A Wheat SIMILAR TO RCD-ONE Gene Enhances Seedling Growth and Abiotic Stress Resistance by Modulating Redox Homeostasis and Maintaining Genomic Integrity  

Abstract

Plant growth inhibition is a common response to salinity. Under saline conditions, Shanrong No. 3 (SR3), a bread wheat (Triticum aestivum) introgression line, performs better than its parent wheat variety Jinan 177 (JN177) with respect to both seedling growth and abiotic stress tolerance. Furthermore, the endogenous reactive oxygen species (ROS) was also elevated in SR3 relative to JN177. The SR3 allele of sro1, a gene encoding a poly(ADP ribose) polymerase (PARP) domain protein, was identified to be crucial for both aspects of its superior performance. Unlike RADICAL-INDUCED CELL DEATH1 and other Arabidopsis thaliana SIMILAR TO RCD-ONE (SRO) proteins, sro1 has PARP activity. Both the overexpression of Ta-sro1 in wheat and its heterologous expression in Arabidopsis promote the accumulation of ROS, mainly by enhancing the activity of NADPH oxidase and the expression of NAD(P)H dehydrogenase, in conjunction with the suppression of alternative oxidase expression. Moreover, it promotes the activity of ascorbate-GSH cycle enzymes and GSH peroxidase cycle enzymes, which regulate ROS content and cellular redox homeostasis. sro1 is also found to be involved in the maintenance of genomic integrity. We show here that the wheat SRO has PARP activity; such activity could be manipulated to improve the growth of seedlings exposed to salinity stress by modulating redox homeostasis and maintaining genomic stability.

Transcriptome profiling reveals the genetic basis of alkalinity tolerance in wheat

“…3 (SR3) were reported as salinity tolerant lines due to their more tolerant of salinity than JN177 [4, 5], which were selected from the derivatives of an asymmetric somatic hybridization between the salinity sensitive line, bread wheat cultivar Jinan 177 (JN177) and the highly tolerant related species, tall wheatgrass ( Thinopyrum ponticum ) [4, 5]. Transcriptomic and proteomic experiments showed that imposing salinity stress induced the differential up- or down-regulation of many genes present in SR3, and some of these, when expressed as transgenes, produced a marked positive impact on the plant’s level of salinity tolerance [6–11]. Although field trials showed that SR3 out-performs SR4 in pH neutral saline soils, the reverse was the case in alkaline pH saline soils (unpublished data).…”

THI1, a Thiamine Thiazole Synthase, Interacts with Ca2+-Dependent Protein Kinase CPK33 and Modulates the S-Type Anion Channels and Stomatal Closure in Arabidopsis

“…The THI1 open reading frame (ORF) was amplified and cloned into either pBI221-GFP (Liu et al, 2014) or pAVA321-RFP. CPK33…”

Protein ADP-Ribosylation Takes Control in Plant–Bacterium Interactions

“…Interestingly, land plants possess a group of conserved and plant-specific PARP-like family proteins, with the PARP signature carrying the characteristic catalytic triad, H-Y-E, including Radical-induced Cell Death 1 (RCD1), Similar-to-RCD-One (SROs), and RCD-like proteins [16]. Although the Arabidopsis RCD1 was shown to be enzymatically inactive, the wheat SRO protein Ta-sro1 confers PARP activity in vivo and in vitro [17], suggesting the existence of additional and functional PARPs in plants. This may provide an explanation as to why the Arabidopsis atparp1parp2 mutant is phenotypically indistinguishable from the wild-type plants at the vegetative growth stage (Fig 1C), whereas the mouse parp1parp2 mutant is embryonically lethal.…”