P. euphratica leaves were also widely involved in hormone responses and drought stress responses. GUS activity assay showed that PeuGASA15 was widely present in various organs of the plant, especially in vascular bundles, and was induced by auxin and inhibited by mannitol dramatically. In summary, this present study provides a theoretical foundation for further research on the function of GASA genes in P. euphratica.


2020 ◽  
Author(s):  
Ruiqi Wang ◽  
Mengxuan Ren ◽  
Shuanghui Tian ◽  
Cong Liu ◽  
He Cheng ◽  
...  

Abstract Background: MicroRNAs (miRNAs) are small, non-coding RNAs that have important regulatory functions in plant growth and development. However, the miRNAs that are involved in different developmental stages of tree stems have not been systemically characterized. In this study, we applied miRNA expression profiling method to the Populus trichocarpa trunks of the three distinct developmental stages defined as the primary stem (PS), transitional stem (TS), and secondary stem (SS) to investigate the miRNA species, their dynamic regulation and functions during the transitions of wood formation in different developmental stages at the genome-wide scale by Solexa sequencing.Results: We obtained 892, 872, and 882 known miRNAs and 1,727, 1,723, and 1,597 novel miRNAs, from PS, TS, and SS, respectively. And identified 114, 306, and 152 differentially expressed miRNAs (DE-miRNAs) with 921, 2,639, and 2,042 candidate target genes (CTGs), which formed 158, 855, and 297 DE-miRNA-CTG pairs in PS vs TS, PS vs SS, and TS vs SS , respectively. Among these, 47, 439, and 71 DE-miRNA-CTG pairs showed a significant negative correlation, respectively. Finally, we identified 39, 9, and 92 miRNA-CTG pairs involved in PS, TS, and SS, respectively. These DE-miRNA-CTG pairs in poplar or whose counterparts in other plant species are known to be transcriptional factors or structural genes involved in cell division and differentiation, cell wall modification, secondary cell wall (SCW) biosynthesis, lignification, and programmed cell death processes of wood formation. Moreover, qRT–PCR analysis confirmed that the results of small RNA-seq were robust and reliable and most miRNA-CTG pairs exhibited an inverse correlation.Conclusions: This is the first report on an integrated analysis of genome-wide mRNA and miRNA profiling of diverse phases of wood formation in poplar trunks. We showed that even though miRNAs involved in diverse developmental phases were not in a considerable number, their roles in the regulatory network that govern wood formation during different developmental stages cannot be negligible or underestimated. The information and data obtained in this paper significantly advanced our understanding of these miRNAs and their essential, dynamic and diversified roles as well as functions in diverse phases of wood formation in tree species.


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