To understand the role of small heat shock protein (sHSPs) in rice plant response to various stresses such as the heat and oxidative stresses, a cDNA encoding a 24.1 kDa mitochondrial small HSP (Oshsp24.1) was isolated from rice by rapid amplification of cDNA ends (RACE) PCR. The deduced amino acid sequence shows very high similarity with other plant small HSPs. DNA gel blot analysis suggests that the rice genome contains more than one copy of Oshsp24.1. High level of expression of Oshsp24.1 transcript was observed in rice seedlings in response to heat, methyl viologen, hydrogen peroxide, ozone, salt and heavy metal stresses. Recombinant OsHSP24.1 protein was produced in E. coli cells for biochemical assay. The protein formed oligomeric complex when incubated with Sulfo-EGS (ethylene glycol bis (succinimidyl succinate)). Our results shows that Oshsp24.1 has an important role in abiotic stress response and have potential for developing stress-tolerant plants.

The object of this study is to compare the shock isolation characteristics of the commercially available rubber washers due to the difference in a tightening torque and hardness. Drop impact test using a steel ball which can simulate the pyroshock acceleration was devised. The test results show that silicon had the highest shock isolation performances followed by urethane, nitrile showed the least performances. In addition, the test results show that the smaller a tightening torque and hardness, the shock isolation characteristics are improved. And this study propose an analysis method using the shock transmissibility function in order to minimize some uncertainty of the impact excitation in the shock response spectrum analysis.