Abstract
Aquaporins facilitate membrane transport of water and other small molecules to support plant growth. We introduced radish aquaporins PIPs into eucalyptus and determined physiological properties of the transformants. Radish PIP2, but not PIP1, has been demonstrated to have water channel activity.
Radish PIP cDNAs linked with 35S promoter were introduced by the Agrobacterium infection method. Plants were generated from the transformed calli and grown in the soil. PIP2 mRNA was detected and PIP2 protein level was remarkably increased in the PIP2 transformants. The PIP2-transgenic lines showed higher values of CO2 assimilation, water efficiency and branch growth rate. For PIP1-transgenic lines, the protein level of PIP1 was decreased and their growth rate was lower than that of the wild type. These results indicate that PIP1 and PIP2 are essential for normal growth. We also report the relationship of PIP content to physiological properties of wild eucalyptus trees.
