The Roles of J-protein AtJ8 in Adapting to Osmotic Stress in Arabidopsis thaliana

Abstract: AtJ8 is a member of the Arabidopsis thaliana J-protein family. It is reported that AtJ8 is targeted to the chloroplast and involved in optimization of photosynthetic reactions in A. thaliana. Herein， the roles of AtJ8 in adapting to saline and water stresses were studied in A. thaliana. The result of Real-time PCR analysis showed that AtJ8 expression was induced through salinity， dehydration and abscisic acid (ABA) in young seedlings. The result of reverse genetic analysis showed that seed germination rate and cotyledon greening rate of AtJ8 mutant plants (atj8-1) were not clearly different from those of wild-type (WT) and the rescued mutant plants (R4-1) under standard culture conditions. However， under saline or water stress condition， atj8-1 seeds broke dormancy after the WT and R4-1 seeds， and cotyledon greening rate for atj8-1 seedlings was clearly lower than that for the WT and R4-1 seedlings， which suggested that AtJ8 played important roles in regulating the responses of seeds and seedlings to osmotic stress. Moreover， Real-time PCR analysis indicated that AtJ8 gene knockout altered the expression levels of several ABA-responsive genes， ABI1， ABI2， RAB18， RD29A and RD29B， which suggested that AtJ8 modulated the adaptability of plants to osmotic stress likely through its effects on ABA signaling pathways.

CSTR: 32200.14.cjcb.2015.03.0007