Drought Stress and Polyamines in Creeping Bentgrass.

Polyamines (PAs) such as spermidine (Spd), spermine (Spm) and putrescine (Put) are involved in various biological functions including abiotic stress responses. Whether PAs play an important role in turfgrass tolerance of drought stress is not well investigated. We have conducted a series of growth chamber studies with creeping bentgrass ‘penncross’ and ‘Penn-G2’ to determine how PAs are regulated in response to drought stress and whether exogenous application of PAs may affect plant growth and stress tolerance. We have also performed RNA- seq analysis of drought stressed and Spd (500uM) treated plants to explore whole transcriptome changes in response to drought and PA treatment in leaf tissues. Application of Spd or Spm moderated the damages associated with drought stress primarily by promoting membrane health (photosynthetic and cell membrane). The relatively low level of exogenous PAs used in this study did not affect plant water relations under drought stress. Results of physiological parameters, PA content, and transcriptome changes will be discussed.