Synergistic secondary metabolites

Like many traits, concentrations of secondary metabolites in algae are determined by a combination of genetic and environmental factors. Secondary metabolites are known to respond to changes in a variety of environmental conditions, including light,14,49,70 herbivory,43" 6, nutrients,44,45,49,73,74 desiccation,75 and salinity.76 Most of these studies have looked at the effects of a single environmental stress at once. However, in nature, multiple stresses often occur simultaneously and may have synergistic effects. 

These pleiotropic multitarget bioactivities are not spedflc, but are nevertheless effective, and this is critical in an ecological context. Compounds with pleiotropic properties have the advantage that they can attack any enemy that is encormtered by a plant, be it a herbivore or a bacterium, fungus, or vims. These classes of compounds are seldom unique constituents quite often plants produce a mixture of secondary metabolites, often both phenolics and terpenoids, and thus exhibit both covalent and noncovalent interactions. These activities are probably not only additive but synergistic [10,25]. 

These experiments and observations clearly prove the importance of QAs for lupines, but it should not be forgotten that other secondary metabolites, such as phenolics, isoflavones, terpenes, saponins, stachy-ose, erucic acid, and phytic acid, are also present in lupines and may exert additional or even synergistic effects. 

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