PUB16 gene expression under abiotic stress and their putative role as an ARM repeat protein in <i>Arabidopsis thaliana</i> self-pollination pathway

Abstract

The armadillo repeat super-family proteins (ARM repeat super-family proteins) possess tandem armadillo repeats and have been postulated to play different roles in plant development, morphogenesis, defense, cell death, and signal transduction through hormone signalling. In The Arabidopsis Information Resource (TAIR), we found 113 loci closely related to ARM repeat family proteins. This extensive group of proteins was studied in flowers tissues by western blot using antibodies directed against the most conserved region of the ARM repeat family proteins. The amino acid residues sequences from TAIR were aligned and the resulting phylogenetic tree allows us to inferring their evolutionary relationships. The main finding was the high similarity between the gene product of PUB16 (At5g01830, <i>A. thaliana</i>) and ARC1 (<i>Brassica napus</i>). In order to search a possible role for PUB16 we carried out stress bioassays using hormonal and saline approaches. Gene expression using RT-PCR showed that some of the ARM repeat super-family proteins are expressed both under salt or hormonal stress conditions. Particularly these studies allowed to detect and semi-quantify PUB16 gene expression in normal or stress growth conditions. In this approach it was revealed that, only in presence of GA, the expression of mRNA-PUB16 became evident. To morphologically verify the increasing number of germinated pollen grain in gibberellins treated flowers, we used epi-fluorescence microscopy assay. These results suggest that PUB16 may participate in GA signaling pathway favoring self-pollination

Classification and Expression Profile of the U-Box E3 Ubiquitin Ligase Enzyme Gene Family in Maize (Zea mays L.)

“…ZmPUB27 was homologous with AtPUB16 and OsPUB3 . In Arabidopsis, AtPUB16 participated in the GA pathway, which favored self-pollination [ 67 ]. In maize seedling, a similar ZmPUB27 up-regulation was observed at 3 and 12 h after GA treatment.…”

Genome-Wide Identification and Functional Analysis of NADPH Oxidase Family Genes in Wheat During Development and Environmental Stress Responses

“…Among the eight TaNOXs examined here, four genes including TaNOX2, 3, 8 , and 13 have distinct coexpression with the genes encoding several protein degradation-related proteins including one ubiquitin-specific protease family C19-related protein, two ARM repeat superfamily proteins, one RING/U-box superfamily protein, and five COP1-interacting protein-related proteins (Figure S6 , Table S5 ). All these coexpressed proteins function as E3 ubiquitin ligase or involve in ubiquitination of proteins (Zeng et al, 2008 ; Acosta et al, 2012 ; Xu et al, 2014 ), implying these TaNOXs might participate in protein degradation in wheat under stress conditions. Furthermore, a set of signal transduction-related genes were found to be highly coexpressed with TaNOXs, especially under stress conditions.…”

Expansion and Function of Repeat Domain Proteins During Stress and Development in Plants

“…Interestingly, few other unrelated U-box/ARM proteins were identified as the regulator of SI response in Arabidopsis suggesting functional redundancy among these proteins ( Liu et al, 2007 ). The structural homolog of ARC1, AtPUB16 was identified to express in response to GA and salt stress in order to mediate self-pollination in Arabidopsis ( Acosta et al, 2012 ). The above studies suggest a possible role of ARC1 related genes in hormonal and stress signaling pathways.…”