scholarly journals Overexpression of AtAHL20 causes delayed flowering in Arabidopsis via repression of  FT expression

2020 ◽  
Author(s):  
Reuben Tayengwa ◽  
Pushpa Sharma-Koirala ◽  
Courtney F. Pierce ◽  
Breanna E Werner ◽  
Michael M Neff
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Gene Family ◽  
Stress Tolerance ◽  
Flowering Time ◽  
Camelina Sativa ◽  
Negative Regulator ◽  
Wild Type ◽  
Late Flowering ◽  
Drought Stress Tolerance

Abstract Background The 29-member Arabidopsis AHL gene family is classified into three main classes based on nucleotide and protein sequence evolutionary differences. These differences include the presence or absence of introns, type and/or number of conserved AT-hook and PPC domains. AHL gene family members are divided into two phylogenetic clades, Clade-A and Clade-B. A majority of the 29 members remain functionally uncharacterized. Furthermore, the biological significance of the DNA and peptide sequence diversity, observed in the conserved motifs and domains found in the different AHL types, is a subject area that remains largely unexplored. Results Transgenic plants overexpressing AtAHL20 flowered later than the wild type. Transcript accumulation analyses showed that 35S:AtAHL20 plants contained reduced FT, TSF, AGL8 and SPL3 mRNA levels. Similarly, overexpression of AtAHL20’s orthologue in Camelina sativa, Arabidopsis’ closely related Brassicaceae family member species, conferred a late-flowering phenotype via suppression of CsFT expression. In addition, 35S:AtAHL20 seedlings exhibited suppressed hypocotyl length and enhanced water stress tolerance. However, overexpression of an aberrant AtAHL20 gene harboring a missense mutation in the AT-hook domain’s highly conserved R-G-R core motif abolished the late-flowering phenotype. Data from targeted yeast-two-hybrid assays showed that AtAHL20 interacted with itself and several other Clade-A Type-I AHLs which have been previously implicated in flowering-time regulation: AtAHL22, AtAHL27 and AtAHL29. Conclusion We showed via gain-function analysis that AtAHL20 is a negative regulator of FT expression, as well as other downstream flowering time regulating genes. A similar outcome in Camelina sativa transgenic plants overexpressing CsAHL20 suggest that this is a conserved function. Additionally, overexpression of AtAHL20 resulted in shorter hypocotyls and enhanced drought stress tolerance compared to wild-type plants. Our results demonstrate that AtAHL20 is a negative regulator of transition to flowering and hypocotyl elongation, but a positive regulator of drought stress tolerance.

scholarly journals Overexpression of AtAHL20 causes delayed flowering in Arabidopsis via repression of FT expression

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Reuben Tayengwa ◽  
Pushpa Sharma Koirala ◽  
Courtney F. Pierce ◽  
Breanna E. Werner ◽  
Michael M. Neff
Keyword(s):  
Transgenic Plants ◽  
Gene Family ◽  
Flowering Time ◽  
Camelina Sativa ◽  
Negative Regulator ◽  
Peptide Sequence ◽  
Type I ◽  
Mrna Levels ◽  
Core Motif ◽  
Late Flowering

Abstract Background The 29-member Arabidopsis AHL gene family is classified into three main classes based on nucleotide and protein sequence evolutionary differences. These differences include the presence or absence of introns, type and/or number of conserved AT-hook and PPC domains. AHL gene family members are divided into two phylogenetic clades, Clade-A and Clade-B. A majority of the 29 members remain functionally uncharacterized. Furthermore, the biological significance of the DNA and peptide sequence diversity, observed in the conserved motifs and domains found in the different AHL types, is a subject area that remains largely unexplored. Results Transgenic plants overexpressing AtAHL20 flowered later than the wild type under both short and long days. Transcript accumulation analyses showed that 35S:AtAHL20 plants contained reduced FT, TSF, AGL8 and SPL3 mRNA levels. Similarly, overexpression of AtAHL20’s orthologue in Camelina sativa, Arabidopsis’ closely related Brassicaceae family member species, conferred a late-flowering phenotype via suppression of CsFT expression. However, overexpression of an aberrant AtAHL20 gene harboring a missense mutation in the AT-hook domain’s highly conserved R-G-R core motif abolished the late-flowering phenotype. Data from targeted yeast-two-hybrid assays showed that AtAHL20 interacted with itself and several other Clade-A Type-I AHLs which have been previously implicated in flowering-time regulation: AtAHL19, AtAHL22 and AtAHL29. Conclusion We showed via gain-of-function analysis that AtAHL20 is a negative regulator of FT expression, as well as other downstream flowering time regulating genes. A similar outcome in Camelina sativa transgenic plants overexpressing CsAHL20 suggest that this is a conserved function. Our results demonstrate that AtAHL20 acts as a photoperiod-independent negative regulator of transition to flowering.

scholarly journals Overexpression of AtAHL20 causes delayed flowering in Arabidopsis via repression of  FT expression

2020 ◽  
Author(s):  
Reuben Tayengwa ◽  
Pushpa Sharma-Koirala ◽  
Courtney F. Pierce ◽  
Breanna E Werner ◽  
Michael M Neff
Keyword(s):  
Transgenic Plants ◽  
Gene Family ◽  
Flowering Time ◽  
Camelina Sativa ◽  
Negative Regulator ◽  
Peptide Sequence ◽  
Type I ◽  
Mrna Levels ◽  
Core Motif ◽  
Late Flowering

Abstract Background The 29-member Arabidopsis AHL gene family is classified into three main classes based on nucleotide and protein sequence evolutionary differences. These differences include the presence or absence of introns, type and/or number of conserved AT-hook and PPC domains. AHL gene family members are divided into two phylogenetic clades, Clade-A and Clade-B. A majority of the 29 members remain functionally uncharacterized. Furthermore, the biological significance of the DNA and peptide sequence diversity, observed in the conserved motifs and domains found in the different AHL types, is a subject area that remains largely unexplored. Results Transgenic plants overexpressing AtAHL20 flowered later than the wild type under both short and long days. Transcript accumulation analyses showed that 35S:AtAHL20 plants contained reduced FT, TSF, AGL8 and SPL3 mRNA levels. Similarly, overexpression of AtAHL20’s orthologue in Camelina sativa, Arabidopsis’ closely related Brassicaceae family member species, conferred a late-flowering phenotype via suppression of CsFT expression. However, overexpression of an aberrant AtAHL20 gene harboring a missense mutation in the AT-hook domain’s highly conserved R-G-R core motif abolished the late-flowering phenotype. Data from targeted yeast-two-hybrid assays showed that AtAHL20 interacted with itself and several other Clade-A Type-I AHLs which have been previously implicated in flowering-time regulation: AtAHL22, AtAHL27 and AtAHL29. Conclusion We showed via gain-function analysis that AtAHL20 is a negative regulator of FT expression, as well as other downstream flowering time regulating genes. A similar outcome in Camelina sativa transgenic plants overexpressing CsAHL20 suggest that this is a conserved function. Our results demonstrate that AtAHL20 acts as a photoperiod-independent negative regulator of transition to flowering.

scholarly journals Overexpression of AtAHL20 causes delayed flowering in Arabidopsis via repression of FT expression

2020 ◽  
Author(s):  
Reuben Tayengwa ◽  
Pushpa Sharma-Koirala ◽  
Courtney F. Pierce ◽  
Breanna E Werner ◽  
Michael M Neff
Keyword(s):  
Transgenic Plants ◽  
Gene Family ◽  
Flowering Time ◽  
Camelina Sativa ◽  
Negative Regulator ◽  
Peptide Sequence ◽  
Type I ◽  
Mrna Levels ◽  
Core Motif ◽  
Late Flowering

Abstract Background: The 29-member Arabidopsis AHL gene family is classified into three main classes based on nucleotide and protein sequence evolutionary differences. These differences include the presence or absence of introns, type and/or number of conserved AT-hook and PPC domains. AHL gene family members are divided into two phylogenetic clades, Clade-A and Clade-B. A majority of the 29 members remain functionally uncharacterized. Furthermore, the biological significance of the DNA and peptide sequence diversity, observed in the conserved motifs and domains found in the different AHL types, is a subject area that remains largely unexplored. Results: Transgenic plants overexpressing AtAHL20 flowered later than the wild type under both short and long days. Transcript accumulation analyses showed that 35S:AtAHL20 plants contained reduced FT, TSF, AGL8 and SPL3 mRNA levels. Similarly, overexpression of AtAHL20’s orthologue in Camelina sativa, Arabidopsis’ closely related Brassicaceae family member species, conferred a late-flowering phenotype via suppression of CsFT expression. However, overexpression of an aberrant AtAHL20 gene harboring a missense mutation in the AT-hook domain’s highly conserved R-G-R core motif abolished the late-flowering phenotype. Data from targeted yeast-two-hybrid assays showed that AtAHL20 interacted with itself and several other Clade-A Type-I AHLs which have been previously implicated in flowering-time regulation: AtAHL22, AtAHL27 and AtAHL29.Conclusion: We showed via gain-function analysis that AtAHL20 is a negative regulator of FT expression, as well as other downstream flowering time regulating genes. A similar outcome in Camelina sativa transgenic plants overexpressing CsAHL20 suggest that this is a conserved function. Our results demonstrate that AtAHL20 acts as a photoperiod-independent negative regulator of transition to flowering.

scholarly journals Genome-Wide Analysis of MADS-Box Genes in Foxtail Millet (Setaria italica L.) and Functional Assessment of the Role of SiMADS51 in the Drought Stress Response

2021 ◽  
Vol 12 ◽  
Author(s):  
Wan Zhao ◽  
Li-Li Zhang ◽  
Zhao-Shi Xu ◽  
Liang Fu ◽  
Hong-Xi Pang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Abiotic Stresses ◽  
Survival Rates ◽  
Foxtail Millet ◽  
Negative Regulator ◽  
Setaria Italica ◽  
Mads Box ◽  
Drought Stress Tolerance ◽  
Genome Wide

MADS-box transcription factors play vital roles in multiple biological processes in plants. At present, a comprehensive investigation into the genome-wide identification and classification of MADS-box genes in foxtail millet (Setaria italica L.) has not been reported. In this study, we identified 72 MADS-box genes in the foxtail millet genome and give an overview of the phylogeny, chromosomal location, gene structures, and potential functions of the proteins encoded by these genes. We also found that the expression of 10 MIKC-type MADS-box genes was induced by abiotic stresses (PEG-6000 and NaCl) and exogenous hormones (ABA and GA), which suggests that these genes may play important regulatory roles in response to different stresses. Further studies showed that transgenic Arabidopsis and rice (Oryza sativa L.) plants overexpressing SiMADS51 had reduced drought stress tolerance as revealed by lower survival rates and poorer growth performance under drought stress conditions, which demonstrated that SiMADS51 is a negative regulator of drought stress tolerance in plants. Moreover, expression of some stress-related genes were down-regulated in the SiMADS51-overexpressing plants. The results of our study provide an overall picture of the MADS-box gene family in foxtail millet and establish a foundation for further research on the mechanisms of action of MADS-box proteins with respect to abiotic stresses.

scholarly journals Overexpression of StDREB2 Transcription Factor Enhances Drought Stress Tolerance in Cotton (Gossypium barbadense L.)

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 142 ◽  
Author(s):  
Mohamed El-Esawi ◽  
Aisha Alayafi
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Gas Exchange ◽  
Stress Tolerance ◽  
Plant Biomass ◽  
Oilseed Crop ◽  
Wild Type ◽  
Ros Scavenging ◽  
Antioxidant Genes ◽  
Drought Stress Tolerance

Drought stress significantly restricts plant growth and crop productivity. Cotton is the most important textile fiber and oilseed crop worldwide, and its cultivation is affected by drought stress, particularly in dry regions. Improving cotton tolerance to drought stress using the advanced genetic engineering technologies is a promising strategy to maintain crop production and fiber quality and meet the increasing worldwide fiber and oil demand. Dehydration-responsive element binding (DREB) transcription factors play a main role in regulating stresses-tolerance pathways in plant. This study investigated whether potato DREB2 (StDREB2) overexpression can improve drought tolerance in cotton. StDREB2 transcription factor was isolated and overexpressed in cotton. Plant biomass, boll number, relative water content, soluble sugars content, soluble protein content, chlorophyll content, proline content, gas-exchange parameters, and antioxidants enzymes (POD, CAT, SOD, GST) activity of the StDREB2-overexpressing cotton plants were higher than those of wild type plants. By contrast, the contents of malondialdehyde, hydrogen peroxide and superoxide anion of StDREB2-overexpressing transgenic plants were significantly lower than that of the wild type plants. Moreover, the transgenic cotton lines revealed higher expression levels of antioxidant genes (SOD, CAT, POD, GST) and stress-tolerant genes (GhERF2, GhNAC3, GhRD22, GhDREB1A, GhDREB1B, GhDREB1C) compared to wild-type plants. Taken together, these findings showed that StDREB2 overexpression augments drought stress tolerance in cotton by inducing plant biomass, gas-exchange characteristics, reactive oxygen species (ROS) scavenging, antioxidant enzymes activities, osmolytes accumulation, and expression of stress-related genes. As a result, StDREB2 could be an important candidate gene for drought-tolerant cotton breeding.

scholarly journals Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants

2016 ◽  
Vol 15 (4) ◽  
pp. 458-471 ◽  
Author(s):  
Madoka Kudo ◽  
Satoshi Kidokoro ◽  
Takuya Yoshida ◽  
Junya Mizoi ◽  
Daisuke Todaka ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Transgenic Plants ◽  
Stress Tolerance ◽  
Cell Elongation ◽  
Drought Stress Tolerance

scholarly journals Ectopic Expression of CrPIP2;3, a Plasma Membrane Intrinsic Protein Gene from the Halophyte Canavalia rosea, Enhances Drought and Salt-Alkali Stress Tolerance in Arabidopsis

2021 ◽  
Vol 22 (2) ◽  
pp. 565
Author(s):  
Jiexuan Zheng ◽  
Ruoyi Lin ◽  
Lin Pu ◽  
Zhengfeng Wang ◽  
Qiming Mei ◽  
...  
Keyword(s):  
Drought Stress ◽  
Transgenic Plants ◽  
Osmotic Stress ◽  
Stress Tolerance ◽  
High Salinity ◽  
High Salt ◽  
Marker Genes ◽  
Transcriptional Level ◽  
Wild Type ◽  
Ros Scavenging

Aquaporins are channel proteins that facilitate the transmembrane transport of water and other small neutral molecules, thereby playing vital roles in maintaining water and nutrition homeostasis in the life activities of all organisms. Canavalia rosea, a seashore and mangrove-accompanied halophyte with strong adaptability to adversity in tropical and subtropical regions, is a good model for studying the molecular mechanisms underlying extreme saline-alkaline and drought stress tolerance in leguminous plants. In this study, a PIP2 gene (CrPIP2;3) was cloned from C. rosea, and its expression patterns and physiological roles in yeast and Arabidopsis thaliana heterologous expression systems under high salt-alkali and high osmotic stress conditions were examined. The expression of CrPIP2;3 at the transcriptional level in C. rosea was affected by high salinity and alkali, high osmotic stress, and abscisic acid treatment. In yeast, the expression of CrPIP2;3 enhanced salt/osmotic and oxidative sensitivity under high salt/osmotic and H2O2 stress. The overexpression of CrPIP2;3 in A. thaliana could enhance the survival and recovery of transgenic plants under drought stress, and the seed germination and seedling growth of the CrPIP2;3 OX (over-expression) lines showed slightly stronger tolerance to high salt/alkali than the wild-type. The transgenic plants also showed a higher response level to high-salinity and dehydration than the wild-type, mostly based on the up-regulated expression of salt/dehydration marker genes in A. thaliana plants. The reactive oxygen species (ROS) staining results indicated that the transgenic lines did not possess stronger ROS scavenging ability and stress tolerance than the wild-type under multiple stresses. The results confirmed that CrPIP2;3 is involved in the response of C. rosea to salt and drought, and primarily acts by mediating water homeostasis rather than by acting as an ROS transporter, thereby influencing physiological processes under various abiotic stresses in plants.

Assessment of rice (Oryza sativa L.) genotypes for drought stress tolerance using morpho-physiological indices as a screening technique

2020 ◽  
Vol 53 (1) ◽  
Author(s):  
Asma Asma ◽  
Iqbal Hussain ◽  
Muhammad Yasin Ashraf ◽  
Muhammad Arslan Ashraf ◽  
Rizwan Rasheed ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Drought Stress ◽  
Stress Tolerance ◽  
Oryza Sativa L ◽  
Screening Technique ◽  
Drought Stress Tolerance ◽  
Physiological Indices
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