AUTHOR=Gaussand Gwenael M., Jia Qi , Van Der Graaff Eric , Lamers Gerda E., Fransz Paul F., Hooykaas Paul J., De Pater Sylvia 

TITLE=Programmed Cell Death in the Leaves of the Arabidopsis Spontaneous Necrotic Spots (sns-D) Mutant Correlates with Increased Expression of the Eukaryotic Translation Initiation Factor eIF4B2

JOURNAL=Frontiers in Plant Science

VOLUME=2

YEAR=2011

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2011.00009

DOI=10.3389/fpls.2011.00009

ISSN=1664-462X

ABSTRACT=<p>From a pool of transgenic <italic>Arabidopsis</italic> (<italic>Arabidopsis thaliana</italic>) plants harboring an activator T-DNA construct, one mutant was identified that developed spontaneous necrotic spots (<italic>sns-D</italic>) on the rosette leaves under aseptic conditions. The <italic>sns-D</italic> mutation is dominant and homozygous plants are embryo lethal. The mutant produced smaller rosettes with a different number of stomata than the wild-type. DNA fragmentation in the nuclei of cells in the necrotic spots and a significant increase of caspase-3 and caspase-6 like activities in <italic>sns-D</italic> leaf extracts indicated that the <italic>sns-D</italic> mutation caused programmed cell death (PCD). The integration of the activator T-DNA caused an increase of the expression level of At1g13020, which encodes the eukaryotic translation initiation factor eIF4B2. The expression level of <italic>eIF4B2</italic> was positively correlated with the severity of <italic>sns-D</italic> mutant phenotype. Overexpression of the <italic>eIF4B2</italic> cDNA mimicked phenotypic traits of the <italic>sns-D</italic> mutant indicating that the <italic>sns-D</italic> mutant phenotype is indeed caused by activation tagging of <italic>eIF4B2</italic>. Thus, incorrect regulation of translation initiation may result in PCD.</p>