The role and proteomic analysis of ethylene in hydrogen gas-induced adventitious rooting development in cucumber (Cucumis sativus L.) explants

Dengjing Huang; Biting Bian; Meiling Zhang; Chunlei Wang; Changxia Li; Weibiao Liao

doi:10.7717/peerj.8896

The role and proteomic analysis of ethylene in hydrogen gas-induced adventitious rooting development in cucumber (Cucumis sativus L.) explants

PeerJ. 2020 Apr 7:8:e8896. doi: 10.7717/peerj.8896. eCollection 2020.

Authors

Dengjing Huang¹, Biting Bian¹, Meiling Zhang², Chunlei Wang¹, Changxia Li¹, Weibiao Liao¹

Affiliations

¹ College of Horticulture, Gansu Agricultural University, Lanzhou, PR China, Lanzhou, China.
² College of Science, Gansu Agricultural University, Lanzhou, China.

Abstract

Previous studies have shown that both hydrogen gas (H₂) and ethylene (ETH) play positive roles in plant adventitious rooting. However, the relationship between H₂and ETH during this process has not been explored and remains insufficiently understood. In this study, cucumber (Cucumis sativus L.) was used to explore the proteomic changes in ETH-H₂-induced rooting. Our results show that hydrogen-rich water (HRW) and ethylene-releasing compound (ethephon) at proper concentrations promote adventitious rooting, with maximal biological responses occurring at 50% HRW or 0.5 µM ethephon. ETH inhibitors aminoethoxyvinylglycine (AVG) and AgNO₃ cause partial inhibition of adventitious rooting induced by H₂, suggesting that ETH might be involved in H₂-induced adventitious rooting. According to two-dimensional electrophoresis (2-DE) and mass spectrometric analyses, compared with the control, 9 proteins were up-regulated while 15 proteins were down-regulated in HRW treatment; four proteins were up-regulated while 10 proteins were down-regulated in ethephon treatment; and one protein was up-regulated while nine proteins were down-regulated in HRW+AVG treatment. Six of these differentially accumulated proteins were further analyzed, including photosynthesis -related proteins (ribulose-1,5-bisphosphate carall boxylase smsubunit (Rubisco), sedoheptulose-1,7-bisphosphatase (SBPase), oxygen-evolving enhancer protein (OEE1)), amino and metabolism-related protein (threonine dehydratase (TDH)), stress response-related protein (cytosolic ascorbate peroxidase (CAPX)), and folding, modification and degradation-related protein (protein disulfide-isomerase (PDI)). Moreover, the results of real-time PCR about the mRNA levels of these genes in various treatments were consistent with the 2-DE results. Therefore, ETH may be the downstream signaling molecule during H₂- induced adventitious rooting and proteins Rubisco, SBPase, OEE1, TDH, CAPX and PDI may play important roles during the process.

Keywords: Adventitious root formation; Cucumber; Ethylene; Hydrogen gas; Proteomics.

Grants and funding

This work was supported by the National Key Research and Development Program (2018YFD1000800), the National Natural Science Foundation of China (Nos. 31860568, 31560563 and 31160398), the Research Fund of Higher Education of Gansu, China (2018C-14), the Natural Science Foundation of Gansu Province, China (Nos. 1606RJZA073 and 1308RJZA179), Scientific Research Foundation for the Yong Graduate Supervisor of Gansu Agricultural University in Lanzhou P. R. China (GAU-QNDS-201709) and Feitian and Fuxi Excellent Talents in Gansu Agricultural University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.