9520707 Woody plants vary in their ability to tolerate wind stress. Many trees respond to wind stress by adding woody secondary growth which increases wind tolerances, but the genetic basis of traits that improve wind tolerance is nearly unknown. This research will compare the genes expressed in poplar trees subjected to wind stress to those in trees which have not been stressed. Poplars are selected as a model woody plant system because of their economic value in biomass production, ease of propagation, small genome size, ease of isolation of DNA and RNA, and transformability. The comparison of genes will be accomplished using differential display of polymerase chain reaction (PCR) products. This technique enables a side by side comparison of those messenger RNAs (mRNAs) which become active in wind-stressed versus the unstressed plants. These mRNAs will represent genes which are activated by wind stress and may contribute to the structural tolerance of the plants. The differentially expressed genes will be cloned, sequenced and used to probe (screen) poplar varieties which vary in their response to wind stress. That procedure will identify the role of the genes in the signal cascade pathway for wind stress response in plants having secondary growth. Plants that are successful in wind exposed sites should possess and express these genes. Identification and cloning of the genes will allow early identification of wind-tolerant individuals and strains, and may allow transformation of poplars and other woody plant subjects to improve tolerance to wind and decrease the risk of wind damage.
