CLE14 functions as a “brake signal” to suppress age-dependent and stress-induced leaf senescence by promoting JUB1-mediated ROS scavenging in Arabidopsis

Abstract

Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture. When facing harsh environmental conditions, monocarpic plants often initiate early leaf senescence as an adaptive mechanism to ensure a complete life cycle. Upon initiation, the senescence process is fine-tuned through the coordination of both positive and negative regulators. Here, we report that the small secreted peptide CLAVATA3/ESR-RELATED 14 (CLE14) functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis. Expression of the CLE14-encoding gene in leaves was significantly induced by age, high salinity, abscisic acid (ABA), salicylic acid, and jasmonic acid. CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence, whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence. CLE14 peptide treatments also delayed ABA-induced senescence in detached leaves. Further analysis showed that overexpression of CLE14 led to reduced ROS levels in leaves, where higher expression of ROS scavenging genes was detected. Moreover, CLE14 signaling resulted in transcriptional activation of JUB1, a NAC family transcription factor previously identified as a negative regulator of senescence. Notably, the delay of leaf senescence, reduction in H 2O2 level, and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1. Collectively, these results suggest that the small peptide CLE14 serves as a novel ''brake signal'' to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.

CLE42 delays leaf senescence by antagonizing ethylene pathway in Arabidopsis

“…As the largest group of such peptides, CLE plays a crucial role in regulating meristem activity in shoots and roots as well as in vascular tissues (Cock & McCormick, 2001; Fiers et al ., 2005; Ito et al ., 2006; Kondo et al ., 2006). Recently, CLE14 was found to delay age‐dependent and stress‐induced leaf senescence by enhancing JUB1‐mediated scavenge of reactive oxygen species in Arabidopsis (Zhang et al ., 2021). Here, we found that mutation of CLE42 led to premature senescence, whereas overexpression of CLE42 resulted in prolonged plant longevity (Fig.…”

CLE42 Delays Leaf Senescence by Antagonizing Ethylene Pathway in Arabidopsis

“…As the largest group of such peptides, CLE plays crucial roles in regulating meristem activity in shoots and roots as well as in vascular tissues (Cock & McCormick, 2001; Fiers et al , 2005; Ito et al , 2006; Kondo et al , 2006). Recently, CLE14 was found to delay age-dependent and stress-induced leaf senescence by enhancing JUB1-mediated scavenge of reactive oxygen species (ROS) in Arabidopsis (Zhang et al, 2021b). Here, we found that mutation of CLE42 led to premature senescence, whereas overexpression of CLE42 resulted in prolonged plant longevity (Fig.…”

“…S3). Interestingly, CLE14 also delays these factors-induced leaf senescence by governing H 2 O 2 homeostasis (Zhang et al, 2021b). These findings suggest that CLE14 and CLE42 regulate leaf senescence probably through similar pathways.…”

Dynamic Changes in Reactive Oxygen Species in the Shoot Apex Contribute to Stem Cell Death in Arabidopsis thaliana

“…The method of qRT–PCR was described previously [ 32 ]. Arabidopsis ACTIN2 ( AT3G18780 ) [ 34 ] was used as the internal reference. The relative expression levels of genes were showed the ratio of gene to ACTIN2 .…”