20096
Although the main organic acid , succinate , exhibited a strong tendency to decrease under P - deficiency , the more efficient symbiotic ability observed in M . truncatula coincided with an apparent increase in the content of malate in its nodules .
 succinate, P
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 succinate, P