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

Abstract

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.

Genome-Wide Identification and Expression Analysis of the NAC Gene Family in Kandelia obovata, a Typical Mangrove Plant

“…Deletion of the LTR element will result in complete loss of promoter activity under cold stress [ 79 ]. STRE is a common cis-regulatory element in eukaryotes, and involved in response to multiple environmental stimuli [ 80 ]. ARE is an antioxidant response element in rapid response to anaerobic stress [ 81 ].…”

Biosynthetic Pathways of Hormones in Plants

“…However, other authors speculate that the ODC pathway is mainly involved in regulation of plant growth, development, differentiation of organs, and reproduction, while the ADC pathway is activated in plants that grow under unfavorable environmental conditions. These two pathways are commonly found in plants [ 10 , 16 , 17 , 18 , 19 , 20 ].…”

“…The last step of the biosynthesis of PAs, i.e., the transfer of aminopropyl groups to propylamine acceptor Spd, leads to the formation of Spm. In this reaction, this Spm is formed via the action of spermine synthase (SPMS) [ 18 , 24 , 25 , 26 ]. The biosynthesis of PAs in plants is closely connected to the biosynthetic pathways of other plant hormones.…”

Silicon-mediated Improvement of Drought Tolerance in Two Wheat Genotypes

“…Plants' molecular, morphological, physiological, and biochemical characteristics alter as a result of drought stress (Ebeed 2019;Ebeed, 2020). Drought symptoms in plants differ depending on the species, developmental stage, growth conditions, and other external factors (Salehi-Lisar & Bakhshayeshan-Agdam, 2016;Ebeed, 2022). Loss of leaf turgor, yellowing, wilting, and premature leaf fall are some of the common indicators of drought (Corso et al, 2020).…”

“…To cope with drought stress, plants have created their own defence mechanisms. However, these mechanisms depend on the plant type (Ebeed et al, 2019;Hassan et al, 2020;Ebeed, 2022). The general mechanism used by plants to withstand drought is to maintain cell homeostasis in water-deficient environments by improving the water entry to plant cells (Hassan et al, 2020).…”