scholarly journals Arabidopsis thaliana NGATHA1 transcription factor induces ABA biosynthesis by activating NCED3 gene during dehydration stress

2018 ◽  
Vol 115 (47) ◽  
pp. E11178-E11187 ◽  
Author(s):  
Hikaru Sato ◽  
Hironori Takasaki ◽  
Fuminori Takahashi ◽  
Takamasa Suzuki ◽  
Satoshi Iuchi ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stress Responses ◽  
Plant Hormone ◽  
Stomatal Closure ◽  
Transcriptional Regulators ◽  
Dehydration Stress ◽  
Knockout Mutant ◽  
Knockout Mutants ◽  
Aba Biosynthesis ◽  
Single Knockout

The plant hormone abscisic acid (ABA) is accumulated after drought stress and plays critical roles in the responses to drought stress in plants, such as gene regulation, stomatal closure, seed maturation, and dormancy. Although previous reports revealed detailed molecular roles of ABA in stress responses, the factors that contribute to the drought-stress responses—in particular, regulation of ABA accumulation—remain unclear. The enzyme NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3) is essential for ABA biosynthesis during drought stress, and the NCED3 gene is highly induced by drought stress. In the present study, we isolated NGATHAs (NGAs) as candidate transcriptional regulators of NCED3 through a screen of a plant library harboring the transcription factors fused to a chimeric repressor domain, SRDX. The NGA proteins were directly bound to a cis-element NGA-binding element (NBE) in the 5′ untranslated region (5′ UTR) of the NCED3 promoter and were suggested to be transcriptional activators of NCED3. Among the single-knockout mutants of four NGA family genes, we found that the NGATHA1 (NGA1) knockout mutant was drought-stress-sensitive with a decreased expression level of NCED3 during dehydration stress. These results suggested that NGA1 essentially functions as a transcriptional activator of NCED3 among the NGA family proteins. Moreover, the NGA1 protein was degraded under nonstressed conditions, and dehydration stress enhanced the accumulation of NGA1 proteins, even in ABA-deficient mutant plants, indicating that there should be ABA-independent posttranslational regulations. These findings emphasize the regulatory mechanisms of ABA biosynthesis during early drought stress.

scholarly journals miR2105 regulates ABA biosynthesis via OsbZIP86-OsNCED3 module to contribute to drought tolerance in rice

2021 ◽  
Author(s):  
Weiwei Gao ◽  
Mingkang Li ◽  
Songguang Yang ◽  
Chunzhi Gao ◽  
Yan Su ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Transgenic Rice ◽  
Crucial Role ◽  
Agronomic Traits ◽  
Stomatal Closure ◽  
Plant Tolerance ◽  
Rice Plants ◽  
Transgenic Rice Plants ◽  
Aba Biosynthesis

AbstractInduced abscisic acid (ABA) biosynthesis plays an important role in plant tolerance to abiotic stresses, including drought, cold and salinity. However, regulation pathway of the ABA biosynthesis in response to stresses is unclear. Here, we identified a rice miRNA, osa-miR2105 (miR2105), which plays a crucial role in ABA biosynthesis under drought stress. Analysis of expression, transgenic rice and cleavage site showed that OsbZIP86 is a target gene of miR2105. Subcellular localization and luciferase activity assays showed that OsbZIP86 is a nuclear transcription factor. In vivo and in vitro analyses showed that OsbZIP86 directly binds to the promoter of OsNCED3, and interacts with OsSAPK10, resulting in enhanced-expression of OsNCED3. Transgenic rice plants with knock-down of miR2105 or overexpression of OsbZIP86 showed higher ABA content, more tolerance to drought, a lower rate of water loss, more stomatal closure than wild type rice ZH11 under drought stress. These rice plants showed no penalty with respect to agronomic traits under normal conditions. By contrast, transgenic rice plants with miR2105 overexpression, OsbZIP86 downregulation, or OsbZIP86 knockout displayed less tolerance to drought stress and other phenotypes. Collectively, our results show that a regulatory network of ‘miR2105-OsSAPK10/OsbZIP86-OsNCED3’ control ABA biosynthesis in response to drought stress.One-sentence summary‘miR2105-OsbZIP86-OsNCED3’ module plays crucial role in mediating ABA biosynthesis to contribute to drought tolerance with no penalty with respect to agronomic traits under normal conditions.

scholarly journals A Soybean bZIP Transcription Factor GmbZIP19 Confers Multiple Biotic and Abiotic Stress Responses in Plant

2020 ◽  
Vol 21 (13) ◽  
pp. 4701
Author(s):  
Qing He ◽  
Hanyang Cai ◽  
Mengyan Bai ◽  
Man Zhang ◽  
Fangqian Chen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Drought Stress ◽  
Pseudomonas Syringae ◽  
Stress Responses ◽  
Stomatal Closure ◽  
Negative Regulator ◽  
Marker Genes ◽  
Genes Expression ◽  
Salt And Drought Stress ◽  
Salt And Drought Stresses

The basic leucine zipper (bZIP) is a plant-specific transcription factor family that plays crucial roles in response to biotic and abiotic stresses. However, little is known about the function of bZIP genes in soybean. In this study, we isolated a bZIP gene, GmbZIP19, from soybean. A subcellular localization study of GmbZIP19 revealed its nucleus localization. We showed that GmbZIP19 expression was significantly induced by ABA (abscisic acid), JA (jasmonic acid) and SA (salicylic acid), but reduced under salt and drought stress conditions. Further, GmbZIP19 overexpression Arabidopsis lines showed increased resistance to S. sclerotiorum and Pseudomonas syringae associated with upregulated ABA-, JA-, ETH- (ethephon-)and SA-induced marker genes expression, but exhibited sensitivity to salt and drought stresses in association with destroyed stomatal closure and downregulated the salt and drought stresses marker genes’ expression. We generated a soybean transient GmbZIP19 overexpression line, performed a Chromatin immunoprecipitation assay and found that GmbZIP19 bound to promoters of ABA-, JA-, ETH-, and SA-induced marker genes in soybean. The yeast one-hybrid verified the combination. The current study suggested that GmbZIP19 is a positive regulator of pathogen resistance and a negative regulator of salt and drought stress tolerance.

scholarly journals Implications of Abscisic Acid in the Drought Stress Tolerance of Plants

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1323 ◽  
Author(s):  
Shahid Ali ◽  
Kashif Hayat ◽  
Amjad Iqbal ◽  
Linan Xie
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Stress Tolerance ◽  
Signaling Pathways ◽  
Environmental Changes ◽  
Stomatal Closure ◽  
Mitigation Strategies ◽  
Stress Signals ◽  
Post Transcriptional Regulation ◽  
Aba Biosynthesis

Drought is a severe environmental constraint, which significantly affects plant growth, productivity, and quality. Plants have developed specific mechanisms that perceive the stress signals and respond to external environmental changes via different mitigation strategies. Abscisic acid (ABA), being one of the phytohormones, serves as an important signaling mediator for plants’ adaptive response to a variety of environmental stresses. ABA triggers many physiological processes, including bud dormancy, seed germination, stomatal closure, and transcriptional and post-transcriptional regulation of stress-responsive gene expression. The site of its biosynthesis and action must be clarified to understand the signaling network of ABA. Various studies have documented multiple sites for ABA biosynthesis, their transporter proteins in the plasma membrane, and several components of ABA-dependent signaling pathways, suggesting that the ABA response to external stresses is a complex networking mechanism. Knowing about stress signals and responses will increase our ability to enhance crop stress tolerance through the use of various advanced techniques. This review will elaborate on the ABA biosynthesis, transportation, and signaling pathways at the molecular level in response to drought stress, which will add a new insight for future studies.

scholarly journals Transcriptomic Analysis of Female Panicles Reveals Gene Expression Responses to Drought Stress in Maize (Zea mays L.)

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 313 ◽  
Author(s):  
Shuangjie Jia ◽  
Hongwei Li ◽  
Yanping Jiang ◽  
Yulou Tang ◽  
Guoqiang Zhao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Drought Stress ◽  
Stress Responses ◽  
Plant Hormone ◽  
Zea Mays L ◽  
Kegg Pathway ◽  
Summer Maize ◽  
Kegg Pathway Analysis ◽  
Moderate Drought

Female panicles (FPs) play an important role in the formation of yields in maize. From 40 days after sowing to the tasseling stage for summer maize, FPs are developing and sensitive to drought. However, it remains unclear how FPs respond to drought stress during FP development. In this study, FP differentiation was observed at 20 and 30 days after drought (DAD) and agronomic trait changes of maize ears were determined across three treatments, including well-watered (CK), light drought (LD), and moderate drought (MD) treatments at 20, 25, and 30 DAD. RNA-sequencing was then used to identify differentially expressed genes (DEGs) in FPs at 30 DAD. Spikelets and florets were suppressed in LD and MD treatments, suggesting that drought slows FP development and thus decreases yields. Transcriptome analysis indicated that 40, 876, and 887 DEGs were detected in LD/CK, MD/CK, and MD/LD comparisons. KEGG pathway analysis showed that ‘biosynthesis of other secondary metabolites’ and ‘carbohydrate metabolism’ were involved in the LD response, whereas ‘starch and sucrose metabolism’ and ‘plant hormone signal transduction’ played important roles in the MD response. In addition, a series of molecular cues related to development and growth were screened for their drought stress responses.

scholarly journals ZmASR3 from the Maize ASR Gene Family Positively Regulates Drought Tolerance in Transgenic Arabidopsis

2019 ◽  
Vol 20 (9) ◽  
pp. 2278 ◽  
Author(s):  
Yani Liang ◽  
Yingli Jiang ◽  
Ming Du ◽  
Baoyan Li ◽  
Long Chen ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Stomatal Closure ◽  
Molecular Features ◽  
Ros Accumulation ◽  
Drought Conditions ◽  
Relative Water ◽  
Transgenic Lines ◽  
Related Stress

Abscisic acid (ABA)-, stress-, and ripening-induced (ASR) proteins are reported to be involved in drought stress responses. However, the function of maize ASR genes in enhancing drought tolerance is not known. Here, nine maize ASR members were cloned, and the molecular features of these genes were analyzed. Phenotype results of overexpression of maize ZmASR3 gene in Arabidopsis showed lower malondialdehyde (MDA) levels and higher relative water content (RWC) and proline content than the wild type under drought conditions, demonstrating that ZmASR3 can improve drought tolerance. Further experiments showed that ZmASR3-overexpressing transgenic lines displayed increased stomatal closure and reduced reactive oxygen species (ROS) accumulation by increasing the enzyme activities of superoxide dismutase (SOD) and catalase (CAT) under drought conditions. Moreover, overexpression of ZmASR3 in Arabidopsis increased ABA content and reduced sensitivity to exogenous ABA in both the germination and post-germination stages. In addition, the ROS-related, stress-responsive, and ABA-dependent pathway genes were activated in transgenic lines under drought stress. Taken together, these results suggest that ZmASR3 acts as a positive regulator of drought tolerance in plants.

scholarly journals Distinct Cellular Strategies Determine Sensitivity to Mild Drought of Arabidopsis Natural Accessions

2020 ◽  
Author(s):  
Ying Chen ◽  
Marieke Dubois ◽  
Mattias Vermeersch ◽  
Dirk Inzé ◽  
Hannes Vanhaeren
Keyword(s):  
Drought Stress ◽  
Stress Responses ◽  
Cell Expansion ◽  
Leaf Growth ◽  
Stomatal Closure ◽  
Wide Distribution ◽  
Abiotic Stress Response ◽  
Transcriptional Responses ◽  
Drought Tolerant ◽  
Mild Drought

AbstractThe world-wide distribution of Arabidopsis thaliana (Arabidopsis) accessions imposes different types of evolutionary pressures, which contributes to various responses of these accessions to environmental stresses. Drought stress responses have been well studied, particularly in Columbia, a common Arabidopsis accession. However, the reactions to drought stress are complex and our understanding of which of these responses contribute to the plant’s tolerance to mild drought is very limited. Here, we studied the mechanisms by which natural accessions react to mild drought at a physiological and molecular level during early leaf development. We documented variations in mild drought tolerance among natural accessions and used transcriptome sequencing of a drought-sensitive accession, ICE163, and a drought-tolerant accession, Yeg-1, to get insights into the mechanisms underlying this tolerance. This revealed that ICE163 preferentially induces jasmonates and anthocyanin-related pathways, which are beneficial in biotic stress defense, while Yeg-1 has a more pronounced activation of abscisic acid signaling, the classical abiotic stress response. Related physiological traits, including content of proline, anthocyanins and ROS, stomatal closure and cellular leaf parameters, were investigated and linked to the transcriptional responses. We conclude that most of these processes constitute general drought response mechanisms that are regulated similarly in drought-tolerant and -sensitive accessions. However, the capacity to close stomata and maintain cell expansion under mild drought appeared to be major factors that contribute to a better leaf growth under mild drought.One-sentence summaryThis paper demonstrates that an efficient closure of stomata and maintenance of cell expansion during drought conditions are crucial to maximally preserve plant growth during water deficit.

scholarly journals Sulfate enhances drought tolerance in foxtail millet seedlings by promoting ABA biosynthesis and inducing stomatal closure

2021 ◽  
Author(s):  
Yansha Han ◽  
Dianqing Gong ◽  
Huilan Yi
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stomatal Closure ◽  
Foxtail Millet ◽  
Natural Soil ◽  
Plant Responses ◽  
Crop Tolerance ◽  
Molecular Approaches ◽  
Sulfate Application ◽  
Aba Biosynthesis

Abstract Background and aims Sulfate, the main source of sulfur in natural soil, is critical for plant growth and development, as well as plant responses to environmental stress, including drought. However, our understanding of the detailed mechanisms of sulfate-modulated drought tolerance in crop plants is far from complete. In the present study, by using foxtail millet (Setaria italica L.), an emerging model crop, we investigated the possible mechanisms involved in sulfate-induced crop tolerance to drought stress. Methods A combination of biochemical and molecular approaches, as well as stomatal apertures analyses were applied to determine the effect of sulfate application on sulfur assimilation, ABA biosynthesis, and stomatal movement. Results Upon drought exposure, sulfate (4 mM) pretreatment significantly alleviated the decrease in relative water content in foxtail millet leaves. Exogenous sulfate increased endogenous sulfate content and markedly enhanced the enzyme activity of sulfite reductase (SiR) and O-acetylserine(thiol)lyase (OASTL), as well as levels of their transcripts, leading to an increase in cysteine (Cys) production in drought-stressed leaves. Furthermore, in comparison with drought stress alone, sulfate application significantly upregulated the transcriptional expression of SiABA3 and SiAAO3, which contributed to the increased ABA levels in the leaves of drought-stressed foxtail millet seedlings. Moreover, the addition of sulfate decreased stomatal aperture, thus resulting in reduced leaf water loss in foxtail millet exposed to drought. Conclusion Our data suggest that sulfate application was able to promote drought tolerance of foxtail millet plants, at least partially by increasing ABA biosynthesis and triggering stomatal closure.

scholarly journals The content of polyphenolic compounds in the Arabidopsis thaliana knockout mutant Cat2 under salt stress

2016 ◽  
Vol 14 (2) ◽  
pp. 174-177
Author(s):  
N. O. Didenko ◽  
I. M. Buzduga ◽  
R. A. Volkov ◽  
I. I. Panchuk
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Sodium Chloride ◽  
Stress Responses ◽  
Stress Proteins ◽  
Polyphenolic Compounds ◽  
Knockout Mutant ◽  
Knockout Mutants ◽  
Multigenic Family

Aim. In plants, the defense response to abiotic stress includes induction of stress proteins and increase in content of protective metabolites. To date, the role of specific isoforms of antioxidant enzymes in stress responses and their relation to low-molecular weight protective compounds are still not clarified. To study this question the content of polyphenolic compounds (PPC) was evaluated under salt stress in Arabidopsis thaliana wild-type (WT) and in catalase 2 (Cat2) knockout mutant plants. Methods. PPC content in different variants of treatment with sodium chloride was measured. Results. It was shown that under optimal cultivation conditions the content of PPC in leaves of cat2 mutants is higher than in WT leaves. However, cultivation of isolated shoots in nutrient medium resulted in a faster depletion of the PPC pool in the cat2 line. Also, short-term salt stress results in equal depletion of the PPC pool in both, WT and cat2. Conclusions. The increase of PPC content in cat2 leaves is a manifestation of metabolic alterations that aim to compensate the reduced catalase activity.Keywords: multigenic family, knockout mutants, polyphenolic compounds, sodium chloride, Arabidopsis thaliana.

scholarly journals Abscisic Acid Application Enhances Drought Stress Tolerance in Bedding Plants

HortScience ◽  
2010 ◽  
Vol 45 (3) ◽  
pp. 409-413 ◽  
Author(s):  
Nicole L. Waterland ◽  
Craig A. Campbell ◽  
John J. Finer ◽  
Michelle L. Jones
Keyword(s):  
Abscisic Acid ◽  
Drought Stress ◽  
Shelf Life ◽  
Stress Responses ◽  
Water Loss ◽  
Stomatal Closure ◽  
Severe Drought ◽  
Bedding Plants ◽  
Leaf Chlorosis ◽  
Bedding Plant

Drought stress is a major cause of postproduction decline in bedding plants. The plant hormone abscisic acid (ABA) regulates drought stress responses by mediating stomatal closure, thereby reducing transpirational water loss. Exogenous ABA applications delay wilting and allow plants to survive short periods of severe drought. The effectiveness of the ABA biochemical, s-ABA (ConTego™; Valent BioSciences Corp., Libertyville, IL), at delaying wilting and extending shelf life during drought stress was evaluated in six bedding plant species. Spray and drench applications of 0 or 500 mg·L−1 s-ABA were applied to Impatiens walleriana (impatiens), Pelargonium ×hortorum (seed geranium), Petunia ×hybrida (petunia), Tagetes patula (marigold), Salvia splendens (salvia), and Viola ×wittrockiana (pansy). Water was subsequently withheld and wilting symptoms were compared between treated and control plants. s-ABA applications delayed wilting in all crops by 1.7 to 4.3 days. Leaf chlorosis was observed after s-ABA application in drought-stressed seed geraniums, marigolds, and pansies. In seed geraniums and marigolds, the drought stress itself resulted in leaf chlorosis that was equivalent to or more severe than the s-ABA application alone. In pansies, s-ABA applications induced leaf chlorosis that was more severe than the drought treatment. Overall, s-ABA was consistently effective at reducing water loss and extending shelf life for all species treated. Applications of s-ABA to bedding plants before shipping and retailing would allow plants to maintain marketability even under severe drought stress conditions.

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