Pathogens chemical defenses against

Kristensen BK, Bloch H, Rasmussen SK (1999) Barley coleoptile peroxidases. Purification, molecular cloning, and induction by pathogens. Plant Physiol 120 501-512 Kubanek J, Jensen PR, Keifer PA, Sullards MC, Collins DO, Fenical W (2003) Seaweed resistance to microbial attack a targeted chemical defense against marine fungi. Proc Natl Acad Sci USA 100 6916-6921... 

Prohibitins isolated so far include eleven flavonoid derivatives, such as albanins A-E (64-68) (71-73), F (25) (74) [ = kuwanon G (55)=mor-acenin B (75)], G (26) (74) [(=kuwanon H (5 )=moracenin A (76)], H (69) (7, morusin (24) (72), kuwanons C (33) (72), and E (42) (73), and three 2-arylbenzofuran derivatives such as albafurans A-C (70-72) (78, 79) (Fig. 16). These prohibitins are obtained from the epidermis and not from the xylem tissue of the shoot, which suggests that the epidermis of the mulberry shoot plays an important role not only as a physical defense structure but also as a chemical defense against pathogens. Details concerned with the Diels-Alder type adducts albanins F (25), G (26), and H (69), will be presented later in this article. 

That the oxidative burst is directly involved in the chemical defense of these algae is clear. This reaction can be inhibited by diphenyleneiodonium, a suicide inhibitor of NADPH-oxidase which suppresses both the production of reactive oxygen species and the natural resistance to epiphytic bacteria. In addition a role in the defense against endophytes was indicated, since pre-treatment with oligomeric guluronates resulted in decreased infection of L. digitata with the pathogen Laminariocolax tomentosoides [141]. 

Algal chemical defenses that inhibit the settlement and attachment of pathogens or biofoulers represent the first line of defense against microbial challenge. Unlike compounds that function through growth inhibition or lethality, most settlement and... 

Thaler, J. S., Fidantsef, A. L., Duffey, S. S. and Bostock, R. M. (1999). Trade-offs in plant defense against pathogens and herbivores a field demonstration of chemical elicitors of induced resistance. Journal of Chemical Ecology 25 1597-1609. 

DIMBOA (2,4-dihydroxy-7-methoxy-l, 4-benzoxazin-3-one) play an important role in the chemical defense of cereals against insects, pathogenic fungi and bacteria (Niemeyer, 1988). Researches with maize indicate thatmycorrizal colonization induced accumulation of DIMBOA and increase in transcript levels of Bx9. Concentrations of DIMBOA in maize roots inoculated both G. mosseae and Rhizoctonia solani were significantly higher than those roots inoculated separately with G. mosseae or Rhizoctonia solani. 

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