Differential Induction of mRNAs by Light and Elicitor in Cultured Plant Cells

UV irradiation and invasion by microbial pathogens are two potential dangers to which plants must respond by the rapid induction of appropriate defense reactions. A large body of evidence indicates that more than one biochemical pathway is activated in the process of active defense, particularly in the case of microbial attack. At present, however, we are far from understanding — even from being able to enumerate — all of the individual reactions which participate in the complex entirety of the various defense mechanisms against phytopathogens. On the other hand, it is possible, though not known with certainty, that the response to UV irradiation involves fewer biochemical reactions than the response to pathogenic organisms. At least in some cases, partially identical reactions take place in the two responses. One such example is the subject of our present studies.