2.1 Plant hormones as Elicitors
Salicylic acid (SA) and Jasmonic acid (JA) are
seen as the key signals for defense gene
expression. It was generally thought that SA
regulates resistance to fungal, bacterial and viral
pathogens , Whereas JA induce the productiopn
of various protiens via the octadecanoid pathway
that provides plants that resistance against insect.
However this distinction between the two
pathways is not that clear and pathogens and
arthropods may sometimes trigger both.SA and
JA as well as synthetic mimics, can be applied
exogenously to plants to induce the same
metabolic changes that lead to resistance as
induce by pathogen and insects. The common
elicitors like JA and SA knowledge about the
biochemical pathways that they induce makes
them useful in the studying of plant elicitation
processes, for example various genes that induced
by JA and related compounds have been
identified.