2008 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative project is:. 1)to determine the differences in the expression of genes and proteins in plants grown in a greenhouse environment (no UV-B) compared to those in 'field conditions' (normal ambient UV-B concentrations), and. 2)to identify the protein and genetic changes during hidden hunger, and using this information, deveolop a technique that growers can use to test their plants for specific and/or general nutrient deficiencies. 1b.Approach (from AD-416) Microarray techniques will be used to rapidly screen for global differences in gene expression between the two different UV-B environments and nutrient (i.e., N,P,K,Fe,B, and Mg) stress. The initial use of an existing model plant system (i.e., Arabidopsis thaliana) for this work will facilitate identification of specific genes that are responsive to the absence of UV-B during growth. After identifying such UV-B and nutrient stress responsive genes in Arabidopsis, we can then identify related genes in bedding plant species (i.e., impatiens, petunia, begonia, geranium, marigold, pansy, chrysanthemum, and New Guinea impatiens). Simultaneously, proteomics techniques (i.e., identification of proteins of interest by 2-D gel analysis, followed by protein sequencing) will be used to screen for global differences in protein expression between the two different UV-B environments. 3.Progress Report Continued identification of molecular responses (gene level) to boron deficiency stress was made for both the model plant Arabidopsis and floriculture crop Pelargonium x hortorum. These markers were tested for their usefulness as stress indicators in a scaled up laboratory/greenhouse study investigating boron deficiency stress at three levels in Pelargonium. Three studies were completed on Pelargonium investigating the interactive effects of boron stress and light or CO2 concentration. It was found that increased light and CO2 both had suppressive effects on the initial onset of boron symptoms, including visual, biochemical, and protein responses. Further tests revealed that photosynthesis is an early target (within days) of boron deficiency stress. A follow up to the nutrient survey of the Ornamental Plant Germplasm Center’s Pelargonium collection was made to identify the whole plant and proteomic response to boron deficiency and toxicity. These findings have been written in a journal article currently under review. This project was monitored through twice weekly face-to-face conversations, committee meetings of all involved personnel, and co-advised graduate students and post-doctoral associations.