2012 Annual Report
1a.Objectives (from AD-416):
Determine the molecular mechanisms by which plants perceive and respond to developmental, biotic and abiotic signals throughout the life cycle to enhance the quality and production efficiency of agriculturally important crops.
1b.Approach (from AD-416):
A combination of modern molecular, genetic, genomic, proteomic and bioinformatic approaches will be used to address this multifaceted problem. Particular emphasis will be placed on identifying signaling components, regulatory genes and transcriptional networks involved in controlling plant responses to developmental, biotic and abiotic signals. Genes that respond to light under control of the phytochrome photosensory system will be identified and the regulatory mechanisms defined. Genes involved in regulating the circadian clock will be identified and functionally defined. Genes controlling vegetative and reproductive development will be identified and characterized. Plant hormone function in mediating growth and developmental responses will be explored. Genes involved in plant responses to biotic and abiotic challenges will be identified and characterized. On an ongoing basis, cutting-edge strategies and technologies in areas such as targeted reverse-genetic gene disruption, high-density microarray analysis, and biocomputational approaches, will be assimilated and will be identified and characterized. Formerly 5335-21000-027-03S (1/10). BSL-1; 7/1/10. Documents SCA with UC Berkeley.
ARS scientists at Albany, California, collaborated with scientists from University of California Berkeley to carry out studies aimed at determining the function of plant genes. They showed that overexpression of PTEN, a protein and lipid phosphatase, caused disturbed lipid signaling and excessive autophagy in pollen tubes, which led to gametophytic male sterility. Another group developed a high-throughput quantitative membrane-based yeast-two hybrid system, providing a genomics-era platform for the analysis of protein-protein interactions. Further, they described new virulence strategies employed by bacterial type III secreted effectors to manipulate plant defense mechanisms. A third group demonstrated that the small signaling molecule CLE8 regulates embryo and endosperm development. This lab showed that CLE8 activity promotes overall seed size, and thus may be targeted to improve plant yield. A fourth group cloned and characterized a kinase that regulates leaf growth and reproductive development. Using microarray-based expression profiling, a fifth group has defined a core set of genes, regulated by the phytochrome (phy)-PIF transcription-factor signaling pathway, that respond rapidly and reciprocally to light and shade, in emergent seedlings and vegetative-canopy-exposed plants, respectively. These genes are enriched for transcription-factor-encoding loci, providing targets for manipulating light-shade-modulated sculpturing of vegetational architecture, of potential relevance to biofuel production. The sixth lab identified mutations in the maize homologs of Gigantea, an important protein for regulating flowering time and the circadian clock. Finally, the seventh group discovered that small RNAs regulate levels of disease resistance loci in Solanaceous species.