A mitochondria-targeted coenzyme Q peptoid induces superoxide dismutase and alleviates salinity stress in plant cells

Abstract

Salinity is a serious challenge to global agriculture and threatens human food security. plant cells can respond to salt stress either by activation of adaptive responses, or by programmed cell death. the mechanisms deciding the respective response are far from understood, but seem to depend on the degree, to which mitochondria can maintain oxidative homeostasis. Using plant peptoQ, a Trojan Peptoid, as vehicle, it is possible to transport a coenzyme Q10 (CoQ10) derivative into plant mitochondria. We show that salinity stress in tobacco BY-2 cells (Nicotiana tabacum L. cv Bright Yellow-2) can be mitigated by pretreatment with plant PeptoQ with respect to numerous aspects including proliferation, expansion, redox homeostasis, and programmed cell death. We tested the salinity response for transcripts from nine salt-stress related-genes representing different adaptive responses. While most did not show any significant response, the salt response of the transcription factor NtNAC, probably involved in mitochondrial retrograde signaling, was significantly modulated by the plant peptoQ. Most strikingly, transcripts for the mitochondrial, Mn-dependent Superoxide Dismutase were rapidly and drastically upregulated in presence of the peptoid, and this response was disappearing in presence of salt. the same pattern, albeit at lower amplitude, was seen for the sodium exporter SOS1. The findings are discussed by a model, where plant PeptoQ modulates retrograde signalling to the nucleus leading to a strong expression of mitochondrial SoD, what renders mitochondria more resilient to perturbations of oxidative balance, such that cells escape salt induced cell death and remain viable. By the year 2050, world agriculture should be able to boost production of food crops by 70% to feed the projected 9.1 billion people 1. Salt stress is one of the major challenges to this effort and has already affected 20% of cultivated land worldwide. Global warming and suboptimal irrigation accentuate the problem 2,3. The molecular, cellular, and physiological mechanisms underlying the severe effect of salinity on plant growth, development and yield have been reviewed comprehensively 3-5. Based on their response to salt stress, plants are categorised into the tolerant halophytes and the sensitive glycophytes. Unfortunately, most of the crop species belong to the

Switching cell fate by the actin–auxin oscillator in Taxus: cellular aspects of plant cell fermentation

“…The shift in mitochondrial redox homeostasis is conveyed to the nucleus through retrograde signalling, leading to defence-related cellular responses that depend on the context. A mild stress can be faced, for instance, by activation of mitochondrial superoxide dismutase that will buffer redox homeostasis as concluded from experiments using a mitochondria-targeted peptoid mimick of the ROS scavenger Coenzyme Q (Asfaw et al 2020 ). However, in case of a severe stress, as it may be caused by pathogen attack or wounding, the superoxide will not be mitigated, leading to leakage of the inner mitochondrial membrane, the formation of a permeability pore, release of calcium and cytochrome c and, eventually, the activation of programmed cell death (for review see Zancani et al 2015 ).…”

Cell size: a key determinant of meristematic potential in plant protoplasts

“…Several methods have been demonstrated to attain cell synchrony in plant cultures. Some of the simple yet effective techniques include rendering osmotic shock to cells in culture, substituting fresh growth medium intermittently and supplying antimetabolites (Constabel et al 1974;Asfaw et al 2020). The procedure served cells to gain partial synchrony in cultures which lasted for about * 1-3 cell cycles.…”

Quantifying Polypeptoid Conformational Landscapes through Integrated Experiment and Simulation

“…They can now be routinely synthesized at gram scale, sequence-specifically up to 50 monomers in length in a process that eliminates the need for protection/deprotection procedures common in polypeptide synthesis, allowing access to a wide variety of chemistries . As such, they have been extensively explored for a broad range of applications, including as antifoulants, antimicrobials, − other therapeutics, delivery agents, , sensing applications such as stimuli-responsive materials, binder materials for batteries, crystallization modulators, and programmable self-assembly. − Many of these applications leverage the sequence-specificity of polypeptoids that has been shown to significantly modulate secondary − and self-assembled structures , and therefore function. Thus, advancement of polypeptoid-containing materials and the fundamental design rules that they follow requires elucidation of sequence–structure–function relationships.…”