5. Conclusions
To the best of our knowledge, this study is the
first
systematic report on endophytic actinobacterial population
associated with energy and medicinal plant J. curcas L. and
our study has demonstrated that J. curcas L. collected from Panxi
dry-hot valley soils harbour a greater diversity of endophytic
actinobacteria. Several of these actinobacteria were able to
produce ACC deaminase and some of them can also produce
indolic compounds, siderophores, and solubilize phosphate.
Compared with control treatments, inoculation with selective
PGPEs achieved a significant plant growth promotion effect. The
presence of specific PGP traits also suggests that these particular
organisms can promote J. curcas L. seedling growth by more than
one mechanism. The use of ACC deaminase-producing endophytes,
with multiple PGP activities for the facilitation of plant
growth in different soil environments, will be a highly important
area for future research. Therefore, future evaluation of these
strains is needed to uncover their efficiency as plant growth
promoting endophytes in the
field conditions.