Elucidating the Molecular Mechanisms by which Seed-Borne Endophytic Fungi, , Increases the Tolerance of to NaCl Stress.

Seed-borne endophyte enhance NaCl tolerance in and increase its biomass. However, the molecular mechanism by which increases the tolerance of host grasses to NaCl stress is unclear. Hence, we firstly explored the full-length transcriptome information of by PacBio RS II. In this work, we obtained 738,588 full-length non-chimeric reads, 36,105 transcript sequences and 27,202 complete CDSs from . We identified 3558 transcription factors (TFs), 15,945 simple sequence repeats and 963 long non-coding RNAs of . The present results show that 2464 and 1817 genes were differentially expressed by in the leaves of E+ and E- plants at 0 mM and 200 mM NaCl concentrations, respectively. In addition, NaCl stress significantly regulated 4919 DEGs and 502 DEGs in the leaves of E+ and E- plants, respectively. Transcripts associated with photosynthesis, plant hormone signal transduction, amino acids metabolism, flavonoid biosynthetic process and WRKY TFs were differentially expressed by ; importantly, up-regulated biology processes (brassinosteroid biosynthesis, oxidation-reduction, cellular calcium ion homeostasis, carotene biosynthesis, positive regulation of proteasomal ubiquitin-dependent protein catabolism and proanthocyanidin biosynthesis) of host grass under NaCl stress, which indicated an increase in the ability of host grasses' adaptation to NaCl stress. In conclusion, our study demonstrates the molecular mechanism for to increase the tolerance to salt stress in the host, which provides a theoretical basis for the molecular breed to create salt-tolerant forage with endophytes.