bims-polyam 2022-11-06 papers

Issue of 2022–11–06
four papers selected by
Sebastian J. Hofer, University of Graz

BMC Genomics. 2022 Oct 30. 23(1): 734

Genome-wide analysis of polyamine biosynthesis genes in wheat reveals gene expression specificity and involvement of STRE and MYB-elements in regulating polyamines under drought.

Heba Talat Ebeed.

BACKGROUND: Polyamines (PAs) are considered promising biostimulants that have diverse key roles during growth and stress responses in plants. Nevertheless, the molecular basis of these roles by PAs has not been completely realized even now, and unfortunately, the transcriptional analyses of the biosynthesis pathway in various wheat tissues have not been investigated under normal or stress conditions. In this research, the findings of genome-wide analyses of genes implicated in the PAs biosynthesis in wheat (ADC, Arginine decarboxylase; ODC, ornithine decarboxylase; AIH, agmatine iminohydrolase; NPL1, Nitrlase like protein 1; SAMDC, S-adenosylmethionine decarboxylase; SPDS, spermidine synthase; SPMS, spermine synthase and ACL5, thermospermine synthase) are shown.
RESULTS: In total, thirty PAs biosynthesis genes were identified. Analysis of gene structure, subcellular compartmentation and promoters were discussed. Furthermore, experimental gene expression analyses in roots, shoot axis, leaves, and spike tissues were investigated in adult wheat plants under control and drought conditions. Results revealed structural similarity within each gene family and revealed the identity of two new motifs that were conserved in SPDS, SPMS and ACL5. Analysis of the promoter elements revealed the incidence of conserved elements (STRE, CAAT-box, TATA-box, and MYB TF) in all promoters and highly conserved CREs in >80% of promoters (G-Box, ABRE, TGACG-motif, CGTCA-motif, as1, and MYC). The results of the quantification of PAs revealed higher levels of putrescine (Put) in the leaves and higher spermidine (Spd) in the other tissues. However, no spermine (Spm) was detected in the roots. Drought stress elevated Put level in the roots and the Spm in the leaves, shoots and roots, while decreased Put in spikes and elevated the total PAs levels in all tissues. Interestingly, PA biosynthesis genes showed tissue-specificity and some homoeologs of the same gene family showed differential gene expression during wheat development. Additionally, gene expression analysis showed that ODC is the Put biosynthesis path under drought stress in roots.
CONCLUSION: The information gained by this research offers important insights into the transcriptional regulation of PA biosynthesis in wheat that would result in more successful and consistent plant production.

Keywords: Cis-elements; Drought; Gene expression; Genome-wide analysis; Polyamines; Subcellular localization

DOI: https://doi.org/10.1186/s12864-022-08946-2

Cancer Discov. 2022 Nov 04. OF1

Spermidine Supplementation Enhances Immune Checkpoint Blockade Response.

Spermidine enhances T-cell mitochondrial metabolism and the antitumor response to anti-PD-L1.

DOI: https://doi.org/10.1158/2159-8290.CD-RW2022-196

Alzheimers Dement. 2022 Nov 02.

Association of spermidine plasma levels with brain aging in a population-based study.

Silke M Wortha, Stefan Frenzel, Martin Bahls, Mohamad Habes, Katharina Wittfeld, Sandra Van der Auwera, Robin Bülow, Stephanie Zylla, Nele Friedrich, Matthias Nauck, Henry Völzke, Hans J Grabe, Claudia Schwarz, Agnes Flöel.

INTRODUCTION: Supplementation with spermidine may support healthy aging, but elevated spermidine tissue levels were shown to be an indicator of Alzheimer's disease (AD).
METHODS: Data from 659 participants (age range: 21-81 years) of the population-based Study of Health in Pomerania TREND were included. We investigated the association between spermidine plasma levels and markers of brain aging (hippocampal volume, AD score, global cortical thickness [CT], and white matter hyperintensities [WMH]).
RESULTS: Higher spermidine levels were significantly associated with lower hippocampal volume (ß = -0.076; 95% confidence interval [CI]: -0.13 to -0.02; q = 0.026), higher AD score (ß = 0.118; 95% CI: 0.05 to 0.19; q = 0.006), lower global CT (ß = -0.104; 95% CI: -0.17 to -0.04; q = 0.014), but not WMH volume. Sensitivity analysis revealed no substantial changes after excluding participants with cancer, depression, or hemolysis.
DISCUSSION: Elevated spermidine plasma levels are associated with advanced brain aging and might serve as potential early biomarker for AD and vascular brain pathology.

Keywords: Alzheimer's disease; cortical thickness; epidemiology; hippocampal volume; spermidine; white matter hyperintensities

DOI: https://doi.org/10.1002/alz.12815

Front Plant Sci. 2022 ;13 1003155

Versatile roles of polyamines in improving abiotic stress tolerance of plants.

Jinhua Shao, Kai Huang, Maria Batool, Fahad Idrees, Rabail Afzal, Muhammad Haroon, Hamza Armghan Noushahi, Weixiong Wu, Qiliang Hu, Xingda Lu, Guoqin Huang, Muhammad Aamer, Muhammad Umair Hassan, Ayman El Sabagh.

In recent years, extreme environmental cues such as abiotic stresses, including frequent droughts with irregular precipitation, salinity, metal contamination, and temperature fluctuations, have been escalating the damage to plants' optimal productivity worldwide. Therefore, yield maintenance under extreme events needs improvement in multiple mechanisms that can minimize the influence of abiotic stresses. Polyamines (PAs) are pivotally necessary for a defensive purpose under adverse abiotic conditions, but their molecular interplay in this remains speculative. The PAs' accretion is one of the most notable metabolic responses of plants under stress challenges. Recent studies reported the beneficial roles of PAs in plant development, including metabolic and physiological processes, unveiling their potential for inducing tolerance against adverse conditions. This review presents an overview of research about the most illustrious and remarkable achievements in strengthening plant tolerance to drought, salt, and temperature stresses by the exogenous application of PAs. The knowledge of underlying processes associated with stress tolerance and PA signaling pathways was also summarized, focusing on up-to-date evidence regarding the metabolic and physiological role of PAs with exogenous applications that protect plants under unfavorable climatic conditions. Conclusively, the literature proposes that PAs impart an imperative role in abiotic stress tolerance in plants. This implies potentially important feedback on PAs and plants' stress tolerance under unfavorable cues.

Keywords: abiotic stress; antioxidant system; hormonal regulation; polyamines; stress tolerance

DOI: https://doi.org/10.3389/fpls.2022.1003155