Chloroplast Localized FIBRILLIN11 Is Involved in the Osmotic Stress Response during Arabidopsis Seed Germination

Plants live in ever-changing environments, facing adverse environmental conditions including pathogen infection, herbivore attack, drought, high temperature, low temperature, nutrient deficiency, toxic metal soil contamination, high salt, and osmotic imbalance that inhibit overall plant growth and development. Plants have evolved mechanisms to cope with these stresses. In this study, we found that the FIBRILLIN11 (FBN11) gene in Arabidopsis, which has a lipid-binding FBN domain and a kinase domain, is involved in the plant’s response to abiotic stressors, including salt and osmotic stresses. FBN11 protein localizes to the chloroplast. FBN11 gene expression significantly changed when plants were exposed to the abiotic stress response mediators such as abscisic acid (ABA), sodium chloride (NaCl), and mannitol. The seed germination rates of fbn11 homozygous mutants in different concentrations of mannitol and NaCl were significantly reduced compared to wild type. ABA-dependent and -independent stress response regulatory genes were differentially expressed in the fbn11 mutant compared with wild type when grown in mannitol medium. These results suggest a clear role for chloroplast-localized FBN11 in mediating osmotic stress tolerance via the stress response regulatory signaling pathway in the nucleus.

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ALKBH10B, an mRNA m6A Demethylase, Modulates ABA Response During Seed Germination in Arabidopsis

Frontiers in Plant Science ◽

10.3389/fpls.2021.712713 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jun Tang ◽

Junbo Yang ◽

Hongchao Duan ◽

Guifang Jia

Keyword(s):

Abscisic Acid ◽

Salt Stress ◽

Abiotic Stress ◽

Stress Response ◽

Seed Germination ◽

Chemical Modification ◽

Aba Signaling ◽

Wild Type ◽

Abiotic Stress Response ◽

Aba Response

As the most abundant and reversible chemical modification in eukaryotic mRNA, the epitranscriptomic mark N6-methyladenine (m6A) regulates plant development and stress response. We have previously characterized that ALKBH10B is an Arabidopsis mRNA m6A demethylase and regulates floral transition. However, it is unclear whether ALKBH10B plays a role in abiotic stress response. Here, we found that the expression of ALKBH10B is increased in response to abscisic acid (ABA), osmotic, and salt stress. The alkbh10b mutants showed hypersensitive to ABA, osmotic, and salt stress during seed germination. Transcriptome analysis revealed that the expression of several ABA response genes is upregulated in alkbh10b-1 than that of wild type, indicating ALKBH10B negatively affects the ABA signaling. Furthermore, m6A sequencing showed that ABA signaling genes, including PYR1, PYL7, PYL9, ABI1, and SnRK2.2 are m6A hypermethylated in alkbh10b-1 after ABA treatment. Taken together, our work demonstrated that ALKBH10B negatively modulates ABA response during seed germination in Arabidopsis.

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CAND2/PMTR1 Is Required for Melatonin-Conferred Osmotic Stress Tolerance in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms22084014 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4014

Author(s):

Lin-Feng Wang ◽

Ting-Ting Li ◽

Yu Zhang ◽

Jia-Xing Guo ◽

Kai-Kai Lu ◽

...

Keyword(s):

Osmotic Stress ◽

Stress Tolerance ◽

Wild Type Plant ◽

Wild Type ◽

Melatonin Receptor ◽

Ros Scavenging ◽

Exogenous Melatonin ◽

Osmotic Stress Tolerance ◽

Osmotic Stress Response ◽

In The Wild

Osmotic stress severely inhibits plant growth and development, causing huge loss of crop quality and quantity worldwide. Melatonin is an important signaling molecule that generally confers plant increased tolerance to various environmental stresses, however, whether and how melatonin participates in plant osmotic stress response remain elusive. Here, we report that melatonin enhances plant osmotic stress tolerance through increasing ROS-scavenging ability, and melatonin receptor CAND2 plays a key role in melatonin-mediated plant response to osmotic stress. Upon osmotic stress treatment, the expression of melatonin biosynthetic genes including SNAT1, COMT1, and ASMT1 and the accumulation of melatonin are increased in the wild-type plants. The snat1 mutant is defective in osmotic stress-induced melatonin accumulation and thus sensitive to osmotic stress, while exogenous melatonin enhances the tolerance of the wild-type plant and rescues the sensitivity of the snat1 mutant to osmotic stress by upregulating the expression and activity of catalase and superoxide dismutase to repress H2O2 accumulation. Further study showed that the melatonin receptor mutant cand2 exhibits reduced osmotic stress tolerance with increased ROS accumulation, but exogenous melatonin cannot revert its osmotic stress phenotype. Together, our study reveals that CADN2 functions necessarily in melatonin-conferred osmotic stress tolerance by activating ROS-scavenging ability in Arabidopsis.

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NMR and LC-MS-Based Metabolomics to Study Osmotic Stress in Lignan-Deficient Flax

Molecules ◽

10.3390/molecules26030767 ◽

2021 ◽

Vol 26 (3) ◽

pp. 767

Author(s):

Kamar Hamade ◽

Ophélie Fliniaux ◽

Jean-Xavier Fontaine ◽

Roland Molinié ◽

Elvis Otogo Nnang ◽

...

Keyword(s):

Stress Response ◽

Osmotic Stress ◽

Biosynthetic Pathway ◽

Potential Role ◽

Plant Secondary Metabolites ◽

Wild Type ◽

Osmotic Stress Response ◽

Transgenic Flax ◽

Insight Into

Lignans, phenolic plant secondary metabolites, are derived from the phenylpropanoid biosynthetic pathway. Although, being investigated for their health benefits in terms of antioxidant, antitumor, anti-inflammatory and antiviral properties, the role of these molecules in plants remains incompletely elucidated; a potential role in stress response mechanisms has been, however, proposed. In this study, a non-targeted metabolomic analysis of the roots, stems, and leaves of wild-type and PLR1-RNAi transgenic flax, devoid of (+) secoisolariciresinol diglucoside ((+) SDG)—the main flaxseed lignan, was performed using 1H-NMR and LC-MS, in order to obtain further insight into the involvement of lignan in the response of plant to osmotic stress. Results showed that wild-type and lignan-deficient flax plants have different metabolic responses after being exposed to osmotic stress conditions, but they both showed the capacity to induce an adaptive response to osmotic stress. These findings suggest the indirect involvement of lignans in osmotic stress response.

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Rootstocks Overexpressing StNPR1 and StDREB1 Improve Osmotic Stress Tolerance of Wild-Type Scion in Transgrafted Tobacco Plants

International Journal of Molecular Sciences ◽

10.3390/ijms22168398 ◽

2021 ◽

Vol 22 (16) ◽

pp. 8398

Author(s):

Yasmine S. Hezema ◽

Mukund R. Shukla ◽

Alok Goel ◽

Murali M. Ayyanath ◽

Sherif M. Sherif ◽

...

Keyword(s):

Osmotic Stress ◽

Transgenic Tobacco ◽

Physiological Status ◽

Wild Type ◽

Long Distance ◽

Graft Union ◽

Tobacco Plants ◽

Osmotic Stress Tolerance ◽

And Function ◽

Gene Expression Levels

In grafted plants, the movement of long-distance signals from rootstocks can modulate the development and function of the scion. To understand the mechanisms by which tolerant rootstocks improve scion responses to osmotic stress (OS) conditions, mRNA transport of osmotic responsive genes (ORGs) was evaluated in a tomato/potato heterograft system. In this system, Solanum tuberosum was used as a rootstock and Solanum lycopersicum as a scion. We detected changes in the gene expression levels of 13 out of the 21 ORGs tested in the osmotically stressed plants; of these, only NPR1 transcripts were transported across the graft union under both normal and OS conditions. Importantly, OS increased the abundance of StNPR1 transcripts in the tomato scion. To examine mRNA mobility in transgrafted plants, StNPR1 and StDREB1 genes representing the mobile and non-mobile transcripts, respectively, were overexpressed in tobacco (Nicotiana tabacum). The evaluation of transgenic tobacco plants indicated that overexpression of these genes enhanced the growth and improved the physiological status of transgenic plants growing under OS conditions induced by NaCl, mannitol and polyethylene glycol (PEG). We also found that transgenic tobacco rootstocks increased the OS tolerance of the WT-scion. Indeed, WT scions on transgenic rootstocks had higher ORGs transcript levels than their counterparts on non-transgenic rootstocks. However, neither StNPR1 nor StDREB1 transcripts were transported from the transgenic rootstock to the wild-type (WT) tobacco scion, suggesting that other long-distance signals downstream these transgenes could have moved across the graft union leading to OS tolerance. Overall, our results signify the importance of StNPR1 and StDREB1 as two anticipated candidates for the development of stress-resilient crops through transgrafting technology.

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Genome-Wide Identification and Expression Analyses of the Chitinases under Cold and Osmotic stress in Ammopiptanthus nanus

Genes ◽

10.3390/genes10060472 ◽

2019 ◽

Vol 10 (6) ◽

pp. 472 ◽

Cited By ~ 5

Author(s):

Cao ◽

Wang ◽

Li ◽

Shi ◽

Gao ◽

...

Keyword(s):

Abiotic Stress ◽

Stress Response ◽

Low Temperature ◽

Osmotic Stress ◽

Fungal Pathogens ◽

Glycosyl Hydrolase ◽

Class Iii ◽

Abiotic Stress Response ◽

Ammopiptanthus Nanus ◽

Genome Wide

Chitinase is a kind of hydrolase with chitin as a substrate and is proposed to play an essential role in plant defense system by functioning against fungal pathogens through degrading chitin. Recent studies indicated chitinase is also involved in abiotic stress response in plants, helping plants to survive in stressful environments. A. nanus, a rare evergreen broad-leaved shrub distrusted in deserts in Central Asia, exhibits a high level of tolerance to drought and low temperature stresses. To identify the chitinase gene involved in drought and low temperature responses in A. nanus, we performed genome-wide identification, classification, sequence alignment, and spatio-temporal gene expression analysis of the chitinases in A. nanus under osmotic and low temperature stress. A total of 32 chitinase genes belonging to glycosyl hydrolase 18 (GH18) and GH19 families were identified from A. nanus. Class III chitinases appear to be amplified quantitatively in A. nanus, and their genes carry less introns, indicating their involvement in stress response in A. nanus. The expression level of the majority of chitinases varied in leaves, stems, and roots, and regulated under environmental stress. Some chitinases, such as EVM0022783, EVM0020238, and EVM0003645, are strongly induced by low temperature and osmotic stress, and the MYC/ICE1 (inducer of CBF expression 1) binding sites in promoter regions may mediate the induction of these chitinases under stress. These chitinases might play key roles in the tolerance to these abiotic stress in A. nanus and have potential for biotechnological applications. This study provided important data for understanding the biological functions of chitinases in A. nanus.

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Arabidopsis thaliana calcium-dependent lipid-binding protein (AtCLB): a novel repressor of abiotic stress response

Journal of Experimental Botany ◽

10.1093/jxb/erq468 ◽

2011 ◽

Vol 62 (8) ◽

pp. 2679-2689 ◽

Cited By ~ 46

Author(s):

Kanishka de Silva ◽

Bozena Laska ◽

Christopher Brown ◽

Heike Winter Sederoff ◽

Mariya Khodakovskaya

Keyword(s):

Arabidopsis Thaliana ◽

Abiotic Stress ◽

Stress Response ◽

Binding Protein ◽

Lipid Binding ◽

Abiotic Stress Response ◽

Lipid Binding Protein ◽

Calcium Dependent

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AtEXP2 Is Involved in Seed Germination and Abiotic Stress Response in Arabidopsis

PLoS ONE ◽

10.1371/journal.pone.0085208 ◽

2014 ◽

Vol 9 (1) ◽

pp. e85208 ◽

Cited By ~ 43

Author(s):

An Yan ◽

Minjie Wu ◽

Limei Yan ◽

Rui Hu ◽

Imran Ali ◽

...

Keyword(s):

Abiotic Stress ◽

Stress Response ◽

Seed Germination ◽

Abiotic Stress Response

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Oncogenic mutations mimic and enhance dynamic events in the natural activation of phosphoinositide 3-kinase p110α (PIK3CA)

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1205508109 ◽

2012 ◽

Vol 109 (38) ◽

pp. 15259-15264 ◽

Cited By ~ 152

Author(s):

John E. Burke ◽

Olga Perisic ◽

Glenn R. Masson ◽

Oscar Vadas ◽

Roger L. Williams

Keyword(s):

Membrane Surface ◽

Kinase Domain ◽

Lipid Binding ◽

Binding Domain ◽

Catalytic Subunit ◽

Activation Mechanism ◽

Wild Type ◽

Helical Domain ◽

Dynamic Events ◽

Oncogenic Mutations

The p110α catalytic subunit (PIK3CA) is one of the most frequently mutated genes in cancer. We have examined the activation of the wild-type p110α/p85α and a spectrum of oncogenic mutants using hydrogen/deuterium exchange mass spectrometry (HDX-MS). We find that for the wild-type enzyme, the natural transition from an inactive cytosolic conformation to an activated form on membranes entails four distinct events. Analysis of oncogenic mutations shows that all up-regulate the enzyme by enhancing one or more of these dynamic events. We provide the first insight into the activation mechanism by mutations in the linker between the adapter-binding domain (ABD) and the Ras-binding domain (RBD) (G106V and G118D). These mutations, which are common in endometrial cancers, enhance two of the natural activation events: movement of the ABD and ABD–RBD linker relative to the rest of the catalytic subunit and breaking the C2–iSH2 interface on binding membranes. C2 domain mutants (N345K and C420R) also mimic these events, even in the absence of membranes. A third event is breaking the nSH2–helical domain contact caused by phosphotyrosine-containing peptides binding to the enzyme, which is mimicked by a helical domain mutation (E545K). Interaction of the C lobe of the kinase domain with membranes is the fourth activation event, and is potentiated by kinase domain mutations (e.g., H1047R). All mutations increased lipid binding and basal activity, even mutants distant from the membrane surface. Our results elucidate a unifying mechanism in which diverse PIK3CA mutations stimulate lipid kinase activity by facilitating allosteric motions required for catalysis on membranes.

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Developing a Screening Tool for Osmotic Stress Tolerance Classification of Rice Cultivars Based on In Vitro Seed Germination

Crop Science ◽

10.2135/cropsci2016.03.0196 ◽

2016 ◽

Vol 57 (1) ◽

pp. 387-394 ◽

Cited By ~ 9

Author(s):

Bhupinder Singh ◽

K. Raja Reddy ◽

Edilberto D. Redoña ◽

Timothy Walker

Keyword(s):

Seed Germination ◽

Osmotic Stress ◽

Stress Tolerance ◽

Screening Tool ◽

Rice Cultivars ◽

Osmotic Stress Tolerance

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OsCBE1, a Substrate Receptor of Cullin4-Based E3 Ubiquitin Ligase, Functions as a Regulator of Abiotic Stress Response and Productivity in Rice

International Journal of Molecular Sciences ◽

10.3390/ijms22052487 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2487

Author(s):

Juyoung Choi ◽

Wonkyung Lee ◽

Gynheung An ◽

Seong-Ryong Kim

Keyword(s):

Abiotic Stress ◽

Stress Response ◽

Cold Stress ◽

Stress Tolerance ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

In Silico Analysis ◽

Wild Type ◽

Abiotic Stress Response ◽

Environmental Stress Response

Ubiquitination is an important environmental stress response, and E3 ubiquitin ligases play a major role in the process. T-DNA insertion mutants of rice, Oscbe1-1, and Oscbe1-2, were identified through the screening of cold stress tolerance at seedling stage. Oscbe1 mutants showed a significantly higher cold stress tolerance in the fresh weight, chlorophyll content, and photosynthetic efficiency than wild type. Molecular prediction showed that OsCBE1 (Oryza sativa Cullin4-Based E3 ubiquitin ligase1) encoded a novel substrate receptor of Cullin4-based E3 ubiquitin ligase complex (C4E3). Whereas Oscbe1 mutants had fewer panicles and grains than wild type in the paddy field, the overexpression lines of OsCBE1 had more panicles and grains, suggesting that OsCBE1 is involved in the regulation of both abiotic stress response and development. Oscbe1 mutants also showed ABA hypersensitivity during seed germination, suggesting OsCBE1 function for the stress response via ABA signaling. In silico analysis of OsCBE1 activity predicted a CCCH-type transcription factor, OsC3H32, as a putative substrate. Co-IP (Co-immunoprecipitation) study showed that OsCBE1 interacts with OsDDB1, an expected binding component of OsCBE1 and OsC3H32. Additionally, expression of OsOLE16, OsOLE18, and OsBURP5 were negatively related with expression of OsCBE1. These results suggest that OsCBE1 functions as a regulator of the abiotic stress response via CCCH as a member of the C4E3.

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