Proteome analysis of gametophores identified a metallothionein involved in various abiotic stress responses in Physcomitrella patens

• Published in: Plant cell reports Vol. 25; no. 5; pp. 475 - 488
• Main Authors: Cho, Sung Hyun, Hoang, Quoc Truong, Kim, Yoon Young, Shin, Hyun Young, Ok, Sung Han, Bae, Jung Myung, Shin, Jeong Sheop
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.05.2006; Springer Nature B.V
• Subjects: Amino Acid Sequence; Bacteria; Biological and medical sciences; Biotechnology; Bryopsida - metabolism; Cadmium - toxicity; Cold Temperature; Copper - toxicity; Electrophoresis, Gel, Two-Dimensional; Ethylenes - toxicity; Expressed Sequence Tags; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Indoleacetic Acids - toxicity; Metallothionein - physiology; Molecular Sequence Data; Physcomitrella patens; Plant Proteins - metabolism; Proteins; Proteome - analysis; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Proteome; Plant; Metallothionein; Stress
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-005-0079-0

Physcomitrella patens is a model plant for studying gene function using a knockout strategy. To establish a proteome database for P. patens, we resolved over 1,500 soluble proteins from gametophore and protonema tissues by two-dimensional electrophoresis (2-DE) and obtained peptide mass fingerprints (PMFs) by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Using expressed sequence tags (ESTs), we were able to predict the identities of 90 protein spots. Most of these were related to energy or primary metabolism. Comparative proteome analysis was used to identify proteins specific for each of the tissue types. One of these was a metallothionein type-2 (PpMT2) protein that was highly upregulated in gametophore tissue. PpMT2 was induced in both the gametophore and protonema following culture on solid media and in response to various abiotic stresses such as copper, cadmium, cold, indole-3-acetic acid, and ethylene. We suggest that PpMT2 is not only involved in metal binding and detoxification, but also in many biological aspects as a metal messenger or a protein with additional functions.