02869nas a2200253 4500008004100000022001400041245012500055210006900180260009000249300001200339490000700351520190100358653001802259653002402277653002102301653003402322653001902356653001102375100001802386700002102404700003702425700002102462856013202483 2015 eng d a0885-576500aRole of methyl jasmonate in the expression of mycorrhizal induced resistance against Fusarium oxysporum in tomato plants0 aRole of methyl jasmonate in the expression of mycorrhizal induce a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD- ELSEVIER SCIENCE LTDcOCT a139-1450 v923 a

Arbuscular mycorrhiza (AM) colonization led to a decrease in the severity of fusarium wilt disease caused by Fusarium oxysporum f. sp. lycopersici in tomato plants. The involvement of two plant defense hormones, namely methyl jasmonate (MeJA) and salicylic acid (SA), in the expression of mycorrhiza induced resistance (MIR) against this vascular pathogen was studied in the AM colonized and non-colonized (controls) plants. Activity of lipoxygenase (LOX), which plays a role in jasmonic acid (JA) biosynthesis, as well as levels of methyl jasmonate (MeJA) increased in AM colonized plants as compared to controls, but did not show any further changes in response to F. oxysporum inoculation. On the other hand, activity of phenylalanine ammonia lyase (PAL), which is an enzyme from salicylic acid (SA) biosynthetic pathway, as well as SA levels, increased in both controls and AM colonized plants in response to application of F. oxysporum spores. Hence the JA and not the SA signalling pathway appeared to play a role in the expression of MIR against this vascular pathogen. The resistance observed in AM colonized plants was completely compromised when plants were treated with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM). This confirmed that the AM-induced increase in JA levels was involved in the expression of resistance toward F. oxysporum. The SA response gene pathogenesis-related 1 (PR1) showed an increased expression in response to F. oxysporum infection in SHAM treated AM colonized plants as compared to plants that were not treated with this JA inhibitor. This suggested the possibility that JA inhibited SA responses, at least in the roots. AM colonization therefore appeared to prime plants for improved tolerance against the vascular pathogen F. oxysporum, which was mediated through the JA signalling pathway. (C) 2015 Elsevier Ltd. All rights reserved.

10aFusarium wilt10aGlomus fasciculatum10aMethyl jasmonate10aMycorrhiza induced resistance10aSalicylic acid10aTomato1 aNair, Aswathy1 aKolet, Swati, P.1 aThulasiram, Hirekodathakallu, V.1 aBhargava, Sujata uhttps://library.ncl.res.in/content/role-methyl-jasmonate-expression-mycorrhizal-induced-resistance-against-fusarium-oxysporum-001533nas a2200157 4500008004100000245009500041210006900136260001300205300001200218490000900230520095300239100001801192700002301210700002101233856012101254 2020 eng d00aRole of jasmonate in modulation of mycorrhizae-induced resistance against fungal pathogens0 aRole of jasmonate in modulation of mycorrhizaeinduced resistance bSpringer a109-1150 v20853 a

Symbiotic association of plants with arbuscular mycorrhizal (AM) fungi brings about changes in levels of the phytohormone jasmonate (JA) in root and shoot tissues of a plant. The enhanced JA levels not only play a role in controlling the extent of AM colonization but are also involved in the expression of mycorrhizal-induced resistance (MIR) against pathogens. We describe a method used to study the levels of a volatile jasmonate derivative, methyl jasmonate (MeJA), in tomato plants colonized by AM fungi and in response to subsequent attack by the foliar pathogen Alternaria alternata.

1 aNair, Aswathy1 aThulasiram, H., V.1 aBhargava, Sujata uhttps://library.ncl.res.in/content/role-jasmonate-modulation-mycorrhizae-induced-resistance-against-fungal-pathogens