小背景：Recent studies highlighted a key role for reactive oxygen species (ROS) signaling in mediating systemic responses and SAA during light stress in Arabidopsis thaliana. These studies further identified the RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD) protein as a key player in mediating rapid systemic ROS responses.

提出问题：However, the identity of the plant tissues and cells that transmit systemic ROS signals in plants, as well as the identity of other ROS-producing proteins involved in this process are currently unknown.

结果1-RBOHD：Here, we report that tissue-specific expression of RBOHD in phloem or xylem parenchyma cells of the rbohD mutant restores systemic ROS signaling, systemic stress-response transcript expression and SAA to a local treatment of light stress.

结果2-RBOHD/F：We further demonstrate that RBOHD and RBOHF are both required for local and systemic ROS signaling at the vascular bundlesof Arabidopsis.

结论1：Taken together our findings highlight a key role for RBOHD-driven ROS production at the vascular bundles of Arabidopsis in mediating light stress-induced systemic signaling and SAA.

结论2：In addition, they suggest that the integration of ROS, calcium, electric and hydraulic signals, during systemic signaling, occurs at the vascular bundles.