Table 2.

Impact of chosen mRNA modifications on plants

Modified nucleotide	Abbreviation	Plant species	Impact on plant functioning and possible involvement in stress response
N6-methyladenosine	m6A	Arabidopsis, rice	• m6A occurrence in transcripts associated with tissue specific function indicates its putative role in differentiation • Arabidopsis thaliana mutant with alerted methylation machinery show severe developmental defects including embryonic lethality, overgrown shoot epical meristem, changes in trichome, leaf and flower formation • YHT-domain proteins, known as m6A readers regulate lifetime of specific methylated mRNAs and are engaged in proper development of leaves and trichomes [12–35]
5-methylcytosine	m5C	Arabidpsis, rice, maize, barrelclover, foxtail millet	• Dependent on the activity of tRNA methyltransferase 4 (TRM4). The trm4 mutants show decreased cell proliferation, hampered roots growth and increased sensitivity to oxidative stress • The level of m5C is modulated by stress factors (heat and drought) and phytohormones (auxins, abscisic acid and cytokinins) [36, 37]
8-hydoxyguanine; (8-hydroxy-2′-guanosine)	8-OHG	sunflower, wheat, soybean, Arabidopsis	• Selective oxidation of defined transcripts leads to hampered translation and decreased level of encoded proteins • Involved in breakage of seeds dormancy • Increase in 8-OHG levels in total RNA and/or mRNA constitutes an early response to stress factors: cadmium in soybean and nematode infection in Arabidopsis [47–50]
8-nitroguanine	8-NO2-G	Potato	• Overaccumulation of 8-NO2-G in total RNA and mRNA represents an early event preceding or coincident with the first symptoms of programmed cell death during hypersensitive response of potato leaves inoculated with P. infestans [62]