Table 3.

Biochemical implication of HG-modifying enzymes (PMEs, PAEs, and PLLs) and their inhibitor proteins (PMEIs, PGIPs, and PNLIP) in plant resistance against bioaggressors

Gene name	Utilization	Stress		Induction	References
Pectin methylation and PME activity
Sorghum bicolor (sorgho) DM of pectin		Aphid	Schzaphis graminum	Resistant variety has higher methylated pectins than the suceptible	Dreyer and Campbell (1984)
Phaseolus vulgaris (bean)		Fungus	Collectotrichum lindemuthianum	Resistant line has higher methylated pectins than the suceptible	Boudart et al. (1998)
DM of pectin	Near-isogenic lines
Solanum tuberosum cv Bintje or ADG (potato) DM of pectin		Bacterium	Pectobacterium carotovorum	Resistant genotype (ADG) has higher methylated pectins than the susceptible genotype (Bintje)	Marty et al. (1997)
Potato DM of pectin	Somatic hybrid of 3 cv (Record, Estima, Katahdin)	Bacterium	Pectobacterium carotovorum	Resistant genotype has higher methylated pectins than the susceptible genotype	McMillan et al (1993)
Solanum lycopersicum (tomato) DM of pectin		Bacterium	Ralstonia solanacearum	Resistant genotype (Hawaii7996) has higher methylated pectins than the susceptible genotype (Wva700)	Wydra and Beri (2006)
	(Hawaii7996, Wva700)
Nicotiana attenuata (tobacco) PME activity		Chewing insect	Manduca sexta OS	Leaf wounded with a pattern wheel; 20 μl of diluted insect OS applied; PME activity increased (29%) 30min after OS applied	Von Dahl et al. (2006)
	Wild type
Nicotiana tabacum (tobacco) PME		Virus	TMV	PME specifically recognized the TMV MP (movement protein)	Dorokhov et al. (1999)
Nicotiana tabacum cv. Turk (tobacco) PME		Virus	TMV	Mutant TMV without MP proteins cannot link to tobacco PME (no lesions on leaves after TMV mutant infection)	Chen et al. (2000)
Nicotiana tabacum cv. Samsun (tobacco)		Virus	TMV	PME activity increased >resistance increased	Gasanova et al. (2008)
PME activity	ProPME			(size of leaf necrosis and short- and long-distance transport decreased)
Nicotiana tabacum cv. Turk (tobacco)		Virus	TMV	PME activity decreased >symptome appearence delayed (5–12 times slower in the antisense line than in the wild type)	Chen and Citovsky (2003)
PME activity	Antisense suppression
	pme3 KO	Fungus	Botrytis cinerea	PME activity decreased >DM decreased>resistance decreased	Raiola et al. (2011)
AtPME3	At3g14310
AtPME3	pme3 KO At3g14310	Bacterium	Pectobacterium carotovorum	PME activity decreased >DM decreased >resistance decreased	Raiola et al. (2011)
Fragaria vesca (wild strawberry)		Fungus	Botrytis cinerea	OGA with low DM >resistance increased	Osorio et al. (2008)
PME activity	Overexpression line (FaPE1)
Pectin acetylation
	Mutant Atrwa2	Fungus	Botrytis cinerea	Pectin acetylation decreased >resistance increased	Manabe et al. (2011)
DA of pectin	(with 20% decreased acetylester content)
Triticum aestivum (wheat)		Fungus	Blumeria graminis	OGA with high DA >resistance increased	Randoux et al. (2010)
DA of pectin	Chemical acetylation
Pectate lyase-like (PLL)
		Fungus	Erysiphe cichoracearum	108 cfu ml–1; 1, 2, 4 dpi	Vogel et al. (2002)
AtPMR6	At3g54920			confers resitance to E. cichoracearum
Pectin methyl esterase inhibitors (PMEIs)
	overexpression lines	Fungus	Botrytis cinerea	ATPMEI increased>PME activity decreased>DM increased>resistance increased	Lionetti et al. (2007)
AtPMEI1	At1g48020
ATPMEI2	At3g17220
Capsicum annuum (pepper)		Bacterium	Xanthomonas campestris	CaPMEI inhibited >susceptibility increased	An et al. (2008)
CaPMEI1	Transgenic pepper silences CaPMEI1		pv. vesicatoria
Capsicum annuum (pepper)		Bacterium	Pseudomonas syringae pv. tomato	CaPMEI overexpressed >resistance increased, but no resistance to the biotrophic fungus Hyaloperonospora parasitica	An et al. (2008)
CaPMEI1	Transgenic A. thaliana overexpresses CaPMEI1
Actinidia chinensis (kiwi)		Fungus	Fusarium graminearum	AcPMEI expression >PME activity decreased >DM increased >resistance increased	Volpi et al. (2011)
AcPMEI	Transgenic wheat expresses AcPMEI
Actinidia chinensis (Kiwi)		Fungus	Bipolaris sorokiniana	AcPMEI expression >PME activity decreased >DM increased >resistance increased	Volpi et al. (2011)
AcPMEI	Transgenic wheat expresses AcPMEI
Polygalactuonase inhibitor proteins (PGIPs)
		Fungus	Botrytis cinerea	AtPGIP1 increased >resistance increased	Ferrari et al. (2006)
AtPGIP1	Antisense suppression
Brassica rapa (Chinese cabbage)		Bacterium	Pectobacterium carotovorum	BrPGIP2 overexpressed > resistance increased	Hwang et al. 2010
PGIP	Overexpression lines
Solanum lycopersicum (tomato)		Fungus	Botrytis cinerea	pPGIP increased >resistance increased (B. cinerea endo-PGs inhibited)	Powell et al. (2000)
pPGIP	Expression of a pear PGIP
Vitis vinifera (grape)		Fungus	Botrytis cinerea	VvPGIP1 increased >resistance increased (BcPG1 inhibited)	Joubert et al. (2006)
VvPGIP1	Overexpression lines
Vitis vinifera (grape)		Fungus	Botrytis cinerea	pPGIP increased >resistance increased	Agüero et al. (2005)
pPGIP	Expression of a pear PGIP
		Fungus	Botrytis cinerea	AtPGIPs increased >resistance increased	Ferrari et al. (2003)
AtPGIP1, AtPGIP2	Overexpression lines
Phaseolus vulgaris (bean)		Fungus	Botrytis cinerea	PvPGIP2 increased >resistance increased (BcPG1 inhibited)	Manfredini et al. (2005)
PvPGIP2	Overexpression lines
Phaseolus vulgaris (bean)		Fungus	Fusarium moniliforme	PvPGIP2 inhibits FmPG	Federeci et al. (2001)
PvPGIP2
Phaseolus vulgaris (bean)		Fungus	Aspergillus niger	PvPGIP inhibits AnPG (endoPGII)	King et al. (2002)
PvPGIP
Phaseolus vulgaris (bean)		Fungus	Botrytis cinerea	PvPGIP2 increased >resistance increased (BcPG1 inhibited)	Sicilia et al. (2005)
PvPGIP2
Pectin lyase inhibitor protein (PNLIP)
Beta vulgaris (sugar beet)		Fungus	Rhizoctonia solani	Barley-grain inoculum applied for 2 weeks at 25 °C	Bugbee (1993)
PNLIP	PNLIP			PNLIP activity higher in rotted tissues than in healthy

Piercing–sucking insects (yellow box), chewing insects (turquoise), bacteria (black), fungi (light grey), and viruses (red).

Species names in bold indicate necrotrophic pathogens.