Differential Expression of theS-Adenosyl-l-Methionine Synthase Genes during Pea Development1

Abstract

Two genes coding for S-adenosyl-L-methionine synthase (SAMS, EC 2.5.1.6) were previously isolated from pea (Pisum sativum) ovaries. Both SAMS genes were highly homologous throughout their coding regions but showed a certain degree of sequence divergence within the 5 and the 3 untranslated regions. These regions have been used as gene-specific probes to analyze the differential expression of SAMS1 and SAMS2 genes in pea plants. The ribonuclease protection assay revealed different expression patterns for each individual gene. SAMS1 was strongly expressed in nearly all tissues, especially in roots. SAMS2 expression was weaker, reaching its highest level at the apex. Following pollination, SAMS1 was specifically up-regulated, whereas SAMS2 was expressed constitutively. The up-regulation of SAMS1 during ovary development was also observed in unpollinated ovaries treated with auxins. In unpollinated ovaries an increase in SAMS1 expression was observed as a consequence of ethylene production associated with the emasculation process. In senescing ovaries both SAMS1 and SAMS2 genes showed increased expression. Ethylene treatment of unpollinated ovaries led to an increase in the SAMS1 mRNA level. However, SAMS2 expression remained unchangeable after ethylene treatment, indicating that SAMS2 induction during ovary senescence was not ethylene dependent. SAMS mRNAs were localized by in situ hybridization at the endocarp of developing fruits and in the ovules of senescing ovaries. Our results indicate that the transcriptional regulation of SAMS genes is developmentally controlled in a specific way for each gene.

Differential expression of genes identified from Poncirus trifoliata tissue inoculated with CTV through EST analysis and in silico hybridization

“…In the present work we also identified four TCs (S-adenosylmethionine adoMetDC2) (SAM), ACC synthase, ACC oxidase and ethylene forming enzyme (ACO) whose expression is putatively overexpressed under conditions inducing ethylene biosynthesis (Gomez-Gomez and Carrasco, 1998). SAM serves as a precursor of the plant hormone ethylene, implicated in the control of numerous developmental processes (Kende, 1993).…”

Identification and Functional Analysis of S-AdenosylMethionine Synthetase (HvSAMS) genes in Early Maturing Barley (Hordeum vulgare subsp. vulgare)

“…Usually, SAMS is ubiquitous enzyme and has been found in different tissue parts, such as vascular tissues and sclerenchyma of Arabidopsis (Peleman et al 1989), elongated stems of petunia (Izahaki et al 1996), leaves of rice (Dekeyser et al 1990), and developing ovary of pea (Gómez-Gómez and Carrasco 1998). However, the relationship of SAMS between its expression and biosynthesis is still unknown (Qi et al 2010).…”

S-Adenosylmethionine Synthetase 3 Is Important for Pollen Tube Growth

“…The nomenclature varies in different publications (Lindermayr et al, 2005;Mao et al, 2015); here, we will use the MAT1 to MAT4 designations. MAT1, MAT2, and MAT4 are expressed in nearly all tissues (Gómez-Gómez and Carrasco, 1998;Mao et al, 2015), whereas MAT3 is expressed predominantly in pollen (Loraine et al, 2013). MAT1 and MAT2 are most similar in sequence and expression patterns, and the double mutant mat1;mat2 exhibits decreased ethylene (Mao et al, 2015).…”