Histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat

Abstract

Polyploidy occurs prevalently and plays an important role during plant speciation and evolution. This phenomenon suggests polyploidy could develop novel features that enable them to adapt wider range of environmental conditions compared with diploid progenitors. Bread wheat (Triticum aestivum L., BBAADD) is a typical allohexaploid species and generally exhibits greater salt tolerance than its tetraploid wheat progenitor (BBAA). However, little is known about the underlying molecular basis and the regulatory pathway of this trait. Here, we show that the histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat. Salinity-induced TaHAG1 expression was associated with tolerance variation in polyploidy wheat. Overexpression, silencing and CRISPR-mediated knockout of TaHAG1 validated the role of TaHAG1 in salinity tolerance of wheat. TaHAG1 contributed to salt tolerance by modulating ROS production and signal specificity. Moreover, TaHAG1 directly targeted a subset of genes that are responsible for hydrogen peroxide production, and enrichment of TaHAG1 triggered increased H3 acetylation and transcriptional upregulation of these loci under salt stress. In addition, we found the salinity-induced TaHAG1-mediated ROS production pathway is involved in salt tolerance difference of wheat accessions with varying ploidy. Our findings provide insight into the molecular mechanism of how an epigenetic regulatory factor facilitates adaptability of polyploidy wheat and highlights this epigenetic modulator as a strategy for salt tolerance breeding in bread wheat.

Histone modifications and chromatin remodelling in plants in response to salt stress

“…Recently, TaGCN5 was also reported to target genes controlling hydrogen peroxide production, which was important for salt stress adaptation in wheat (Zheng et al, 2021). These studies around GCN5 reinforce its regulatory role in multiple aspects of salt tolerance mechanisms.…”

Salinity Tolerance in a Synthetic Allotetraploid Wheat (SlSlAA) Is Similar to Its Higher Tolerant Parent Aegilops longissima (SlSl) and Linked to Flavonoids Metabolism

“…Salinity stress exerts negative effects on plants via ion injury, osmotic stress, and reactive oxygen species (ROS) damage ( Parida and Das, 2005 ; Gill and Tuteja, 2010 ; Wu et al, 2018 ; Yang and Guo, 2018 ; Flowers et al, 2019 ; Zhao et al, 2020 ). Previous studies have shown that lowering Na + accumulation and ROS scavenging are major salinity tolerance mechanisms in wheat ( Wei et al, 2013 ; Liu et al, 2014 ; Wang and Xia, 2018 ; Wang et al, 2020 ; Zheng et al, 2021 ). Elevated ROS levels will cause rapid plant death ( Liebthal and Dietz, 2017 ), and enhancement of the capacity to detoxify ROS can significantly improve salinity tolerance of wheat plants ( Liu et al, 2014 ; Wang and Xia, 2018 ; Wang et al, 2020 ; Zheng et al, 2021 ).…”

“…Previous studies have shown that lowering Na + accumulation and ROS scavenging are major salinity tolerance mechanisms in wheat ( Wei et al, 2013 ; Liu et al, 2014 ; Wang and Xia, 2018 ; Wang et al, 2020 ; Zheng et al, 2021 ). Elevated ROS levels will cause rapid plant death ( Liebthal and Dietz, 2017 ), and enhancement of the capacity to detoxify ROS can significantly improve salinity tolerance of wheat plants ( Liu et al, 2014 ; Wang and Xia, 2018 ; Wang et al, 2020 ; Zheng et al, 2021 ). In light of this, as AA was more saline-sensitive than S l S l and S l S l AA, it was expected that Na + concentration should be much higher in AA than in S l S l and S l S l AA under salinity stress.…”

Status and advances in mining for blackleg (Leptosphaeria maculans) quantitative resistance (QR) in oilseed rape (Brassica napus)

“…Genomic resources for Brassicas are rapidly expanding since the sequencing of the first Brassica species (B. rapa; AA) was initiated by the Multinational Brassica Genome Project (Wang et al, 2011). At present, reference genomes for other major species, B. carinata (Song et al 2021 ), B. oleracea (Liu et al 2014 ; Parkin et al 2014 ; Belser et al 2018 )), B. nigra , B. juncea (Yang et al 2016 ) and B. napus (Chalhoub et al 2014 ) are currently available and progressively being enriched as new information are generated from the accelerated development of sequencing platforms and improvement in computational analyses. Recent efforts have concentrated on the construction of pan-genomes, representing the overall genomic repertoire of a species, overcoming the limitation of using single genome reference (Bayer et al 2020 ; Golicz et al 2016a , b ; Hurgobin and Edwards 2017 ).…”