Transgenic Citrange troyer rootstocks overexpressing antimicrobial potato Snakin-1 show reduced citrus canker disease symptoms.

Citrus canker is a major disease caused by Xanthomonas citri pv. citri. Snakin-1 is an antimicrobial peptide, which was previously shown to be effective against different bacterial and fungal diseases in potato, wheat and lettuce when expressed in transgenic plants. We generated transgenic Citrange Troyer citrus rootstocks constitutively expressing this peptide and 5 different transgenic lines were challenged against virulent X. citri isolates. Challenge assays conducted in vitro using detached leaves and in planta by infiltration revealed a significant reduction of the number and size of canker lesions in some of the transgenic lines.

Conditional discrimination with conceptual simultaneous and successive cues in the squirrel monkey (Saimiri sciureus).

At the end of several stages of training, 4 squirrel monkeys met an 87% criterion for choosing correctly between exemplars of the concept "sameness" and the concept "difference," the simultaneous cues, as a function of having been cued by an exemplar either of the concept "triangularity" (cued sameness) or "heptagonality" (cued difference), the successive cues, which were presented in random order. In addition, the best monkey met criterion when the exemplars of sameness and difference were presented 16 s after the withdrawal of the exemplar of triangularity or heptagonality, and the other monkeys performed successfully with shorter delays. The results are discussed in terms of (a) "working memory," (b) the significance for the evolution of behavior of investigating the conceptual capacities of animals, and (c) implications for language in nonhuman animals.