Isolation and characterization of a Glutamate decarboxylase (GAD) gene and their differential expression in response to abiotic stresses from Panax ginseng C. A. Meyer

Abstract

Glutamate decarboxylase (GAD) catalyzes the conversion of L-glutamate to γ-aminobutyric acid (GABA). A full-length cDNA encoding GAD (designated as PgGAD) was isolated and characterized from the root of Panax ginseng C. A. Meyer. The length cDNA of PgGAD was 1881 bp and contained a 1491 bp open reading frame (ORF) encoding a glutamate decarboxylase protein of 496 amino acids, possessing a Ser-X-X-Lys active site, which belongs to the GAD group. The deduced amino acid sequence of the PgGAD was classified in the plant GAD family and has 76-85% high similarity with other plants as like petunia, Arabidopsis, tomato. Secondary structure of PgGAD was predicted by using SOPMA software program. Southern blot analysis of genomic DNA suggests that, there is more than one copy of the PgGAD gene. The organ specific gene expression pattern also studied in P. ginseng seedlings, in which the stem showed elevated expression than root, leaf, bud and rhizomes. Along with this, we also confirmed the gene expression of PgGAD under various abiotic stresses like temperature stress, osmotic stress, anoxia, oxidative stress, and mechanical damage. Temporal analysis of gene expression except exposure of oxidative stress revealed an enhanced expression after each stresses. The enzyme activity of PgGAD was stimulated to 2-fold under cold stress.

Comprehensive Transcriptome Profiling Reveals Long Noncoding RNA Expression and Alternative Splicing Regulation during Fruit Development and Ripening in Kiwifruit (Actinidia chinensis)

“…In Panax ginseng C. A. Meyer, the expression of PgGAD gene was enhanced under various abiotic stresses (Lee et al, 2010). Three argininosuccinate synthase ( ASS ) genes and two argininosuccinate lyase ( ASL ) genes were expressed in among three stages of fruit development, but the ASS gene ( Achn280681 ) was decreased in 127 DAP.…”

Defense Genes Induced by Pathogens and Abiotic Stresses in Panax ginseng C.A. Meyer

“…PgGAD appears to be constitutively expressed in ginseng stems. The mRNA transcription level of PgGAD was up-regulated dramatically by cold and wounding, but declined drastically with oxidative stress [112].…”

“…A unique feature of plant GAD is the presence of a calmodulin-binding domain near the C-terminal [110,111]. We isolated GAD in ginseng, which shows a conserved motif and 76-85% homology with the GADs of other plants including tomato, Arabidopsis, and petunia [112]. PgGAD appears to be constitutively expressed in ginseng stems.…”

“…These genes may be triggered in response to integrated signaling networks involving jasmonic acid (JA), salicylic acid (SA), Mitogen-activated protein kinase (MAPK), or Ca + under unfavorable conditions [29,35,45,54,77,94,112]. These genes may act as potential markers based on their responses to a specifi c factor.…”

Evolutionary Trails of Plant Group II Pyridoxal Phosphate-Dependent Decarboxylase Genes

“…Growing evidences suggest that transcript levels of PLP_deC genes are also influenced by both abiotic (Menke et al, 1999; Lee et al, 2010; Akcay et al, 2012; Liu et al, 2012; Al-Quraan et al, 2013; Hyun et al, 2014; Hu et al, 2015; Kumar et al, 2015) and biotic stresses (Kawalleck et al, 1993; Facchini et al, 1996; Lopez-Meyer and Nessler, 1997; Li et al, 2013; Yogendra et al, 2014). Further, plant hormones such as IAA (Aerts et al, 1992; Goddijn et al, 1992), ABA, salicylic acid, and ethylene (Turano and Fang, 1998; Wang et al, 2000; Kumar et al, 2015) and metal ions Ni 2+ , Mn 2+ , Cu 2+ , Fe 3+ , and Mg 2+ also modulate their expression (Fujimori and Ohta, 2003; Yang et al, 2013).…”