Specific Interaction between NDPK 2 and At MPK

Specific Interaction between NDPK 2 and At. MPK 3 1 2 3 4 5 6 7 8 9 AD vector Positive p. GAD 424: NK 1 p. GAD 424: NK 2 p. GAD 424: NK 3 p. GAD 424: NK 2 Negative BD vector Positive p. AS 2 -1: MK 3 p. AS 2 -1: MK 6 p. AS 2 -1: MK 3 p. AS 2 -1: MK 1 p. AS 2 -1: MK 6 Negative

Specific Interaction between NDPK 2 and At. MPK 3

NDPK 2 Enhances MBP Phosphorylation Activity of At. MPK 3 NDPK 2 At. MPK 3 + - + + + NDPK 2 52 k. D MBP 18 k. D

Plant Defense Response against ROS Environmental stress ROS production Alterations of the redox state Signal Amplication Cell Death Activation of transcription factors Apoptosis gene activation Defense gene activation ROS protectant gene activation

NDPK 2 Enhances Chilling Stress Tolerance in Transgenic Plants wild-type transgenic

NDPK 2 Enhances Multiple Stress Tolerance in Transgenic Plants wild-type transgenic knock-out MV 0 m. M 50 m. M Salt wild-type transgenic Chilling wild-type transgenic

Conclusions 1. Bax, a mammalian pro-apoptotic member of the Bcl-2 family, can induces cell death when expressed in yeast or plant cells. Bax-induced cell death is an evolutionarily conserved mechanism. 2. We developed yeast genetic system to clone plant Bax inhibitors. 3. Through functional study, we found that a number of genes can suppresses Baxtoxicity by inhibiting ROS generation. 4. Novel function of NDPK, nucleoside diphosphate kinase (1) NDPK 2 regulates cellular redox conditions (2) NDPK 2 specifically interacts with At. MPK 3 and At. MPK 6 (3) NDPK 2 enhances the MBP phosphorylation ability of At. MPK 3 (4) Overexpression of NDPK 2 in plants enhanced tolerance to multiple environmental stresses that elicit ROS accumulation in situ. At. NDPK 2 is a novel component of a pathway specific to H 2 O 2 -activated MAPK signaling in plants.

Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, Korea