8817
These results indicated that the expression of both XTH genes might be ethylene dependent action , and closely related to softening of persimmon in the early ( DKXTH1 ) and later ( DKXTH2 ) ripening stages .
 Chemical: ethylene
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ethylene