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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-3-18
pubmed:abstractText
In senescent petals of Ipomoea nil, we investigated the expression of genes showing homology to genes involved in animal programmed cell death (PCD). Three encoded proteins were homologous to apoptotic proteins in animals: Bax inhibitor-1 (BI-1), a vacuolar processing enzyme (VPE; homologous to caspases) and a monodehydroascorbate reductase [MDAR; homologous to apoptosis-inducing factor (AIF)]. AIFs harbor an oxidoreductase domain and an apoptotic domain. MDARs exhibit homology to the AIF oxidoreductase domain, not to the apoptotic domain. The three other genes studied relate to autophagy. They encode homologs to vacuolar protein sorting 34 (VPS34) and to the Arabidopsis autophagy-related proteins 4b and 8a (ATG4b and ATG8a). The transcript abundance of MDAR decreased continuously, whereas that of the other genes studies exhibited a transient increase, except ATG4b whose abundance stayed high after an increase. Treatment with ethylene advanced the time to visible petal senescence, and hastened the changes in expression of each of the genes studied. In order to assess the role of VPS34 in petal senescence, we studied the effect of its inhibitor 3-methyladenine (3-MA). 3-MA reduced the time to visible petal senescence, and also accelerated the time to DNA degradation. Remarkably, 3-MA increased the time to nuclear fragmentation, indicating that the time to visible petal senescence was independent of nuclear fragmentation. The data on 3-MA might suggest the idea that autophagy is not a cause of PCD, but part of the remobilization process.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1471-9053
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
610-25
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Homologs of genes associated with programmed cell death in animal cells are differentially expressed during senescence of Ipomoea nil petals.
pubmed:affiliation
National Institute of Floricultural Science, Tsukuba 305-8519, Japan. teyamada@cc.tuat.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't