Molecular characterization of the Arginine decarboxylase gene family in rice

Abstract

Arginine decarboxylase (ADC) is a key enzyme in plants that converts arginine into putrescine, an important mediator of abiotic stress tolerance. Adc genes have been isolated from a number of dicotyledonous plants but the oat and rice Adc genes are the only representatives of monocotyledonous species described thus far. Rice has a small family of Adc genes, and OsAdc1 expression has been shown to fluctuate under drought and chilling stress. We identified and characterized a second rice Adc gene (OsAdc2) which encodes a 629-amino-acid protein with a predicted molecular mass of 67 kDa. An unusual feature of the OsAdc2 gene is the presence of an intron and a short upstream open reading frame in the 5'-UTR. Sequence comparisons showed that OsAdc2 is more closely related to the oat Adc gene than to OsAdc1 or to its dicot homologs, and mRNA analysis showed that the two rice genes are also differently regulated. Whereas OsAdc1 is expressed in leaf, root and stem, OsAdc2 expression is restricted to stem tissue. Protein expression was investigated with specific antibodies against ADC1 and ADC2, corroborating the mRNA data. We discuss the expression profiles of OsAdc1 and OsAdc2 and potential functions for the two corresponding proteins.

Dissecting Rice Polyamine Metabolism under Controlled Long-Term Drought Stress

“…However, also a similar expression for an ADC and an ODC gene under control conditions in rice was shown [94]. Lower expression of ADC2 than ADC1 was previously reported [95] as well as a low expression of ODC [96]–[98].…”

Expression analysis in response to drought stress in soybean: shedding light on the regulation of metabolic pathway genes

“…Arginine decarboxylase (ADC) is a key plant enzyme that converts arginine into putrescine, an important mediator of abiotic stress tolerance (Figure 2B) (Peremarti et al , 2010). The over-expression of ADC2 in transgenic Arabidopsis showed that higher levels of putrescine increased drought tolerance (Alcazar et al , 2006, 2010).…”

Translational and post-translational regulation of polyamine metabolic enzymes in plants

“…Besides, it was shown that the DcADC uORF1 was able to inhibit translation in trans, since the addition of a synthetic peptide derived from DcADC uORF1 dramatically decreased the amount of ADC protein in an in vitro transcription/translation system. The presence of uORFs is a conserved feature of other plant ADC genes, since they have been described in A. thaliana AtADC2, Gossypium hirsutum GhADC, Nicotiana tabacum NtADC, Pisum sativum PsADC, Malus domestica MdADC, O. sativa OsADC2, among other species (Hao et al, 2005;Peremarti et al, 2010;Pérez-Amador et al, 1995;Vaughn et al, 2012). Likewise, the S. lycopersicon ornithine decarboxylase (SlODC) mRNA contains a uORF encoding a 5amino acid peptide, which inhibits SlODC translation in vitro (Table 2).…”