Dataset Information

Phytochrome and Ethylene Signaling Integration in Arabidopsis Occurs via the Transcriptional Regulation of Genes Co-targeted by PIFs and EIN3.

ABSTRACT: Plant seedlings germinating under the soil are challenged by rough soil grains that can induce physical damage and sudden exposure to light, which can induce photobleaching. Seedlings overcome these challenges by developing apical hooks and by suppressing chlorophyll precursor biosynthesis. These adaptive responses are, respectively, regulated by the phytochrome and ethylene signaling pathways via the PHYTOCHROME-INTERACTING FACTORs (PIFs) and the ETHYLENE INSENSITIVE 3 (EIN3)/EIN3-LIKE transcription factors. Although many processes downstream of phytochrome and ethylene signaling are similar, it remains unclear if and where these pathways converge. Here, we show PIFs and EIN3 induce similar changes in the transcriptome without robustly regulating each other's signaling pathways. PIFs and EIN3 target highly overlapped gene promoters and activate subsets of the co-target genes either interdependently or additively to induce plant responses. For chlorophyll biosynthesis, PIFs and EIN3 target and interdependently activate the expression of HOOKLESS1. HOOKLESS1, in turn, represses chlorophyll synthesis genes to prevent photobleaching. Thus, our results indicate an integration of the phytochrome and ethylene signaling pathways at the level of transcriptional gene regulation by two core groups of transcription factors, PIFs and EIN3.

SUBMITTER: Jeong J

PROVIDER: S-EPMC4949226 | biostudies-other | 2016

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Phytochrome and Ethylene Signaling Integration in Arabidopsis Occurs via the Transcriptional Regulation of Genes Co-targeted by PIFs and EIN3.

Jeong Jinkil J Kim Keunhwa K Kim Mi E ME Kim Hye G HG Heo Gwi S GS Park Ohkmae K OK Park Youn-Il YI Choi Giltsu G Oh Eunkyoo E

Frontiers in plant science 20160719

Plant seedlings germinating under the soil are challenged by rough soil grains that can induce physical damage and sudden exposure to light, which can induce photobleaching. Seedlings overcome these challenges by developing apical hooks and by suppressing chlorophyll precursor biosynthesis. These adaptive responses are, respectively, regulated by the phytochrome and ethylene signaling pathways via the PHYTOCHROME-INTERACTING FACTORs (PIFs) and the ETHYLENE INSENSITIVE 3 (EIN3)/EIN3-LIKE transcri ...[more]

PMID: 27486469

Similar Datasets

Project description:Leaf senescence is induced by various internal and external stimuli. Dark-induced senescence has been extensively investigated, but the detailed mechanism underlying it is not well understood. The red light/far-red light receptor phytochrome B and its downstream transcription factors, PYHTOCHROME INTERACTING FACTORs (PIFs) 4 and 5, are known to play an important role in dark-induced senescence. Furthermore, the senescence-inducing phytohormones, ethylene and abscisic acid (ABA) are reported to be involved in dark-induced senescence. In this study, we analyzed the relationship between ethylene, ABA and PIFs in dark-induced leaf senescence. A triple mutant of the core ABA signaling components; SNF1-related protein kinases 2D (SRK2D), SRK2E, and SRK2I, displayed an ABA insensitive phenotype in ABA-induced senescence, whilst the ethylene insensitive mutant ein2 demonstrated low sensitivity to ABA, suggesting that ethylene signaling is involved in ABA-induced senescence. However, the pif4 pif5 mutant did not display low sensitivity to ABA, suggesting that PIF4 and PIF5 act upstream of ABA signaling. Although PIF4 and PIF5 reportedly regulate ethylene production, the triple mutant ein2 pif4 pif5 showed a stronger delayed senescence phenotype than ein2 or pif4 pif5, suggesting that EIN2 and PIF4/PIF5 partially regulate leaf senescence independently of each other. While direct target genes for PIF4 and PIF5, such as LONG HYPOCOTYL IN FAR-RED1 (HFR1) and PHYTOCHROME INTERACTING FACTOR 3-LIKE 1 (PIL1), showed transient upregulation under dark conditions (as is seen in the shade avoidance response), expression of STAY GREEN1 (SGR1), ORESARA1 (ORE1) and other direct target genes of PIF5, continued to increase during dark incubation. It is possible that transcription factors other than PIF4 and PIF5 are involved in the upregulation of SGR1 and ORE1 at a later stage of dark-induced senescence. Possible candidates are senescence-induced senescence regulators (SIRs), which include the NAC transcription factors ORE1 and AtNAP. In fact, ORE1 is known to bind to the SGR1 promoter and promotes its expression. It is therefore inferred that the phytochrome-PIF pathway regulates initial activation of senescence and subsequently, induced SIRs reinforce leaf senescence during dark-induced senescence.

Dataset Information

Phytochrome and Ethylene Signaling Integration in Arabidopsis Occurs via the Transcriptional Regulation of Genes Co-targeted by PIFs and EIN3.

Publications

Phytochrome and Ethylene Signaling Integration in Arabidopsis Occurs via the Transcriptional Regulation of Genes Co-targeted by PIFs and EIN3.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets