Proteome Modification in Tomato Plants upon Long-Term Aluminum Treatment

• Published in: Journal of proteome research Vol. 15; no. 5; pp. 1670 - 1684
• Main Authors: Zhou, Suping, Okekeogbu, Ikenna, Sangireddy, Sasikiran, Ye, Zhujia, Li, Hui, Bhatti, Sarabjit, Hui, Dafeng, McDonald, Daniel W, Yang, Yong, Giri, Shree, Howe, Kevin J, Fish, Tara, Thannhauser, Theodore W
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.05.2016
• Subjects: Adaptation, Physiological; Aluminum - pharmacokinetics; Aluminum - pharmacology; Lycopersicon esculentum - chemistry; Lycopersicon esculentum - embryology; Plant Leaves - drug effects; Plant Leaves - metabolism; Plant Roots - drug effects; Plant Roots - metabolism; Proteome - drug effects; Proteome - metabolism; Proteomics - methods; Seeds - drug effects; Seeds - metabolism; iTRAQ proteomics; leaves; functional pathways; embryos; tomato; roots; aluminum stress; seed coat
• ISSN: 1535-3893; 1535-3907
• DOI: 10.1021/acs.jproteome.6b00128

This study aimed to identify the aluminum (Al)-induced proteomes in tomato (Solanum lycopersicum, “Micro-Tom”) after long-term exposure to the stress factor. Plants were treated in Magnavaca’s solution (pH 4.5) supplemented with 7.5 μM Al3+ ion activity over a 4 month period beginning at the emergence of flower buds and ending when the lower mature leaves started to turn yellow. Proteomes were identified using a 8-plex isobaric tags for relative and absolute quantification (iTRAQ) labeling strategy followed by a two-dimensional (high- and low-pH) chromatographic separation and final generation of tandem mass spectrometry (MS/MS) spectra of tryptic peptides on an LTQ-Orbitrap Elite mass spectrometer. Principal component analysis revealed that the Al-treatment had induced systemic alterations in the proteomes from roots and leaves but not seed tissues. The significantly changed root proteins were shown to have putative functions in Al3+ ion uptake and transportation, root development, and a multitude of other cellular processes. Changes in the leaf proteome indicate that the light reaction centers of photosynthetic machinery are the primary targets of Al-induced stress. Embryo and seed-coat tissues derived from Al-treated plants were enriched with stress proteins. The biological processes involving these Al-induced proteins concur with the physiological and morphological changes, such as the disturbance of mineral homeostasis (higher contents of Al, P, and Fe and reduced contents of S, Zn, and Mn in Al-treated compared to nontreated plants) in roots and smaller sizes of roots and the whole plants. More importantly, the identified significant proteins might represent a molecular mechanism for plants to develop toward establishing the Al tolerance and adaptation mechanism over a long period of stress treatment.