Genes and pathways associated with drought tolerance in Populus wutunensis under drought stress

Abstract

Background: Populus wutunensis is widely cultivated as part of the Three-North Shelter Forest Program in China. This hybrid grows rapidly and is tolerant to salinity and drought; however, the molecular mechanisms behind the drought resistance of P. wutunensis remain unclear. We performed deep transcriptome sequencing to analyze and compare the differentially expressed genes (DEGs) between drought stress and rehydrationconditions. Results: RNA-sequence analysis identified 5102 DEGs among the control, drought, and rehydration treatments. Further analysis of these DEGs showed that drought response genes are mainly involved in plant hormone signal transduction and galactose metabolism. Rehydration recovery mainly involves plant hormone signal transduction, flavonoid metabolism, photosynthesis-antenna proteins, and ribosome. Transcription factors play an important role in drought and rehydration by participating in signal transduction. In addition, compared with drought and control, photosynthesis-antenna proteins and ribosomewere clearly up-regulated after rewatering, which may have led to the compensatory growth of P. wutunensis during recovery. Conclusions: Our results show that P. wutunensis responds to drought and rehydration through different pathways, and identify candidate genes related to drought and rehydration in those pathways. Our results improve the understanding of the molecular mechanisms of drought tolerance in P. wutunensis and provide a foundation for further research.