Table 1.

Overview of strategies employed by microbes to evade MAMP recognition in plants

Microbe		MAMP or MAMP precursor	Microbial protein	Plant host	Host target (PRR)	References
Level 1: Preventing MAMP production
Strategy 1: Polymorphisms in protein MAMPs
Bacteria	Agrobacterium tumefaciens	flg22	N/A	Arabidopsis	(FLS2)	Felix et al. (1999)
Ralstonia solanacearum		Arabidopsis	Pfund et al. (2004); Wei et al. (2018)
Xanthomonas campestris pv. campestris		Arabidopsis	Sun et al. (2006)
Xanthomonas oryzae pv. and pv. oryzicola		rice	Wang et al. (2015)
Xanthomonas arboricola pv. juglandis		Juglans regia	Cesbron et al. (2015)
Sinorhizobium meliloti		tomato, rice	Felix et al. (1999)
Burkholderia phytofirmans		grapevine	Trdá et al. (2014)
Pseudomonas syringae pv. tomato Col338		flgII-28		tomato	(FLS3)		Cai et al. (2011)
Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. tomato		elf18	N/A		Arabidopsis	(EFR)	Lacombe et al. (2010)
Xanthomonas oryzae pv. oryzae		RaxX	N/A		rice	(Xa21)	Pruitt et al. (2015)
Strategy 2: Polymorphisms in glycan MAMPs
Fungi	Verticillium dahliae	Chitin	VdPDA1	cotton	(CERK1)	Gao et al. (2019)
Puccinia striiformis f. sp. tritici		Pst13661	wheat		Xu et al. (2020)
Puccinia graminis f. sp. tritici		N/A	wheat		El Gueddari et al. (2002)
Uromyces fabae		N/A	broad bean
Colletotrichum graminicola		N/A	maize
Pestalotiopsis sp.		PesCDA	rice		Cord-Landwehr et al. (2016)
Strategy 3: Downregulating MAMP production
Bacteria	Pseudomonas	Flagellin	cdG	N/A	(FLS2)	Hickman and Harwood (2008)
Pseudomonas syringae		N. benthamiana and Arabidopsis	Pfeilmeier et al. (2016)
Pseudomonas aeruginosa
Pseudomonas fluorescens
Pseudomonas syringae pv. tomato	AlgU	N. benthamiana		Bao et al. (2020)
Pseudomonas syringae pv. syringae B728a		fliC		bean	Yu et al. (2013)
Fungi	Colletotrichum graminicola	β-glucan	KRE5 and KRE6	maize	N/A	Oliveira‐Garcia and Deising (2016)
Strategy 4: Hiding MAMP precursors with proteins
Fungi	Cladosporium fulvum	Chitin	Avr4	tomato	(CERK1)	Van den Burg et al. (2006)
Verticillium nonalfalfae		VnaChtBP	hop (Humulus lupulus L.)		Volk et al. (2019)
Verticillium dahliae strain VdLs17		Vd2LysM	tomato		Kombrink et al. (2017)
Colletotrichum higginsianum		ChELP1 and ChELP2	monocot and dicot crops		Takahara et al. (2016)
Parastagonospora nodorum		SnTox1	wheat		Liu et al. (2016)
Clonostachys rosea		Cell wall	LysM1 and LysM2		wheat	Dubey et al. (2020)
Serendipita indica		β-glucan	FGB1		Arabidopsis, barley, and N. benthamiana	Wawra et al. (2016)
Strategy 5: Shielding MAMP precursors with glycans
Bacteria	Pseudomonas syringae pv. tabaci 6605	Flagellin	flagellin glycan	tobacco	N/A	Taguchi et al. (2006)
Pseudomonas syringae pv. glycinea race 4		soybean	Takeuchi et al. (2003)
Xanthomonas campestris pv. campestris XcA		cabbage	Ichinose et al. (2013)
Acidovorax avenae K1 strain		rice	Hirai et al. (2011)
Pseudomonas syringae pv. syringae B728a		N. benthamiana	Buscaill et al. (2019)
Xylella fastidiosa	LPS	LPS glycan	grapevine	N/A	Rapicavoli et al. (2018)
Pseudomonas syringae pv. syringae B728a	bean		Helmann et al. (2019)
Fungi	Magnaporthe oryzae	Chitin	α-1,3-glucan	rice	N/A	Fujikawa et al. (2009)
Cochlioborus miyabeanus		Fujikawa et al. (2012)
Rhizoctonia solani
Strategy 6: Blocking MAMP release by inhibiting the activity of host hydrolases
Oomycete	Phytophthora sojae	β-glucan	GIP1	soybean	EGaseA	Rose et al. (2002)
Phytophthora infestans		GIPs	tomato		EGases	Damasceno et al. (2008)
Phytophthora infestans		PC2	EPIs		tomato	P69B	Wang et al. (2021)
Bacteria	Pseudomonas syringae pv. tomato	Flagellin		galactosyrin	N. benthamiana	BGAL1 (FLS2)	Buscaill et al. (2019)
Strategy 7: Disintegrating host-derived hydrolases
Fungi	Verticillium dahlia	Chitin	SSEP1	cotton	Chi28	Han et al. (2019)
Fusarium oxysporum f. sp. lycopersici		FoMep1/Sep1	tomato		Chi1 and Chi13	Jashni et al. (2015)
Fusarium verticillioides		fungalysin	maize		ChitA and ChitB	Naumann et al. (2011)
Colletotrichum graminicola		Cgfl	maize		chitinases	Sanz‐Martín et al. (2016)
Colletotrichum cinereus		fungalysin	N/A		N/A	Lilly et al. (2008)
Ustilago maydis		UmFly1	maize		ZmChiA	Ökmen et al. (2018)
Level 3: Preventing MAMP perception
Strategy 8: Degrading MAMPs
Bacteria	Pseudomonas aeruginosa and Pseudomonas syringae pv. tomato	Flagellin/flg22	AprA	Arabidopsis	(FLS2)	Bardoel et al. (2011)
Fungi	Podosphaera xanthii	Chitin	EWCAs	melon	(CERK1)	Martínez-Cruz et al. (2021)
Strategy 9: Sequestering released MAMPs
Fungi	Cladosporium fulvum	Chitin	Ecp6	tomato	(CERK1)	De Jonge et al. (2010)
Mycosphaerella graminicola		Mg3LysM	wheat		Marshall et al. (2011)
Magnaporthe oryzae		Slp1	rice		Mentlak et al. (2012)
Verticillium dahliae strain VdLs17		Vd2LysM	tomato		Kombrink et al. (2017)
Colletotrichum higginsianum		ChELP1 and ChELP2	monocot and dicot crops		Takahara et al. (2016)
Rhizoctonia solani		RsLysM	sugar beet		Dölfors et al. (2019)
Trichoderma atroviride		Tal6	Arabidopsis and tomato		Romero-Contreras et al. (2019)
Rhizophagus irregularis		RiSLM	Medicago truncatula		Zeng et al. (2020)
Moniliophthora perniciosa		MpChi	cacao		Fiorin et al. (2018)
Magnaporthe oryzae		MoChia1	rice		Yang et al. (2019)
Bacteria	Bacillus subtilis	Flagellin		BSn5	Arabidopsis and voodoo lily	(FLS2)	Deng et al. (2019)

See Supplemental Data Set S1 for a version of this table in excel format.

N/A, nonapplicable.