SINGLE AND COMBINED ABIOTIC STRESSES IMPACT THE ROOT EXUDATION PATTERNS
IN DIFFERENT MAIZE ROOT TYPES
Abstract
Root exudates play an essential role in plant-soil-abiotic stress
interactions. However, we still know little about the influence of
stress combinations on the root exudation profile. Using targeted and
untargeted metabolomics, here we test the effect of drought, heat
stress, and their combination on the maize root exudates, also
considering the differences that might exist between root types (seminal
and primary) and root zones (apical and sub-apical). In addition, we
built an analytical framework that relate the root exudation profile
with the characterization of the rhizosphere bacterial community,
enabling us to dissect the interactions between specific root exudates
and microbial taxa. Our results suggest that the composition of root
exudates has a different outcome according to the single or combined
stress and to the root zone but not between root types. Further, we
found that stress-specific exudates influence the relative abundance of
specific microbial taxa, some of which are known to be beneficial
microorganisms. Therefore, the stress-specific root exudate composition
selecting specific microbial taxa, here observed, represent a contribute
on the effects of climate changes on crops increasing thus the potential
impact on the current trend of crafting agricultural practices within a
wider point of view of plants-microbe-environment interactions.