China is the largest chemical nitrogen (N) fertilizer producer and consumer in the world, the high rate N loss and low use efficiency are major problems in a large proportion of Chinese farmlands. In the China North Plain, one of the largest crop production areas in China, nitrogen fertilizer is deemed overused by more than 30%. The overuse of nitrogen fertilizer has resulted in a series of environmental issues. Since most N turnover processes are driven by microorganisms and are strongly affected by the nitrogen use efficiency of crops, understanding the mechanisms involved in these microbial-facilitated processes is of great importance.
Through characterization of the bacterial and fungal microbiomes from the rhizosphere and roots of wheat (Triticum aestivum L.) at the three growth stages and under four levels of long-term N fertilization treatments, the researchers found that both plant growth status and N input drive the changes in the microbial community structure in the root zone of wheat. The plant growth stage showed a stronger effect on bacterial communities than that on fungal communities. The researchers also found a number of plant growth-promoting rhizobacteria positively responded to N fertilization, and their abundance was significantly correlated with the level of some organic acids, suggesting that the secretion of organic acids could be a strategy developed by plants to recruit beneficial microbes in the root zone to cope with high N input.
The work entitled “Root-associated microbiomes of wheat under the combined effect of plant development and nitrogen fertilization” was published in Microbiome on 22 October 2019 (https://doi.org/10.1186/s40168-019-0750-2)
This work was supported by the Ministry of Science and Technology of China, the National Natural Science Foundation of China, and The Netherlands Organization for Scientific Research and The Netherlands Institute of Ecology.
Fig 1. Bacterial and fungal community compositions of the rhizosphere (a) and root (b) samples at three growth stages and under four nitrogen fertilization levels.
