• VB₂ pretreatment to rice seedlings improves salinity tolerance in rice
• VB₂ has a scavenging ability of reactive oxygen species generated by salinity stress
• VB₂ priming induces expression of the genes related to VB₂ biosynthesis and Na transport

Salinized soils are generated by excessive salts accumulation in arid and coastal areas around the world. Because crop productivity is seriously decreased in salinized soils, creation of salinity tolerant crop cultivars by molecular breeding is expected to solve this problem. In this study, we aimed to assess whether VB₂ pretreatment to seedlings can improve salinity tolerance in rice and to investigate molecular mechanisms of VB₂-mediated salinity tolerance.

Seedlings of an indica rice cultivar IR29, which is salinity-sensitive, were treated with VB₂ for 24 hours, then grown under salinity stress (50 mM NaCl) conditions. As a result, we found that VB₂ treatment increases biomass production and ameliorates cell membrane damages caused by generation of reactive oxygen species in rice under salinity stress. In vitro experiment revealed that VB₂ has a scavenging ability of reactive oxygen species. Also, exogenous VB₂ application highly induced expression of the genes related to endogenous VB₂ biosynthesis, which may facilitate VB₂ accumulation in rice. Transcriptome analysis identified that expression of numerous genes related to Na transporters and novel functions is governed by VB₂.

We have already reported that seed priming with VB₂ can effectively improve salinity tolerance in rice (Jiadkong et al. (2022), J. Plant Growth Regulation). In the future, seed priming and seedling priming with VB₂ can be combined to develop new cultivation techniques, without relying on molecular breeding, to further improve salinity tolerance in rice during the initial growth stage.

This research was supported by JSPS KAKENHI grant number 20KK0129.
 

• Journal: Plant Science
• Title: Exogenous riboflavin (vitamin B2) application enhances salinity tolerance through the activation of its biosynthesis in rice seedlings under salinity stress
• Authors: Kamonthip Jiadkong, Anisa Nazera Fauzia, Nobuo Yamaguchi, Akihiro Ueda
• DOI: https://doi.org/10.1016/j.plantsci.2023.111929