scholarly journals ABSCISIC ACID INSENSITIVE5 Interacts With RIBOSOMAL S6 KINASE2 to Mediate ABA Responses During Seedling Growth in Arabidopsis

2021 ◽  
Vol 11 ◽  
Author(s):  
Linxuan Li ◽  
Tingting Zhu ◽  
Yun Song ◽  
Li Feng ◽  
Essam Ali Hassan Farag ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seedling Growth ◽  
Stress Responses ◽  
Underlying Mechanism ◽  
Aba Signaling ◽  
Drought Treatment ◽  
Biochemical Interaction ◽  
Transcriptional Regulatory ◽  
Physiological Analysis ◽  
Transcriptional Regulatory Mechanisms

ABSCISIC ACID INSENSITIVE5 (ABI5) is an important regulator of abscisic acid (ABA) signaling pathway involved in regulating seed germination and postgerminative growth in Arabidopsis, which integrates various phytohormone pathways to balance plant growth and stress responses. However, the transcriptional regulatory mechanisms underlying ABI5 and its interacting proteins remain largely unknown. Here, we found that inhibition of AtTOR could increase ABA content by up-regulating the expression levels of ABA biosynthesis-related genes, and thus activated the expression of ABA-responsive genes. Pharmacological assay showed that abi5-1 mutant was insensitive to TOR inhibitor AZD8055, whereas AtABI5 overexpression lines were hypersensitive to AZD8055 in Arabidopsis. Biochemical interaction assays demonstrated that ABI5 physically interacted with the RIBOSOMAL S6 KINASE2 (S6K2) protein in plant cell. S6K2 positively regulated ABA responses during seedling growth and upregulated ABA-responsive genes expression. Furthermore, genetic and physiological analysis indicated that AtS6K2 overexpression lines enhanced resistance to drought treatment while AtS6K2 interference lines were sensitive to drought. These results indicated that AtABI5 interacted with AtS6K2 to positively modulate ABA responses during seedling growth and shed light on a underlying mechanism of the crosstalk between TOR and ABA signaling pathways in modulating seedling growth in Arabidopsis.

ABI5 regulates ABA-induced anthocyanin biosynthesis by modulating the MYB1-bHLH3 complex in apple

2020 ◽  
Author(s):  
Jian-Ping An ◽  
Xiao-Wei Zhang ◽  
Ya-Jing Liu ◽  
Xiao-Fei Wang ◽  
Chun-Xiang You ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Target Genes ◽  
Anthocyanin Biosynthesis ◽  
Aba Signaling ◽  
Plant Growth And Development ◽  
Biochemical Tests ◽  
Positive Role ◽  
Helix Loop Helix ◽  
Transcriptional Regulatory ◽  
Transcriptional Regulatory Mechanisms

Abstract Abscisic acid (ABA) induces anthocyanin biosynthesis in many plant species. However, the molecular mechanism of ABA-regulated anthocyanin biosynthesis remains unclear. As a crucial regulator of ABA signaling, ABSCISIC ACID-INSENSITIVE5 (ABI5) is involved in many aspects of plant growth and development, yet its regulation of anthocyanin biosynthesis has not been elucidated. In this study, we found that MdABI5, the apple homolog of Arabidopsis ABI5, positively regulated ABA-induced anthocyanin biosynthesis. A series of biochemical tests showed that MdABI5 specifically interacts with basic helix-loop-helix 3 (MdbHLH3), a positive regulator of anthocyanin biosynthesis. MdABI5 enhanced the binding of MdbHLH3 to its target genes dihydroflavonol 4-reductase (MdDFR) and UDP flavonoid glucosyl transferase (MdUF3GT). In addition, MdABI5 directly bound to the promoter of MdbHLH3 to activate its expression. Moreover, MdABI5 enhanced ABA-promoted interaction between MdMYB1 and MdbHLH3. Finally, antisense suppression of MdbHLH3 significantly reduced anthocyanin biosynthesis promoted by MdABI5, indicating that MdABI5-promoted anthocyanin biosynthesis was dependent on MdbHLH3. Taken together, our data suggest that MdABI5 plays a positive role in ABA-induced anthocyanin biosynthesis by modulating the MdbHLH3-MdMYB1 complex. Our work broadens the regulatory network of ABA-mediated anthocyanin biosynthesis, providing new insights to further study the transcriptional regulatory mechanisms behind this process.

scholarly journals Plant-Specific AtS40.4 Acts as a Negative Regulator in Abscisic Acid Signaling During Seed Germination and Seedling Growth in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao-Pu Shi ◽  
Jing-Jing Ren ◽  
Hao-Dong Qi ◽  
Yi Lin ◽  
Yu-Yi Wang ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Seedling Growth ◽  
Stress Responses ◽  
Negative Regulator ◽  
Aba Signaling ◽  
Early Seedling Growth ◽  
Early Seedling ◽  
Increased Sensitivity ◽  
Aba Response

Abscisic acid (ABA) is an important phytohormone regulating plant growth, development and stress responses. A multitude of key factors implicated in ABA signaling have been identified; however, the regulation network of these factors needs for further information. AtS40.4, a plant-specific DUF584 domain-containing protein, was identified previously as a senescence regulator in Arabidopsis. In this study, our finding showed that AtS40.4 was negatively involved in ABA signaling during seed germination and early seedling growth. AtS40.4 was highly expressed in seeds and seedlings, and the expression level was promoted by ABA. AtS40.4 was localized both in the nucleus and the cytoplasm. Moreover, the subcellular localization pattern of AtS40.4 was affected by ABA. The knockdown mutants of AtS40.4 exhibited an increased sensitivity to ABA, whereas the overexpression of AtS40.4 decreased the ABA response during seed germination and seedling growth of Arabidopsis. Furthermore, AtS40.4 was involved in ABRE-dependent ABA signaling and influenced the expression levels of ABA INSENTIVE (ABI)1-5 and SnRK2.6. Further genetic evidence demonstrated that AtS40.4 functioned upstream of ABI4. These findings support the notion that AtS40.4 is a novel negative regulator of the ABA response network during seed germination and early seedling growth.

scholarly journals Genome-Wide Analysis of Abscisic Acid Biosynthesis, Catabolism, and Signaling in Sorghum Bicolor under Saline-Alkali Stress

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 823 ◽  
Author(s):  
Siqi Ma ◽  
Lin Lv ◽  
Chen Meng ◽  
Chao Zhou ◽  
Jie Fu ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Sorghum Bicolor ◽  
Stress Responses ◽  
Interaction Analysis ◽  
Amino Acid Sequences ◽  
Future Research ◽  
Alkali Stress ◽  
Aba Signaling ◽  
Genome Wide ◽  
Aba Biosynthesis

Sorghum (Sorghum bicolor) is the fifth most important cereal crop in the world. It is an annual C4 crop due to its high biomass and wide usage, and has a strong resistance to stress. Obviously, there are many benefits of planting sorghum on marginal soils such as saline-alkali land. Although it is known that abscisic acid (ABA) is involved in plant abiotic stress responses, there are few reports on sorghum. Here, we obtained RNA-seq data, which showed gene expression at the genome-wide level under saline-alkali stress. The genes related to ABA biosynthesis, catabolism, and signaling were identified and analyzed. Meanwhile, their amino acid sequences were intermingled with rice genes to form several distinct orthologous and paralogous groups. ABA-related differentially expressed genes under saline-alkali stress were identified, and family members involved in ABA signaling were hypothesized based on the expression levels and homologous genes in rice. Furthermore, the ABA signaling pathway in Sorghum bicolor was understood better by interaction analysis. These findings present a comprehensive overview of the genes regulating ABA biosynthesis, catabolism, and signaling in Sorghum bicolor under saline-alkali stress, and provide a foundation for future research regarding their biological roles in sorghum stress tolerance.

scholarly journals Integration of Abscisic Acid Signaling with Other Signaling Pathways in Plant Stress Responses and Development

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 592 ◽  
Author(s):  
Manu Kumar ◽  
Mahipal Singh Kesawat ◽  
Asjad Ali ◽  
Sang-Choon Lee ◽  
Sarvajeet Singh Gill ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Signaling Pathways ◽  
Stress Responses ◽  
Growth Regulation ◽  
Molecular Mechanisms ◽  
Stomatal Closure ◽  
Plant Stress ◽  
Aba Signaling ◽  
Complex Signaling

Plants are immobile and, to overcome harsh environmental conditions such as drought, salt, and cold, they have evolved complex signaling pathways. Abscisic acid (ABA), an isoprenoid phytohormone, is a critical signaling mediator that regulates diverse biological processes in various organisms. Significant progress has been made in the determination and characterization of key ABA-mediated molecular factors involved in different stress responses, including stomatal closure and developmental processes, such as seed germination and bud dormancy. Since ABA signaling is a complex signaling network that integrates with other signaling pathways, the dissection of its intricate regulatory network is necessary to understand the function of essential regulatory genes involved in ABA signaling. In the present review, we focus on two aspects of ABA signaling. First, we examine the perception of the stress signal (abiotic and biotic) and the response network of ABA signaling components that transduce the signal to the downstream pathway to respond to stress tolerance, regulation of stomata, and ABA signaling component ubiquitination. Second, ABA signaling in plant development processes, such as lateral root growth regulation, seed germination, and flowering time regulation is investigated. Examining such diverse signal integration dynamics could enhance our understanding of the underlying genetic, biochemical, and molecular mechanisms of ABA signaling networks in plants.

scholarly journals Arabidopsis group C Raf-like protein kinases negatively regulate abscisic acid signaling and are direct substrates of SnRK2

2021 ◽  
Vol 118 (30) ◽  
pp. e2100073118
Author(s):  
Yoshiaki Kamiyama ◽  
Misaki Hirotani ◽  
Shinnosuke Ishikawa ◽  
Fuko Minegishi ◽  
Sotaro Katagiri ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Protein Kinase ◽  
Stress Responses ◽  
Reverse Genetic ◽  
Optimal Conditions ◽  
Aba Signaling ◽  
Wild Type ◽  
In Planta ◽  
Dependent Inhibition ◽  
Biochemical Analyses

The phytohormone abscisic acid (ABA) plays a major role in abiotic stress responses in plants, and subclass III SNF1-related protein kinase 2 (SnRK2) kinases mediate ABA signaling. In this study, we identified Raf36, a group C Raf-like protein kinase in Arabidopsis, as a protein that interacts with multiple SnRK2s. A series of reverse genetic and biochemical analyses revealed that 1) Raf36 negatively regulates ABA responses during postgermination growth, 2) the N terminus of Raf36 is directly phosphorylated by SnRK2s, and 3) Raf36 degradation is enhanced in response to ABA. In addition, Raf22, another C-type Raf-like kinase, functions partially redundantly with Raf36 to regulate ABA responses. A comparative phosphoproteomic analysis of ABA-induced responses of wild-type and raf22raf36-1 plants identified proteins that are phosphorylated downstream of Raf36 and Raf22 in planta. Together, these results support a model in which Raf36/Raf22 function mainly under optimal conditions to suppress ABA responses, whereas in response to ABA, the SnRK2 module promotes Raf36 degradation as a means of alleviating Raf36-dependent inhibition and allowing for heightened ABA signaling to occur.

scholarly journals SNF1-related protein kinase 2 directly regulate group C Raf-like protein kinases in abscisic acid signaling

2020 ◽  
Author(s):  
Yoshiaki Kamiyama ◽  
Misaki Hirotani ◽  
Shinnosuke Ishikawa ◽  
Fuko Minegishi ◽  
Sotaro Katagiri ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Protein Kinase ◽  
Stress Responses ◽  
Reverse Genetic ◽  
Aba Signaling ◽  
Related Protein ◽  
Wild Type ◽  
In Planta ◽  
Interacting Protein ◽  
Biochemical Analyses

ABSTRUCTA phytohormone abscisic acid (ABA) has a major role in abiotic stress responses in plants, and subclass III SNF1-related protein kinase 2 (SnRK2) mediates ABA signaling. In this study, we identified Raf36, a group C Raf-like protein kinase in Arabidopsis, as an interacting protein with SnRK2. A series of reverse genetic and biochemical analyses revealed that Raf36 negatively regulates ABA responses and is directly phosphorylated by SnRK2s. In addition, we found that Raf22, another C-type Raf-like kinase, functions partially redundantly with Raf36 to regulate ABA responses. Comparative phosphoproteomic analysis using Arabidopsis wild-type and raf22raf36-1 plants identified proteins that are phosphorylated downstream of Raf36 and Raf22 in planta. Together, these results reveal a novel subsection of ABA-responsive phosphosignaling pathways branching from SnRK2.

scholarly journals Expression of the Malus sieversii NF-YB21 Encoded Gene Confers Tolerance to Osmotic Stresses in Arabidopsis thaliana

2021 ◽  
Vol 22 (18) ◽  
pp. 9777
Author(s):  
Chen Feng ◽  
Yanyan Wang ◽  
Yueting Sun ◽  
Xiang Peng ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Stress Responses ◽  
Functional Characterization ◽  
Compatible Solutes ◽  
Antioxidant Systems ◽  
Drought Treatment ◽  
Malus Sieversii ◽  
Yield And Quality ◽  
Genes Encoding ◽  
Physiological Analysis

Drought is the main environmental factor that limits the yield and quality of apples (Malus × domestica) grown in arid and semi-arid regions. Nuclear factor Ys (NF-Ys) are important transcription factors involved in the regulation of plant growth, development, and various stress responses. However, the function of NF-Y genes is poorly understood in apples. Here, we identified 43 NF-Y genes in the genome of apples and conducted an initial functional characterization of the apple NF-Y. Expression analysis of NF-Y members in M. sieversii revealed that a large number of NF-Ys were highly expressed in the roots compared with the leaves, and a large proportion of NF-Y genes responded to drought treatment. Furthermore, heterologous expression of MsNF-YB21, which was significantly upregulated by drought, led to a longer root length and, thus, conferred improved osmotic and salt tolerance in Arabidopsis. Moreover, the physiological analysis of MsNF-YB21 overexpression revealed enhanced antioxidant systems, including antioxidant enzymes and compatible solutes. In addition, genes encoding catalase (AtCAT2, AtCAT3), superoxide dismutase (AtFSD1, AtFSD3, AtCSD1), and peroxidase (AtPER12, AtPER42, AtPER47, AtPER51) showed upregulated expression in the MsNF-YB21 overexpression lines. These results for the MsNF-Y gene family provide useful information for future studies on NF-Ys in apples, and the functional analysis of MsNF-YB21 supports it as a potential target in the improvement of apple drought tolerance via biotechnological strategies.

scholarly journals Updates on the Role of ABSCISIC ACID INSENSITIVE 5 (ABI5) and ABSCISIC ACID-RESPONSIVE ELEMENT BINDING FACTORs (ABFs) in ABA Signaling in Different Developmental Stages in Plants

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1996
Author(s):  
Anna Collin ◽  
Agata Daszkowska-Golec ◽  
Iwona Szarejko
Keyword(s):  
Transcription Factors ◽  
Abscisic Acid ◽  
Stress Responses ◽  
Leucine Zipper ◽  
Developmental Stages ◽  
Feedback Regulation ◽  
Aba Signaling ◽  
Basic Leucine Zipper ◽  
Protein Levels ◽  
The Core

The core abscisic acid (ABA) signaling pathway consists of receptors, phosphatases, kinases and transcription factors, among them ABA INSENSITIVE 5 (ABI5) and ABRE BINDING FACTORs/ABRE-BINDING PROTEINs (ABFs/AREBs), which belong to the BASIC LEUCINE ZIPPER (bZIP) family and control expression of stress-responsive genes. ABI5 is mostly active in seeds and prevents germination and post-germinative growth under unfavorable conditions. The activity of ABI5 is controlled at transcriptional and protein levels, depending on numerous regulators, including components of other phytohormonal pathways. ABFs/AREBs act redundantly in regulating genes that control physiological processes in response to stress during vegetative growth. In this review, we focus on recent reports regarding ABI5 and ABFs/AREBs functions during abiotic stress responses, which seem to be partially overlapping and not restricted to one developmental stage in Arabidopsis and other species. Moreover, we point out that ABI5 and ABFs/AREBs play a crucial role in the core ABA pathway’s feedback regulation. In this review, we also discuss increased stress tolerance of transgenic plants overexpressing genes encoding ABA-dependent bZIPs. Taken together, we show that ABI5 and ABFs/AREBs are crucial ABA-dependent transcription factors regulating processes essential for plant adaptation to stress at different developmental stages.

scholarly journals ABC transporter AtABCG25 is involved in abscisic acid transport and responses

2010 ◽  
Vol 107 (5) ◽  
pp. 2361-2366 ◽  
Author(s):  
Takashi Kuromori ◽  
Takaaki Miyaji ◽  
Hikaru Yabuuchi ◽  
Hidetada Shimizu ◽  
Eriko Sugimoto ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Abscisic Acid ◽  
Signaling Pathway ◽  
Abc Transporter ◽  
Stress Responses ◽  
Fluorescent Protein ◽  
Plant Cells ◽  
Membrane Vesicles ◽  
Aba Signaling ◽  
Vascular Tissues

Abscisic acid (ABA) is one of the most important phytohormones involved in abiotic stress responses, seed maturation, germination, and senescence. ABA is predominantly produced in vascular tissues and exerts hormonal responses in various cells, including guard cells. Although ABA responses require extrusion of ABA from ABA-producing cells in an intercellular ABA signaling pathway, the transport mechanisms of ABA through the plasma membrane remain unknown. Here we isolated an ATP-binding cassette (ABC) transporter gene, AtABCG25, from Arabidopsis by genetically screening for ABA sensitivity. AtABCG25 was expressed mainly in vascular tissues. The fluorescent protein-fused AtABCG25 was localized at the plasma membrane in plant cells. In membrane vesicles derived from AtABCG25-expressing insect cells, AtABCG25 exhibited ATP-dependent ABA transport. The AtABCG25-overexpressing plants showed higher leaf temperatures, implying an influence on stomatal regulation. These results strongly suggest that AtABCG25 is an exporter of ABA and is involved in the intercellular ABA signaling pathway. The presence of the ABA transport mechanism sheds light on the active control of multicellular ABA responses to environmental stresses among plant cells.

Protein Kinase Cascade Involved in Rapid ABA-signaling in Guard Cells of Vicia faba

2005 ◽  
Vol 60 (9-10) ◽  
pp. 769-773 ◽  
Author(s):  
Takuya Furuichi ◽  
Izumi C. Mori ◽  
Shoshi Muto
Keyword(s):  
Abscisic Acid ◽  
Protein Kinase ◽  
Stress Responses ◽  
Guard Cells ◽  
Aba Signaling ◽  
Carboxy Terminus ◽  
Mrna Binding Protein ◽  
Kinase Cascade ◽  
Mrna Binding ◽  
Protein Kinase Cascade

Abstract Protein kinases are involved in signal transduction for environmental stress responses. In response to drought and salinity, a 48-kDa protein kinase (AAPK; abscisic acid-activated protein kinase (AAPK) in guard cells is activated by abscisic acid (ABA) and phosphorylates several targets such as the carboxy-terminus of inward-rectifying K+ channel and heterogeneous mRNA binding protein to adopt to the changing environment. The AAPK expressed specifically in guard cells, and recombinant AAPK was phosphorylated only with the extract from ABA-treated guard cells but not from untreated cells. This indicates the presence of an AAPK kinase (AAPKK), which is activated by ABA and phosphorylates AAPK preceding the activation of AAPK. Both AAPK and AAPKK are involved in the protein kinase cascade for the rapid ABA-signaling.

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