Pharmacognosy and Medicinal Plants

Biography

Nik Kovinich is an expert in Genetics of Plant Metabolism. He is a Beginning Investigator at the West Virginia University since July 2015. His focus is on understanding the genetic regulation of the biosynthesis of medicinal natural products (NPs) in plants, enhancing NP bioproduction by genetic engineering, and improving the bioactivities of NPs using semi-synthesis. He teaches Genetics and Bioinformatics courses and had a major role in establishing an Undergraduate Program in Genetics at the West Virginia University

Abstract

Statement of the Problem: Phytoalexins are natural products (NPs) produced by plants that are biosynthesized in response to pathogen infection or abiotic stresses. Many phytoalexins have potent medicinal activities and are desirable for use as clinical therapeutics or as scaffolds for the semi-synthesis thereof. The major problem is that phytoalexins are absent from non-challenged plant tissues and may be present in challenged plant tissues at relatively low amounts rendering commercial production uneconomical. This is particularly problematic for phytoalexins that cannot be synthesized.

Methodology: Chemical and pathogen treatments in combination with RNA sequencing (RNA-seq) were used to identify treatments and genes that can be used to enhance the biosynthesis of the anticancer phytoalexin glyceollin in soybean.

Findings: A combination of the inorganic heavy metal silver nitrate (AgNO₃) and the wall glucan elicitor (WGE) from the pathogen Phytophthora sojae demonstrated an additive effect on the elicitation of glyceollin in soybeans. The additive effect was due to distinct elicitation mechanisms of AgNO₃ and WGE. Comparative transcriptome analyses by RNA-seq of pathogen and abiotic stress-treated soybean tissues identified three transcription factor (TF) genes that can enhance the production of glyceollin when overexpressed in soybean hairy roots. The TFs were of the WRKY, MYB, and NAC gene families.

Conclusion & Significance: Combined elicitor and gene engineering approaches can successfully enhance the biosynthesis of glyceollin phytoalexins in soybean. Our transcription factor data suggests the potential existence of a conserved regulatory network for phytoalexin regulation in plants.