Mitigating heat induced damages in rice ( oryza sativa l . ) by hsp 70 modulation

Stress induced cell damages leading necrosis is considered as major challenges in sustainable agriculture production in times of climate change and can be prevented by various factors particularly remediate effect of HSP70. Rice (Oryza sativa L.) thermo-tolerance at molecular level are still enigmatic hence expression pattern of heat shock protein (HSP70) was determined in eight rice cultivars subjected to heat stress (42±2oC) followed by recovery (28±2oC) treatments at early growth stage. Growth characteristics along with free radicals (H2O2) accumulation and level of lipid peroxidation (MDA) were determined as stress damage indicators while expression pattern of HSP70 protein was used as stress tolerance scoring. Results revealed that expression level of HSP70 was increased with duration of thermal stress and declined upon recovery. Among all the cultivars relatively “Sada” Hayat had maximum malondialdehyde (MDA) and H2O2 accumulation and late induction and fast decay of HSP70 showed susceptibility towards heat stress while such a damage was the least observed in K-95, having consistent and strong expression of HSP70 during heat stress and recovery treatments. This study concludes that prompt induction in expression of HSP70 during heat stress condition and slow decay during recovery for long-term memory is desirable trait for acquisition of thermo-tolerance in rice.