A cell-wall-modifying gene-dependent CLE26 peptide signaling confers drought resistance in .

Plants respond to various environmental stimuli in sophisticated ways. Takahashi et al. (2018) revealed that CLAVATA3/EMBRYO SURROUNDING REIGON-related 25 (CLE25) peptide is produced in roots under drought stress and transported to shoots, where it induces abscisic acid biosynthesis, resulting in drought resistance in . However, the drought-related function of the CLE26 peptide, which has the same amino acid sequence as CLE25 (except for one amino acid substitution), is still unknown. In this study, a phenotypic analysis of plants under repetitive drought stress treatment indicates that is associated with drought stress memory and promotes survival rate at the second dehydration event. Additionally, we find that a loss-of-function mutant of a cell-wall-modifying gene, (), exhibits improved resistance to drought, which is suppressed by the mutation of . is down-regulated in response to drought in wild-type plants. A further analysis shows that the synthetic CLE26 peptide is well transported in both and drought-pretreated wild-type plants but not in untreated wild-type plants. These results suggest a novel cell wall function in drought stress memory; short-term dehydration down-regulates in xylem cells, leading to probable cell wall modification, which alters CLE26 peptide transport, resulting in drought resistance under subsequent long-term dehydration.