Identification of an Apoplastic Protein Involved in the Initial Phase of Salt Stress Response in Rice Root by Two-Dimensional Electrophoresis      

Abstract

The apoplast of plant cells, which carries out multiple functions in plant metabolism and signaling, is not only a barrier but also the linker between the environment and the protoplast. To investigate the role of apoplastic proteins in the salt stress response, 10-d-old rice (Oryza sativa) plants were treated with 200 mM NaCl for 1, 3, or 6 h, and the soluble apoplast proteins were extracted for differential analysis compared with untreated controls using two-dimensional electrophoresis. Ten protein spots that increased or decreased significantly in abundance were identified by mass spectrometry. These proteins included some well-known biotic and abiotic stress-related proteins. Among them, an apoplastic protein, with extracellular domain-like cysteine-rich motifs (DUF26), O. sativa root meander curling (OsRMC), has shown drastically increased abundance in response to salt stress during the initial phase. OsRMC RNA interference transgenic rice has been generated to assess the function of OsRMC in the salt stress response. The results show that knocking down the expression level of OsRMC in transgenic rice led to insensitive seed germination, enhanced growth inhibition, and improved salt stress tolerance to NaCl than in untransgenic plants. These results indicate that plant apoplastic proteins may have important roles in the plant salt stress response.

The Rice High-Affinity Potassium Transporter1;1 Is Involved in Salt Tolerance and Regulated by an MYB-Type Transcription Factor

“…Fresh weight, shoot length, and total chlorophyll content were determined. The survival rate of seedlings was analyzed according to the method of Zhang et al (2009). Briefly, the seedlings after salt treatment were transferred to culture solution without NaCl for recovery.…”

Proteomic analysis ofPhyscomitrella patenstreated with 12-oxo-phytodienoic acid, an important oxylipin in plants

“…Dynamic exclusion was employed within 90 s to prevent the repetitive selection of peptides. 19) Protein identification using MASCOT. The MS/ MS spectra acquired were converted to individual DTA files using BioWorks software (version 3.3.1, Thermo Fisher Science).…”

An Apoplastic H-Type Thioredoxin Is Involved in the Stress Response through Regulation of the Apoplastic Reactive Oxygen Species in Rice

“…The apoplast, which is the portion of the plant cell outside of the cell membrane, plays crucial roles in cell division (Tian et al, 2009), cell differentiation (Takeda et al, 2003), pollen germination , plantpathogen interaction (Misas-Villamil and van der Hoorn, 2008), and abiotic stress responses (Dietz, 1997;Dani et al, 2005;Moschou et al, 2008;Zhang et al, 2009a;Song et al, 2011). In the last decade, extensive literature has accumulated that demonstrates a role for the apoplastic redox state in the regulation of plant growth, hormone action, gene expression, systemic acquired resistance, and signal transduction (Pei et al, 2000;Murata et al, 2001;Rodríguez et al, 2002;Schopfer et al, 2002;Mittler et al, 2011).…”