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

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.

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Genome-wide Identification and Characterization of FCS-Like Zinc Finger (FLZ) Family Genes in Maize (Zea mays) and Functional Analysis of ZmFLZ25 in Plant Abscisic Acid Response

International Journal of Molecular Sciences ◽

10.3390/ijms22073529 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3529

Author(s):

Shunquan Chen ◽

Xibao Li ◽

Chao Yang ◽

Wei Yan ◽

Chuanliang Liu ◽

...

Keyword(s):

Abscisic Acid ◽

Zinc Finger ◽

Stress Responses ◽

Profile Analysis ◽

Aba Signaling ◽

Mesophyll Cells ◽

Α Subunit ◽

Expression Profile Analysis ◽

Genome Wide ◽

Comprehensive Information

FCS-like zinc finger family proteins (FLZs), a class of plant-specific scaffold of SnRK1 complex, are involved in the regulation of various aspects of plant growth and stress responses. Most information of FLZ family genes was obtained from the studies in Arabidopsis thaliana, whereas little is known about the potential functions of FLZs in crop plants. In this study, 37 maize FLZ (ZmFLZ) genes were identified to be asymmetrically distributed on 10 chromosomes and can be divided into three subfamilies. Protein interaction and subcellular localization assays demonstrated that eight typical ZmFLZs interacted and partially co-localized with ZmKIN10, the catalytic α-subunit of the SnRK1 complex in maize leaf mesophyll cells. Expression profile analysis revealed that several ZmFLZs were differentially expressed across various tissues and actively responded to diverse abiotic stresses. In addition, ectopic overexpression of ZmFLZ25 in Arabidopsis conferred hypersensitivity to exogenous abscisic acid (ABA) and triggered higher expression of ABA-induced genes, pointing to the positive regulatory role of ZmFLZ25 in plant ABA signaling, a scenario further evidenced by the interactions between ZmFLZ25 and ABA receptors. In summary, these data provide the most comprehensive information on FLZ family genes in maize, and shed light on the biological function of ZmFLZ25 in plant ABA signaling.

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

Frontiers in Plant Science ◽

10.3389/fpls.2020.598654 ◽

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.

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

Plants ◽

10.3390/plants8120592 ◽

2019 ◽

Vol 8 (12) ◽

pp. 592 ◽

Cited By ~ 7

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.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2100073118 ◽

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.

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

10.1101/2020.02.04.933978 ◽

2020 ◽

Cited By ~ 1

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.

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Genome-wide characterization and expression analysis of the Dof gene family related to abiotic stress in watermelon

PeerJ ◽

10.7717/peerj.8358 ◽

2020 ◽

Vol 8 ◽

pp. e8358 ◽

Cited By ~ 2

Author(s):

Yong Zhou ◽

Yuan Cheng ◽

Chunpeng Wan ◽

Jingwen Li ◽

Youxin Yang ◽

...

Keyword(s):

Gene Family ◽

Stress Responses ◽

Expression Patterns ◽

Future Research ◽

Promoter Regions ◽

Syntenic Relationship ◽

Specific Expression ◽

Qrt Pcr ◽

Genome Wide ◽

Intron Structure

The plant DNA-binding with one finger (Dof) gene family is a class of plant-specific transcription factors that play vital roles in many biological processes and stress responses. In the present study, a total of 36 ClDof genes were identified in the watermelon genome, which were unevenly distributed on 10 chromosomes. Phylogenetic analysis showed that the ClDof proteins could be divided into nine groups, and the members in a particular group had similar motif arrangement and exon–intron structure. Synteny analysis indicated the presence of a large number of syntenic relationship events between watermelon and cucumber. In promoter analysis, five kinds of stress-related and nine kinds of hormone-related cis-elements were identified in the promoter regions of ClDof genes. We then analyzed the expression patterns of nine selected ClDof genes in eight specific tissues by qRT-PCR, and the results showed that they have tissue-specific expression patterns. We also evaluated the expression levels of 12 selected ClDof genes under salt stress and ABA treatments using qRT-PCR. As a result, they showed differential expression under these treatments, suggesting their important roles in stress response. Taken together, our results provide a basis for future research on the biological functions of Dof genes in watermelon.

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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 ◽

10.3390/cells10081996 ◽

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.

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Abscisic Acid Mediates Drought and Salt Stress Responses in Vitis vinifera—A Review

International Journal of Molecular Sciences ◽

10.3390/ijms21228648 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8648 ◽

Cited By ~ 1

Author(s):

Daniel Marusig ◽

Sergio Tombesi

Keyword(s):

Abscisic Acid ◽

Vitis Vinifera ◽

Stress Responses ◽

Abiotic Stresses ◽

Future Research ◽

Stress Effect ◽

Evaporative Demand ◽

Rainfall Occurrence ◽

Drought And Salt Stress ◽

Mediating Mechanisms

The foreseen increase in evaporative demand and reduction in rainfall occurrence are expected to stress the abiotic constrains of drought and salt concentration in soil. The intensification of abiotic stresses coupled with the progressive depletion in water pools is a major concern especially in viticulture, as most vineyards rely on water provided by rainfall. Because its economical relevance and its use as a model species for the study of abiotic stress effect on perennial plants, a significant amount of literature has focused on Vitis vinifera, assessing the physiological mechanisms occurring under stress. Despite the complexity of the stress-resistance strategy of grapevine, the ensemble of phenomena involved seems to be regulated by the key hormone abscisic acid (ABA). This review aims at summarizing our knowledge on the role of ABA in mediating mechanisms whereby grapevine copes with abiotic stresses and to highlight aspects that deserve more attention in future research.

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ABC transporter AtABCG25 is involved in abscisic acid transport and responses

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0912516107 ◽

2010 ◽

Vol 107 (5) ◽

pp. 2361-2366 ◽

Cited By ~ 298

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.

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

Zeitschrift für Naturforschung C ◽

10.1515/znc-2005-9-1017 ◽

2005 ◽

Vol 60 (9-10) ◽

pp. 769-773 ◽

Cited By ~ 3

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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