From jgruv@wam.umd.edu Tue Nov 2 00:08:24 1999 Date: Wed, 13 Oct 1999 12:06:20 -0400 (EDT) From: Joel Brooks Gruver To: sanet-mg@amani.ces.ncsu.edu Subject: harnessing endophytic and epiphytic relationships Hello to all... While pondering the ecological implications of crops with resistance to herbivory through plant expression of microbial endotoxins (e.g. BT), I wondered about the potential for increased utilization of endophytic and epiphytic microbe/plant relationships to manage phytophagous insects. My understanding is that some turf grasses (e.g. tall fescue) have few insect pest problems as a result of their hosting of endophytic microbes which live within the plant and produce compounds that are toxic to plant feeders... yet this same relationship causes serious problems for livestock that graze upon endohyte infected forages. I wondering about the potential for utilizing endophytes to protect grain species from insect herbivory. Would the endophyte's endotoxins be expressed in the grain causing problems for grain consumers ? My vague understanding of the tall fescue endophyte lifecycle is that the endophyte is carried by the seed. A major focus in the Ecology of Agriculture class that I am teaching is positive interactions between species and the potential for much greater utilization of these interactions in agriculture. What would be the benefits of having an endotoxin synthesized by an endophytic organism rather than by the plant itself ? My understanding is the BT is not an effective epiphytic organism otherwise live cultures could be sprayed on crop foliage that would persist and multiply. Are there adapted epiphytic microbes that can be used to reduce insect feeding ? What would be the benefits of having an endotoxin synthesized by an adapted epiphytic microbe rather than the host plant ? What is the potential for utilizing endophytic and epiphytic/plant relationships in agricultural systems ? Joel Gruver Center for Agriculture, Food and Environment Tufts University To Unsubscribe: Email majordomo@ces.ncsu.edu with the command "unsubscribe sanet-mg". If you receive the digest format, use the command "unsubscribe sanet-mg-digest". To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command "subscribe sanet-mg-digest". All messages to sanet-mg are archived at: http://www.sare.org/san/htdocs/hypermail