To understand fully the mechanisms behind the observed
bacterial-mediated drought tolerance, there is a need for more
systematic studies and screening protocols that would allow
scientists to obtain accurate data that can be replicated with
greater precision. Currently, it is difficult to compare the responses
of plants submitted to a progressive drought stress, imposed by
withdrawing water for several days, to the responses of PGPRtreated
plants submitted to a more immediate drought stress,
imposed by watering with an osmotically active agent such as PEG
for several hours. Similarly, it is difficult to compare results
generated from using sterilized soils to results obtained from
agriculturally relevant soils. Moreover, there is the need to take
into consideration the diversity of physical-chemical characteristics
of soils which may be impacted by drought stress and the
PGPR, and which may also further impact beneficial microbes
including PGPR (Bérard et al., 2015). Further, results generated
from using plants that have been subjected to different screening
protocols cannot be easily compared.