Background : Both Panax ginseng Meyer and Panax quinquefolius are obligate shade-loving plants whose natural habitats are broadleaved forests of Eastern Asia and North America. Panax species are easily damaged by photoinhibition when they are exposed to high temperatures or insufficient shade. In this study, a cytohistological study of the leaf structures of two of the most well-known Panax species was performed to better understand the physiological processes that limit photosynthesis. Leaves of ginseng plants grown in soil and hydroponic culture were sectioned for analysis. Methods and Results : Leaf structures of both Panax species were observed using a light microscope, scanning electron microscope, and transmission electron microscope. The mesostructure of both P. ginseng and P. quinquefolius frequently had one layer of noncylindrical palisade cells and three or four layers of spongy parenchymal cells. P. quinquefolius contained a similar number of stomata in the abaxial leaf surface but more tightly appressed enlarged grana stacks than P. ginseng. The adaxial surface of the epidermis in P. quinquefolius showed cuticle ridges with a pattern similar to that of P. ginseng. Conclusion : The anatomical leaf structure of both P. ginseng and P. quinquefolius shows that they are typical shade-loving sciophytes. Slight differences in chloroplast structure suggests that the two different species can be authenticated using transmission electron microscopy images, and light-resistant cultivar breeding can be performed via controlling photosynthesis efficiency.

Background : Prenyltransferases catalyze the sequential addition of IPP units to allylic prenyl diphosphate acceptors and are classified as either trans-prenyltransferases (TPTs) or cis-prenyltransferases (CPTs). Although CPTs and TPTs share similar substrate preferences and reaction products, they can be easily distinguished by their primary amino acid sequences. The characterization of cis-prenyltransferases has been less studied than that of trans-prenyltransferases. Methods and Results : Gene expression patterns of PgCPT1 was analyzed by qRT-PCR. In planta transformation was generated by floral dipping using Agrobacterium tumefaciens. Yeast transformation was performed by lithium acetate and heat-shock for rer2Δ complementation and yeast-two-hybrid assay. Ginseng genome contains at least one family of three putative CPT genes. PgCPT1 is expressed in all organs, but more predominantly in the leaves. Overexpression of PgCPT1 did not show any plant growth defect, and can complement yeast mutant rer2Δ via possible protein-protein interaction with PgCPTL2. Conclusion : Partial complementation of the yeast dolichol biosynthesis mutant rer2Δ suggested that PgCPT1 is involved in some of dolichol biosynthesis. Direct protein interaction between PgCPT1 and a human Nogo-B receptor homolog suggests that PgCPT1 requires an accessory component for proper function.

Background : Glycosylation of natural compounds results in great diversity of secondary metabolites. Glycosylation steps are implicated not only in plants growth and development but also in plant defense responses to various environmental stresses. This process is mediated by members of a multigene superfamily glycosyltransferase (GT), which catalyze the transfer of single or multiple activated sugars to a wide range of substrates, thus influences their chemical property and bioactivity. Although its activity has been recognized for a long time and genes coding UGTs in several higher plants have been identified, specific function of GTs in detail still remains elusive. Methods and Results : Spatial and temporal expression patterns of a ginseng UDP-dependent glycosyltransferase, was analyzed by qRT-PCR. It was expressed highly in rhizome, upper root and youngest leaf compared that of other organs. Spacial expression was observed by GUS histochemical assay after generating promoter::GUS fusion. Noticeably, it expressed axillary branch as well as other organs tested by qRT-PCR. Overexpression of PgUGT in Arabidopsis resulted in fused organ in axillary branch. Stress responsiveness against various abiotic stresses and subcellular localization in Arabidopsis are also addressed. Conclusion : PgUGT phylogenetically closed to PgUGT71A27 involved in ginsenoside compound K (C-K) production. Considering that the C-K is not reported in raw ginseng material, further characterization of this gene may shed light on the biological function of C-K in ginseng growth and development. Organ fusion phenotype could be caused by defective growth of cells in boundary region, commonly regulated by phytohormones such as auxins or brassinosteroids, which in needs to be analyzed further.

Ramie is one of the oldest fiber crops. It has been used mostly for the fabric production at least for six thousand years worldwide. However ramie is recently focused on for the rice cake production in the area of Yeonggwang, Korea, in the name of “Yeonggwang Moshie Songpyeon”. It is well recognized as a local food, and its sales rate and the cultivation area is correspondingly increased. Ramie (Boehmeria nivea) is a flowering plant in the nettle family Urticaceae, native to eastern Asia mostly in China, Philippines, India, South Korea, and Thailand. The importance of rice cake called “Yeonggwang Moshie Songpyeon” was recognized based on its possibility of raw material self-sufficiency and its value of utilization as for the local resources. Currently there are some progresses for the purpose of rice cake. From the past, Yoenggwang has been spread young ramie to local farmers based on the breeding technique and the “know-how” how to propagate it largely. Here we want introduce how to cultivate ramie in reasonable way, and discuss further necessity needs.