4.2 | Root secretion and soil phosphorus utilization
Phosphorus is one of the essential elements for plants (Arwenyo et al.,
2022), and the distribution and transport of soil phosphorus affect
plant growth and productivity (Xia et al., 2020, Yadav et al., 2020).
S-PT is an enzyme that catalyzes the transfer of phosphate groups from
donors to acceptors and is closely related to phosphorus uptake and
transport. This study found that under D, T, and N stresses, S.
miltiorrhiza up-regulates the activity of root-secreted S-PT, while
other stresses down-regulate this activity significantly. In the context
of nitrogen stress, synergistic stress of drought or synergistic stress
of high-temperature, or synergistic stresses of drought and
high-temperature, can significantly down-regulate the activity of
root-secreted S-PT (Figure 3-a) (e.g., DN, TN, and DTN stresses).
However, under nitrogen and phosphorus stress, synergistic stress of
drought or synergistic stress of high-temperature or synergistic
stresses of drought and high-temperature synergistic stress can
significantly up-regulate the activity of root-secreted S-PT (Figure
3-c) (e.g., DNP, TNP, and DTNP stresses). This also supports the claim
that plants respond uniquely to different synergistic stress. It is also
suggested that in the absence of microbial participation, most stress
environments are not conducive to phosphorus uptake and transport. Most
stressful environments that promote phosphorus uptake and transport in
plant roots may be directly related to rhizosphere microorganisms
(Glaesner et al., 2016).