OsTRXh1 regulates the redox state of the apoplast and influences stress responses in rice.

The plant cell apoplast is the compartment beyond the cell plasmalemma, including the cell wall and intercellular space. Many environmental elements can trigger reactive oxygen species (ROS) burst at the plasma membrane which then alters the redox state of the apoplast. Recently, h-type thioredoxin (Trx), OsTRXh1, was identified to be involved in apoplastic redox state regulation in rice. OsTRXh1 is conserved redox-active Trx and can be secreted into the extracellular regions. Through transgenic rice plant, we found that OsTRXh1 regulated ROS accumulation in apoplast and influenced plant development and stress responses. This provides new insights into apoplastic redox state regulation pathway and expands our understanding of h-type Trxs function.