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United States Department of Agriculture

Agricultural Research Service

Research Project: CHARACTERIZATION AND ENHANCEMENT OF PLANT RESISTANCE TO WATER-DEFICIT AND THERMAL STRESSES

Location: Plant Stress and Germplasm Development Research

2007 Annual Report


1a.Objectives (from AD-416)
1)Identify and functionally characterize genes central to the adaptation of plant to water-deficit and thermal stresses. 2)Discover and/or develop germplasm enhanced for stress resistance traits. 3)Identify and characterize water-deficit and thermal stress-responding promoters for use in controlled expression of stress resistance genes and for testing of a user-friendly plant stress reporter system for crop management.


1b.Approach (from AD-416)
A multidisciplinary research approach will be utilized because of the complexity of the problems to be addressed. Genes will be identified via expression databases and mutational analyses. Physiological and molecular characterizations will be used to identify germplasm with enhanced stress tolerances. Transformational technologies will be used in the development of plants with enhanced stress tolerances and plants with stress responsive reporter genes.


4.Accomplishments
Heat Tolerance Genes Identified: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, have identified 17 genes contributing to basal heat tolerance in plants. This discovery advances our understanding on the many cellular components impacting heat tolerance. The scientists evaluated tDNA mutants of Arabidopsis for high temperature sensitivity. This discovery, in combination with additional gene discoveries, will allow scientists to develop more heat-tolerant crops. (NP302, Component 2, Problem Statement 2B)

New Weapon for Plant Breeding Arsenal: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, have developed a new assay for breeders and plant physiologists to detect water stress. This assay allows plant breeders to evaluate greater numbers of plants for water-deficit stress responses than had been previously available. The scientists placed plant tissues under an elevated respiratory demand and monitored their vital signs. This assay aids in the identification of genetic diversity in water-deficit stress tolerance. (NP302, Component 2, Problem Statement 2B)

The Color Purple: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, have used anthocyanin pigment production as an indicator of gene silencing in plants. The induction of and induced loss of this purple pigment provides a visual tool for evaluating the location and degree of gene silencing. The scientists have evaluated suppressors of silencing as a means to enhance gene expression in plant vegetative tissues. This study is dissecting one of the newly discovered mechanisms that plants use to regulate gene expression. (NP302, Component 2, Problem Statement 2A)

Stress-Induced Genes Identified: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, used a meta-analysis of heat and water-deficit stress expression profiles in cotton, peanut, and Arabidopsis to identify candidate genes for ectopic expression studies. Fifty-eight full-length clones are currently being prepared for ectopic expression studies in cotton and peanut. This represents one of the first public, large-scale examinations of genetically engineered crop plants under relevant field conditions. (NP302, Component 2, Problem Statement 2B)

Working for Peanuts: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, (in collaboration with Agilent Technologies) have developed the first publicly available microarray for gene expression profiling in peanut. The array represents approximately 10,000 unique genes from leaf, root, stem, and pod under a variety of growth conditions including drought, pathogen infection, and heat stress, in addition to genes from wild-species. The scientists have completed two expression-profiling studies. The first study demonstrates the utility of the array with both vegetative and reproductive tissues, while the second represents a significant part of ongoing studies toward the elucidation of molecular and physiological responses to water-deficit and heat stress. (NP302, Component 2, Problem Statement 2B)

Optimization of Electrophoresis-Based Proteomics for Peanut Seeds: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, (collaboration with New Mexico State and Texas A&M Universities) have optimized a 2-DGE-based proteomics approach for peanut seed as a first step in our quest to establish comprehensive seed proteomes in peanut. The results suggest that identified proteins might serve as potential markers for cultivar differentiation and may be associated with underlying sensory and nutritional traits of peanut cultivars. (NP302, Component 2, Problem Statement 2A)

Low Cost Infrared Thermometry System: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, in conjunction with a private sector cooperator, have incorporated off-the-shelf low cost infrared thermometers (IRTs) into a custom designed wireless IRT system. Comparisons of performance between the lower cost IRT ($20/unit) and the IRTs previously used in the laboratory ($250/unit) indicate that the lower cost IRTs are suitable replacements for the higher cost units in agricultural settings. (NP302, Component 2, Problem Statement 2B)

Field Evaluation of Cotton Root Development From the Top Down: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, evaluated a series of cotton varieties for differences in root system development in greenhouse studies. Significant differences were measured in the development of total root length in the cotton, and there was a significant linear relationship between the development of leaf area in the plants and total root length. These findings could lead to a non-destructive approach for assessing differences in root system development. (NP302, Component 2, Problem Statement 2B)

Eskimo 1 Protects Against The Big Chill: Scientists within the Plant Stress and Germplasm Development Unit in Lubbock, Texas, have identified a gene mutation that enhances freezing tolerance in plants. The Eskimo1 (esk1) mutation of Arabidopsis resulted in a 5.5 degree C improvement in freezing tolerance in the absence of cold acclimation. The results indicate that ESK1 is a novel negative regulator of cold acclimation. These findings provide a new mechanism for enhancing freezing tolerance in crops. (NP302, Component 2, Problem Statement 2B)


5.Significant Activities that Support Special Target Populations
Participated in a Farm Safety program for children of minority farmers.


6.Technology Transfer

Number of active CRADAs and MTAs3
Number of invention disclosures submitted1
Number of patent applications filed1
Number of new commercial licenses granted2
Number of web sites managed2
Number of non-peer reviewed presentations and proceedings19
Number of newspaper articles and other presentations for non-science audiences23

Review Publications
Welti, R., Shah, J., Li, W., Li, M., Chen, J., Burke, J.J., Fauconnier, M., Chapman, K., Chye, M., Wang, X. 2007. Plant lipidomics: Discerning biological function by profiling plant complex lipids using mass spectrometry. Frontiers in Bioscience. 12:2494-2506.

Burke, J.J. 2007. Evaluation of source leaf responses to water-deficit stresses in cotton using a novel stress bioassay. Plant Physiology. 42(1):108-121.

Xin, Z., Chen, J., Mandaokar, A., Last, R., Browse, J. 2007. Arabidopsis ESK1 encodes a novel regulator of freezing tolerance. Plant Journal. 49:786-799.

Kottapalli, K., Burow, M., Burow, G.B., Burke, J.J., Puppala, N. 2007. Molecular characterization of the US peanut mini core collection using microsatellite markers. Crop Science. 47(4):1718-1727.

Cazzonelli, C., Velten, J.P. 2007. Synthetic plan promoters as a tool for characterizing the function of individual promoter elements. Transgenic Research [serial online]. Available: http://www.springerlink.com/content/w969356312625861/.

Lee, J.J., Hassan, O.S., Gao, W., Wang, J.J., Wei, N.E., Kohel, R.J., Chen, X., Payton, P.R., Stelly, D.M., Chen, Z. 2006. Gene expression analysis in a cotton naked seed mutant using cotton oligo-gene microarrays designed from Arabidopsis orthologous genes. Planta. 223(3):418-432.

Ramani, S.R., Barabote, R.D., Wheeler, D.H., Reverchon, S., Tatum, O., Malouf, J., Lui, H., Pritchard, L., Hedley, P.E., Birch, P.R., Toth, I.K., Payton, P.R., San Francisco, M.J. 2007. Efflux pump gene expression in Erwinia Chrysanthemi is induced by exposure to phenolic acids. Molecular Plant-Microbe Interactions. 20(3):313-320.

Last Modified: 9/10/2014
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