Chin J Plan Ecolo ›› 2014, Vol. 38 ›› Issue (1): 54-61.DOI: 10.3724/SP.J.1258.2014.00006

• Research Articles • Previous Articles     Next Articles

Effects of fungal endophyte infection on soil properties and microbial communities in the host grass habitat

ZHOU Yong, ZHENG Lu-Yu, ZHU Min-Jie, LI Xia, REN An-Zhi*, and GAO Yu-Bao   

  1. College of Life Sciences, Nankai University, Tianjin 300071, China
  • Received:2013-08-22 Revised:2013-12-26 Online:2014-01-01 Published:2014-01-15
  • Contact: REN An-Zhi

Abstract:

Aims Leymus chinensis is a dominant grass native to the mid-eastern Inner Mongolia Steppe. The plants of this species are sometimes heavily infected with fungal endophytes that produce alkaloids, which in turn affect insect herbivory, plant production, and litter decomposition. Our objective was to investigate the effects of the L. chinensis-endophyte association on soil properties and soil microbial communities in field and pot experiments.
Methods We concurrently conducted a field and a pot experiment. The soil total carbon (C) and nitrogen (N) were analyzed with an Elemental Analyzer, and C mineralization was determined by using a soil incubation test over a 30-day period. Soil microbial biomass and community composition were assayed by using phospholipid fatty acid (PLFA) technique.
Important findings In the field experiment, where L. chinensis plants had grown for longer time and there was litter decomposition, fungal endophyte infection significantly increased soil N content, the initial C mineralization rate, the C mineralization during the first three days, and the accumulative C mineralization during the 30-day soil incubation. In the pot experiment, where L. chinensis plants had grown for shorter time and there was no litter decomposition, the soil total C and N contents and the C mineralization did not differ between the endophyte-infected (E+) and endophyte-free (E–) treatments. We found no significant difference in the types of PLFAs between the E+ and the E– treatments in both field and pot experiment, but endophyte infection tended to increase the soil microbial biomass. The PLFA contents of bacteria, gram-negative bacteria (G–), fungi, and total PLFA were significantly higher in the E+ treatment than in the E– treatment in the pot experiment; whereas in the field experiment, the PLFA contents of gram-positive bacteria (G+) and actinomycetes were significantly higher in the E+ treatment than in the E– treatment. This study suggests that endophyte infection may change the soil N accumulation and the rate of C mineralization, and alter soil microbial community structure. Our findings can help with understanding the relationship between fungal endophytes and L. chinensis and its role in ecosystem C and N cycling.