CeBiTec – Colloquium
Monday, May 22th 2017, 17 c.t.
G2-104, CeBiTec Building
Dr. Prabodh Kumar Trivedi
CSIR-National Botanical Research Institute, India
Pathway Engineering of Flavonoid Biosynthesis for Improved Crop Productivity and Human Health
Plants have developed very efficient approaches to magnetize pollinators or seed-dispersing animals, shielding themselves against UV-light and for their defence against herbivores, micro-organisms and other plants. In natural growth conditions, one of the major strategies adopted by plants for these purpose are based on the production of secondary metabolites, including alkaloids, flavonoids, phytosterols. Out of these, flavonoids play important roles throughout plant life, regulate development and are beneficial for human health. Biosynthesis of flavonoids is species-specific and under spatial and temporal regulation by specific transcription factors and miRNAs. In addition, accumulation of flavonoids fluctuates depending upon cellular, climatic and developmental conditions that limit their proper industrial utilization. Therefore, there is an urgent need to enhance biosynthesis of these secondary plant products through pathway engineering. Due to complexity of regulation, single gene strategies have not been successful in enhancing flavonoid biosynthesis. We used transcription factors and carried out gene pyramiding to engineer plants with enhanced flavonoid biosynthesis. Expression and metabolite analysis of tobacco and tomato transgenic lines revealed that use of specific transcription factors can lead to enhanced flux availability for phenylpropanoid pathway in general and flavonol biosynthesis in particular. The transgenic lines with enhanced flavonols developed resistance against the insect pests. Transgenic tobacco lines co-expressing MYB transcription factor and isoflavone synthase gene accumulated substantial amount of isoflavonoid being at the highest levels which could be engineered in non-leguminous plants. In addition, flavonoid rich tobacco and tomato showed value addition in relation to bone health improvement in animal model. Study also suggests involvement of light-regulated miR858 in regulation of flavonoid biosynthesis. Our results establish an efficient strategy for pathway engineering of secondary plant products which can be used for improving medicinal value as well as stress resistance in plants.
Host: Dr. Ralf Stracke