2013 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.
These accomplishments relate to the parent project, 5335-21000-032-00D, in connecting networks between growth and environmental response. ARS scientists made significant advances in identifying components of the regulatory networks involved in how plants grow and perceive their environment. They identified a key modifier of fruit patterning activity in Arabidopsis. They also identified stem cell signaling proteins in the rice (Oryza sativa) genomic sequence database, as well as in the maize genome sequence database. Another key accomplishment was the first comprehensive analysis of circadian clock-driven gene expression in maize and detailed analysis of genes that regulate flowering time in maize. The circadian clock analysis is also being carried out under drought conditions. A third key accomplishment was the discovery of gene(s) that regulate maize growth and respond to the environment. A fourth accomplishment is progress in characterizing a pollen specific transcription factor. Plants that are mutant in this gene have reduced seed set, implicating this transcription factor in controlling processes required for correct double fertilization. A fifth accomplishment was progress in understanding of the virulence mechanisms of bacteria that infect plants and the innate mechanisms in disease resistance. A final accomplishment was a detailed understanding of the role of phytocrome and interacting partners in seedling emergence. The overall impact of these many accomplishments is that a number of novel regulatory genes that affect plant biomass and yield were identified and their functions analyzed, benefiting agriculture by facilitating the characterization and manipulation of related genes in many crop plant species.