Trichostatin A Affects Developmental Reprogramming of Bread Wheat Microspores towards an Embryogenic Route

Abstract

Microspores can be developmentally reprogrammed by the application of different stress treatments to initiate an embryogenic pathway leading to the production of doubled haploid (DH) plants. Epigenetic modifications are involved in cell reprogramming and totipotency in response to stress. To increase microspore embryogenesis (ME) efficiency in bread wheat, the effect of the histone deacetylase inhibitor trichostatin A (TSA) has been examined in two cultivars of wheat with different microspore embryogenesis response. Diverse strategies were assayed using 0–0.4 µM TSA as a single induction treatment and after or simultaneously with cold or mannitol stresses. The highest efficiency was achieved when 0.4 µM TSA was applied to anthers for 5 days simultaneously with a 0.7 M mannitol treatment, producing a four times greater number of green DH plants than mannitol. Ultrastructural studies by transmission electron microscopy indicated that mannitol with TSA and mannitol treatments induced similar morphological changes in early stages of microspore reprogramming, although TSA increased the number of microspores with ’star-like’ morphology and symmetric divisions. The effect of TSA on the transcript level of four ME marker genes indicated that the early signaling pathways in ME, involving the TaTDP1 and TAA1b genes, may be mediated by changes in acetylation patterns of histones and/or other proteins.

Comparative proteomic analysis provides new insights into regulation of microspore embryogenesis induction in winter triticale (× Triticosecale Wittm.) after 5-azacytidine treatment

“…Therefore, it could be assumed that a higher abundance of actin filaments (AF) in winter triticale anthers was not required for high ME effectiveness. Similar conclusions, based on AF depolymerization associated with elevated Ca 2+ levels, observed in embryogenic microspores of oilseed rape and wheat, were drawn by Gervais et al 45 and Castillo et al 46 .…”

“…Expression of this gene was induced in wheat zygotic embryos 56 and in wheat anthers on the 5 th day of in vitro culture 13 . Moreover, an increased transcript level of this gene was observed after treatment with histone deacetylase inhibitor (trichostatin A, TSA) on the 3 rd day of culture in two bread wheat cultivars with different androgenic response 46 . Similarly, its up-regulation was observed in triticale anthers after 4 days of in vitro culture 12 , and in triticale microspores after ME-inducing low temperature treatment 26 .…”

Proteins, Small Peptides and Other Signaling Molecules Identified as Inconspicuous but Possibly Important Players in Microspores Reprogramming Toward Embryogenesis

“…Golden Promise; GP), it can be speculated that MAN may also participate in epigenetic processes, inhibiting the activity of the enzymes involved in the synthesis of SAM (our unpublished results). Our interpretation is partially supported by the work of Castillo et al (2020), who found that the histone deacetylase inhibitor trichostatin A (TSA) together with MAN treatment led to microspore reprogramming, increased the number of embryogenic microspores and regenerated green plants in bread wheat. However, this hypothesis needs to be further investigated.…”

Epigenetics for Crop Improvement in Times of Global Change

“…If they were used, it was mainly as a treatment within plant tissue cultures. Specifically, the use of Trichostatin A induced microspore embryogenesis in wheat [ 142 ] and somatic embryogenesis in Arabidopsis [ 143 ]. Treatment by trichostatin A and sodium butyrate also improved regeneration efficiency from mature wheat embryos [ 144 ].…”

“…Recent advances in chemically controlled mammalian cell reprogramming have shown the high potential of application of synthetic small molecules, including epigenetic inhibitors, to control cellular reprogramming, proliferation, and differentiation, as well as cancer cell reprogramming [ 291 , 292 ]. In plants, epigenetics chemical targeting with inhibitors of DNA methylation (5-AzaC, Zebularine), H3K9 methylation (BIX-01294), or histone deacetylases (Trichostatin A, Suberoylanilide hydroxamic acid, SAHA) has been demonstrated to improve in vitro plant cell reprogramming and regeneration, to produce DHs, and to propagate selected clonal plants in a number of crop and forest species, such as rapeseed, barley, wheat, and cork oak [ 128 , 142 , 284 , 286 , 293 , 294 ].…”