18731
The present study investigates the possible regulatory role of exogenous nitric oxide ( NO ) in mitigating oxidative stress in wheat seedlings exposed to arsenic ( As ) .
 Chemical: nitric oxide; Chemical: NO; Chemical: arsenic; Chemical: As
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: nitric oxide; Chemical: NO; Chemical: arsenic; Chemical: As