Nasir S A Malik
US Department of Agriculture
USA
Title: The role of arbuscular fungi on crop quality
Biography
Biography: Nasir S A Malik
Abstract
It is well known that mycorrhizal symbiosis can improve plant growth and productivity under limited supply of phosphorus, water, or other nutrients. We have started studies to investigate if the mycorrhizal symbiosis would also affect food quality by changing the levels of polyphenols/flavonoid in different plant species. In addition, we are examining changes in polyphenol levels of a cultivar when inoculated with different species a plant. Using UHPLC/UV-MS, our initial studies, with leeks have identified 8 species of kaempferol glycosides in the leek shoots. In addition to different numbers of hexose residues attached to kaempferol, we also identified hexuronic acid, malonyl, feruloyl, coumaroylmoiets attached to agylcone. Of these flavonoids, five occurred in significantly higher amounts in mycorrhizal plants compared to control. The levels of twoflavonoid species were found lower, and one unchanged, in mycorrhizal plants compared to controls. It was interesting to note that some of these flavonoid glycosides increased substantially even in the presence of full nutrient supply under which condition there was no overall increase in plant growth of the mycorrhizal plants compared to controls. Thus indicating the direct involvement of mycorrhizae in plant secondary metabolism Changes in polyphenol levels in mycorrhizal lettuce, corn, peppers, and tomato are being investigated and will be presented at the meeting.