The present invention generally relates to a modified Rubisco large
subunit .sup..epsilon.N-Methyltransferase (Rubisco LSMT, or RLSMT). The
present invention also relates to a modified RLSMT-carbonic anhydrase
(RLSMT-CA). This modified RLSMT-CA improves the efficiency of the
reduction of CO.sub.2 during photosynthesis, which may increase plant
growth rates. The present invention also relates to nucleic acids
encoding the modified RLSMT-CA or modified RLSMT. Also, the present
invention relates to cells including the modified RLSMT-CA or modified
RLSMT, plants containing the modified RLSMT-CA or modified RLSMT, and
methods using compositions of the present invention. In addition, the
present invention relates to antibodies conjugated to CA which may bind
to Rubisco, and antibodies which bind a modified RLSMT-CA. The invention
also relates to modified forms of the LS and SS of Rubisco where the
modified forms are fusions with CA or biologically active fragments
thereof. The present invention provides methods of altering Rubisco
carboxylase activity and altering plant growth.