OsABCI7 and OsHCF222 Interaction Stabilizes Rice Thylakoid Membrane

A research team from China National Rice Research Institute revealed that the OsABCI7 transporter interacts with OsHCF222 to stabilize the thylakoid membrane in rice. The results are reported in Plant Physiology.

The thylakoid membrane is a highly complex membrane system in plants and has vital functions in the development of plant parts used for photosynthesis. However, the genetic factors involved in chloroplast development and its linkage with intracellular metabolites remain unclear. Thus, Yan He and his team conducted a study to investigate this relationship.

Through a rice chlorotic and necrotic leaf 1 (cnl1) mutant and map-based cloning, it was revealed that a single base substitution followed by a 6-bp deletion in the ATP-binding cassette transporter I family member 7 (OsABCI7) resulted in chlorotic and necrotic leaves with thylakoid membrane degradation, chlorophyll breakdown, photosynthesis disruption and cell death in cnl1. It was also shown that the expression of OsABCI7 was inducible under lower temperatures, which heavily impacted cnl1 chloroplast development, and the cnl1 seedlings grown in the absence of light were unable to recover to a normal green state when transferred under light conditions. In addition, the application of ascorbic acid reduced leaf yellowing by boosting chlorophyll content and reducing reactive oxygen species stress in cnl1. Unlike cnl1, the CRISPR-Cas9-mediated OsHCF222 knockout lines showed chlorotic leaves but were seedling lethal.

Read more findings in Plant Physiology.