Page 120 - ebook

[A. Biochemistry/Molecular Biology] A-60

OsRab11 is Required for Resistance to Salt Stress in Rice

Jae Bok Heo¹*

¹Molecular Genetic Bioengineering, Dong-A University, Busan 49315, Korea

Rab proteins are key regulators of intracellular trafficking between specific compartments in a cell. Among them,
Rab11, a widely conserved sub-group, mainly regulates plasma membrane (PM) trafficking. Previously, we reported

that Oryza sativa Rab11 (OsRab11) plays an important role in the intracellular trafficking from the trans-Golgi-
network (TGN) to the plasma membrane (PM) and prevacuolar compartments (PVCs), and in the plant’s response

to high salt stress. In this study, when the constitutively active mutant of OsRab11, (CA OsRab11(Q73L)) was co-
transformed with Arabidopsis Ca2+-ATPase8-GFP (ACA8-GFP) or sporamin-GFP (Spo-GFP) into Arabidopsis

protoplasts, the PM or vacuolar trafficking proportion of the reporter proteins was highly increased. Transgenic
Arabidopsis plants overexpressing (OE) CA OsRab11(Q73L) exhibited enhanced tolerance to high salt stress and

exogenous abscisic acid (ABA) compared to Col plants. Moreover, certain stress-responsive genes were expressed
under high salt stress and ABA treatment in OEOsRab11(Q73L) plants. Thus, these results suggest that the active

conformation of OsRab11 may be required to modulate plant responses to salt and ABA via the regulation of the
expression of stress-responsive genes.