8 results on '"Qi, Tianxiong"'
Search Results
2. Alteration of S‐adenosylhomocysteine levels affects lignin biosynthesis in switchgrass
- Author
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Zetao Bai, Zhenying Wu, Wenwen Liu, Yuchen Liu, Yingping Cao, Chunxiang Fu, Lichao Ma, Yan Bao, and Qi Tianxiong
- Subjects
0106 biological sciences ,0301 basic medicine ,Carbon-Oxygen Lyases ,S‐adenosylhomocysteine ,Down-Regulation ,Plant Science ,Biology ,Panicum ,01 natural sciences ,Lignin ,Cell wall ,03 medical and health sciences ,chemistry.chemical_compound ,cystathionine γ‐synthase ,Biosynthesis ,Cell Wall ,S‐adenosylhomocysteine hydrolase ,Aromatic amino acids ,cardiovascular diseases ,Amino Acids ,Research Articles ,chemistry.chemical_classification ,Methionine ,Panicum virgatum L. (switchgrass) ,Adenosylhomocysteinase ,fungi ,food and beverages ,Methylation ,Plants, Genetically Modified ,S-Adenosylhomocysteine ,Amino acid ,nervous system diseases ,030104 developmental biology ,chemistry ,Biochemistry ,methionine metabolism ,Monolignol ,Genetic Engineering ,Agronomy and Crop Science ,lignin biosynthesis ,S‐adenosylmethionine ,Metabolic Networks and Pathways ,010606 plant biology & botany ,Biotechnology ,Research Article - Abstract
Summary Methionine (Met) synthesized from aspartate is a fundamental amino acid needed to produce S‐adenosylmethionine (SAM) that is an important cofactor for the methylation of monolignols. As a competitive inhibitor of SAM‐dependent methylation, the effect of S‐adenosylhomocysteine (SAH) on lignin biosynthesis, however, is still largely unknown in plants. Expression levels of Cystathionine γ‐synthase (PvCGS) and S‐adenosylhomocysteine hydrolase 1 (PvSAHH1) were down‐regulated by RNAi technology, respectively, in switchgrass, a dual‐purpose forage and biofuel crop. The transgenic switchgrass lines were subjected to studying the impact of SAH on lignin biosynthesis. Our results showed that down‐regulation of PvCGS in switchgrass altered the accumulation of aspartate‐derived and aromatic amino acids, reduced the content of SAH, enhanced lignin biosynthesis and stunted plant growth. In contrast, down‐regulation of PvSAHH1 raised SAH levels in switchgrass, impaired the biosynthesis of both guaiacyl and syringyl lignins and therefore significantly increased saccharification efficiency of cell walls. This work indicates that SAH plays a crucial role in monolignol methylation in switchgrass. Genetic regulation of either PvCGS or PvSAHH1 expression in switchgrass can change intracellular SAH contents and SAM to SAH ratios and therefore affect lignin biosynthesis. Thus, our study suggests that genes involved in Met metabolism are of interest as new valuable targets for cell wall bioengineering in future.
- Published
- 2018
3. Alteration ofS-adenosylhomocysteine levels affects lignin biosynthesis in switchgrass
- Author
-
Bai, Zetao, primary, Qi, Tianxiong, additional, Liu, Yuchen, additional, Wu, Zhenying, additional, Ma, Lichao, additional, Liu, Wenwen, additional, Cao, Yingping, additional, Bao, Yan, additional, and Fu, Chunxiang, additional
- Published
- 2018
- Full Text
- View/download PDF
4. Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop
- Author
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Zhenying Wu, Yingping Cao, Zeng-Yu Wang, Gongke Zhou, Qi Tianxiong, Chunxiang Fu, Hao Lin, Ruijuan Yang, and Yuqing Hang
- Subjects
0106 biological sciences ,0301 basic medicine ,Tiller initiation ,Transgenic switchgrass ,Biomass ,Tiller (botany) ,Genetically modified crops ,Management, Monitoring, Policy and Law ,Lignin ,01 natural sciences ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,Bioenergy ,Molecular breeding ,Energy crop ,biology ,SPL transcription factor ,Renewable Energy, Sustainability and the Environment ,Research ,food and beverages ,Herbaceous plant ,biology.organism_classification ,030104 developmental biology ,General Energy ,Agronomy ,Panicum virgatum ,010606 plant biology & botany ,Biotechnology - Abstract
Background Switchgrass (Panicum virgatum L.) is a dedicated lignocellulosic feedstock for bioenergy production. The SQUAMOSA PROMOTER-BINDING PROTEIN (SBP-box)-LIKE transcription factors (SPLs) change plant architecture and vegetative-to-reproductive phase transition significantly, and as such, they are promising candidates for genetic improvement of switchgrass biomass yield. However, the genome-wide identification and functional characterization of SPL genes have yet to be investigated in herbaceous energy crops. Results We identified 35 full-length SPL genes in the switchgrass genome. The phylogenetic relationship and expression pattern of PvSPLs provided baseline information for their function characterization. Based on the global overview of PvSPLs, we explored the biological function of miR156-targeted PvSPL1 and PvSPL2, which are closely related members of SPL family in switchgrass. Our results showed that PvSPL1 and PvSPL2 acted redundantly to modulate side tiller initiation, whereas they did not affect phase transition and internode initiation. Consistently, overexpression of the miR156-resistant rPvSPL2 in the miR156-overexpressing transgenic plants greatly reduced tiller initiation, but did not rescue the delayed flowering and increased internode numbers. Furthermore, suppression of PvSPL2 activity in switchgrass increased biomass yield and reduced lignin accumulation, which thereby elevated the total amount of solubilized sugars. Conclusions Our results indicate that different miR156-targeted PvSPL subfamily genes function predominantly in certain biological processes in switchgrass. We suggest that PvSPL2 and its paralogs can be utilized as the valuable targets in molecular breeding of energy crops for developing novel germplasms with high biofuel production. Electronic supplementary material The online version of this article (doi:10.1186/s13068-016-0516-z) contains supplementary material, which is available to authorized users.
- Published
- 2016
5. Genome-wide characterization of GRAS family genes in Medicago truncatula reveals their evolutionary dynamics and functional diversification
- Author
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Zhang, Hailing, primary, Cao, Yingping, additional, Shang, Chen, additional, Li, Jikai, additional, Wang, Jianli, additional, Wu, Zhenying, additional, Ma, Lichao, additional, Qi, Tianxiong, additional, Fu, Chunxiang, additional, Bai, Zetao, additional, and Hu, Baozhong, additional
- Published
- 2017
- Full Text
- View/download PDF
6. Alteration of S‐adenosylhomocysteine levels affects lignin biosynthesis in switchgrass.
- Author
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Bai, Zetao, Qi, Tianxiong, Liu, Yuchen, Wu, Zhenying, Ma, Lichao, Liu, Wenwen, Cao, Yingping, Bao, Yan, and Fu, Chunxiang
- Subjects
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ADENOSYLHOMOCYSTEINE , *LIGNINS , *BIOSYNTHESIS , *METHIONINE , *CYSTATHIONINE , *AROMATIC amino acid decarboxylases - Abstract
Summary: Methionine (Met) synthesized from aspartate is a fundamental amino acid needed to produce S‐adenosylmethionine (SAM) that is an important cofactor for the methylation of monolignols. As a competitive inhibitor of SAM‐dependent methylation, the effect of S‐adenosylhomocysteine (SAH) on lignin biosynthesis, however, is still largely unknown in plants. Expression levels of Cystathionine γ‐synthase (PvCGS) and S‐adenosylhomocysteine hydrolase 1 (PvSAHH1) were down‐regulated by RNAi technology, respectively, in switchgrass, a dual‐purpose forage and biofuel crop. The transgenic switchgrass lines were subjected to studying the impact of SAH on lignin biosynthesis. Our results showed that down‐regulation of PvCGS in switchgrass altered the accumulation of aspartate‐derived and aromatic amino acids, reduced the content of SAH, enhanced lignin biosynthesis and stunted plant growth. In contrast, down‐regulation of PvSAHH1 raised SAH levels in switchgrass, impaired the biosynthesis of both guaiacyl and syringyl lignins and therefore significantly increased saccharification efficiency of cell walls. This work indicates that SAH plays a crucial role in monolignol methylation in switchgrass. Genetic regulation of either PvCGS or PvSAHH1 expression in switchgrass can change intracellular SAH contents and SAM to SAH ratios and therefore affect lignin biosynthesis. Thus, our study suggests that genes involved in Met metabolism are of interest as new valuable targets for cell wall bioengineering in future. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
7. Genome-wide characterization of GRAS family genes in Medicago truncatula reveals their evolutionary dynamics and functional diversification
- Author
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Chunxiang Fu, Lichao Ma, Hailing Zhang, Zetao Bai, Baozhong Hu, Jikai Li, Zhenying Wu, Qi Tianxiong, Chen Shang, Jianli Wang, and Yingping Cao
- Subjects
Evolutionary Genetics ,0106 biological sciences ,0301 basic medicine ,Subfamily ,lcsh:Medicine ,Gene Expression ,Plant Science ,Plant Genetics ,Plant Root Nodulation ,Biochemistry ,01 natural sciences ,Genome ,Database and Informatics Methods ,Gene Expression Regulation, Plant ,Gene Duplication ,Gene duplication ,Plant Genomics ,lcsh:Science ,Phylogeny ,Plant Proteins ,Multidisciplinary ,biology ,Chromosome Mapping ,Genomics ,Plants ,Medicago truncatula ,Experimental Organism Systems ,Multigene Family ,Sequence Analysis ,Research Article ,Biotechnology ,Bioinformatics ,Arabidopsis Thaliana ,Brassica ,Computational biology ,Genes, Plant ,Research and Analysis Methods ,Genome Complexity ,Chromosomes, Plant ,Evolution, Molecular ,03 medical and health sciences ,Model Organisms ,Stress, Physiological ,Plant and Algal Models ,Sequence Motif Analysis ,Phylogenetics ,Nitrogen Fixation ,DNA-binding proteins ,Botany ,Genetics ,Gene family ,Gene Regulation ,Amino Acid Sequence ,Grasses ,Gene ,Evolutionary Biology ,Sequence Homology, Amino Acid ,Gene Expression Profiling ,lcsh:R ,Organisms ,Biology and Life Sciences ,Computational Biology ,Duplicated Genes ,Proteins ,biology.organism_classification ,Regulatory Proteins ,Gene expression profiling ,030104 developmental biology ,lcsh:Q ,Plant Biotechnology ,Rice ,Transcription Factors ,010606 plant biology & botany - Abstract
The GRAS gene family is a large plant-specific family of transcription factors that are involved in diverse processes during plant development. Medicago truncatula is an ideal model plant for genetic research in legumes, and specifically for studying nodulation, which is crucial for nitrogen fixation. In this study, 59 MtGRAS genes were identified and classified into eight distinct subgroups based on phylogenetic relationships. Motifs located in the C-termini were conserved across the subgroups, while motifs in the N-termini were subfamily specific. Gene duplication was the main evolutionary force for MtGRAS expansion, especially proliferation of the LISCL subgroup. Seventeen duplicated genes showed strong effects of purifying selection and diverse expression patterns, highlighting their functional importance and diversification after duplication. Thirty MtGRAS genes, including NSP1 and NSP2, were preferentially expressed in nodules, indicating possible roles in the process of nodulation. A transcriptome study, combined with gene expression analysis under different stress conditions, suggested potential functions of MtGRAS genes in various biological pathways and stress responses. Taken together, these comprehensive analyses provide basic information for understanding the potential functions of GRAS genes, and will facilitate further discovery of MtGRAS gene functions.
- Published
- 2017
8. Switchgrass SBP-box transcription factors PvSPL1 and 2 function redundantly to initiate side tillers and affect biomass yield of energy crop
- Author
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Wu, Zhenying, primary, Cao, Yingping, additional, Yang, Ruijuan, additional, Qi, Tianxiong, additional, Hang, Yuqing, additional, Lin, Hao, additional, Zhou, Gongke, additional, Wang, Zeng-Yu, additional, and Fu, Chunxiang, additional
- Published
- 2016
- Full Text
- View/download PDF
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