Phenotypic and microarray analysis reveals salinity stress-induced oxidative tolerance in transgenic rice expressing a DEAD-box RNA helicase, OsDB10

Helicases are the motor proteins not only involved in the process of mRNA metabolism but also played a significant role in providing abiotic stresses tolerance. In this study, a DEAD-box RNA helicase OsDB10 was cloned and functionally characterized. The transcript levels of OsDB10 were increased both in shoot and root upon salt, heat, cold, and ABA application and was more prominent in shoot compared to root. Genomic integration of OsDB10 in transgenic rice was confirmed by PCR, Southern blot and qRT-PCR analysis. The transgenic plants showed quicker seed germination, reduced necrosis, higher chlorophyll, more survival rate, better seedling growth, and produced more grain yield under salinity stress. Furthermore, transgenic lines also accumulated less Na+ and high K+ ions and salinity tolerance of the transgenic were also assayed by measuring different bio-physiological indices. Moreover, the OsDB10 transgenic plants showed enhanced tolerance to salinity-induced oxidative stress by scavenging ROS and increased activity of antioxidants enzymes. Microarray analysis showed upregulation of transcriptional regulations and metabolic reprogramming as OsDB10 overexpression modulates the expression of many other genes. Altogether, our results confirmed that OsDB10 is a functional DEAD-box RNA helicase and played vital roles in plant defence response against salinity stress. Key messageOverexpression of OsDB10 provides salinity tolerance in rice plant through maintaining photosynthesis, ionic, reactive oxygen species (ROS) homeostasis as well as by controlling transcriptional regulation.

Automated summary

In this study, a DEAD-box RNA helicase OsDB10 was cloned and functionally characterized. The results showed that OsDB10 expression was upregulated in response to salt, heat, cold, and ABA treatment, and transgenic rice plants overexpressing OsDB10 exhibited improved tolerance to salinity stress. This enhanced tolerance was attributed to improved photosynthesis, ion homeostasis, reactive oxygen species (ROS) scavenging, and transcriptional regulation.