Time-evolving genetic networks reveal a NAC troika that negatively regulates leaf senescence in Arabidopsis
 Authors and Affiliations
 Authors and Affiliations
Hyo Jung Kima,1, Ji-Hwan Parka,1, Jingil Kima, Jung Ju Kima, Sunghyun Honga, Jeongsik Kima, Jin Hee Kima, Hye Ryun Woob, Changbong Hyeonc, Pyung Ok Limb,2, Hong Gil Nama,b,2, and Daehee Hwanga,b,2
aCenter for Plant Aging Research, Institute for Basic Science (IBS), Daegu 42988, Republic of Korea; bDepartment of New Biology, Daegi Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea; and cKorea Institute for Advanced Study, Seoul 02455, Republic of Korea
1H.J.K. and J.-H.P. contributed equally to this work. 2To whom correspondence may be addressed.
Abstract Senescence is controlled by time-evolving networks that describe the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks for NAM/ATAF/CUC (NAC) transcription factors in Arabidopsis during leaf aging. The most evident characteristic of these time-dependent networks was a shift from positive to negative regulation among NACs at a presenescent stage. ANAC017, ANAC082, and ANAC090, referred to as a “NAC troika,” govern the positive-to-negative regulatory shift. Knockout of the NAC troika accelerated senescence and the induction of other NACs, whereas overexpression of the NAC troika had the opposite effects. Transcriptome and molecular analyses revealed shared suppression of senescence-promoting processes by the NAC troika, including salicylic acid (SA) and reactive oxygen species (ROS) responses, but with predominant regulation of SA and ROS responses by ANAC090 and ANAC017, respectively. Our time-evolving networks provide a unique regulatory module of presenescent repressors that direct the timely induction of senescence-promoting processes at the presenescent stage of leaf aging.
leaf senescence, time-evolving network, NAC, presenescent repressors, salicylic acid response
|