Suaeda salsa (S. salsa) is a euhalophytic plant that is highly tolerant to the environmental stresses such as high salinity and alkalinity. Identification and functional characterization of tolerance-related genes from S. salsa can provide insight on the molecular mechanisms of plant stress-tolerance and candidate genes for genetic engineering of salt tolerance.

Recently, researchers led by Prof. XIA Guixian in Institute of Microbiology, Chinese Academy of Sciences cloned a newgene(SsOEP8) from S. salsa, which encodes a small chloroplast outer envelope protein. The researches analyzed the expression pattern of SsOEP8 and characterized its cellular functionusing Arabidopsis and tobacco BY-2 cell as model systems. They showed that: expression of SsOEP8 inS. salsa were up-regulated in response to various abiotic stresses such as H2O2 and NaCl; transgenic plants overexpressing SsOEP8 acquired significantly enhanced oxidative stress tolerance; in SsOEP8 transgenic Arabidopsis, chloroplasts aggregated along the sides of mesophyll cells and this event was accompanied with inhibited expression of genes encoding proteins for chloroplast movements; organization of actin cytoskeleton was altered in SsOEP8 transgenic BY-2 cells.

Together, these researches demonstrate that SsOEP8 may play a critical role in oxidative stress tolerance by changing actin cytoskeleton-dependent chloroplast distribution, which may consequently lead to the suppressed production of reactive oxygen species (ROS) in chloroplasts. They find the small chloroplast envelope protein contributes to oxidative stress tolerance. The results were published in Plant, Cell & Environment in March 2012.

RESEARCHER CONTACT:
XIA Guixian, Ph.D., Professor
Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Tel: +86-10- 64845674; E-mail: xiagx@im.ac.cn