Phytosulfokine α (PSKα) delays senescence and reinforces SUMO1/SUMO E3 ligase SIZ1 signaling pathway in cut rose flowers (Rosa hybrida cv. Angelina)

AbstractRoses are widely used as cut flowers worldwide. Petal senescence confines the decorative quality of cut rose flowers, an impressively considerable economic loss. Herein, we investigated the SUMO1/SUMO E3 ligase SIZ1 signaling pathway during bud opening, and petal senescence of cut rose flowers. Our results exhibited that the higher expression of SUMO1 and SUMO E3 ligase SIZ1 during bud opening was accompanied by lower endogenous H2O2 accumulation arising from higher expression and activities of SOD, CAT, APX, and GR, promoting proline accumulation by increasing P5CS expression and activity and enhancing GABA accumulation by increasing GAD expression and activity. In harvested flowers, lower expressions of SUMO1 and SUMO E3 ligase SIZ1 during petal senescence were associated with higher endogenous H2O2 accumulation due to lower expression and activities of SOD, CAT, APX, and GR. Therefore, promoting the activity of the GABA shunt pathway as realized by higher expression and activities of GABA-T and SSADH accompanied by increasing OAT expression and activity for sufficiently supply proline in rose flowers during petal senescence might serve as an endogenous antisenescence mechanism for slowing down petals senescence by avoiding endogenous H2O2 accumulation. Following phytosulfokine α (PSKα) application, postponing petal senescence in cut rose flowers could be ascribed to higher expression of SUMO1 and SUMO E3 ligase SIZ1 accompanied by higher expression and activities of SOD, CAT, APX, and GR, higher activity of GABA shunt pathway as realized by higher expression and activities of GAD, GABA-T, and SSADH, higher expression and activities of P5CS and OAT for supplying proline and higher expression of HSP70 and HSP90. Therefore, our results highlight the potential of the PSKα as a promising antisenescence signaling peptide in the floriculture industry for postponing senescence and extending the vase life of cut rose flowers.

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SOCS1, SOCS3, and PIAS1 Promote Myogenic Differentiation by Inhibiting the Leukemia Inhibitory Factor-Induced JAK1/STAT1/STAT3 Pathway

Molecular and Cellular Biology ◽

10.1128/mcb.00267-09 ◽

2009 ◽

Vol 29 (18) ◽

pp. 5084-5093 ◽

Cited By ~ 49

Author(s):

Yarui Diao ◽

Xi Wang ◽

Zhenguo Wu

Keyword(s):

Signaling Pathway ◽

Molecular Mechanism ◽

Leukemia Inhibitory Factor ◽

Myogenic Differentiation ◽

E3 Ligase ◽

Inhibitory Factor ◽

Dual Roles ◽

Stat3 Pathway ◽

Myoblast Proliferation ◽

Sumo E3 Ligase

ABSTRACT We recently showed that a leukemia inhibitory factor (LIF)-engaged signaling pathway consisting of JAK1, STAT1, and STAT3 plays dual roles in myogenic differentiation: while it participates in myoblast proliferation, it also actively represses differentiation. Downregulation of this pathway is required at the onset of differentiation. However, it remained unclear how this is achieved mechanistically. We now show that SOCS1, SOCS3, and PIAS1 promote myogenic differentiation by specifically inhibiting the LIF-induced JAK1/STAT1/STAT3 pathway via distinct targets; whereas SOCS1 and SOCS3 selectively bind and inhibit JAK1 and gp130, respectively, PIAS1 targets mainly the activated STAT1 and prevents its binding to DNA. We further demonstrated that the SUMO E3-ligase activity of PIAS1 is dispensable for its role in myogenic differentiation. Collectively, our current study revealed a molecular mechanism that explains how the LIF-induced JAK1/STAT1/STAT3 pathway is downregulated upon myogenic differentiation.

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Sumoylation of BRI1-EMS-SUPPRESSOR 1 (BES1) by the SUMO E3 Ligase SIZ1 Negatively Regulates Brassinosteroids Signaling in Arabidopsis thaliana

Plant and Cell Physiology ◽

10.1093/pcp/pcz125 ◽

2019 ◽

Vol 60 (10) ◽

pp. 2282-2292 ◽

Cited By ~ 2

Author(s):

Li’e Zhang ◽

Qing Han ◽

Jiawei Xiong ◽

Ting Zheng ◽

Jifu Han ◽

...

Keyword(s):

Signaling Pathway ◽

Double Mutant ◽

E3 Ligase ◽

Insertion Mutant ◽

Post Translational Modifications ◽

Sumo Conjugation ◽

Dna Insertion ◽

Sumo E3 Ligase

Abstract Brassinosteroids (BRs), a group of plant steroid hormones, participate in the regulation of plant growth and developmental processes. BR functions through the BES1/BZR1 family of transcription factors, however, the regulation of the BES1 activity by post-translational modifications remains largely unknown. Here, we present evidence that the SUMO E3 ligase SIZ1 negatively regulates BR signaling pathway. T-DNA insertion mutant siz1-2 shows BL (Brassinolide, the most active BR) hypersensitivity and BRZ (Brassinazole, a BR biosynthesis inhibitor) insensitivity during hypocotyl elongation. In addition, expression of BES1-dependent BR-response genes is hyper-regulated in siz1-2 seedlings. The siz1-2bes1-D double mutant exhibits longer hypocotyl than bes1-D. Moreover, SIZ1 physically interacts with BES1 in vivo and in vitro and mediates the sumoylation of BES1. A K302R substitution in BES1 blocks its sumoylation mediated by SIZ1 in plants, indicating that K302 is the principal site for SUMO conjugation. Consistently, we find that sumoylation inhibits BES1 protein stability and activity. Taken together, our data show that the sumoylation of BES1 via SIZ1 negatively regulates the BR signaling pathway.

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