The 9-lipoxygenase GhLOX1 gene is associated with the hypersensitive reaction of cotton Gossypium hirsutum to Xanthomonas campestris pv malvacearum.
Hypersensitive reaction (HR) cell death of cotton to the incompatible race 18 from Xanthomonas campestris pathovar malvacearum (Xcm) is associated with 9S-lipoxygenase activity (LOX) responsible for lipid peroxidation. Here, we report the cloning of cotton (Gossypium hirsutum L.) LOX gene (GhLOX1) and the sequencing of its promoter. GhLOX1 was found to be highly expressed during Xcm induced HR. Sequence analysis showed that GhLOX1 is a putative 9-LOX, and GhLOX1 promoter contains SA and JA responsive elements. Investigation on LOX signalisation on cotyledons infiltrated with salicylic acid (SA), or incubated with methyl-jasmonate (MeJA) revealed that both treatments induced LOX activity and GhLOX1 gene expression. HR-like symptoms were observed when LOX substrates were then injected in treated (MeJA and SA) cotyledons or when Xcm compatible race 20 was inoculated on MeJA treated cotyledons. Together these results support the fact that GhLOX1 encodes a 9 LOX whose activity would be involved in cell death during cotton HR.
Marmey
Philippe
P
IRD, UMR RPB Résistance des Plantes aux Bioagresseurs, 911 Avenue Agropolis, B.P. 64501, 34394 Montpellier cedex 5, France.
Jalloul
Aïda
A
Alhamdia
Majd
M
Assigbetse
Komi
K
Cacas
Jean-Luc
JL
Voloudakis
Andreas E
AE
Champion
Antony
A
Clerivet
Alain
A
Montillet
Jean-Luc
JL
Nicole
Michel
M
D000085:Acetates / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D018548:Cotyledon / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D003368:Gossypium / Q000235:genetics* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry; D008084:Lipoxygenase / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000378:metabolism; D010802:Phylogeny; D018515:Plant Leaves / Q000378:metabolism; D011401:Promoter Regions, Genetic; D020156:Salicylic Acid / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D014974:Xanthomonas / Q000378:metabolism*
D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; C072239:methyl jasmonate; D006861:Hydrogen Peroxide; D008084:Lipoxygenase; D020156:Salicylic Acid