PpARF6 acts as an integrator of auxin and ethylene signaling to promote fruit ripening in peach

Xiaomei Chen; Yudi Liu; Xian Zhang; Beibei Zheng; Yuepeng Han; Ruo-Xi Zhang

doi:10.1093/hr/uhad158

PpARF6 acts as an integrator of auxin and ethylene signaling to promote fruit ripening in peach

Hortic Res. 2023 Jul 31;10(9):uhad158. doi: 10.1093/hr/uhad158. eCollection 2023 Sep.

Authors

Xiaomei Chen^{1

2}, Yudi Liu^{1

2}, Xian Zhang^{1

2}, Beibei Zheng^{1

3}, Yuepeng Han^{1

3}, Ruo-Xi Zhang^{1

3}

Affiliations

¹ CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan 430074, China.
² University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China.
³ Hubei Hongshan Laboratory, Wuhan 430070, China.

Abstract

Although auxin is known to induce ethylene biosynthesis in some Rosaceae fruit crops, the mechanisms underlying the auxin-ethylene interaction during fruit ripening remain largely unknown. Here, the regulatory role of an auxin response factor, PpARF6, in fruit ripening was investigated in peach. Peach fruits showed accelerated ripening after treatment with auxin and PpARF6 was found to be significantly induced. PpARF6 not only could induce ethylene synthesis by directly activating the transcription of ethylene biosynthetic genes, but also competed with EIN3-binding F-box proteins PpEBF1/2 for binding to ethylene-insensitive3-like proteins PpEIL2/3, thereby keeping PpEIL2/3 active. Moreover, PpARF6 showed an interaction with PpEIL2/3 to enhance the PpEIL2/3-activated transcription of ethylene biosynthetic genes. Additionally, ectopic overexpression of PpARF6 in tomato accelerated fruit ripening by promoting the expression of genes involved in ethylene synthesis and fruit texture. In summary, our results revealed a positive regulatory role of PpARF6 in peach fruit ripening via integrating auxin and ethylene signaling.