Leucine aminopeptidase regulates defense and wound signaling in tomato downstream of jasmonic acid.
Leucine aminopeptidase A (LapA) is a late wound-response gene of tomato (Solanum lycopersicum). To elucidate the role of LapA, transgenic plants that overexpressed or abolished LapA gene expression were used. The early wound-response gene RNA levels were similar in wild-type and Lap-silenced (LapA-SI), -antisense (LapA-AS), and -overexpressing (LapA-OX) plants. By contrast, late wound-response gene RNA levels and protection against Manduca sexta damage were influenced by LapA RNA and protein levels. While LapA-OX plants had elevated levels of LapA RNAs and protein, ectopic expression of LapA was not sufficient to induce Pin (Ser proteinase inhibitor) or PPO (polyphenol oxidase) transcripts in nonwounded leaves. M. sexta larvae damaged less foliage and displayed delays in growth and development when feeding on LapA-OX plants. By contrast, LapA-SI and LapA-AS lines had lower levels of Pin and PPO RNAs than wild-type controls. Furthermore, larvae consumed more foliage and attained larger masses when feeding on LapA-SI plants. Jasmonic acid (JA) did not complement the wound-signaling phenotype of LapA-SI plants. Based on root elongation in the presence of JA, JA perception appeared to be intact in LapA-SI lines. Collectively, these data suggested that LAP-A has a role in modulating essential defenses against herbivores by promoting late wound responses and acting downstream of JA biosynthesis and perception.
Fowler
Jonathan H
JH
Department of Botany and Plant Sciences, Center for Plant Cell Biology and University of California, Riverside, California 92521-0124, USA.
Narváez-Vásquez
Javier
J
Aromdee
Dale N
DN
Pautot
Véronique
V
Holzer
Frances M
FM
Walling
Linda L
LL
D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology*; D005247:Feeding Behavior; D020868:Gene Silencing; D007931:Leucyl Aminopeptidase / Q000378:metabolism / Q000502:physiology*; D018551:Solanum lycopersicum / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D018402:Manduca / Q000254:growth & development / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology*; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction
D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C011006:jasmonic acid; D007931:Leucyl Aminopeptidase