Salicylic acid and jasmonic acid are essential for systemic resistance against tobacco mosaic virus in Nicotiana benthamiana.
Systemic resistance is induced by pathogens and confers protection against a broad range of pathogens. Recent studies have indicated that salicylic acid (SA) derivative methyl salicylate (MeSA) serves as a long-distance phloem-mobile systemic resistance signal in tobacco, Arabidopsis, and potato. However, other experiments indicate that jasmonic acid (JA) is a critical mobile signal. Here, we present evidence suggesting both MeSA and methyl jasmonate (MeJA) are essential for systemic resistance against Tobacco mosaic virus (TMV), possibly acting as the initiating signals for systemic resistance. Foliar application of JA followed by SA triggered the strongest systemic resistance against TMV. Furthermore, we use a virus-induced gene-silencing-based genetics approach to investigate the function of JA and SA biosynthesis or signaling genes in systemic response against TMV infection. Silencing of SA or JA biosynthetic and signaling genes in Nicotiana benthamiana plants increased susceptibility to TMV. Genetic experiments also proved the irreplaceable roles of MeSA and MeJA in systemic resistance response. Systemic resistance was compromised when SA methyl transferase or JA carboxyl methyltransferase, which are required for MeSA and MeJA formation, respectively, were silenced. Moreover, high-performance liquid chromatography-mass spectrometry analysis indicated that JA and MeJA accumulated in phloem exudates of leaves at early stages and SA and MeSA accumulated at later stages, after TMV infection. Our data also indicated that JA and MeJA could regulate MeSA and SA production. Taken together, our results demonstrate that (Me)JA and (Me)SA are required for systemic resistance response against TMV.
Feng
F
Zhu
De-Hui
DH
Xi
Shu
S
Yuan
Fei
F
Xu
Da-Wei
DW
Zhang
Hong-Hui
HH
Lin
D000085:Acetates / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D003517:Cyclopentanes / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017930:Genes, Reporter; D054883:Oxylipins / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D052585:Phloem / Q000276:immunology / Q000821:virology; D010935:Plant Diseases / Q000276:immunology* / Q000821:virology; D010937:Plant Growth Regulators / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D018515:Plant Leaves / Q000276:immunology / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D012459:Salicylates / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D020156:Salicylic Acid / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D015398:Signal Transduction; D014026:Nicotiana / Q000276:immunology* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity* / Q000502:physiology
D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D012459:Salicylates; C011006:jasmonic acid; C072239:methyl jasmonate; C033069:methyl salicylate; D020156:Salicylic Acid