Abstract:
A survey of 59 species of tropical legume seeds revealed high
interspecific variation in pTOlcinaccous capacity to inhibit bovine trypsin (a
digesli"e enzyme) and 10 agglutinate human (type B. Rh positive) and laoorawry
rabbit red blood cells. The legume subfamily Mimosoideae was conspicuous
for the absence of seeds with vcry weak trypsin inhibilion. Congenerics
sometimes differed strongly from each OIher with ~spect to both trypsin
inh ibition and phytohemagglutination. Half the species of seeds d isplayed no
hemagglutinating capacity with one or the OIher kinds of red blood cell s. and
in only 27\11. of the 30 case.~ whe~ there was some activity did the same
species of seed aclh'ely agglutinate both species of red blood cells. A species
of seed that had hemagglutinating capacity was almost invariably associated
witll moderate 10 high levels of trypsin inactiyation . Wllile it lias been long
known that a g~at diyersity of small toxic and potemiaJly defensive molecules
occur in legume seeds and that one species of seed often contains sevcral
of them. we now feel that il is ~asonable to consider legume seeds as
also COn13ining a hi gll diver.>ily of potentially toxic protein molecules. A
single seed is likely to contain. al the least. thm: to four classes of defe nsiye
compounds, any or all of which. or somc in combination, may be the cause
of a seed being ~jected by a potential seed predator.
