5-Aminolevulinic Acid Pretreatment Mitigates Drought and Salt Stresses in Poplar Plants

5-aminolevulinic acid (ALA), a key precursor in the biosynthesis of porphyrins, can improve plant tolerance to various environmental stresses. However, it is unclear whether ALA poplar. Here, we investigated effects on poplars under drought and salt pretreatment exhibited less morphological damage, reduced leaf malonaldehyde content (MDA) electrolyte leakage (EL), increased relative water (RWC), proline (PRO), superoxide dismutase (SOD), peroxidase (POD) Furthermore, exogenous mitigated decrease photosynthetic capacity, restored chlorophyll (Chl), net CO2 assimilation rate, stomatal conductance (Gs), transpiration rate (Tr), maximal photochemical quantum yield PSII (Fv/Fm), actual photosynthesis (YII), electron transfer (ETR) poplar qRT-PCR showed that up-regulated expression antiporters aquaporins genes, which are associated with Na+ exclusion cells transport activity aquaporins. In summary, significantly improved stress poplar, decreasing degree membrane lipid peroxidation promoting antioxidant capacity leaves. addition, our results might mediate transporter activity, thereby increasing