Changes in gene expression during hairy root formation byAgrobacterium rhizogenes infection in ginseng

Abstract

Researchers have widely adopted the hairy root culture system as a means for producing secondary metabolites, including ginsenosides from ginseng. Although bacterial genes are involved, the aspects of plant gene expression are unclear. Using a cDNA microarray approach, we identified genes that are differentially expressed in ginseng hairy roots after Agrobacterium rhizogenes infection. Our goal was to gain an initial understanding of the correlation between hairy root morphology and ginsenoside produc'Uon. Among the 250 genes analyzed here, 63 (including 14 that are unclassified) were differentially expressed in a hairy root line containing a high level of ginsenosides. Of the genes that had been functionally categorized, 29% and 17% were active in metabolism and s~ress responses, respectively. Most were primarily associated with ribosomal proteins, thereby functioning in protein synthesis and destination. Their expression was down-regulated in hairy roots having less lateral branching. This phenotype may have resulted from the manipulation of metabolic activities by the translational machinery.

Proteomic analysis of Korean ginseng (Panax ginseng C.A. Meyer)

“…Approximately 3000 activation-tagged hairy root lines have been produced [57]. In order to gain an initial understanding of the correlation between hairy root morphology and ginsenoside production, genes which are differentially expressed in P. ginseng hairy roots, which exhibit a unique morphology were identified using a 5 K cDNA microarray.…”

Induction of adventitious roots and analysis of ginsenoside content and the genes involved in triterpene biosynthesis inPanax ginseng

“…Furthermore, the genes involved in triterpene biosynthesis are up-regulated by MeJa (Lee et al, 2004;Choi et al, 2005). Chung et al (2003) have used DNA microarrays to show that two gene groups (metabolic genes and those that encode heat shock genes) are responsible for ginsenoside production in hairy roots of ginseng.…”

Accumulation of sweet protein monellin is regulated by thepsbA 5′UTR in tobacco chloroplasts

“…Genetic transformation via the nuclear genome has conferred numerous beneficial agronomic traits to crop plants (Chung et al, 2003;Park et al, 2003;Lee et al, 2004). Several useful vaccine antigens, biomaterials, and biopharmaceuticals also have been produced in transgenic plants (Kumar and Daniell, 2004).…”