In biochemical studies we previously demonstrated that the form of Rca in the wild species Oryza australiensis has 19 amino acid changes in comparison to Rca from O.sativa.Furthermore,we showed that this altered protein catalysed the activation of Rubisco at temperatures up to 42◦C while the efficacy of Rca from O. sativa became defective at temperatures exceeding 36◦C. The susceptibility of rice Rca to temperatures above 35◦C is supported by another recent study on Rca temperature sensitivity in vitro