Functional analysis of a novel Rubisco small subunit, OsRbcS1 in rice

2014 Fiscal Year Final Research Report

• Project/Area Number: 24580021
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Crop science/Weed science
• Research Institution: Kobe University
• Principal Investigator: FUKAYAMA Hiroshi 神戸大学, (連合)農学研究科(研究院), 助教 (60373255)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 光合成 / 炭素同化 / イネ / 遺伝子組換え / ルビスコ / 二酸化炭素 / 一次代謝 / 酵素

Outline of Final Research Achievements

Rubisco small subunits (RbcS) are encoded by a nuclear multigene family consisting five RbcS genes (OsRbcS1-5) in rice. Among them, the amino acid sequence of OsRbcS1 differs notably from those of OsRbcS2-5. In addition, OsRbcS1 was not expressed in leaf blade, a major photosynthetic organ, but was expressed in leaf sheath, culm, anther and root central cylinder. In leaf blade of transgenic rice overexpressing OsRbcS1 and leaf sheath of non-transgenic rice, OsRbcS1 was incorporated into the Rubisco holoenzyme. Incorporation of OsRbcS1 into Rubisco increased the catalytic turnover rate and Km for CO2 of the enzyme, indicating that the catalytic properties were shifted to those of a high activity type Rubisco. These results indicate that the catalytic properties of Rubisco can be altered by ectopic expression of OsRbcS1, and useful for improvement of photosynthetic capacity under near future elevated CO2 conditions.

Free Research Field

作物生理学