scholarly journals Overexpression of a microRNA-targeted NAC transcription factor improves drought and salt tolerance in Rice via ABA-mediated pathways

Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Dagang Jiang ◽  
Lingyan Zhou ◽  
Weiting Chen ◽  
Nenghui Ye ◽  
Jixing Xia ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Plant Architecture ◽  
Mutant Gene ◽  
Wild Type ◽  
Drought Treatment ◽  
Stress Regulation ◽  
Qpcr Analysis ◽  
Reverse Transcription Quantitative Pcr ◽  
Drought And Salt Tolerance ◽  
Aba Biosynthesis

Abstract Background The NAC (NAM, AFAT, and CUC) transcription factors play critical roles in rice (Oryza sativa) development and stress regulation. Overexpressing a microRNA (miR164b)-resistant OsNAC2 mutant gene, which generates transcripts that cannot be targeted by miR164b, improves rice plant architecture and yield; however, the performance of these mOsNAC2-overexpressing lines, named ZUOErN3 and ZUOErN4, under abiotic stress conditions such as drought have not yet been fully characterized. Results In this study, we showed that the germination of ZUOErN3 and ZUOErN4 seeds was delayed in comparison with the wild-type (WT) seeds, although the final germination rates of all lines were over 95%. The quantification of the endogenous ABA levels revealed that the germinating mOsNAC2-overexpressing seeds had elevated ABA levels, which resulted in their slower germination. The mOsNAC2-overexpressing plants were significantly more drought tolerance than the WT plants, with the survival rate increasing from 11.2% in the WT to nearly 70% in ZUOErN3 and ZUOErN4 plants after a drought treatment. Salt (NaCl) tolerance was also increased in the ZUOErN3 and ZUOErN4 plants due to significantly increased ABA levels. A reverse transcription quantitative PCR (RT-qPCR) analysis showed a significant increase in the expression of the ABA biosynthesis genes OsNCED1 and OsNCED3 in the mOsNAC2-overexpressing lines, and the expression levels of the stress-responsive genes OsP5CS1, OsLEA3, and OsRab16 were significantly increased in these plants. Moreover, OsNAC2 directly interacted with the promoters of OsLEA3 and OsNCED3 in yeast one-hybrid assays. Conclusions Taken together, our results show that OsNAC2 plays a positive regulatory role in drought and salt tolerance in rice through ABA-mediated pathways.

scholarly journals The Rice Abscisic Acid-Responsive RING Finger E3 Ligase OsRF1 Targets OsPP2C09 for Degradation and Confers Drought and Salinity Tolerance in Rice

2022 ◽  
Vol 12 ◽  
Author(s):  
Suyeon Kim ◽  
Seong-Im Park ◽  
Hyeokjin Kwon ◽  
Mi Hyeon Cho ◽  
Beom-Gi Kim ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Stress Responses ◽  
Transcriptional Activation ◽  
Ring Finger ◽  
E3 Ligase ◽  
Small Ring ◽  
Wild Type ◽  
Drought Treatment ◽  
Drought And Salt Tolerance

Drought and salinity are major important factors that restrain growth and productivity of rice. In plants, many really interesting new gene (RING) finger proteins have been reported to enhance drought and salt tolerance. However, their mode of action and interacting substrates are largely unknown. Here, we identified a new small RING-H2 type E3 ligase OsRF1, which is involved in the ABA and stress responses of rice. OsRF1 transcripts were highly induced by ABA, salt, or drought treatment. Upregulation of OsRF1 in transgenic rice conferred drought and salt tolerance and increased endogenous ABA levels. Consistent with this, faster transcriptional activation of key ABA biosynthetic genes, ZEP, NCED3, and ABA4, was observed in OsRF1-OE plants compared with wild type in response to drought stress. Yeast two-hybrid assay, BiFC, and co-immunoprecipitation analysis identified clade A PP2C proteins as direct interacting partners with OsRF1. In vitro ubiquitination assay indicated that OsRF1 exhibited E3 ligase activity, and that it targeted OsPP2C09 protein for ubiquitination and degradation. Cell-free degradation assay further showed that the OsPP2C09 protein is more rapidly degraded by ABA in the OsRF1-OE rice than in the wild type. The combined results suggested that OsRF1 is a positive player of stress responses by modulating protein stability of clade A PP2C proteins, negative regulators of ABA signaling.

scholarly journals OsMADS23 phosphorylated by SAPK9 confers drought and salt tolerance by regulating ABA biosynthesis in rice

PLoS Genetics ◽  
2021 ◽  
Vol 17 (8) ◽  
pp. e1009699
Author(s):  
Xingxing Li ◽  
Bo Yu ◽  
Qi Wu ◽  
Qian Min ◽  
Rongfeng Zeng ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Osmotic Stress ◽  
Target Genes ◽  
Plant Stress ◽  
Convincing Evidence ◽  
Mads Box ◽  
Osmotic Stress Tolerance ◽  
Drought And Salt Tolerance ◽  
New Strategy ◽  
Aba Biosynthesis

Some of MADS-box transcription factors (TFs) have been shown to play essential roles in the adaptation of plant to abiotic stress. Still, the mechanisms that MADS-box proteins regulate plant stress response are not fully understood. Here, a stress-responsive MADS-box TF OsMADS23 from rice conferring the osmotic stress tolerance in plants is reported. Overexpression of OsMADS23 remarkably enhanced, but knockout of the gene greatly reduced the drought and salt tolerance in rice plants. Further, OsMADS23 was shown to promote the biosynthesis of endogenous ABA and proline by activating the transcription of target genes OsNCED2, OsNCED3, OsNCED4 and OsP5CR that are key components for ABA and proline biosynthesis, respectively. Then, the convincing evidence showed that the OsNCED2-knockout mutants had lower ABA levels and exhibited higher sensitivity to drought and oxidative stress than wild type, which is similar to osmads23 mutant. Interestingly, the SnRK2-type protein kinase SAPK9 was found to physically interact with and phosphorylate OsMADS23, and thus increase its stability and transcriptional activity. Furthermore, the activation of OsMADS23 by SAPK9-mediated phosphorylation is dependent on ABA in plants. Collectively, these findings establish a mechanism that OsMADS23 functions as a positive regulator in response to osmotic stress by regulating ABA biosynthesis, and provide a new strategy for improving drought and salt tolerance in rice.

Dynamics of Telomeric DNA Turnover in Yeast

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 63-73
Author(s):  
Michael J McEachern ◽  
Dana Hager Underwood ◽  
Elizabeth H Blackburn
Keyword(s):  
Kluyveromyces Lactis ◽  
Mutant Gene ◽  
Dna Repeats ◽  
Wild Type ◽  
Telomeric Dna ◽  
Cell Divisions ◽  
Dna Turnover ◽  
Length Regulation ◽  
Turn Over

Abstract Telomerase adds telomeric DNA repeats to telomeric termini using a sequence within its RNA subunit as a template. We characterized two mutations in the Kluyveromyces lactis telomerase RNA gene (TER1) template. Each initially produced normally regulated telomeres. One mutation, ter1-AA, had a cryptic defect in length regulation that was apparent only if the mutant gene was transformed into a TER1 deletion strain to permit extensive replacement of basal wild-type repeats with mutant repeats. This mutant differs from previously studied delayed elongation mutants in a number of properties. The second mutation, TER1-Bcl, which generates a BclI restriction site in newly synthesized telomeric repeats, was indistinguishable from wild type in all phenotypes assayed: cell growth, telomere length, and in vivo telomerase fidelity. TER1-Bcl cells demonstrated that the outer halves of the telomeric repeat tracts turn over within a few hundred cell divisions, while the innermost few repeats typically resisted turnover for at least 3000 cell divisions. Similarly deep but incomplete turnover was also observed in two other TER1 template mutants with highly elongated telomeres. These results indicate that most DNA turnover in functionally normal telomeres is due to gradual replicative sequence loss and additions by telomerase but that there are other processes that also contribute to turnover.

Co-overexpression of AVP1 and AtNHX1 in Cotton Further Improves Drought and Salt Tolerance in Transgenic Cotton Plants

2014 ◽  
Vol 33 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Guoxin Shen ◽  
Jia Wei ◽  
Xiaoyun Qiu ◽  
Rongbin Hu ◽  
Sundaram Kuppu ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Transgenic Cotton ◽  
Drought And Salt Tolerance ◽  
Cotton Plants

Heterologous Overexpression of ZmHDZIV13 Enhanced Drought and Salt Tolerance in Arabidopsis and Tobacco

2021 ◽  
Author(s):  
Fang Wang ◽  
Peng Fang ◽  
Huiping Yan ◽  
Xiangzhuo Ji ◽  
Yunling Peng
Keyword(s):  
Transcription Factor ◽  
Abiotic Stress ◽  
Salt Tolerance ◽  
Leucine Zipper ◽  
Abiotic Stress Tolerance ◽  
Heterologous Overexpression ◽  
Malondialdehyde Content ◽  
Drought And Salt Tolerance ◽  
Relative Water ◽  
Dependent Signaling Pathway

Abstract The homeodomain leucine zipper (HD-Zip) IV transcription factor is indispensable in the response of plants to abiotic stress. Systematic studies have been carried out in Arabidopsis, rice and other species from which a series of stress resistance-related genes have been isolated. However, the function of the HD-Zip-IV protein in maize is not clear. In this study, we cloned the HD-Zip-IV gene ZmHDZIV13 and identified its function in the stress response. Our phylogenetic analysis showed that ZmHDZIV13 and AtHDG11 had high homology and might have similar functions. The heterologous overexpression of ZmHDZIV13 in Arabidopsis resulted in sensitivity to abscisic acid (ABA), salt tolerance during germination and drought tolerance in seedlings. Under drought stress, the transgenic Arabidopsis showed stronger drought resistance than the wild-type showed (control). The malondialdehyde content of ZmHDZIV13 transgenic plants was lower than that of the control, and the relative water content and proline content were significantly higher than those of the control. After the drought was relieved, the expression of P5CS1, RD22, RD29B, RD29A, NCED3 and ERD1 were upregulated in transgenic Arabidopsis. Also, modified tobacco plants (35S::ZmHDZIV13) exhibited proper stomatal changes in response to drought conditions. These results show that ZmHDZIV13, as a stress-responsive transcription factor, plays a role in the positive regulation of abiotic stress tolerance and can regulate an ABA-dependent signaling pathway to regulate drought response in plants.

All-or-none craniorachischisis in Loop-tail mutant mouse chimeras

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 229-237 ◽  
Author(s):  
T.S. Musci ◽  
R.J. Mullen
Keyword(s):  
Neural Tube ◽  
Mutant Gene ◽  
Mutant Phenotype ◽  
Progeny Testing ◽  
Wild Type ◽  
Glucose Phosphate ◽  
Threshold Mechanism ◽  
Mutant Cells ◽  
Intermediate Expression ◽  
Gross Examination

Mouse embryos homozygous for the mutant gene Loop-tail (Lp) are characterized by craniorachischisis, an open neural tube extending from the midbrain to the tail. In the present study, experimental chimeric mice containing mixtures of genetically mutant (from Lp/+ × Lp/+ matings) and genetically normal cells were produced. Our aim was to determine whether a ‘rescue,’ phenotypic gradient, or intermediate expression (i.e. alternating areas of open and closed neural tube) would be observed in these chimeras. We report our analyses of Loop-tail mutant chimeras (n = 82) by gross examination, progeny testing and quantitative analysis of glucose phosphate isomerase (GPI) isozyme levels. An all-or-none craniorachischisis in Loop-tail mutant chimeras was observed. Two multicolored adult chimeras, without any gross evidence of a neural tube defect, were shown to be homozygous Loop-tail chimeras (Lp/Lp in equilibrium +/+) by progeny testing. These results indicate that the normal phenotype can be expressed in the presence of mutant cells. Conversely, six neonates with craniorachischisis were shown to be chimeras by GPI analyses. These results show that the full mutant phenotype can be expressed even when one-third to one-half of the cells are genotypically wild-type. This study did not determine which tissue is primarily responsible for the defective neurulation in this mutant, but suggests that a ‘threshold’ mechanism underlies the Loop-tail mutant phenotype. In some chimeras that threshold is not reached and the neural tube remains open, whereas in other chimeras the threshold is reached and the neural tube closes completely.

scholarly journals DAF1, a mutant gene affecting size control, pheromone arrest, and cell cycle kinetics of Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (11) ◽  
pp. 4675-4684 ◽  
Author(s):  
F R Cross
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Critical Size ◽  
Size Control ◽  
Mutant Gene ◽  
G1 Phase ◽  
Wild Type ◽  
Alpha Factor ◽  
Multiple Copies ◽  
Kinetics Of

The mating pheromone alpha-factor arrests Saccharomyces cerevisiae MATa cells in the G1 phase of the cell cycle. Size control is also exerted in G1, since cells do not exit G1 until they have attained a critical size. A dominant mutation (DAF1-1) which causes both alpha-factor resistance and small cell size (volume about 0.6-fold that of the wild type) has been isolated and characterized genetically and by molecular cloning. Several alpha-factor-induced mRNAs were induced equivalently in daf1+ and DAF1-1 cells. The DAF1-1 mutation consisted of a termination codon two-thirds of the way through the daf1+ coding sequence. A chromosomal deletion of DAF1 produced by gene transplacement increased cell volume about 1.5-fold; thus, DAF1-1 may be a hyperactive or deregulated allele of a nonessential gene involved in G1 size control. Multiple copies of DAF1-1 also greatly reduced the duration of the G1 phase of the cell cycle.

Sign in / Sign up

Export Citation Format

Share Document