The plant hormone auxin (IAA, indole-3-acetic acid) is a crucial informational molecule that controls many aspects of plant development, including differentiation of particular tissues such as xylem, branching of both shoots and roots, and elongation and tropic responses to light and gravity. In the model plant Arabidopsis thaliana, shy2 mutations fall in the IAA3 gene encoding a member of this family. Study of these mutants has shown that SHY2/IAA3 is an important regulator of auxin-controlled development and also affects responses to light. This proposal describes experiments to determine how SHY2/IAA3 may link light perception and auxin responses, and how it regulates development. The approaches will include analyses of shy2 mutant phenotypes; studies of SHY2/IAA3 protein interactions with other regulatory proteins; studies of SHY2/IAA3 protein modification, stability, and localization in plants; studies of global gene expression patterns in shy2 and other mutants; and characterization of genetic modifiers of a shy2 mutation. These experiments will help us understand how auxin regulates development in a model system, and will in the future allow manipulation of morphology of crop plants in ways beneficial to human health.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM052456-07
Application #
6623908
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Anderson, James J
Project Start
1995-05-01
Project End
2006-11-30
Budget Start
2003-04-01
Budget End
2004-11-30
Support Year
7
Fiscal Year
2003
Total Cost
$261,286
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
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Wilmoth, Jill C; Wang, Shucai; Tiwari, Shiv B et al. (2005) NPH4/ARF7 and ARF19 promote leaf expansion and auxin-induced lateral root formation. Plant J 43:118-30
Ellis, Christine M; Nagpal, Punita; Young, Jeffery C et al. (2005) AUXIN RESPONSE FACTOR1 and AUXIN RESPONSE FACTOR2 regulate senescence and floral organ abscission in Arabidopsis thaliana. Development 132:4563-74
Remington, David L; Vision, Todd J; Guilfoyle, Thomas J et al. (2004) Contrasting modes of diversification in the Aux/IAA and ARF gene families. Plant Physiol 135:1738-52