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Overexpression of a chromatin architecture‐controlling AT‐hook protein extends leaf longevity and increases the post‐harvest storage life of plants
Author(s) -
Lim Pyung Ok,
Kim Yumi,
Breeze Emily,
Koo Ja Choon,
Woo Hye Ryun,
Ryu Jong Sang,
Park Don Ha,
Bey Jim,
Tabrett Alex,
BuchananWollaston Vicky,
Nam Hong Gil
Publication year - 2007
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2007.03317.x
Subject(s) - chromatin , biology , mutant , senescence , arabidopsis , microbiology and biotechnology , histone , longevity , transcription factor , gene , gene expression , genetics
Summary Leaf senescence is the final stage of leaf development and is finely regulated via a complex genetic regulatory network incorporating both developmental and environmental factors. In an effort to identify negative regulators of leaf senescence, we screened activation‐tagged Arabidopsis lines for mutants that exhibit a delayed leaf senescence phenotype. One of the mutants ( ore7‐1D ) showed a highly significant delay of leaf senescence in the heterozygous state, leading to at least a twofold increase in leaf longevity. The activated gene ( ORE7 / ESC ) encoded a protein with an AT‐hook DNA‐binding motif; such proteins are known to co‐regulate transcription of genes through modification of chromatin architecture. We showed that ORE7/ESC, in addition to binding to a plant AT‐rich DNA fragment, could also modify the chromatin architecture, as illustrated by an altered distribution of a histone–GFP fusion protein in the nucleus of the mutant. Globally altered gene expression, shown by microarray analysis, also indicated that activation of ORE7 / ESC results in a younger condition in the mutant leaves. We propose that ectopically expressed ORE7 / ESC is negatively regulating leaf senescence and suggest that the resulting chromatin alteration may have a role in controlling leaf longevity. Interestingly, activation of ORE7 / ESC also led to a highly extended post‐harvest storage life.