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Supra‐optimal expression of the cold‐regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development
Author(s) -
PARK MYOUNGRYOUL,
YUN KILYOUNG,
MOHANTY BIJAYALAXMI,
HERATH VENURA,
XU FUYU,
WIJAYA EDWARD,
BAJIC VLADIMIR B.,
YUN SONGJOONG,
DE LOS REYES BENILDO G.
Publication year - 2010
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2010.02221.x
Subject(s) - transcription factor , regulon , biology , myb , microbiology and biotechnology , transcriptome , genetics , gene expression , gene
The R2R3‐type OsMyb4 transcription factor of rice has been shown to play a role in the regulation of osmotic adjustment in heterologous overexpression studies. However, the exact composition and organization of its underlying transcriptional network has not been established to be a robust tool for stress tolerance enhancement by regulon engineering. OsMyb4 network was dissected based on commonalities between the global chilling stress transcriptome and the transcriptome configured by OsMyb4 overexpression. OsMyb4 controls a hierarchical network comprised of several regulatory sub‐clusters associated with cellular defense and rescue, metabolism and development. It regulates target genes either directly or indirectly through intermediary MYB, ERF, bZIP, NAC, ARF and CCAAT‐HAP transcription factors. Regulatory sub‐clusters have different combinations of MYB‐like, GCC‐box‐like, ERD1‐box‐like, ABRE‐like, G‐box‐like, as1/ocs/TGA‐like, AuxRE‐like, gibberellic acid response element (GARE)‐like and JAre‐like cis ‐elements. Cold‐dependent network activity enhanced cellular antioxidant capacity through radical scavenging mechanisms and increased activities of phenylpropanoid and isoprenoid metabolic processes involving various abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C‐repeat binding factor ( DREB/CBF ) and its sub‐regulons operate with possible co‐regulators including nuclear factor‐Y. Because of its upstream position in the network hierarchy, OsMyb4 functions quantitatively and pleiotrophically. Supra‐optimal expression causes misexpression of alternative targets with costly trade‐offs to panicle development.