Protein mechanisms in response to NaCl-stress of salt-tolerant and salt-sensitive industrial hemp based on iTRAQ technology

• Firstly research on hemp under salt stress by iTRAQ-based proteomics technology.
• 3599 proteins were identified in this paper.
• Differentially expressed proteins in the leaves of hemp involve in 14 functions.
• Many important protein related to salt-stress adaption were discovered.

Industrial hemp is one of the important natural green fiber crops and, up to now, there has been a lack of research on its salt tolerance and the metabolic molecular mechanisms involved. Study on the adaptive mechanisms to salt stress in hemp through comparative proteome analysis is one important way to solve this problem. In this paper, iTRAQ-based proteomics technology was first used to study the differential proteomics of leaves of seedling under salt stress (600 mM sodium chloride) for 4 days in salt-resistant industrial hemp and salt-sensitive varieties. There were 403 and 252 differential proteins identified through LC-ESI–MS/MS mass spectrometry, respectively, and these were classified into 14 categories: primary metabolism, energy, protein destination and storage, disease/defense, protein synthesis, photosynthesis, transport, transcription, signal transduction, cell structure, secondary metabolism, intracellular traffic, cell growth/division and unknown. Hemp adapted to stress mainly by improved ATP metabolism, regulating photosynthesis according to light intensity, strengthening chlorophyll synthesis, promoting cell relaxation and enlargement, improving synthesis of osmoregulation substances, enhancing flow of inorganic sulfur in the body, regulating aquaporins, strengthening transmission of ion transport signals, improving signal transmission between proteins and between proteins and cytomembranes, improving selective absorption and transportation speed of organic and inorganic molecular, degrading hemicellulose cell walls, controlling transport of cellular material in and out, and promoting metabolism and cell stability. The results provide important reference information for research on molecular mechanisms of salt-stress adaption in hemp.