OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 143/4/1789    most recent pp.106.093971v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Devaiah, B. N. Articles by Raghothama, K. G. Search for Related Content PubMed PubMed Citation Articles by Devaiah, B. N. Articles by Raghothama, K. G. Agricola Articles by Devaiah, B. N. Articles by Raghothama, K. G.

ENVIRONMENTAL STRESS AND ADAPTATION TO STRESS

WRKY75 Transcription Factor Is a Modulator of Phosphate Acquisition and Root Development in Arabidopsis^{1,[C],[W],[OA]}

Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907–1165

Phosphate (Pi) deficiency limits plant growth and development, resulting in adaptive stress responses. Among the molecular determinants of Pi stress responses, transcription factors play a critical role in regulating adaptive mechanisms. WRKY75 is one of several transcription factors induced during Pi deprivation. In this study, we evaluated the role of the WRKY75 transcription factor in regulating Pi starvation responses in Arabidopsis (Arabidopsis thaliana). WRKY75 was found to be nuclear localized and induced differentially in the plant during Pi deficiency. Suppression of WRKY75 expression through RNAi silencing resulted in early accumulation of anthocyanin, indicating that the RNAi plants were more susceptible to Pi stress. Further analysis revealed that the expression of several genes involved in Pi starvation responses, including phosphatases, Mt4/TPS1-like genes, and high-affinity Pi transporters, was decreased when WRKY75 was suppressed. Consequently, Pi uptake of the mutant plant was also decreased during Pi starvation. In addition, when WRKY75 expression was suppressed, lateral root length and number, as well as root hair number, were significantly increased. However, changes in the root architecture were obvious under both Pi-sufficient and Pi-deficient conditions. This indicates that the regulatory effect of WRKY75 on root architecture could be independent of the Pi status of the plant. Together, these results suggest that WRKY75 is a modulator of Pi starvation responses as well as root development. WRKY75 is the first member of the WRKY transcription factor family reported to be involved in regulating a nutrient starvation response and root development.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Kashchandra G. Raghothama (kraghoth{at}purdue.edu).

^[C] Some figures in this article are displayed in color online but in black and white in the print edition.

^[W] The online version of this article contains Web-only data.

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.106.093971

^* Corresponding author; e-mail kraghoth{at}purdue.edu; fax 765–494–0391.

Received November 30, 2006; accepted February 20, 2007; published February 23, 2007.

This article has been cited by other articles:

				C. Calderon-Vazquez, E. Ibarra-Laclette, J. Caballero-Perez, and L. Herrera-Estrella Transcript profiling of Zea mays roots reveals gene responses to phosphate deficiency at the plant- and species-specific levels J. Exp. Bot., June 6, 2008; (2008) ern115v2. [Abstract] [Full Text] [PDF]

				Y. Wang, D. Secco, and Y. Poirier Characterization of the PHO1 Gene Family and the Responses to Phosphate Deficiency of Physcomitrella patens Plant Physiology, February 1, 2008; 146(2): 646 - 656. [Abstract] [Full Text] [PDF]

				J. P. Hammond and P. J. White Sucrose transport in the phloem: integrating root responses to phosphorus starvation J. Exp. Bot., January 1, 2008; 59(1): 93 - 109. [Abstract] [Full Text] [PDF]

				B. N. Devaiah, V. K. Nagarajan, and K. G. Raghothama Phosphate Homeostasis and Root Development in Arabidopsis Are Synchronized by the Zinc Finger Transcription Factor ZAT6 Plant Physiology, September 1, 2007; 145(1): 147 - 159. [Abstract] [Full Text] [PDF]

				M. Tesfaye, J. Liu, D. L. Allan, and C. P. Vance Genomic and Genetic Control of Phosphate Stress in Legumes Plant Physiology, June 1, 2007; 144(2): 594 - 603. [Full Text] [PDF]

				G. Hernandez, M. Ramirez, O. Valdes-Lopez, M. Tesfaye, M. A. Graham, T. Czechowski, A. Schlereth, M. Wandrey, A. Erban, F. Cheung, et al. Phosphorus Stress in Common Bean: Root Transcript and Metabolic Responses Plant Physiology, June 1, 2007; 144(2): 752 - 767. [Abstract] [Full Text] [PDF]