Analysis of arsenic stress-induced differentially expressed proteins in rice leaves by two-dimensional gel electrophoresis coupled with mass spectrometry.
In the present study, we have investigated the protein expression profile of rice leaves under arsenic (As) stress. Two-week-old rice seedlings were exposed to two concentrations of arsenate (50 or 100 microM), and leaf samples were collected 4d after treatment. To elucidate the As stress-induced differentially expressed proteins in rice leaves, proteins were extracted from the control and treated samples, separated by two-dimensional gel electrophoresis (2-DE), and visualized by staining with Coomassie Brilliant Blue (CBB). A total of 14 protein spots showed reproducible changes in expression of at least 1.5-fold when compared to the control and showed a similar expression pattern in both treatments. Of these 14 spots, 8 were up-regulated and 6 were down-regulated following exposure to As. These proteins were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). The increased expression of several proteins associated with energy production and metabolism suggests that higher energy is required for activation of the metabolic processes in leaves exposed to As. On the other hand, results from the 2-DE analysis, combined with immunoblotting, clearly revealed that the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit was significantly decreased under As stress. Thus, the down-regulation of RuBisCO and chloroplast 29 kDa ribonucleoproteins might be the possible causes of the decreased photosynthesis rate under As stress.
Ahsan
Nagib
N
Division of Applied Life Science, PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
Lee
Dong-Gi
DG
Kim
Kyung-Hee
KH
Alam
Iftekhar
I
Lee
Sang-Hoon
SH
Lee
Ki-Won
KW
Lee
Hyoshin
H
Lee
Byung-Hyun
BH
D001149:Arsenates / Q000633:toxicity*; D015180:Electrophoresis, Gel, Two-Dimensional; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D013058:Mass Spectrometry; D012275:Oryza / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects* / Q000378:metabolism; D010940:Plant Proteins / Q000187:drug effects / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D013312:Stress, Physiological; D018675:Toxicity Tests
D001149:Arsenates; D010940:Plant Proteins; C025657:arsenic acid