Recommendations for Nanomedicine Human Subjects Research Oversight: An Evolutionary Approach for an Emerging Field

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96363/1/j.1748-720X.2012.00703.x.pd

Characterization of the induced response of slach pine to inoc

Summary Six 25-to 30-year-old slash pine, Pinus elliottii Englm. var. elliottii, trees were inoculated with Ophiostoma minus (Hedgc.) H.P. Sydow, O. ips (Rumb.) Nannf or sterile water. Two, 4 and 6 weeks after inoculation, the lengths of developing lesions and the monoterpene concentration of the necrotic tissue within each lesion were measured. Both sterile and fungal wounding resulted in the development of lesions in the phloem--outer xylem. At both 4 and 6 weeks after inoculation, lesions induced by O. minus were significantly larger than lesions induced by O. ips or sterile water, whereas the lesions induced by O. ips and sterile water were similar in size at all sampling periods. At 2, 4 and 6 weeks after inoculation, lesions induced by O. minus had significantly greater concentrations of monoterpenes than lesions induced by O. ips or sterile water. The monoterpene concentration of lesions induced by O. ips was significantly greater than that of lesions induced by sterile water only at the 6-week sampling period. Introduction Pine bark beetles (Scolytidae) initiate attacks on trees by boring through the outer bark to the phloem--xylem interface. Simultaneously, spores of their fungal symbionts, most commonly blue stain fungi of the genus Ophiostoma (formerly Ceratocystis) are introduced into the tree. It is during this initial attack and colonization phase that the beetle--microorganism complex encounters the host's defenses. In pines, defense against attacks by bark beetles and the fungi they vector includes wound cleansing, wound containment and wound healing Although the induced response is considered to be a generalized response to wounding, the intensity of the induced response to beetle-vectored fungi is greater than to a sterile wound. In loblolly pine, Pinus taeda L., The intensity and speed of induction also vary among individual trees and appear to be correlated with tree vigor and the tree's ability to resist beetle attack. For example, grand fir, Abies grandis (D. Don ex Lamb.) Lindl., trees that were resistant to attacks by the fir engraver, Scolytus ventralis LeConte, were characterized by more rapid accumulation of resin and formation of callus tissue at the margins of lesions than susceptible tree