Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signa...Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix(bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS(PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2 A.Z is an evolutionarily conserved H2 A variant which plays essential roles in transcriptional regulation. The replacement of H2 A with H2 A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 coregulate numerous genes in the same direction,some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophandependent auxin biosynthesis pathway. Moreover,phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2 A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions,leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.展开更多
Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in...Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in transcriptional regulation, is deposited in chromatin by the SWI2/SNF2-RELATED 1 complex(SWR1 c). However, the role of H2 A.Z in photomorphogenesis and its deposition mechanism remain unclear. Here, we show that in Arabidopsis thaliana, H2 A.Z deposition at its target loci is induced by light irradiation via NUCLEAR FACTOR-Y, subunit C(NF-YC) proteins, thereby inhibiting photomorphogenic growth. NF-YCs physically interact with ACTIN-RELATED PROTEIN6(ARP6), a key component of the SWR1 c that is essential for depositing H2 A.Z, in a lightdependent manner. NF-YCs and ARP6 function together as negative regulators of hypocotyl growth by depositing H2 A.Z at their target genes during photomorphogenesis. Our findings reveal an important role for the histone variant H2 A.Z in photomorphogenic growth and provide insights into a novel transcription regulatory node that mediates H2 A.Z deposition to control plant growth in response to changing light conditions.展开更多
基金supported by The National Natural Science Foundation of China grants to Z.M.(31900609)The National Key Research and Development Program of China grant(2017YFA0503802)+1 种基金The National Natural Science Foundation of China grants to H.Q.Y.(31530085),W.W.(31900207)and T.G.(32000183)The Science and Technology Commission of Shanghai Municipality grant(18DZ2260500)。
文摘Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor,phytochrome B(phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix(bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS(PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2 A.Z is an evolutionarily conserved H2 A variant which plays essential roles in transcriptional regulation. The replacement of H2 A with H2 A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 coregulate numerous genes in the same direction,some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophandependent auxin biosynthesis pathway. Moreover,phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2 A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions,leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.
基金supported by the National Natural Science Foundation of China(No.32000416)the Natural Science Foundation of Guangdong Province(No.2019A1515110885)。
文摘Inplants,lightsignalstriggeraphotomorphogenic program involving transcriptome changes, epigenetic regulation, and inhibited hypocotyl elongation. The evolutionarily conserved histone variant H2 A.Z, which functions in transcriptional regulation, is deposited in chromatin by the SWI2/SNF2-RELATED 1 complex(SWR1 c). However, the role of H2 A.Z in photomorphogenesis and its deposition mechanism remain unclear. Here, we show that in Arabidopsis thaliana, H2 A.Z deposition at its target loci is induced by light irradiation via NUCLEAR FACTOR-Y, subunit C(NF-YC) proteins, thereby inhibiting photomorphogenic growth. NF-YCs physically interact with ACTIN-RELATED PROTEIN6(ARP6), a key component of the SWR1 c that is essential for depositing H2 A.Z, in a lightdependent manner. NF-YCs and ARP6 function together as negative regulators of hypocotyl growth by depositing H2 A.Z at their target genes during photomorphogenesis. Our findings reveal an important role for the histone variant H2 A.Z in photomorphogenic growth and provide insights into a novel transcription regulatory node that mediates H2 A.Z deposition to control plant growth in response to changing light conditions.
