Effect of Trinexapac-Ethyl Foliar Application On Grass Leaf Proteome Under Drought Stress.

Drought is one of the major limiting factors of plant production worldwide. Growth inhibitors may influence plant responses to stresses. The objective of this study was to investigate effects of pretreatment with trinexapac-ethyl (TE) on protein profiles in Kentucky bluegrass (Poa pratensis L.) under drought stress. Plants of ‘Baron' were treated with TE twice with 14 d interval, then subjected to drought stress by withholding water for 15 days in growth chambers. Application of TE increased relative water content, photochemical efficiency and photosynthetic rate, and reduced electrolyte leakage during drought stress. Leaf proteins were extracted and separated two-dimensional electrophoresis. Approximately seventy protein spots were differentially accumulated in response to drought stress.  These protein spots were analyzed using mass spectrometry and most spots were identified.  Many proteins involved in amino acid metabolism or energy metabolism were down-regulated under drought stress, and application of TE decreased the reduction extent for most of these proteins under drought stress.