title: Molecular analysis of programmed cell death during senescence in Arabidopsis thaliana and Brassica oleracea: cloning broccoli LSD1, Bax inhibitor and serine palmitoyltransferase homologues.
abstract: This study was undertaken to characterize the programmed cell death (PCD) processes that occur during detached and natural on-plant senescence and correlate them with the expression of putative regulatory genes that may be involved in the process. DNA fragmentation and TUNEL analysis of broccoli florets showed that DNA was processed into fragments of approximately 180 bp after 48 h of harvest-induced tissue senescence. Characteristic laddering patterns were also visible in Arabidopsis leaves undergoing natural on-plant senescence and during detached senescence. Several recently isolated plant proteins have been assigned a PCD role, for example, the zinc finger containing protein, LSD1 (lesion simulating disease); Bax inhibitor (BI); and serine palmitoyltransferase (SPT), an enzyme in the sphingolipid signalling pathway. Two cDNAs encoding each of these proteins were isolated from broccoli (BoBI-1, BoBI-2, BoLSD1, BoLSD2, BoSPT1, BoSPT2), and the mRNAs increased during harvest-induced senescence in floret tissue. Expression of the Arabidopsis homologues (AtBI-1, AtLSD1, AtSPT1) were also characterized during detached leaf senescence in Arabidopsis leaves. AtBI-1 expression was constitutively expressed during detached senescence, AtLSD1 expression remained constitutively low, and AtSPT1 expression increased during detached senescence.
authors.affiliation: The New Zealand Institute for Crop and Food Research Limited, Food Industry Science Centre, Private Bag 11 600, Palmerston North, New Zealand.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Coupe
authors.forename: Lyn M
authors.initials: LM
authors.lastname: Watson
authors.forename: Dacey J
authors.initials: DJ
authors.lastname: Ryan
authors.forename: Tatyana T
authors.initials: TT
authors.lastname: Pinkney
authors.forename: Jocelyn R
authors.initials: JR
authors.lastname: Eason
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D017209:Apoptosis / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D015139:Blotting, Southern; D001937:Brassica / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D020287:In Situ Nick-End Labeling; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D051102:Serine C-Palmitoyltransferase; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C491862:ATBI-1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C104920:LSD1 protein, Arabidopsis; D008565:Membrane Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D000217:Acyltransferases; D051102:Serine C-Palmitoyltransferase