The present invention includes modified
Arabidopsis Nucleoside Di-
Phosphate Kinase 2 (NDPK2)
nucleic acid molecules whose enzymatic activity have been increased (i.e. hyperactive). NDPKs are ubiquitous
housekeeping enzymes that catalyze the transfer of γ-phosphoryl group from a
nucleoside triphosphate (NTP) to a
nucleoside diphosphate (NDP), and also multifunctional proteins that regulate a variety of eukaryotic cellular activities, including
cell proliferation, development, and differentiation. In plants, NDPKs are reported to play a key role in the signaling of both stress and light. Among three NDPKs (NDPK1, NDPK2, NDPK3) in a model
plant,
Arabidopsis thaliana, NDPK2 was reported as a positive
signal transducer of
phytochrome-mediated
plant light signaling and to regulate cellular
redox state, which enhances
multiple stress tolerance in transgenic plants. Thus, the plants with the hyperactive NDPK2 are expected to possess higher efficiency of light utilization and enhanced tolerance to various environmental stresses such as cold, salt, and oxidative stresses. Since
abiotic stress is one of the most important factors to limit the productivity of many crops, the hyperactive NDPK2 can be used for the development of high-yielding
multiple stress tolerant plants with higher efficiency of light utilization. In this invention, several hyperactive NDPK2 were generated by C-terminal deletion and site-
directed mutagenesis. Therefore, the present invention can be utilized to develop
multiple stress tolerant and efficiently light-utilizing plants, which can eventually increase
crop yields. The invention also includes plants having at least one
cell expressing the modified NDPK2, vectors comprising at least one portion of the modified NDPK2 nucleic acids, and methods using such vectors for producing plants with enhanced
light sensitivity and stress tolerance.