OsABC1K3, encodes an ABC1-like kinase, involved PGR5-dependent cyclic electron transport in rice

Abstract

Light is an essential environmental factor for the growth and development of plants, but excessive light will damage the photosynthetic system and seriously affect crop yield. ABC1K is a class of atypical protein kinases commonly found in prokaryotes and eukaryotes. Chloroplast ABC1K can participate in the plant response to light signals, but its regulatory network in rice is not fully determined. In this study, a zebra leaf mutant osabc1k3 was isolated and characterized from the japonica rice Shennong9816 after EMS mutagenesis. At the tillering stage, chlorophyll was unevenly distributed, the contents of H2O2, O2- and MDA were increased in the leaves of abc1k3, and apoptosis was detected by TUNEL analysis. Fine mapping and DNA sequencing revealed a single base substitution on OsABC1K3, leading to premature termination of translation. Complementation tests further demonstrated that the mutation in osabc1k3 was responsible for the zebra leaf phenotype. OsABC1K3 belongs to the ABC1K gene family and encodes an activity of bc1 complex (ABC1) kinase 3 protein. OsABC1K3 can interact with FdC2 and PGR5 in vitro and in vivo. Compared with WT, osabc1k3 exhibited weakened photosynthesis. RLC analysis revealed that osabc1k3 showed decreased adaptability to strong light. OsABC1K3, a member of the ABC1K family, encodes an ABC1-like kinase 3 protein. OsABC1K3 can interact with FdC2 and PGR5, and is critical for adaptation to supersaturated light intensity in rice.