test
node1
PECO:0007359
plant experimental
condition
node2
PECO:0001001
plant exposure
node1->node2
node3
PECO:0007191
abiotic plant
exposure
node2->node3
node7
PECO:0007189
chemical exposure
node3->node7
node4
BFO:0000003
occurrent
node4->node4
node8
BFO:0000015
process
node4->node8
node5
PECO:0007149
chemical mutagen
exposure
node6
PECO:0007557
nitrosomethyl urea
exposure
node5->node6
node7->node5
node9
RO:0002310
exposure event or
process
node8->node9
node9->node6
node10
BFO:0000001
entity
node10->node4