Local and systemic hormonal responses in pepper leaves during compatible and incompatible pepper-tobamovirus interactions.
Phytohormone levels and the expression of genes encoding key enzymes participating in hormone biosynthetic pathways were investigated in pepper leaves inoculated with two different tobamoviruses. Obuda pepper virus (ObPV) inoculation led to the development of hypersensitive reaction (incompatible interaction), while Pepper mild mottle virus (PMMoV) inoculation resulted in a systemic, compatible interaction. ObPV-inoculation markedly increased not only the levels of salicylic acid (SA) (73-fold) and jasmonic acid (8-fold) but also those of abscisic acid, indole-3-acetic acid, indole-3-butyric acid, cis-zeatin, cis-zeatin-9-riboside and trans-zeatin-9-riboside in the inoculated pepper leaves 3 days post inoculation. PMMoV infection increased only the contents of gibberellic acid and SA. Hormone contents did not change significantly after ObPV or PMMoV infection in non-infected upper leaves 20 days post inoculation. Concentrations of some brassinosteroids (BRs) and progesterone increased both in ObPV- and PMMoV inoculated leaves. ObPV inoculation markedly induced the expression of three phenylalanine ammonia-lyase (PAL) and a 1-aminocyclopropane-1-carboxylate oxidase (ACO) genes, while that of an isochorismate synthase (ICS) gene was not modified. PMMoV inoculation did not alter the expression of PAL and ICS genes but induced the transcript abundance of ACO although later than ObPV. Pre-treatment of pepper leaves with exogenous 24-epi-brassinolide (24-epi-BR) prior to ObPV-inoculation strongly mitigated the visible symptoms caused by ObPV. In addition, 24-epi-BR pre-treatment markedly altered the level of several hormones in pepper leaves following ObPV-inoculation. These data indicate that ObPV- and PMMoV-inoculations lead to intricate but well harmonized hormonal responses that are largely determined by the incompatible or compatible nature of plant-virus interactions.
Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland.
Michał
M
Dziurka
Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland.
Anna
A
Janeczko
Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary.
Csilla
C
Juhász
Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary.
Gábor
G
Gullner
Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacky University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
Jana
J
Oklestková
Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR & Palacky University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
Ondrej
O
Novák
Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland.
Diana
D
Saja
Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Niezapominajek 21, 30-239 Krakow, Poland.
Andrzej
A
Skoczowski
Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary.
István
I
Tóbiás
Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, 1022 Budapest, Hungary. Electronic address: barna.balazs@agrar.mta.hu.
Balázs
B
Barna
D000594:Amino Acid Oxidoreductases / Q000235:genetics / Q000378:metabolism; D002212:Capsicum / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000502:physiology*; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D010650:Phenylalanine Ammonia-Lyase / Q000235:genetics / Q000378:metabolism; D010935:Plant Diseases / Q000821:virology*; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D015398:Signal Transduction; D013045:Species Specificity; D017898:Tobamovirus / Q000145:classification / Q000472:pathogenicity*
D010937:Plant Growth Regulators; D010940:Plant Proteins; D011374:Progesterone; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D010650:Phenylalanine Ammonia-Lyase; D019751:Intramolecular Transferases; C058486:isochorismate synthase
Brassinosteroids; Ethylene; Hormone; Pepper; Phenylalanine ammonia lyase; Progesterone; Salicylic acid; Tobamovirus