De novo assembly of L. transcriptome in response to drought stress provides insight into the tolerance mechanisms.

Background: L. is a deciduous shrub that is native to North America and has been introduced to China as an ornamental plant. In order to clarify the drought resistance characteristics of L. and excavate the related genes involved in drought resistance regulation pathway, the mechanism of drought resistance stress of L. was revealed by the changes of transcriptome of L. under drought stress.Through the changes of the transcriptome of L. under drought stress, the mechanism of anti-stress of L. could be revealed.

Methods: Different concentrations of polyethylene glycol-6000 (PEG-6000) was used to simulate drought stress, and transcriptomic analysis was used to reveal the changes of gene expression patterns in L. seedlings.

Results: Results showed that L. seedlings were seriously affected by PEG-6000. As for the differently expressed genes (DEGs), most of them were up-regulated. The additional Go and KEGG analysis results showed that DEGs were functionally enriched in cell wall, signal transduction and hormonal regulation related pathways. DEGs like AfSOD, AfHSP, AfTGA, AfbZIP and AfGRX play roles in response to drought stress.

Conclusion: In conclusion, L. seedlings were sensitive to drought, which was different from L. tree, and the genes functions in drought stress responses via ABA-independent pathways. The up-regulation of Salicylic acid signal related DEGs (AfTGA and AfPR-1) indicated that Salicylic acid play a key role in response to drought stress in L.