GDP-D-mannose pyrophosphorylase from Pogonatherum paniceum enhances salinity and drought tolerance of transgenic tobacco

2016 ◽  
Vol 71 (7-8) ◽  
pp. 243-252 ◽  
Author(s):  
Taobo Ai ◽  
Xuehong Liao ◽  
Rui Li ◽  
Linhong Fan ◽  
Fengxue Luo ◽  
...  
Keyword(s):  
Drought Stress ◽  
Transgenic Tobacco ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Germination Rate ◽  
Crop Improvement ◽  
Potential Candidate ◽  
Sod Activity ◽  
Potential Candidate Gene ◽  
Pogonatherum Paniceum

Abstract Pogonatherum paniceum is a highly drought- and salt-tolerant plant species that is typically used for ecological restoration and the conservation of soil and water in many countries. Understanding the molecular mechanisms underlying plant abiotic stress responses, especially to salinity and drought stresses, in species such as P. paniceum could be important to broader crop improvement efforts. GDP-D-mannose pyrophosphorylase (GMPase) is the limiting enzyme in the synthesis of L-ascorbic acid (AsA), which plays a crucial role in the detoxification of reactive oxygen species (ROS). We have cloned and characterized the cDNA of the PpGMP gene of P. paniceum encoding a GMPase. The full-length cDNA sequence contains 1411 nucleotides encoding a putative protein with 361 amino acid residues and an approximate molecular mass of 39.68 kDa. The GMPase transcript was up-regulated in P. paniceum plants subjected to salinity and drought stress, respectively. Transgenic tobacco expressing PpGMPase exhibited enhanced salinity and drought resistance, a higher seed germination rate, better growth performance, a higher AsA content, a more stable redox state, higher superoxide dismutase (SOD) activity, and lower levels of malonaldehyde (MDA) and H2O2 under drought and salinity stress. Taken together, expression of PpGMPase in tobacco conferred salinity and drought stress tolerance by increasing the content of AsA, thereby enhancing ROS-detoxifying functions. Thus, PpGMP is a potential candidate gene for crop improvement.

scholarly journals Comparative Proteomic and Morpho-Physiological Analyses of Maize Wild-Type Vp16 and Mutant vp16 Germinating Seed Responses to PEG-Induced Drought Stress

2019 ◽  
Vol 20 (22) ◽  
pp. 5586 ◽  
Author(s):  
Songtao Liu ◽  
Tinashe Zenda ◽  
Anyi Dong ◽  
Yatong Yang ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Crop Improvement ◽  
Pentose Phosphate ◽  
Glutathione Metabolism ◽  
Abiotic Factor ◽  
Wild Type ◽  
Proteomics Analysis

Drought stress is a major abiotic factor compromising plant cell physiological and molecular events, consequently limiting crop growth and productivity. Maize (Zea mays L.) is among the most drought-susceptible food crops. Therefore, understanding the mechanisms underlying drought-stress responses remains critical for crop improvement. To decipher the molecular mechanisms underpinning maize drought tolerance, here, we used a comparative morpho-physiological and proteomics analysis approach to monitor the changes in germinating seeds of two incongruent (drought-sensitive wild-type Vp16 and drought-tolerant mutant vp16) lines exposed to polyethylene-glycol-induced drought stress for seven days. Our physiological analysis showed that the tolerant line mutant vp16 exhibited better osmotic stress endurance owing to its improved reactive oxygen species scavenging competency and robust osmotic adjustment as a result of greater cell water retention and enhanced cell membrane stability. Proteomics analysis identified a total of 1200 proteins to be differentially accumulated under drought stress. These identified proteins were mainly involved in carbohydrate and energy metabolism, histone H2A-mediated epigenetic regulation, protein synthesis, signal transduction, redox homeostasis and stress-response processes; with carbon metabolism, pentose phosphate and glutathione metabolism pathways being prominent under stress conditions. Interestingly, significant congruence (R2 = 81.5%) between protein and transcript levels was observed by qRT-PCR validation experiments. Finally, we propose a hypothetical model for maize germinating-seed drought tolerance based on our key findings identified herein. Overall, our study offers insights into the overall mechanisms underpinning drought-stress tolerance and provides essential leads into further functional validation of the identified drought-responsive proteins in maize.

scholarly journals Over-expression of poplar NAC15 gene enhances wood formation in transgenic tobacco

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Wenjing Yao ◽  
Dawei Zhang ◽  
Boru Zhou ◽  
Jianping Wang ◽  
Renhua Li ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Wood Formation ◽  
Potential Candidate ◽  
Rna Seq ◽  
Populus Simonii ◽  
Over Expression ◽  
Potential Candidate Gene ◽  
Relative Expression Level ◽  
Transgenic Lines ◽  
Highly Expressed Genes

Abstract Background NAC (NAM/ATAF/CUC) is one of the largest plant-specific transcription factor (TF) families known to play significant roles in wood formation. Acting as master gene regulators, a few NAC genes can activate secondary wall biosynthesis during wood formation in woody plants. Results In the present study, firstly, we screened 110 differentially expressed NAC genes in the leaves, stems, and roots of di-haploid Populus simonii×P. nigra by RNA-Seq. Then we identified a nucleus-targeted gene, NAC15 gene, which was one of the highly expressed genes in the stem among 110 NAC family members. Thirdly, we conducted expression pattern analysis of NAC15 gene, and observed NAC15 gene was most highly expressed in the xylem by RT-qPCR. Moreover, we transferred NAC15 gene into tobacco and obtained 12 transgenic lines overexpressing NAC15 gene (TLs). And the relative higher content of hemicellulose, cellulose and lignin was observed in the TLs compared to the control lines containing empty vector (CLs). It also showed darker staining in the culms of the TLs with phloroglucinol staining, compared to the CLs. Furthermore, the relative expression level of a few lignin- and cellulose-related genes was significantly higher in the TLs than that in the CLs. Conclusions The overall results indicated that NAC15 gene is highly expressed in the xylem of poplar and may be a potential candidate gene playing an important role in wood formation in transgenic tobacco.

scholarly journals Integrated transcriptome and small RNA sequencing analyses reveal a drought stress response network in Sophora tonkinensis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying Liang ◽  
Kunhua Wei ◽  
Fan Wei ◽  
Shuangshuang Qin ◽  
Chuanhua Deng ◽  
...  
Keyword(s):  
Drought Stress ◽  
Rna Sequencing ◽  
Small Rna ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Differentially Expressed ◽  
Small Rna Sequencing ◽  
Severe Drought ◽  
A Genome ◽  
Sophora Tonkinensis

Abstract Background Sophora tonkinensis Gagnep is a traditional Chinese medical plant that is mainly cultivated in southern China. Drought stress is one of the major abiotic stresses that negatively impacts S. tonkinensis growth. However, the molecular mechanisms governing the responses to drought stress in S. tonkinensis at the transcriptional and posttranscriptional levels are not well understood. Results To identify genes and miRNAs involved in drought stress responses in S. tonkinensis, both mRNA and small RNA sequencing was performed in root samples under control, mild drought, and severe drought conditions. mRNA sequencing revealed 66,476 unigenes, and the differentially expressed unigenes (DEGs) were associated with several key pathways, including phenylpropanoid biosynthesis, sugar metabolism, and quinolizidine alkaloid biosynthesis pathways. A total of 10 and 30 transcription factors (TFs) were identified among the DEGs under mild and severe drought stress, respectively. Moreover, small RNA sequencing revealed a total of 368 miRNAs, including 255 known miRNAs and 113 novel miRNAs. The differentially expressed miRNAs and their target genes were involved in the regulation of plant hormone signal transduction, the spliceosome, and ribosomes. Analysis of the regulatory network involved in the response to drought stress revealed 37 differentially expressed miRNA-mRNA pairs. Conclusion This is the first study to simultaneously profile the expression patterns of mRNAs and miRNAs on a genome-wide scale to elucidate the molecular mechanisms of the drought stress responses of S. tonkinensis. Our results suggest that S. tonkinensis implements diverse mechanisms to modulate its responses to drought stress.

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

2018 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ~20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4752 ◽  
Author(s):  
Weiping Shi ◽  
Jingye Cheng ◽  
Xiaojie Wen ◽  
Jixiang Wang ◽  
Guanyan Shi ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Abiotic Factors ◽  
Chlorophyll Biosynthesis ◽  
Foxtail Millet ◽  
Setaria Italica ◽  
Parental Lines

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet (Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ∼20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

scholarly journals Comparative Phenotypic and Transcriptomic Analysis Reveals Key Responses of Upland Cotton to Salinity Stress During Postgermination

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingxia Zhang ◽  
Pei Zhang ◽  
Xuehan Huo ◽  
Yang Gao ◽  
Yu Chen ◽  
...  
Keyword(s):  
Salinity Stress ◽  
Salinity Tolerance ◽  
Molecular Mechanisms ◽  
Germination Rate ◽  
Primary Root ◽  
Carotenoid Biosynthesis ◽  
Mapk Signaling ◽  
Ethylene Response Factor ◽  
Sod Activity ◽  
As Stress

To understand the molecular mechanisms of salinity tolerance during seed germination and post-germination stages, this study characterized phenotypic and transcriptome responses of two cotton cultivars during salinity stress. The two cultivars were salt-tolerant (ST) LMY37 and salt-sensitive (SS) ZM12, with the former exhibiting higher germination rate, growth, and primary-root fresh weight under salinity stress. Transcriptomic comparison revealed that up-regulation of differentially expressed genes (DEGs) was the main characteristic of transcriptional regulation in ST, while SS DEGs were mainly down-regulated. GO and KEGG analyses uncovered both common and specific responses in ST and SS. Common processes, such as reactive oxygen species (ROS) metabolism and cell wall biosynthesis, may be general responses to salinity in cotton. In contrast, DEGs involved in MAPK-signaling pathway activated by ROS, carotenoid biosynthesis pathway and cysteine and methionine metabolism pathway [producing the precursors of stress hormone abscisic acid (ABA) and ethylene (ET), respectively] as well as stress tolerance related transcription factor genes, showed significant expression differences between ST and SS. These differences might be the molecular basis leading to contrasting salinity tolerance. Silencing of GhERF12, an ethylene response factor gene, caused higher salinity sensitivity and increased ROS accumulation after salinity stress. In addition, peroxidase (POD) and superoxide dismutase (SOD) activity obviously declined after silencing GhERF12. These results suggest that GhERF12 is involved in salinity tolerance during early development. This study provides a novel and comprehensive perspective to understand key mechanisms of salinity tolerance and explores candidate genes that may be useful in developing stress-tolerant crops through biotechnology.

Seed Germination and Physiological Characteristics of Amaranthus mangostanus L. under Drought Stress

2011 ◽  
Vol 183-185 ◽  
pp. 1071-1074
Author(s):  
Yong Dong Sun ◽  
Xiao Hua Du ◽  
Wen Jie Zhang ◽  
Li Sun ◽  
Ran Li
Keyword(s):  
Drought Stress ◽  
Seed Germination ◽  
Germination Rate ◽  
Proline Content ◽  
Shoot Length ◽  
Physiological Characteristics ◽  
Sod Activity ◽  
Peg 6000 ◽  
Mda Content ◽  
Effects Of Drought

Effects of drought stress on the seed germination and physiological characteristics of amaranth were investigated. The results were as follows: the germination rate and germination potential of amaranth decreased with the increasing of PEG-6000 concentrations. Meanwhile, the root length, shoot length and peroxidase (POD) activity were significantly increased at lower PEG-6000 concentrations, but then decreased with the increasing of PEG-6000. Malondialdehyde (MDA) content, proline content and superoxide dismutase (SOD) activity were all significantly increased under drought stress, and reached the top at 20% PEG-6000. These findings indicated that amaranth tolerates drought stress through increasing the activities of SOD and POD and accumulating proline content.

scholarly journals Conserved miR396b-GRF Regulation Is Involved in Abiotic Stress Responses in Pitaya (Hylocereus polyrhizus)

2019 ◽  
Vol 20 (10) ◽  
pp. 2501 ◽  
Author(s):  
A-Li Li ◽  
Zhuang Wen ◽  
Kun Yang ◽  
Xiao-Peng Wen
Keyword(s):  
Abiotic Stress ◽  
Drought Stress ◽  
Binding Site ◽  
Stress Responses ◽  
Abiotic Stresses ◽  
Molecular Mechanisms ◽  
Evolutionary Relationship ◽  
Pcr Analysis ◽  
Sequencing Analysis ◽  
Hylocereus Polyrhizus

MicroRNA396 (miR396) is a conserved microRNA family that targets growth-regulating factors (GRFs), which play significant roles in plant growth and stress responses. Available evidence justifies the idea that miR396-targeted GRFs have important functions in many plant species; however, no genome-wide analysis of the pitaya (Hylocereus polyrhizus) miR396 gene has yet been reported. Further, its biological functions remain elusive. To uncover the regulatory roles of miR396 and its targets, the hairpin sequence of pitaya miR396b and the open reading frame (ORF) of its target, HpGRF6, were isolated from pitaya. Phylogenetic analysis showed that the precursor miR396b (MIR396b) gene of plants might be clustered into three major groups, and, generally, a more recent evolutionary relationship in the intra-family has been demonstrated. The sequence analysis indicated that the binding site of hpo-miR396b in HpGRF6 is located at the conserved motif which codes the conserved “RSRKPVE” amino acid in the Trp–Arg–Cys (WRC) region. In addition, degradome sequencing analysis confirmed that four GRFs (GRF1, c56908.graph_c0; GRF4, c52862.graph_c0; GRF6, c39378.graph_c0 and GRF9, c54658.graph_c0) are hpo-miR396b targets that are regulated by specific cleavage at the binding site between the 10th and 11th nucleotides from the 5′ terminus of hpo-miR396b. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that hpo-miR396b is down-regulated when confronted with drought stress (15% polyethylene glycol, PEG), and its expression fluctuates under other abiotic stresses, i.e., low temperature (4 ± 1 °C), high temperature (42 ± 1 °C), NaCl (100 mM), and abscisic acid (ABA; 0.38 mM). Conversely, the expression of HpGRF6 showed the opposite trend to exposure to these abiotic stresses. Taken together, hpo-miR396b plays a regulatory role in the control of HpGRF6, which might influence the abiotic stress response of pitaya. This is the first documentation of this role in pitaya and improves the understanding of the molecular mechanisms underlying the tolerance to drought stress in this fruit.

Overexpression of DnWRKY11 enhanced salt and drought stress tolerance of transgenic tobacco

Biologia ◽  
2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Xiang-Bin Xu ◽  
Yuan-Yuan Pan ◽  
Chun-Ling Wang ◽  
Qi-Cai Ying ◽  
Hong-Miao Song ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Tolerance ◽  
Transgenic Tobacco ◽  
Stress Responses ◽  
Environmental Changes ◽  
Germination Rate ◽  
Defense Responses ◽  
Biotic And Abiotic Stress ◽  
Field Environment

AbstractDendrobium seedlings showed low survival rate when they were transferred from in vitro conditions to greenhouse or field environment. One of the major reasons is their low tolerance to environmental changes. WRKY transcription factors are one of the largest families of transcriptional regulators in plants. They are involved in various biotic and abiotic stress responses. One DnWRKY11 gene was isolated from Dendrobium nobile. To explore the function of DnWRKY11 in Dendrobium defense responses to abiotic stress, it was overexpressed in tobacco. Under salt and drought stresses, the DnWRKY11 transgenic tobacco showed higher germination rate, longer root length, higher fresh weight, higher activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and lower content of malonidialdehyde (MDA) than the wild type. These results proved the important roles of DnWRKY11 in plant response to drought and salt stresses, and provided a potential gene for improving environmental stress tolerance of Dendrobium seedlings.

scholarly journals Global Transcriptome and Weighted Gene Co-expression Network Analyses of Growth-Stage-Specific Drought Stress Responses in Maize

2021 ◽  
Vol 12 ◽  
Author(s):  
Songtao Liu ◽  
Tinashe Zenda ◽  
Anyi Dong ◽  
Yatong Yang ◽  
Nan Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Transcriptome Analysis ◽  
Stress Responses ◽  
Growth Stage ◽  
Molecular Mechanisms ◽  
Grain Filling ◽  
Growth Stages ◽  
Specific Response ◽  
Network Analyses

Drought is the major abiotic stress threatening maize (Zea mays L.) production globally. Despite recent scientific headway in deciphering maize drought stress responses, the overall picture of key genes, pathways, and co-expression networks regulating maize drought tolerance is still fragmented. Therefore, deciphering the molecular basis of maize drought tolerance remains pertinent. Here, through a comprehensive comparative leaf transcriptome analysis of drought-tolerant hybrid ND476 plants subjected to water-sufficient and water-deficit treatment conditions at flared (V12), tasseling (VT), the prophase of grain filling (R2), and the anaphase of grain filling (R4) crop growth stages, we report growth-stage-specific molecular mechanisms regulating maize drought stress responses. Based on the transcriptome analysis, a total of 3,451 differentially expressed genes (DEGs) were identified from the four experimental comparisons, with 2,403, 650, 397, and 313 DEGs observed at the V12, VT, R1, and R4 stages, respectively. Subsequently, 3,451 DEGs were divided into 12 modules by weighted gene co-expression network analysis (WGCNA), comprising 277 hub genes. Interestingly, the co-expressed genes that clustered into similar modules exhibited diverse expression tendencies and got annotated to different GO terms at different stages. MapMan analysis revealed that DEGs related to stress signal transduction, detoxification, transcription factor regulation, hormone signaling, and secondary metabolites biosynthesis were universal across the four growth stages. However, DEGs associated with photosynthesis and amino acid metabolism; protein degradation; transport; and RNA transcriptional regulation were uniquely enriched at the V12, VT, R2, and R4 stages, respectively. Our results affirmed that maize drought stress adaptation is a growth-stage-specific response process, and aid in clarifying the fundamental growth-stage-specific mechanisms regulating drought stress responses in maize. Moreover, genes and metabolic pathways identified here can serve as valuable genetic resources or selection targets for further functional validation experiments.

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