Recipient Organization
UNIV OF MINNESOTA
1035 UNIVERSITY DR
DULUTH,MN 55812-3011
Performing Department
(N/A)
Non Technical Summary
Drought, frost, and other stresses can reduce plant productivity and crop yields. Sugar movement around the plant body to areas of growth and development drives productivity. The timing of stress, may affects current-season productivity. Plant stresses stop or slow sugar movement and plant growth. It is unknown if stress timing can reduce productivity in future growing seasons. This project will determine if the timing of drought or other stresses can reduce sugar movement and thus plant productivity. Does a drought that occurs during summer limit a tree from making fruits or flowers the following spring?We will grow trees in controlled greenhouse conditions and expose them to drought at different times during the year. After each stress treatment, we will make measurements of plant health, ability to make sugar, and ability to move sugar. We will continue making measurements each season for one year. The extra year of measurements will allow us to determine when the trees are able to recover from the stress. The broad implications from this work will be more reliable crop production. Specifically, our data will allow those who grow crop trees to better react to droughts and other stresses. Further, this work will allow stakeholders to better predict yields after plant stress.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
0%
Developmental
0%
Goals / Objectives
1. Conduct a two seasonal studiesof callose deposition after drought and delayed winter dormancy.a. Determine turgor loss points for the target species.b. Measure chlorophyll fluorescence, callose presence, callose location, phloem anatomy, leaf stomatal conductance, leaf photosynthetic rate on the target species once per season.c. record phenological stages for the greenhouse population and outdoor conspecifics seasonally: noting the timing of leaf bud break, floral bud break, open leaves, open flowers, yellow leaves, and leave abcission.c. In the second year, also measure phloem sap flow rate for target species during each seasonal timepoint.2. Analyze the data from each study3. Prepare manuscripts describing the outcome of each study
Project Methods
We will purchase and maintain plants in a greenhouse setting, monitoring them for proper hydration, nutrition, and pests.Proior to beginning the seasonal measurements, plant turgor loss point will be found using a pressure chamber and drought treatment.Seasonally, we will measure:Chlorophyll fluorescence with a fluorometer and with a LiCor portable photosynthesis systemThe amount of callose in the phloem via fluorescence assayThe location of callose and amount of callose occlusion on the sieve plates with scanning electron microscopySieve element and phloem anatomical characteristics using classical histological sectioning with a sliding microtome and staining with Safranin O and Alcian Blue. These measurements will be used to calculate the leafLeaf Stomatal Conductance and leaf Photosynthetic Rate with a LiCor portable photosynthesis system.In year 2 we will also measure the flow rate of the sap within the sieve elements using phloem-mobile dyes such as CFDA or Esculin.We will analyze the results using regressions, t-tests, and ANOVA, to determine differences between phenological stages between and within species.All measurements will provide experiential learning opportunities for an undergraduate student.Evaluation of project success will be determined by:1) Completing all measurements as planned, or completing suitable alternatives in cases where methods do not work.2) Compiling results, analyzing them, and writing them into two manuscripts submitted to peer-reviewed journals.3) Presenting intermediate and final results at two academic conferences.