The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid Alleviates Salinity Stress in Cassava

Abstract

Cassava (Manihot esculenta Crantz) demand has been rising because of its various applications. High salinity stress is a major environmental factor that interferes with normal plant growth and limits crop productivity. As well as genetic engineering to enhance stress tolerance, the use of small molecules is considered as an alternative methodology to modify plants with desired traits. The effectiveness of histone deacetylase (HDAC) inhibitors for increasing tolerance to salinity stress has recently been reported. Here we use the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), to enhance tolerance to high salinity in cassava. Immunoblotting analysis reveals that SAHA treatment induces strong hyper-acetylation of histones H3 and H4 in roots, suggesting that SAHA functions as the HDAC inhibitor in cassava. Consistent with increased tolerance to salt stress under SAHA treatment, reduced Na+ content and increased K+/Na+ ratio were detected in SAHA-treated plants. Transcriptome analysis to discover mechanisms underlying salinity stress tolerance mediated through SAHA treatment reveals that SAHA enhances the expression of 421 genes in roots under normal condition, and 745 genes at 2 h and 268 genes at 24 h under both SAHA and NaCl treatment. The mRNA expression of genes, involved in phytohormone [abscisic acid (ABA), jasmonic acid (JA), ethylene, and gibberellin] biosynthesis pathways, is up-regulated after high salinity treatment in SAHA-pretreated roots. Among them, an allene oxide cyclase (MeAOC4) involved in a crucial step of JA biosynthesis is strongly up-regulated by SAHA treatment under salinity stress conditions, implying that JA pathway might contribute to increasing salinity tolerance by SAHA treatment. Our results suggest that epigenetic manipulation might enhance tolerance to high salinity stress in cassava.

Metabolic and gene expression hallmarks of seed germination uncovered by sodium butyrate in Medicago truncatula

“…Histone acetyltransferases and histone deacetylases (HDACs) modulate acetylation levels in planta (Wang, Cao, Chen, & Liu, ). HDAC inhibitors, causing histone hyperacetylation and transcription activation, have been used to explore the molecular pathways of abiotic stress tolerance, as in the case of salt (Patanun et al, ) and heat (Wang et al, ) stress. In animal cells, HDAC inhibitors have contributed to decipher novel roles of the DNA damage response (DDR) under genotoxic stress.…”

The Distinct Roles of Class I and II RPD3-Like Histone Deacetylases in Salinity Stress Response

“…Differences in their selectivity are believed to alter the activity of HDACs targeted specifically by the HDIs (Bolden et al, 2006;Seto and Yoshida, 2014). Although the inhibition of HDACs may lead to an increased sensitivity to salinity stress (as shown in HDA6), Ky-2 and SAHA treatments enhance salinity stress tolerance in Arabidopsis (Sako et al, 2016) and cassava (Manihot esculenta; Patanun et al, 2017), respectively. These observations strongly support the potential for using HDIs to improve salt tolerance.…”

Versatility of HDA19-deficiency in increasing the tolerance of Arabidopsis to different environmental stresses

“…The use of HDAC inhibitors may have applicability to crops such as cassava and others where there is a critical need for greater tolerance to salinity stress. 25 HDA19 appears to regulate mRNA expression associated with ABA signaling pathways through histone deacetylation. 5 Which transcriptional networks under the control of HDA19 are essential for increasing abiotic stress tolerance, however, is currently unknown.…”