Analysis of regulatory elements of the promoter and the 3′ untranslated region of the maize Hrgp gene coding for a cell wall protein

Abstract

Hydroxyproline-rich glycoproteins (HRGP) are structural components of the plant cell wall. Hrgp genes from maize and related species have a conserved 500 bp sequence in the 5'-flanking region, and all Hrgp genes from monocots have an intron located in the 3' untranslated region. To study the role of these conserved regions, several deletions of the Hrgp gene were fused to the bglucuronidase (GUS) gene and used to transform maize tissues by particle bombardment. The overall pattern of GUS activity directed by sequential deletions of the Hrgp promoter was different in embryos and young shoots. In embryos, the activity of the full-length Hrgp promoter was in the same range as that of the p35SI promoter construct, based on the strong 35S promoter, whereas in the fast-growing young shoots it was 20 times higher. A putative silencer element specific for young shoots was found in the 1,076/700 promoter region. Other major cis elements for Hrgp expression are probably located in the regions spanning 699/510 and 297/160. Sequences close to the initial ATG and mRNA leader were also important since deletion of the region 52/+16 caused a 75% reduction in promoter activity. The presence of the Hrgp intron in the 3' untranslated region changed the levels of GUS activity directed by the Hrgp and the 35S promoters. This pattern of activity was complex, and was dependent on the promoter and cell type analysed.

Positive Selection and Expression Divergence Following Gene Duplication in the Sunflower CYCLOIDEA Gene Family

“…Three of the CYC2-like genes that we identified were found to have introns in their 3# UTRs, which has previously been reported for CYC in Antirrhinum (Luo et al 1996). In general, UTRs are known to play a central role in gene expression by modulating mRNA localization, stability, and translational efficiency (e.g., Morello et al 2002;Menossi et al 2003;Kim et al 2006;Morello et al 2006;reviewed in Wilkie et al 2003 andHughes 2006), and introns in such regions are relatively uncommon. Moreover, the majority of investigations of UTR-borne introns have focused on those located in 5# UTRs, presumably because they are more prevalent than introns in 3# UTRs (Hong et al 2006).…”

Plant 3’ Regulatory Regions From mRNA-Encoding Genes and Their Uses to Modulate Expression

“…Moreover, the presence of introns in 3’UTRs can promote the degradation of mRNA via nonsense-mediated decay (NMD) ( Kertész et al., 2006 ; Schweingruber et al., 2013 ). Also, another point that may explain this controversy would be tissue specificity that some introns present ( Sieburth and Meyerowitz, 1997 ; Menossi et al., 2003 ; Kooiker et al., 2005 ; Showalter et al., 2010 ).…”

“…In fact, a version of Ext without intron, lacking its first 465 nt deleted, showed no expression, probably due to the loss of a putative FUE, demonstrating the importance of this cis -element for gene expression. On the other hand, the presence of a native intron in the maize Hrgp 3’ regulatory region had positive effects on the regulation of expression in maize compared to the 3’ regulatory region in its native conformation ( Menossi et al., 2003 ).…”

“…However, we believe 3’ regulatory region is a more appropriate term, as it will be referred to here. This is because transcription termination is only one of the roles of the 3’ regulatory regions, which, in many cases, can have profound effects on gene expression, as it will be discussed in this review ( Menossi et al., 2003 ; Yang et al., 2009 ; Nagaya et al., 2010 ; Hirai et al., 2011 ; Hiwasa-Tanase et al., 2011 ; Matsui et al., 2014 ; Diamos and Mason, 2018 ; Pérez-González and Caro, 2018 ; Rosenthal et al., 2018 ; Yamamoto et al., 2018 ).…”

Hydroxyproline-rich Glycoproteins and Plant Defence

“…2002). HRGP genes from maize and related species have a conserved 500 bp sequence in the 5′‐flanking region, and all HRGP genes from monocots have an intron located in the 3′ untranslated region (Menossi et al. 2003).…”