Programmed cell death activated by Rose Bengal in Arabidopsis thaliana cell suspension cultures requires functional chloroplasts.
Light-grown Arabidopsis thaliana cell suspension culture (ACSC) were subjected to mild photooxidative damage with Rose Bengal (RB) with the aim of gaining a better understanding of singlet oxygen-mediated defence responses in plants. Additionally, ACSC were treated with H2O2 at concentrations that induced comparable levels of protein oxidation damage. Under low to medium light conditions, both RB and H2O2 treatments activated transcriptional defence responses and inhibited photosynthetic activity, but they differed in that programmed cell death (PCD) was only observed in cells treated with RB. When dark-grown ACSC were subjected to RB in the light, PCD was suppressed, indicating that the singlet oxygen-mediated signalling pathway in ACSC requires functional chloroplasts. Analysis of up-regulated transcripts in light-grown ACSC, treated with RB in the light, showed that both singlet oxygen-responsive transcripts and transcripts with a key role in hormone-activated PCD (i.e. ethylene and jasmonic acid) were present. A co-regulation analysis proved that ACSC treated with RB exhibited higher correlation with the conditional fluorescence (flu) mutant than with other singlet oxygen-producing mutants or wild-type plants subjected to high light. However, there was no evidence for the up-regulation of EDS1, suggesting that activation of PCD was not associated with the EXECUTER- and EDS1-dependent signalling pathway described in the flu mutant. Indigo Carmine and Methylene Violet, two photosensitizers unable to enter chloroplasts, did not activate transcriptional defence responses in ACSC; however, whether this was due to their location or to their inherently low singlet oxygen quantum efficiencies was not determined.
Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de merinas 52, 37008 Salamanca, Spain Department of Nutritional Sciences, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
Jorge
J
Gutiérrez
Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de merinas 52, 37008 Salamanca, Spain.
Sergio
S
González-Pérez
Functional Genomics Node, INB, Computational Medicine, Prince Felipe Research Centre, Av. Autopista del Saler 16, Camino de las Moreras, 46012 Valencia, Spain.
Francisco
F
García-García
School of Science, Department of Chemical and Life Sciences, Waterford Institute of Technology, Cork Road, Waterford, Ireland School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
Cara T
CT
Daly
Departamento de Fisiología Vegetal, Centro Hispano-Luso de Investigaciones Agrarias, Facultad de Biología, Universidad de Salamanca, C/ Río Duero 12, 37185 Salamanca, Spain.
Oscar
O
Lorenzo
Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain.
José L
JL
Revuelta
School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland.
Paul F
PF
McCabe
Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), Cordel de merinas 52, 37008 Salamanca, Spain juan.arellano@irnasa.csic.es.
Juan B
JB
Arellano
D017209:Apoptosis; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D002736:Chloroplasts / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D040081:Protein Array Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012395:Rose Bengal / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D026082:Singlet Oxygen / Q000378:metabolism; D015854:Up-Regulation
D010940:Plant Proteins; D026082:Singlet Oxygen; D012395:Rose Bengal; D006861:Hydrogen Peroxide
Arabidopsis cell cultures; Rose Bengal; photosensitizers; programmed cell death; reactive oxygen species; singlet oxygen; transcriptional defence responses.