luciferase-complementation-imaging-assay-nicotiana-benthamiana-leaves

Luciferase Complementation Imaging Assay in <em>Nicotiana benthamiana</em> Leaves for Transiently Determining Protein-protein Interaction Dynamics

Protein-protein interactions are fundamental mechanisms for relaying signal transduction in most cellular processes; therefore, identification of novel ...

nanjing normal university

ETHYLENE INSENSITIVE 2 (EIN2), an endoplasmic reticulum (ER) localized protein, plays a central role in relaying the ethylene signal from ER perception to the nucleus. Two recent reports reveal the novel role for EIN2 in translational control, providing another layer of regulation for ethylene signal transduction.

Relaying the Ethylene Signal: New Roles for EIN2.

Rethinking the Origin of Auxin Biosynthesis in Plants.

DELLA proteins are central regulators in gibberellin (GA) signaling that interact with PHYTOCHROME-INTERACTING FACTORS (PIFs) and block their DNA-binding capacity, impairing their function in integrating light signals. A recent report demonstrates that DELLAs also negatively control PIF stability, thus providing a new layer of coordination of light and GA signaling.

DELLA-PIF Modules: Old Dogs Learn New Tricks.

A germinating seedling undergoes skotomorphogenesis to emerge from the soil and reach for light. During this phase, the cotyledons are closed, and the hypocotyl elongates. Upon exposure to light, the seedling rapidly switches to photomorphogenesis by opening its cotyledons and suppressing hypocotyl elongation. The E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) is critical for maintaining skotomorphogenesis. Here, we report that jasmonate (JA) suppresses hypocotyl elongation and stimulates cotyledon opening in etiolated seedlings, partially phenocopying cop1 mutants in the dark. We also find that JA stabilizes several COP1-targeted transcription factors in a COP1-dependent manner. RNA-seq analysis further defines a JA-light co-modulated and cop1-dependent transcriptome, which is enriched for auxin-responsive genes and genes participating in cell wall modification. JA suppresses COP1 activity through at least two distinct mechanisms: decreasing COP1 protein accumulation in the nucleus; and reducing the physical interaction between COP1 and its activator, SUPPRESSOR OF PHYTOCHROME A-105 1 (SPA1). Our work reveals that JA suppresses COP1 activity to stabilize COP1 targets, thereby inhibiting hypocotyl elongation and stimulating cotyledon unfolding in etiolated Arabidopsis seedlings.

Jasmonate inhibits COP1 activity to suppress hypocotyl elongation and promote cotyledon opening in etiolated Arabidopsis seedlings.

In addition to defense response, phytohormone jasmonate participates in various plant growth and developmental processes. Nonetheless, its role in the seedling stage is not well defined. We recently report that jasmonate suppresses hypocotyl elongation and promotes cotyledon unfolding in etiolated Arabidopsis seedlings. The molecular basis underlying this phenotype is that jasmonate treatment reduces the biochemical activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) to stabilize several COP1-targetted transcription factors for eliciting a proportion of light responsive transcriptome. We further reveal that jasmonate receptor CORONATINE INSENSITIVE 1 (COI1) and bHLH transcription factor MYC2 are required for the suppression of COP1 activity. Because elongated hypocotyl and closed cotyledons secure the success for seedling soil emergence, here we investigate seedling soil emergence under jasmonate treatment and find that jasmonate reduces the seedling emerging rates in the wild-type plants. Consistent with the largely insensitive to jasmonate in the suppression of skotomorphogenesis, the soil emerging rates in coi1 or myc2 mutants are almost not altered in the presence of jasmonate. Our data addendum describe that jasmonate-triggered inhibition of etiolation growth results in the defects in seedling soil emergence and suggest that defense-stimulated jasmonate biosynthesis might affect seedling germination in soil.

Article	Year
Relaying the Ethylene Signal: New Roles for EIN2. Trends in plant science\| PubMed ID: 26679045	2016
Rethinking the Origin of Auxin Biosynthesis in Plants. Frontiers in plant science\| PubMed ID: 26697046	2015
DELLA-PIF Modules: Old Dogs Learn New Tricks. Trends in plant science\| PubMed ID: 27569991	2016
Jasmonate inhibits COP1 activity to suppress hypocotyl elongation and promote cotyledon opening in etiolated Arabidopsis seedlings. The Plant journal : for cell and molecular biology\| PubMed ID: 28321936	2017
Jasmonate suppresses seedling soil emergence in Arabidopsis thaliana. Plant signaling & behavior\| PubMed ID: 28534718	2017

Yuyu Zheng

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