Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Functional Genomic Analysis of the Auxin Response Factor Gene Family Members in Arabidopsis Thaliana: Unique and Overlapping Functions of Arf7 and Arf19

Authors
item Okushima, Yoko - ARS-UCB PLNT GENE EXP CTR
item Overvoorde, Paul - ARS-UCB PLNT GENE EXP CTR
item Arima, Kazunari - ARS-UCB PLNT GENE EXP CTR
item Alonso, Jose - SALK INSTITUTE LA JOLLA C
item Chan, April - ARS-UCB PLNT GENE EXP CTR
item Chang, Charlie - ARS-UCB PLNT GENE EXP CTR
item Ecker, Joseph - SALK INSTITUTE LA JOLLA C
item Hughes, Beth - ARS-UCB PLNT GENE EXP CTR
item Lui, Amy - ARS-UCB PLNT GENE EXP CTR
item Nguyen, Diana - ARS-UCB PLNT GENE EXP CTR
item Onodera, Courtney - ARS-UCB PLNT GENE EXP CTR
item Quach, Hong - ARS-UCB PLNT GENE EXP CTR
item Smith, Alison - ARS-UCB PLNT GENE EXP CTR
item Yu, Guixia - ARS-UCB PLNT GENE EXP CTR
item Theologis, Athanasios

Submitted to: The Plant Cell
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 2004
Publication Date: January 19, 2005
Citation: Okushima, Y., Overvoorde, P.J., Arima, K., Alonso, J.M., Chan, A., Chang, C., Ecker, J.R., Hughes, B., Lui, A., Nguyen, D., Onodera, C., Quach, H., Smith, A., Yu, G., Theologis, A. 2005. Functional Genomic Analysis of the AUXIN RESPONSE FACTOR Gene Family Members in Arabidopsis thaliana: Unique and Overlapping Functions of ARF7 and ARF19. The Plant Cell 17:444-463.

Interpretive Summary: The AUXIN RESPONSE FACTOR (ARF) gene family products, together with the AUXIN/INDOLE-3-ACETIC ACID proteins, regulate auxin-mediated transcriptional activation/repression. The biological function(s) of most ARFs is poorly understood. Here, we report the identification and characterization of T-DNA insertion lines for 18 of the 23 ARF gene family members in Arabidopsis thaliana. Most of the lines fail to show an obvious growth phenotype except of the previously identified arf2/hss, arf3/ett, arf5/mp, and arf7/nph4 mutants, suggesting that there are functional redundancies among the ARF proteins. Subsequently, we generated double mutants. arf7 arf19 has a strong auxin-related phenotype not observed in the arf7 and arf19 single mutants, including severely impaired lateral root formation and abnormal gravitropism in both hypocotyl and root. Global gene expression analysis revealed that auxin-induced gene expression is severely impaired in the arf7 single and arf7 arf19 double mutants. For example, the expression of several genes, such as those encoding members of LATERAL ORGAN BOUNDARIES domain proteins and AUXIN-REGULATED GENE INVOLVED IN ORGAN SIZE, are disrupted in the double mutant. The data suggest that the ARF7 and ARF19 proteins play essential roles in auxin-mediated plant development by regulating both unique and partially overlapping sets of target genes. These observations provide molecular insight into the unique and overlapping functions of ARF gene family members in Arabidopsis.

Technical Abstract: The AUXIN RESPONSE FACTOR (ARF) gene family products, together with the AUXIN/INDOLE-3-ACETIC ACID proteins, regulate auxin-mediated transcriptional activation/repression. The biological function(s) of most ARFs is poorly understood. Here, we report the identification and characterization of T-DNA insertion lines for 18 of the 23 ARF gene family members in Arabidopsis thaliana. Most of the lines fail to show an obvious growth phenotype except of the previously identified arf2/hss, arf3/ett, arf5/mp, and arf7/nph4 mutants, suggesting that there are functional redundancies among the ARF proteins. Subsequently, we generated double mutants. arf7 arf19 has a strong auxin-related phenotype not observed in the arf7 and arf19 single mutants, including severely impaired lateral root formation and abnormal gravitropism in both hypocotyl and root. Global gene expression analysis revealed that auxin-induced gene expression is severely impaired in the arf7 single and arf7 arf19 double mutants. For example, the expression of several genes, such as those encoding members of LATERAL ORGAN BOUNDARIES domain proteins and AUXIN-REGULATED GENE INVOLVED IN ORGAN SIZE, are disrupted in the double mutant. The data suggest that the ARF7 and ARF19 proteins play essential roles in auxin-mediated plant development by regulating both unique and partially overlapping sets of target genes. These observations provide molecular insight into the unique and overlapping functions of ARF gene family members in Arabidopsis.

Last Modified: 10/25/2014
Footer Content Back to Top of Page