TABLE 2.

Systemic defense activation by mycorrhizal plants.

Gene name	Gene function	Proposed defense pathway	Mycorrhiza Type	Mycorrhiza species	Effects of mycorrhiza	Plant host	Resistance against	Disease/Effect	References
PMR4	Callose synthase	JA pathway	AMF	Rhizoglomus irregularis	Fungal biomass- B. cinerea reduced to 66%	Tomato- Solanum lycopersicum	Fungus- Botrytis cinerea	Gray mold	Sanmartín et al., 2020
ATL31	Carbon/Nitrogen insensitive 1(Arabidopsis Toxicos en Levadura 31)
SYP121	Vesicular trafficking protein
VCH3	Chitinase	Chitinase induced defense pathway	AMF	Glomus versiforme	Significant reduction in M. incognita infection	Grapevine- Vitis amurensis	Nematode- Meloidogyne incognita	Root knot	Li et al., 2006
CHI	Chitinase 1b	JA and SA pathway	AMF	Glomus intraradices	X. index count in soil and galls reduced significantly (after 35 days)	Grapevine- Vitis berlandieri × Vitis riparia	Nematode- Xiphinema index	Root gall	Hao et al., 2012
PR10	Pathogenesis-related 10
GST	Glutathione S-transferase
STS	Stilbene synthase 1
ESPS	5-enolpyruvyl shikimate-3-phosphate synthase
PR1-a	Pathogenesis-related 1	SA pathway	AMF	Glomus mosseae	74—84% decrease in necroses andintraradical pathogen hyphae of P. phytophthora	Tomato- Solanum lycopersicum	Pathogen- Phytophthora parasitica	Fruit rot	Cordier et al., 1998
OsNPR1	Non-expressor of PR1	JA and SA pathway	AMF	Glomus intraradices	Significant reduction in spore count of M. oryzae	Rice- Oryza sativa L.	Fungus- Magnaporthe oryzae	Rice blast	Campos-Soriano et al., 2012
OsAP2	APETALA2
OsEREBP	Ethylene-responsive element-binding protein
OsJAmyb	JA-regulated myb transcription factor
PR	Pathogenesis-related
PR2a	Pathogenesis-related 2a	DIMBOA- phytoalexin based defense and JA pathway	AMF	Glomus mosseae	Disease index of R. solani reduced by 50%	Corn- Zea mays	Fungus- Rhizoctonia solani	Sheath blight	Song et al., 2011
PAL	Phenylalanine ammonia-lyase
AOS	Allene oxide synthase
BX9	DIMBOA (2,4-dihydroxy-7-methoxy-2 H-1,4-benzoxazin-3(4 H)-one) biosynthesis pathway gene
PR1, PR2	Pathogenesis-related 1, pathogenesis-related 2	SA pathway	AMF	Glomus sp.	Leaf infection index decreased significantly.	Potato- Solanum tuberosum	Pathogen- Phytophthora infestans	Late blight	Gallou et al., 2011
POX381	Peroxidase	SA pathway	AMF	Funneliformis mosseae	B. graminis infection on leaves reduced to 78%.	Wheat- Triticum sp.	Fungus- Blumeria graminis f. sp. Tritici	Powdery mildew	Mustafa et al., 2017
PAL	Phenylalanine ammonia lyase
CHI1	Chitinase 1
NPR1	Non-expressor of pathogenesis-related proteins 1
PAL	Phenylalanine ammonia lyase	JA pathway	AMF	Glomus Macrocarpum; Glomus Fasciculatum	F. oxysporum disease severity reduced to ∼ 75%	Tomato- Solanum lycopersicum	Fungus- Fusarium Oxysporum f. sp. Lycopersici	Fusarium wilt	Kapoor, 2008
LOX	Lipoxygenase	JA pathway	AMF	Glomus fasciculatum	Significant decrease in the severity of fusarium wilt disease.	Tomato- Solanum lycopersicum	Fungus- Fusarium Oxysporum f. sp. Lycopersici	Fusarium wilt	Nair et al., 2015
LOX	Lipoxygenase	JA pathway	AMF	Glomus fasciculatum	Decrease in disease severity of A. alternata	Tomato- Solanum lycopersicum	Pathogen-Alternaria alternata	Fruit rot	Nair et al., 2015
OPR3	12-oxophytodienoate reductase 3
COI1	Coronatine-insensitive1
PR1, PR2, PR3	Pathogenesis related1, Pathogenesis related 2, Pathogenesis related 3	JA and SA pathway	AMF	Funneliformis mosseae	Disease index of A. solani reduced by 54.3%	Tomato- Solanum lycopersicum	Pathogen- Alternaria solani	Early blight	Song et al., 2015
LOX	Lipoxygenase
AOC	Allene oxide cyclase
PAL	Phenylalanine ammonia-lyase
LOXD	Lipoxygenase D	JA pathway	AMF	Glomus mosseae	62.3% less weight gain of H. arimegera larvae	Solanum lycopersicum Mill.	Insect- Helicoverpa arimigera	Herbivory	Song et al., 2013
AOC	Allene oxide cyclase
PI-I and PI-II	Serine protease inhibitors I and II
AOS1	Allene oxide synthase 1	JA pathway, phenylpropanoid pathway and protease inhibitor activity	AMF	Rhizophagus irregularis	Larvae weigh ∼40 mg which is significantly lower than the control (after 8 days).	Potato- Solanum tuberosum	Insect- Trichoplusia ni	Herbivory	Schoenherr et al., 2019
OPR3	12-oxo-phytodienoate reductase 3
PI-I	Protease inhibitor type
PAL	Phenylalanine ammonia lyase
JAZ(JAR1, JAR8)	Jasmonate zim domain 1	JA pathway	EMF	Laccaria bicolor	Significant less oviposition by beetles on mycorrhizal host plant.	Poplar- Populus × canescens	Insect- Chrysomela populi	Herbivory	Kaling et al., 2018
MYB (MYB4, MYB5, MYB14 and MYB108)	Transcription factors of JA
NAS3	Nicotianamine synthase
KPI	Kunitz protease inhibitors
CHI	Chitinases
CERK1	Chitin receptor	Both JA and SA pathway	EMF	Laccaria bicolor	27% reduction in larval weight on L. bicolor colonized host plant.	Arabidopsis	Insect- Trichoplusia ni	Herbivory	Vishwanathan et al., 2020
PR1, PR2 and PR5	Pathogenesis related 1, Pathogenesis related 2, Pathogenesis related 5	SA pathway	Endophyte	Piriformospora indica	33—59% reduction in colony numbers of B. graminis	Barley- Hordeum vulgare	Fungus- Blumeria graminis f. sp. Hordei	Powdery mildew	Molitor et al., 2011
Hsp70, Hsp17.9	Heat shock proteins70; Heat shock proteins17.9
BCI-7	Barley chemically induced 7
PR1, PR5	Pathogenesis-related 1, Pathogenesis-related 5	JA and SA pathway	Endophyte	Piriformospora indica	∼ 50% reduction in the number of conidia of G. orontii formed per mycelium.	Arabidopsis	Fungus- Golovinomyces orontii	Powdery mildew	Stein et al., 2008
ERF1	Ethylene response factor 1
PDF1.2	Plant defensin 1.2
VSP	Vegetative storage protein

Symbiotic relationships between mycorrhiza and plants were reviewed with regard to the defense induction by mycorrhiza. Genes were grouped upon their function as well as their effect on the disease of pathogens on their hosts.