Abstract
We report the characterization of a member of the auxin-induced IAA gene family from zinnia, designated zIAA8, which is expressed by mesophyll cells differentiating as tracheary elements in vitro. Transcription of zIAA8 is up-regulated within 3 h after cell isolation in inductive medium, indicating that cells perceive and respond to growth factor stimulus early in culture. Transcript levels of zIAA8 remain high through 72 h of culture in medium containing auxin and cytokinin or auxin alone, but low in medium containing only cytokinin or control medium lacking growth factors, demonstrating auxin-specific induction and consistent with lack of desensitization to prolonged auxin stimulation. In situ localization shows zIAA8 is localized to primary vasculature, root tips, and nascent leaves in zinnia seedlings. The observation that zIAA8 is expressed during vascular development in planta supports the hypothesis that expression early in culture reflects early events during normal vascular differentiation. The promoter of Arabidopsis IAA8 drives expression of the GUS reporter in a pattern in Arabidopsis similar to that for zIAA8 in zinnia, suggesting conservation of cisregulatory elements between the species and confirming the results from in situ localization. The vascular expression pattern of the IAA8 promoter in leaves mirrors the developmentally regulated auxin gradient in expanding leaf blades. The expression patterns of zIAA8 and IAA8 yield new insight into vascular development in vitro and in planta, and provide much needed markers for early vascular differentiation.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abel, S., Oeller, P. and Theologis, A. 1994. Early auxin-induced genes encode short-lived nuclear proteins. Proc. Natl. Acad. Sci. USA 91: 326–330.
Abel, S., Nguyen, M. and Theologis, A. 1995. The PS-IAA4/5-like family of early auxin-inducible mRNAs in Arabidopis thaliana. J. Cell Biol. 251: 533–549.
Beers, E. and Freeman, T. 1997. Proteinase activity during tracheary element differentiation in Zinnia mesophyll cultures. Plant Physiol. 113: 873–880.
Chen, J.-G., Shimomura, S., Sitbon, F., Sandberg, G. and Jones, A. 2001. The role of auxin-binding protein 1 in the expansion of tobacco leaf cells. Plant J. 28: 607–617.
Cho, H. and Kende, H. 1998. Tissue localization of expansins in deepwater rice. Plant J. 15: 805–812.
Church, D. and Galston, A. 1988. Kinetics of determination in the differentiation of isolated mesophyll cells of Zinnia elegans to tracheary elements. Plant Physiol. 88: 92–96.
Demura, T. and Fukuda, H. 1994. Novel vascular cell-specific genes whose expression is regulated temporally and spatially during vascular system development. Plant Cell 6: 967–981.
Dolan, L., Janmaat, K., Willemsen, V., Linstead, P., Poethig, S., Roberts, K. and Scheres, B. 1993. Cellular organization of the Arabidopsis thaliana root. Development 119: 71–84.
Fukuda, H. and Komamine, A. 1980. Establishment of an experimental system for the study of tracheary element differentiation from single cells isolated from the mesophyll of Zinnia elegans. Plant Physiol. 65: 57–60.
Fukuda, H. and Komamine, A. 1985. Cytodifferentiation. In: I.K. Vasil (Ed.) Cell Culture and Somatic Cell Genetics of Plants, vol. 2, Academic Press, New York, pp. 149–212.
Gray, W., Kepinski, S., Rouse, D., Leyser, O. and Estelle, M. 2001. Auxin regulates SCFT IR1-dependent degradation of AUX/IAA proteins. Nature 414: 271–276.
Groover, A., DeWitt, N., Heidel, A. and Jones, A. 1997. Programmed cell death of plant tracheary elements differentiating in vitro. Protoplasma 196: 197–211.
Groover, A. and Jones, A. 1999. Tracheary element differentiation uses a novel mechanisms coordinating programmed cell death and secondary cell wall synthesis. Plant Physiol. 119: 375–384.
Hall, T. 1999. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucl. Acids Symp. Ser. 41: 95–98.
Kim, J., Harter, K. and Theologis, A. 1997. A protein-protein interaction among the Aux/IAA proteins. Proc. Natl. Acad. Sci. USA 94: 11786–11791.
Ljung, K., Bhalerao, R. and Sandberg, G. 2001. Sites and homeostatic control of auxin biosynthesis in Arabidopsis during vegetative growth. Plant J. 28: 465–474.
Milioni, D., Sado, P., Stacey, N., Domingo, C., Roberts, K. and McCann, M. 2001. Differential expression of cell-wall-related genes during the formation of tracheary elements in the Zinnia mesophyll cell system. Plant Mol. Biol. 47: 221–238.
Sachs, T. 1981. The control of the patterned differentiation of vascular tissues. Adv. Bot. Res. 9: 152–262.
Sambrook, J., Fritsch, E. and Maniatis, T. 1989. Molecular Cloning: A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press, Plainview, NY.
Tiwari, S., Wang, X., Hagen, G. and Guilfoyle, T. 2001. AUX/IAA Proteins are active repressors, and their stability and activity are modulated by auxin. Plant Cell 13: 2809–2822.
Ulmasov, T., Hagen, G. and Guilfoyle, T. 1997. ARF1, a transcription factor that binds to auxin response elements. Science 276: 1865–1868.
Ye, Z. and Droste, D. 1996. Isolation and characterization of cDNAs encoding xylogenesis-associated and wounding-induced ribonucleases in Zinnia elegans. Plant Mol. Biol. 30: 697–709.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Groover, A.T., Pattishall, A. & Jones, A.M. IAA8 expression during vascular cell differentiation. Plant Mol Biol 51, 427–435 (2003). https://doi.org/10.1023/A:1022039815537
Issue Date:
DOI: https://doi.org/10.1023/A:1022039815537