AtPep3 is a hormone-like peptide that plays a role in the salinity stress tolerance of plants

作者：Nakaminami Kentaro; Okamoto Masanori; Higuchi Takeuchi Mieko; Yoshizumi Takeshi; Yamaguchi Yube; Fukao Yoichiro; Shimizu Minami; Ohashi Chihiro; Tanaka Maho; Matsui Minami; Shinozaki Kazuo; Seki Motoaki^*; Hanada Kousuke^*

来源：Proceedings of the National Academy of Sciences of the United States of America, 2018, 115(22): 5810-5815.

DOI：10.1073/pnas.1719491115

• peptide hormone
• small coding gene
• abiotic stress
• salt tolerance
• Arabidopsis

Peptides encoded by small coding genes play an important role in plant development, acting in a similar manner as phytohormones. Few hormone-like peptides, however, have been shown to play a role in abiotic stress tolerance. In the current study, 17 Arabidopsis genes coding for small peptides were found to be up-regulated in response to salinity stress. To identify peptides leading salinity stress tolerance, we generated transgenic Arabidopsis plants over-expressing these small coding genes and assessed survivability and root growth under salinity stress conditions. Results indicated that 4 of the 17 overexpressed genes increased salinity stress tolerance. Further studies focused on AtPROPEP3, which was the most highly up-regulated gene under salinity stress. Treatment of plants with synthetic peptides encoded by AtPROPEP3 revealed that a C-terminal peptide fragment (AtPep3) inhibited the salt-induced bleaching of chlorophyll in seedlings. Conversely, knockdown AtPROPEP3 transgenic plants exhibited a hypersensitive phenotype under salinity stress, which was complemented by the AtPep3 peptide. This functional AtPep3 peptide region overlaps with an AtPep3 elicitor peptide that is related to the immune response of plants. Functional analyses with a receptor mutant of AtPep3 revealed that AtPep3 was recognized by the PEPR1 receptor and that it functions to increase salinity stress tolerance in plants. Collectively, these data indicate that AtPep3 plays a significant role in both salinity stress tolerance and immune response in Arabidopsis.

• 出版日期2018-5-29