**5. Conclusions**

Our results indicated that *R. glutinosa* replant disease promoted *Fusarium oxysporum* proliferation in rhizospheres soil, but *NB-LRRs* were not consecutively responsive to the FO proliferation at the transcriptional level in *R. glutinosa* roots. The analysis on the relationships between *Fusarium oxysporum* numbers and *NB-LRRs* expression showed that the *NB-LRRs* responded to the *Fusarium oxysporum* invasion with a typical phenomenon of "promotion in low concentration and suppression in high concentration", and 6 *NB-LRRs* were identified as candidates for responding to *R. glutinosa* replant disease. Salicylic acid (SA), jasmonic acid (JA), ethylene (ET) and abscisic acid (ABA) involved in the formation mechanism of *R. glutinosa* replant disease. Importantly, salicylic acid, as an important signaling molecule, which may be inhibited by *Fusarium oxysporum*, was involved in the formation of replant disease in *R. glutinosa*. Concomitantly, the physiological indexes acting downstream of life activities were affected by complex replant disease stresses and exhibited strong fluctuations, resulting in the death of *R. glutinosa*. These findings provide important insights and clues into further revealing the mechanism of replant disease.

**Supplementary Materials:** Supplementary materials can be found at http://www.mdpi.com/1422-0067/20/13/ 3203/s1.

**Author Contributions:** Conceptualization, Z.Z. and M.L.; Methodology, A.C., L.G., N.X., F.F., D.C., C.Y. and B.Z.; Validation, A.C., M.L. and Z.Z.; Formal analysis, A.C., N.X. and M.L.; Investigation, A.C., L.G. and F.F.; Resources, A.C. and M.L.; Data curation, A.C., M.L.; Writing—original draft preparation, A.C.; Writing—review and editing, M.L. and Z.Z.; Supervision, A.C., M.L. and Z.Z.; Project administration, A.C., M.L. and Z.Z.; Funding acquisition, M.L. and Z.Z.

**Funding:** This research was funded by the National Natural Science Foundation of China (Grant No. 81573538, 81603243, 81503193 and 81403042), the National Key Research and Development Program of China (No. 2017YFC1700705), and the Natural Science Foundation of Fujian Province of China (No. 2017J01804).

**Conflicts of Interest:** The authors declare no conflict of interest.
