Saline-alkali land amelioration by cultivating Melia azedarach and
characterization of underlying mechanisms via metabolome analysis
Soil salinization leading to ecological degradation and Melia
azedarach can be effective in improving soil characteristics, such as
reducing soil salinity. However, the mechanisms underlying the
adaptation of Melia azedarach to saline-alkali land are unknown.
In this study, we analyzed the soil properties and metabolome of
Melia azedarach roots grown in high-salt (11.5 g/kg), medium-salt
(7.5 g/kg), and low-salt soils (0.37 g/kg) to explore the mechanisms of
adaptation of Melia azedarach to salt stress. Soil Na
+ was decreased, while soil organic matter, alkaline
phosphatase and urease activities were increased when Melia
azedarach was planted in low-, medium- and high- saline alkali soil.
The metabolome analysis showed that the number of differential
metabolites (DEMs), especially the up-regulated DEMs rose with the soil
salinity increased. The sugar, amino acid and flavonoid DEMs produced by
Melia azedarach were mostly up-regulated with the increase of
soil salinity. The results demonstrated Melia azedarach was able
to alleviate saline stress and reduce soil salinity. We propose that in
situ bioremediation with Melia azedarach could be considered to
ameliorate the coastal saline-alkali soil.