Overexpression of ginseng patatin-related phospholipase alters the polarity of cell growth and decreases lignin content in .

BACKGROUND

The patatin-related phospholipase AIII family () genes alter cell elongation and cell wall composition in and rice plant, suggesting diverse commercial purposes of the economically important medicinal ginseng plant. Herein, we show the functional characterization of a ginseng gene for the first time and discuss its potential applications.

METHODS

were identified from ginseng expressed sequence tag clones and further confirmed by search against ginseng database and polymerase chain reaction. A clone showing the highest homology with was shown to be overexpressed in using . Quantitative polymerase chain reaction was performed to analyze ginseng expression Phenotypes were observed using a low-vacuum scanning electron microscope. Lignin was stained using phloroglucinol and quantified using acetyl bromide.

RESULTS

The transcripts were observed in all organs of 2-year-old ginseng. Overexpression of ginseng () in resulted in small and stunted plants. It shortened the trichomes and decreased trichome number, indicating defects in cell polarity. Furthermore, lines exhibited enlarged seeds with less number per silique. The gene was downregulated in the lines, which is reported to be associated with lignification. Accordingly, lignin was stained less in the lines, and the expression of two transcription factors related to lignin biosynthesis was also decreased significantly.

CONCLUSION

Overexpression of retarded cell elongation in all the tested organs except seeds, which were longer and thicker than those of the controls. Shorter root length is related to auxin-responsive genes, and its stunted phenotype showed decreased lignin content.