Understanding physiological and molecular mechanisms of Populus deltoides ‘DanHongYang’ tolerance to waterlogging by comparative transcriptome analysis

Abstract

Populus deltoides ‘DanHongYang’ (DHY) was identified as a waterlogging-resistant cultivar in our previous study. Here, the phenotype, physiological features and transcriptome profiling of P. deltoides ‘DHY’ between the treatments of waterlogging and control were compared. Waterlogging treatment led to distinctly formation of adventitious roots from P. deltoides ‘DHY’ stems. The activities of ascorbate peroxidase and glutathione reductase significantly increased in the leaves of P. deltoides ‘DHY’ by waterlogging treatment. Comparative transcriptomic analysis showed that 2,447 and 9,465 differentially expressed genes (DEGs) were screened between the leaves and roots of P. deltoides ‘DHY’ under waterlogging and control, respectively. The KEGG analysis showed the most significantly up-regulated DEGs in the leaves and roots were enriched to the pathways of glycolyis and proline synthesis. Some genes involved in stress response, endogenous hormones, antioxidant system and adventitious root development in the waterlogged were identified to contribute to the waterlogging tolerance of P. deltoides ‘DHY’. In addition, some candidate transcription factors such as RAP, NAC, WRKY, and bHLH were also found to be associated with the waterlogging tolerance of P. deltoides ‘DHY’. These findings provided the insights into the physiological and molecular mechanisms underlying the tolerance of P. deltoides ‘DHY’ to waterlogging stresses.