Polygalacturonase inhibiting protein: isolation, developmental regulation and pathogen related expression in Panax ginseng C.A. Meyer

Abstract

Polygalacturonase inhibiting proteins (PGIPs) are the major defense proteins which play an important role in resistance to infection of pathogens. A putative novel gene encoding PGIP was isolated from Panax ginseng C.A. Meyer, which shows 70.3 and 68.4% homology with chick pea and Arabidopsis PGIPs. The RACE PCR was preformed to isolate the full-length PGIP cDNA from Panax ginseng. Sequence analysis revealed that the cDNA of PgPGIP is of 1,275 bp in length and that it's containing ORF encodes for a polypeptide of 366 amino acids. Domain analysis revealed that the deduced amino acid sequences of PgPGIP have a typical PGIP topology. The transcription level of PgPGIP was up-regulated in ginseng in response to wounding and infection with phytopathogenic fungi i.e., Rhizoctonia solani, Fusarium oxysporum, Phythium ultimum, Botrytis cinerea, Colletotrichum gloeosporioides and Cylindrocarpon destructans, which causes drastic damage in ginseng plants. The constitutive PgPGIP expression of 4 years old plant, showed elevated transcript level, especially roots, showed maximum then buds, stems and leaves, indicating that the gene is developmentally regulated. The crude PGIP extracts derived from the fungal infected plants directly reduces the aggressive potential of PGs from diverse group of fungi. Like other PGIPs, PgPGIP also possess board spectrum of inhibitory activity. Thus, the presence of PgPGIP gene and their active role in defense mechanism was proved. The structural model of PgPGIP was predicted based on the alignment generated by EBI-Align, the program "MOODELLER" and the predicted structure showed 10 β-strands and 10 α-helixes region.

Partial purification and characterization of polygalacturonase-inhibitor proteins from pearl millet

“…Recent studies in various host-pathogen systems such as ginseng (Rhizoctonia solani) and other fungal pathogens (Sathiyaraj et al, 2010) and in bean-Sclerotinia sclerotiorum (Oliveira et al, 2010), as well as the transgenic expres-sion studies in wheat and Arabidopsis to successfully counter Fusarium graminearum (Ferrari et al, 2011) triggered our interest to explore PGIPs in pearl millet. The present study was aimed at exploring the presence of PGIPs in millets.…”

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

“…In ginseng, a PgPGIP that showed sequence identity with proteins from chickpea (70.3%), Arabidopsis (68.4%), and cotton (60.6%), with ten leucine-rich repeat domains was recently characterized [77]. The mature form of PGIP is characterized by the presence of ten leucine-rich repeat domains that represent over two-thirds of the protein; this motif forms a solvent-exposed surface of parallel β-sheets that mediates protein-protein interactions [74,78,79].…”

“…In the potato plant, PGIP accumulation increased fi ve-fold after infection with Phytophthora infestans [81]. PGIPs are known to exist in many copies in different groups of plants [82,83], as well as in ginseng [77]. In particular, ginseng's PgPGIP has shown a wide spectrum of inhibitory effects against many pathogenic fungi, including Colletotrichum gloeosporoides, Rhizoctonia solani, Fusarium oxysporum, and Phythium ultimum.…”

“…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.…”

Spatial distribution of polygalacturonase-inhibiting proteins in Arabidopsis and their expression induced by Stemphylium solani infection

“…PGs degrade plant cell wall which allows other hydrolyzation enzymes to degrade cell wall more easily (Karr and Albersheim, 1970;Reymond et al, 1994). Polygalacturonase-inhibiting proteins (PGIPs) are present in the cell walls and play a key role in plant disease resistance (Prabhu et al, 2012;Sathiyaraj et al, 2010;Schacht et al, 2011;Veronico et al, 2011). PGIPs specifically trigger their effect through inhibiting PGs activity, retarding the pathogens invasion, preventing pathogen spread, and also involving in defence responses in plants, such as hypersensitive response (Ferrari et al, 2006;Janni et al, 2008;Kortekamp, 2006;Spinelli et al, 2009).…”