Proteome Analysis in Arabidopsis Reveals Shoot- and Root-Specific Targets of Cytokinin Action and Differential Regulation of Hormonal Homeostasis
Open Access
- 3 December 2012
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 161 (2), 918-930
- https://doi.org/10.1104/pp.112.202853
Abstract
The plant hormones cytokinins (CKs) regulate multiple developmental and physiological processes in Arabidopsis (Arabidopsis thaliana). Responses to CKs vary in different organs and tissues (e.g. the response to CKs has been shown to be opposite in shoot and root samples). However, the tissue-specific targets of CKs and the mechanisms underlying such specificity remain largely unclear. Here, we show that the Arabidopsis proteome responds with strong tissue and time specificity to the aromatic CK 6-benzylaminopurine (BAP) and that fast posttranscriptional and/or posttranslational regulation of protein abundance is involved in the contrasting shoot and root proteome responses to BAP. We demonstrate that BAP predominantly regulates proteins involved in carbohydrate and energy metabolism in the shoot as well as protein synthesis and destination in the root. Furthermore, we found that BAP treatment affects endogenous hormonal homeostasis, again with strong tissue specificity. In the shoot, BAP up-regulates the abundance of proteins involved in abscisic acid (ABA) biosynthesis and the ABA response, whereas in the root, BAP rapidly and strongly up-regulates the majority of proteins in the ethylene biosynthetic pathway. This was further corroborated by direct measurements of hormone metabolites, showing that BAP increases ABA levels in the shoot and 1-aminocyclopropane-1-carboxylic acid, the rate-limiting precursor of ethylene biosynthesis, in the root. In support of the physiological importance of these findings, we identified the role of proteins mediating BAP-induced ethylene production, METHIONINE SYNTHASE1 and ACC OXIDASE2, in the early root growth response to BAP.Keywords
This publication has 59 references indexed in Scilit:
- Comparative Analysis of Different Label-Free Mass Spectrometry Based Protein Abundance Estimates and Their Correlation with RNA-Seq Gene Expression DataJournal of Proteome Research, 2012
- Evidence for the localization of the Arabidopsis cytokinin receptors AHK3 and AHK4 in the endoplasmic reticulumJournal of Experimental Botany, 2011
- The Cytokinin Receptors of Arabidopsis Are Located Mainly to the Endoplasmic ReticulumPlant Physiology, 2011
- Proteomic responses in Arabidopsis thaliana seedlings treated with ethyleneMolecular BioSystems, 2011
- Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profilingJournal of Experimental Botany, 2010
- Cytokinin regulates root meristem activity via modulation of the polar auxin transportProceedings of the National Academy of Sciences, 2009
- Cytokinins modulate auxin-induced organogenesis in plants via regulation of the auxin effluxProceedings of the National Academy of Sciences, 2009
- Cytokinin deficiency causes distinct changes of sink and source parameters in tobacco shoots and rootsJournal of Experimental Botany, 2008
- Cytokinins Determine Arabidopsis Root-Meristem Size by Controlling Cell DifferentiationCurrent Biology, 2007
- Direct control of shoot meristem activity by a cytokinin-activating enzymeNature, 2007