AUTHOR=Liu Feng , Hu Li , Cai Yuanping , Lin Hong , Liu Juanxu , Yu Yixun 

TITLE=Molecular Characterization and Functional Analysis of Two Petunia PhEILs

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.01606

DOI=10.3389/fpls.2016.01606

ISSN=1664-462X

ABSTRACT=<p>Ethylene plays an important role in flower senescence of many plants. <italic>Arabidopsis</italic> ETHYLENE INSENSITIVE3 (EIN3) and its homolog EIL1 are the downstream component of ethylene signaling transduction. However, the function of EILs during flower senescence remains unknown. Here, a petunia <italic>EIL</italic> gene, <italic>PhEIL2</italic>, was isolated. Phylogenetic tree showed that PhEIL1, whose coding gene is previously isolated, and PhEIL2 are the homologs of <italic>Arabidopsis</italic> AtEIL3 and AtEIL1, respectively. The expression of both <italic>PhEIL1</italic> and <italic>PhEIL2</italic> is the highest in corollas and increased during corolla senescence. Ethylene treatment increased the mRNA level of <italic>PhEIL1</italic> but reduced that of <italic>PhEIL2</italic>. VIGS-mediated both <italic>PhEIL1</italic> and <italic>PhEIL2</italic> silencing delayed flower senescence, and significantly reduced ethylene production and the expression of <italic>PhERF3</italic> and <italic>PhCP2</italic>, two senescence-associated genes in petunia flowers. The PhEIL2 protein activating transcription domain is identified in the 353-612-amino acids at C-terminal of PhEIL2 and yeast two-hybrid and bimolecular fluorescence complementation assays show that PhEIL2 interacts with PhEIL1, suggesting that PhEIL1 and PhEIL2 might form heterodimers to recognize their targets. These molecular characterizations of PhEIL1 and PhEIL2 in petunia are different with those of in <italic>Vigna radiata</italic> and <italic>Arabidopsis</italic>.</p>