Expression level of Rubisco activase negatively correlates with Rubisco content in transgenic rice

• Fukayama, Hiroshi

• Mizumoto, Akina

• Ueguchi, Chiaki

• Katsunuma, Jun

• Morita, Ryutaro

• Sasayama, Daisuke

• Hatanaka, Tomoko

• Azuma, Tetsushi

Abstract

The relationship between ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and Rubisco activase (Rca) levels was studied using transgenic rice overexpressing maize Rca (OX-mRca) and knockdown transgenic rice expressing antisense Rca (KD-Rca). The ratio of Rubisco to total soluble protein was lower in OX-mRca, whereas it was higher in KD-Rca than in WT, indicating that Rca expression was negatively correlated with Rubisco content. The expressions of other Calvin–Benson–Bassham cycle enzymes such as sedoheptulose-1,7-bisphosphatase and phosphoribulokinase analyzed by immunoblotting did not show such a negative correlation with Rca, suggesting that the effect of Rca on protein expression may be specific for Rubisco. Although Rubisco content was decreased in OX-mRca, the transcript levels of the Rubisco large subunit (OsRbcL) and the Rubisco small subunit mostly increased in OX-mRca as well as in KD-Rca. Additionally, polysome loading of OsRbcL was slightly higher in OX-mRca than it was in WT, suggesting that the OsRbcL translation activity was likely stimulated by overexpression of Rca. 35S-methionine labeling experiments demonstrated that there was no significant difference in the stability of newly synthesized Rubisco among genotypes. However, 35S-methionine-labeled Rubisco was marginally decreased in OX-mRca and increased in KD-Rca compared to the WT. These results suggest that Rca negatively affects the Rubisco content, possibly in the synthesis step.

Journal

• Photosynthesis Research

  Photosynthesis Research 137 (3), 465-474, 2018-09

  Springer

Keywords

• Photosynthesis
• Polysome loading
• Rice
• Rubisco
• Rubisco activase
• Protein turnover

Details

• CRID: 1050012570392911232
• NII Article ID: 120006647368
• DOI: 10.1007/s11120-018-0525-9
• ISSN: 15735079
• ISSN: 01668595
• HANDLE: 20.500.14094/90006130
• Web Site: http://link.springer.com/article/10.1007/s11120-018-0525-9/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1007/s11120-018-0525-9.pdf
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN