2016 article

Auxin catabolism unplugged: Role of IAA oxidation in auxin homeostasis

Stepanova, A. N., & Alonso, J. M. (2016, September 27). PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol. 113, pp. 10742–10744.

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
MeSH headings : Arabidopsis / metabolism; Arabidopsis Proteins / metabolism; Genes, Plant; Homeostasis; Indoleacetic Acids / metabolism
Source: Web Of Science
Added: August 6, 2018

Plants rely on the levels and concentration gradients of the hormone auxin as crucial information cues to trigger and modulate almost every aspect of their life cycle, from establishing embryo polarity to promoting phototropic and gravitropic responses (1). Thus, it is critical for plants to finely control the levels of the bioactive form of this hormone, both at spatial and temporal levels. Local production, transport, conjugation, storage, and catabolism are all well-known processes participating in the dynamic regulation of auxin homeostasis (2). It is, however, unknown whether or how these different auxin homeostasis mechanisms talk to each other. In the past 30 y, the identification of the genes coding for the key components of the auxin biosynthetic, transport, and conjugation machineries has proven instrumental in assessing the contribution of each of these processes to concrete developmental pathways, as well as to specific plant responses to environmental changes. Although much less is known about the ways the predominant auxin, indole-3-acetic acid (IAA), is catabolized, classical labeling and metabolite quantification experiments indicate that the oxidation of IAA into 2-oxindole-3-acetic acid (oxIAA) is one of the most prevalent mechanisms to inactivate this hormone (3). Identifying the specific enzymes catalyzing this reaction in vivo has proved to be more challenging than anticipated, as different plant peroxidases and oxygenases, the original suspects for catalyzing this reaction, were found not to play a significant physiological role in the production of oxIAA (3). The recent identification of a rice 2-oxoglutarate-dependent-Fe(II) dioxygenase, DIOXYGENASE FOR AUXIN OXIDATION ( DAO ), originally linked to male fertility in rice and capable of oxidizing IAA into oxIAA (1⇓⇓–4), has opened new avenues for addressing the physiological significance of auxin catabolism in plant growth and development. In PNAS, Zhang et al. (5), Porco et al. (6), and Mellor et al. (7 … [↡][1]1To whom correspondence should be addressed. Email: jmalonso{at}ncsu.edu. [1]: #xref-corresp-1-1