24333
In the present study , S - adenosylmethionine decarboxylase ( SAMDC ) , a key gene involved in polyamine biosynthesis , has been targeted in tapetal tissue of tomato using RNAi to examine its effect on tapetum development and pollen viability .
 Chemical: S - adenosylmethionine; Chemical: polyamine
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: S - adenosylmethionine, polyamine 
Answer:
 Chemical: S - adenosylmethionine; Chemical: polyamine