Plants respond to mild warm temperature conditions by increased elongation growth of organs to en... more Plants respond to mild warm temperature conditions by increased elongation growth of organs to enhance cooling capacity, in a process called thermomorphogenesis. To this date, the regulation of thermomorphogenesis has been exclusively shown to intersect with light signalling pathways. To identify regulators of thermomorphogenesis that are conserved in flowering plants, we map changes in protein phosphorylation in both dicots and monocots exposed to warm temperature. We identify MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASE4 (MAP4K4)/TARGET OF TEMPERATURE3 (TOT3) as a regulator of thermomorphogenesis that impinges on brassinosteroid signalling inArabidopsis thaliana. In addition, we show that TOT3 plays a role in thermal response in wheat, a monocot crop. Altogether, the conserved thermal regulation by TOT3 expands our knowledge of thermomorphogenesis beyond the well-studied pathways and can contribute to ensuring food security under a changing climate.
Summary Accumulating data indicate that strigolactones (SLs) are implicated in the response to en... more Summary Accumulating data indicate that strigolactones (SLs) are implicated in the response to environmental stress, implying a potential effect of SLs on stomatal response and thus stress acclimatization. In this study, we investigated the molecular mechanism underlying the effect of SLs on stomatal response and their interrelation with abscisic acid (ABA) signaling. The impact of SLs on the stomatal response was investigated by conducting SL‐feeding experiments and by analyzing SL‐related mutants. The involvement of endogenous ABA and ABA‐signaling components in SL‐mediated stomatal closure was physiologically evaluated using genetic mutants. Pharmacological and genetic approaches were employed to examine hydrogen peroxide (H2O2) and nitric oxide (NO) production. SL‐related mutants exhibited larger stomatal apertures, while exogenous SLs were able to induce stomatal closure and rescue the more widely opening stomata of SL‐deficient mutants. The SL‐biosynthetic genes were induced b...
The CLAVATA2 (CLV2) gene encodes a leucine-rich repeat receptor-like protein, a class of cell sur... more The CLAVATA2 (CLV2) gene encodes a leucine-rich repeat receptor-like protein, a class of cell surface receptors that lacks a cytoplasmic kinase domain. As such, CLV2 is capable of functioning in concert with additional receptor(s), possibly receptor-like kinase(s), to activate cellular responses upon ligand perception. Accumulating data indicate that CLV2 is implicated in distinct biological processes including plant growth and development as well as innate immunity to microbe and nematode infections. This article focuses on recent advances in our understanding of multiple signaling pathways mediated by multifunctional CLV2 that modulate various physiological processes. The challenges and future perspectives of elucidating the specificity of CLV2-mediated signaling pathways and identifying potential co-receptors and putative ligands for CLV2 are also discussed.
The kinase-mediated phosphorylation impacts every basic cellular process. While mitogen-activated... more The kinase-mediated phosphorylation impacts every basic cellular process. While mitogen-activated protein kinase technology kinase kinases (MAP4Ks) are evolutionarily conserved, there is no comprehensive overview of the MAP4K family in the green lineage (Viridiplantae). In this study, we identified putative MAP4K members from representative species of the two core groups in the green lineage: Chlorophyta, which is a diverse group of green algae, and Streptophyta, which is mostly freshwater green algae and land plants. From that, we inferred the evolutionary relationships of MAP4K proteins through a phylogenetic reconstruction. Furthermore, we provided a classification of the MAP4Ks in the green lineage into three distinct.
The CLE (CLAVATA3/Embryo Surrounding Region-related) peptides are small secreted signaling peptid... more The CLE (CLAVATA3/Embryo Surrounding Region-related) peptides are small secreted signaling peptides that are primarily involved in the regulation of stem cell homoeostasis in different plant meristems. Particularly, the characterization of the CLE41-PXY/TDR signaling pathway has greatly advanced our understanding on the potential roles of CLE peptides in vascular development and wood formation. Nevertheless, our knowledge on this gene family in a tree species is limited. In a recent study, we reported on a systematically investigation of the CLE gene family in Populus trichocarpa. The potential roles of PtCLE genes were studied by comparative analysis and transcriptional profiling. Among fifty PtCLE members, many PtCLE proteins share identical CLE motifs or contain the same CLE motif as that of AtCLEs, while PtCLE genes exhibited either comparable or distinct expression patterns comparing to their Arabidopsis counterparts. These findings indicate the existence of both functional con...
Phosphorylation-mediated signaling cascades control plant growth and development or the response ... more Phosphorylation-mediated signaling cascades control plant growth and development or the response to stress conditions. One of the best studied signaling cascades is the one regulated by MITOGEN-ACTIVATED PROTEIN KINASEs (MAPKs). However, MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASEs (MAP4Ks) are hardly explored. Here, we will give a comprehensive overview of what is known about plant MAP4Ks and highlight some outstanding questions associated with this largely uncharacterized class of kinases in plants.
Brief summary statement: CLE peptides have been implicated in various developmental processes of ... more Brief summary statement: CLE peptides have been implicated in various developmental processes of plants and mediate their responses to environmental stimuli. Here we reported an essential role of CLE9 in the induction of stomatal closure. CLE9 stimulated stomatal closure in an ABA-dependent manner, accompanied with H2O2/NO production. Further investigation revealed that OST1, SLAC1, and MPK3/MPK6 are required for CLE9-mediated guard cell signaling.
Plants respond to mild warm temperature conditions by increased elongation growth of organs to en... more Plants respond to mild warm temperature conditions by increased elongation growth of organs to enhance cooling capacity, in a process called thermomorphogenesis. To this date, the regulation of thermomorphogenesis has been exclusively shown to intersect with light signalling pathways. To identify regulators of thermomorphogenesis that are conserved in flowering plants, we map changes in protein phosphorylation in both dicots and monocots exposed to warm temperature. We identify MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASE4 (MAP4K4)/TARGET OF TEMPERATURE3 (TOT3) as a regulator of thermomorphogenesis that impinges on brassinosteroid signalling inArabidopsis thaliana. In addition, we show that TOT3 plays a role in thermal response in wheat, a monocot crop. Altogether, the conserved thermal regulation by TOT3 expands our knowledge of thermomorphogenesis beyond the well-studied pathways and can contribute to ensuring food security under a changing climate.
Summary Accumulating data indicate that strigolactones (SLs) are implicated in the response to en... more Summary Accumulating data indicate that strigolactones (SLs) are implicated in the response to environmental stress, implying a potential effect of SLs on stomatal response and thus stress acclimatization. In this study, we investigated the molecular mechanism underlying the effect of SLs on stomatal response and their interrelation with abscisic acid (ABA) signaling. The impact of SLs on the stomatal response was investigated by conducting SL‐feeding experiments and by analyzing SL‐related mutants. The involvement of endogenous ABA and ABA‐signaling components in SL‐mediated stomatal closure was physiologically evaluated using genetic mutants. Pharmacological and genetic approaches were employed to examine hydrogen peroxide (H2O2) and nitric oxide (NO) production. SL‐related mutants exhibited larger stomatal apertures, while exogenous SLs were able to induce stomatal closure and rescue the more widely opening stomata of SL‐deficient mutants. The SL‐biosynthetic genes were induced b...
The CLAVATA2 (CLV2) gene encodes a leucine-rich repeat receptor-like protein, a class of cell sur... more The CLAVATA2 (CLV2) gene encodes a leucine-rich repeat receptor-like protein, a class of cell surface receptors that lacks a cytoplasmic kinase domain. As such, CLV2 is capable of functioning in concert with additional receptor(s), possibly receptor-like kinase(s), to activate cellular responses upon ligand perception. Accumulating data indicate that CLV2 is implicated in distinct biological processes including plant growth and development as well as innate immunity to microbe and nematode infections. This article focuses on recent advances in our understanding of multiple signaling pathways mediated by multifunctional CLV2 that modulate various physiological processes. The challenges and future perspectives of elucidating the specificity of CLV2-mediated signaling pathways and identifying potential co-receptors and putative ligands for CLV2 are also discussed.
The kinase-mediated phosphorylation impacts every basic cellular process. While mitogen-activated... more The kinase-mediated phosphorylation impacts every basic cellular process. While mitogen-activated protein kinase technology kinase kinases (MAP4Ks) are evolutionarily conserved, there is no comprehensive overview of the MAP4K family in the green lineage (Viridiplantae). In this study, we identified putative MAP4K members from representative species of the two core groups in the green lineage: Chlorophyta, which is a diverse group of green algae, and Streptophyta, which is mostly freshwater green algae and land plants. From that, we inferred the evolutionary relationships of MAP4K proteins through a phylogenetic reconstruction. Furthermore, we provided a classification of the MAP4Ks in the green lineage into three distinct.
The CLE (CLAVATA3/Embryo Surrounding Region-related) peptides are small secreted signaling peptid... more The CLE (CLAVATA3/Embryo Surrounding Region-related) peptides are small secreted signaling peptides that are primarily involved in the regulation of stem cell homoeostasis in different plant meristems. Particularly, the characterization of the CLE41-PXY/TDR signaling pathway has greatly advanced our understanding on the potential roles of CLE peptides in vascular development and wood formation. Nevertheless, our knowledge on this gene family in a tree species is limited. In a recent study, we reported on a systematically investigation of the CLE gene family in Populus trichocarpa. The potential roles of PtCLE genes were studied by comparative analysis and transcriptional profiling. Among fifty PtCLE members, many PtCLE proteins share identical CLE motifs or contain the same CLE motif as that of AtCLEs, while PtCLE genes exhibited either comparable or distinct expression patterns comparing to their Arabidopsis counterparts. These findings indicate the existence of both functional con...
Phosphorylation-mediated signaling cascades control plant growth and development or the response ... more Phosphorylation-mediated signaling cascades control plant growth and development or the response to stress conditions. One of the best studied signaling cascades is the one regulated by MITOGEN-ACTIVATED PROTEIN KINASEs (MAPKs). However, MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASEs (MAP4Ks) are hardly explored. Here, we will give a comprehensive overview of what is known about plant MAP4Ks and highlight some outstanding questions associated with this largely uncharacterized class of kinases in plants.
Brief summary statement: CLE peptides have been implicated in various developmental processes of ... more Brief summary statement: CLE peptides have been implicated in various developmental processes of plants and mediate their responses to environmental stimuli. Here we reported an essential role of CLE9 in the induction of stomatal closure. CLE9 stimulated stomatal closure in an ABA-dependent manner, accompanied with H2O2/NO production. Further investigation revealed that OST1, SLAC1, and MPK3/MPK6 are required for CLE9-mediated guard cell signaling.
Uploads
Papers by LIXIA PAN