Table 3.

Classification of histone deacetylases in Arabidopsis.

Enzyme group	Family	Regulator	Gene	Target	Role in Stress (References)
Deacetylases	RPD3/HDA1	HDA2	At5G26040	H3Ac and H2BAc
		HDA5	At5G61060	H3Ac
		HDA6	At5G63110	H3K9, H3K14, H4	Drought and salt stress (Chen and Wu, 2010; Kim et al., 2017), cold (To et al., 2011; Jung et al., 2013; Luo et al., 2017), heat (Popova et al., 2013), pathogen defense, JA, and salicylic acid-mediated defense responses (Zhou et al., 2005; Wu et al., 2008; Choi et al., 2012)
		HDA7	At5G35600	H3K9, H3K14
		HDA8	At1G08460
		HDA9	At3G44680	H3K9	Drought and salinity (Mehdi et al., 2016; Zheng et al., 2016)
		HDA10	At3G44660
		HDA14	At4G33470
		HDA15	At3G18520		Drought (Lee and Seo, 2018; Tu et al., 2022)
		HDA17	At3G44490
		HDA18	At5G61070
		HDA19	At4G38130	H3K9, H3K14, H3K18, H2B	ABA and salt stress (Chen and Wu, 2010). Pathogen defense, JA, and salicylic acid-mediated defense responses (Zhou et al., 2005; Wu et al., 2008; Choi et al., 2012)
	HD2	HDT1/HD2A	At3G44750	H3K18, H3K27, andH2B	Repressed in ABA and salt (Luo et al., 2012)
		HDT2/HD2B	At5G22650	H3K18 and H3K27	Repressed in ABA and salt (Luo et al., 2012)
		HDT3/HD2C	At5G03740	H3K9, H3K18	Salinity and drought tolerance (Luo et al., 2012), cold (Park et al., 2018), heat (Buszewicz et al., 2016)
		HDT4/HD2D	At2G27840	H3K27	Salinity tolerance, cold and drought (Luo et al., 2012; Han et al., 2016)
	SIR2	SRT1	At5G55760	H3K9	Ethylene response (Zhang et al., 2018)
		SRT2	At5G09230	H3K9	Ethylene response (Zhang et al., 2018)