Potato glandular trichomes, defensive

Potato Glandular Trichomes A Physicochemical Defense Mechanism Against Insects... 

Glandular trichome constituents have been associated with insect resistance in a number of other crops, including cotton, tomato, potato, tobacco and alfalfa (73). However, this is the first time that glandular trichomes or any plant natural product has been implicated in the defense of pollen against predation. 

The exudate of the glandular trichomes of Solanum ber-thaultii are effective against aphids and similar insect pests. One part of the defense involves the immobilization of the insects in the exudate which hardens (Harbome, 1989). This exudate proved to be a mixture of sucrose esters, of which 3,4-di-0-isobutyryl-6-C>-caprylsucrose is a major component. These compounds also appear to provide resistance to potato blight (Harbome, 1989). A similar series of compounds is found in the trichomes of other solanaceous plants of the genera Datura, Lycopersicon, Nicotiana, and Petunia. A series of esters of sucrose with -p-coumaric acid (such as 104) and acetate from Prunus maximowiczii proved to be responsible for the very bitter taste of the fruits (Shimazaki et al., 1991) (Fig. 15.18). 

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