Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress.
BACKGROUND
The transcriptional regulatory network involved in low temperature response leading to acclimation has been established in Arabidopsis. In japonica rice, which can only withstand transient exposure to milder cold stress (10 degrees C), an oxidative-mediated network has been proposed to play a key role in configuring early responses and short-term defenses. The components, hierarchical organization and physiological consequences of this network were further dissected by a systems-level approach.


RESULTS
Regulatory clusters responding directly to oxidative signals were prominent during the initial 6 to 12 hours at 10 degrees C. Early events mirrored a typical oxidative response based on striking similarities of the transcriptome to disease, elicitor and wounding induced processes. Targets of oxidative-mediated mechanisms are likely regulated by several classes of bZIP factors acting on as1/ocs/TGA-like element enriched clusters, ERF factors acting on GCC-box/JAre-like element enriched clusters and R2R3-MYB factors acting on MYB2-like element enriched clusters.Temporal induction of several H2O2-induced bZIP, ERF and MYB genes coincided with the transient H2O2 spikes within the initial 6 to 12 hours. Oxidative-independent responses involve DREB/CBF, RAP2 and RAV1 factors acting on DRE/CRT/rav1-like enriched clusters and bZIP factors acting on ABRE-like enriched clusters. Oxidative-mediated clusters were activated earlier than ABA-mediated clusters.


CONCLUSIONS
Genome-wide, physiological and whole-plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress and developmental responses leads to modulated growth and vigor maintenance contributing to a delay of plastic injuries.
Yun
Kil-Young
KY
School of Biology and Ecology, University of Maine, Orono, ME 04469, USA.
Park
Myoung Ryoul
MR
Mohanty
Bijayalaxmi
B
Herath
Venura
V
Xu
Fuyu
F
Mauleon
Ramil
R
Wijaya
Edward
E
Bajic
Vladimir B
VB
Bruskiewich
Richard
R
de Los Reyes
Benildo G
BG
D003080:Cold Temperature; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D053263:Gene Regulatory Networks; D006861:Hydrogen Peroxide / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D018749:RNA, Plant / Q000235:genetics; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; D006861:Hydrogen Peroxide