Proteomic analysis of heat stress resistance of cucumber leaves when grafted onto Momordica rootstock

Abstract

Various biotic and abiotic stresses threaten the cultivation of future agricultural crops. Among these stresses, heat stress is a major abiotic stress that substantially reduces agricultural productivity. Many strategies to enhance heat stress tolerance of crops have been developed, among which is grafting. Here, we show that Momordica-grafted cucumber scions have intrinsically enhanced chlorophyll content, leaf area, and net photosynthetic rate under heat stress compared to plants grafted onto cucumber rootstock. To investigate the mechanisms by which Momordica rootstock enhanced cucumber scions heat stress tolerance, comparative proteomic analysis of cucumber leaves in response to rootstock-grafting and/or heat stress was conducted. Seventy-seven differentially accumulated proteins involved in diverse biological processes were identified by two-dimensional electrophoresis (2-DE) in conjunction with matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS). The following four main categories of proteins were involved: photosynthesis (42.8%), energy and metabolism (18.2%), defense response (14.3%), and protein and nucleic acid biosynthesis (11.7%). Proteomic analysis revealed that scions grafted onto Momordica rootstocks upregulated more proteins involved in photosynthesis compared to scions grafted onto cucumber rootstocks under heat stress and indicated enhanced photosynthetic capacity when seedlings were exposed to heat stress. Furthermore, the expression of photosynthesis-related genes in plants grafted onto Momordica rootstocks significantly increased in response to heat stress. In addition, increased high-temperature tolerance of plants grafted onto Momordica rootstock was associated with the accumulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and oxygen-evolving enhancer protein 1 (OEE1). Taken together, the data indicated that Momordica rootstock might alleviate growth inhibition caused by heat stress by improving photosynthesis, providing valuable insight into enhancing heat stress tolerance in the global warming epoch.

A fast, simple, high efficient and one-step generation of composite cucumber plants with transgenic roots by Agrobacterium rhizogenes-mediated transformation

“…In 2016, gross production value is 40,229 million US$ (FAO). However, cucumber is high sensitive to low/high temperature, drought/waterlogging and salt stresses that cause significant reductions in yields (Liu et al 2013Ma et al 2018;Xu et al 2017Xu et al , 2018. In addition, a wide range of soilborne diseases (pathogenes), viruses and nematodes are one of the main constraints on cucumber production (Li and Chen 2017;Liang et al 2019;Liu et al 2017).…”

“…In addition, a wide range of soilborne diseases (pathogenes), viruses and nematodes are one of the main constraints on cucumber production (Li and Chen 2017;Liang et al 2019;Liu et al 2017). Although grafting of cucumber plants onto cucurbitaceous rootstocks is an efficiency way to improve abiotic/biotic stress, this technique is labor-intensive (Xu et al 2018). Genetic engineering is a powerful and high efficient way to improve cucumber abiotic/biotic stress tolerance.…”

iTRAQ-Based Quantitative Proteomic Analysis of Heat Stress-Induced Mechanisms in Pepper Seedlings

“…6B), suggesting that HT was subjected to minor damage from ROS. It has also been suggested that the up-regulation of antioxidant enzymes can regulate the ROS level and protect the plant cells from oxidative damage when they are under heat stress [13,20,38,39]. In the present study, some antioxidant enzymes were identi ed, including GST, POD, SOD, APX, and CAT (Fig.…”

Systemic Long-Distance Signaling and Communication Between Rootstock and Scion in Grafted Vegetables

“…In horticultural plants, different rootstocks can induce significant changes in physiological responses (Ren et al, 2018), photosynthesis (Xu et al, 2018), hormonal responses (Ren et al, 2018), environmental adaptation (Yu et al, 2017;Xu et al, 2018), and the sugars and aromatic flavors of the plants (Zhao et al, 2018). Extensive mRNA signaling networks have been reported in the model plants A. thaliana (Thieme et al, 2015) and N. benthamiana (Zhang W. et al, 2014) by bioinformatics and "omics" analyses.…”

“…Proteomics can be used to analyze the major categories of proteins in different treatments to investigate the mechanisms of graft-enhanced stress tolerance in scions. For example, comparative proteomic analysis was used to show that cucumber scions grafted to Momordica rootstocks could respond to heat stress by differentially accumulating photosynthesis-related proteins (Xu et al, 2018). Therefore, "omics" analyses are important techniques that can be used to unravel the differential accumulation and transport of macromolecular signals in grafted vegetables.…”