Neighbor signals perceived by phytochrome B increase thermotolerance in Arabidopsis

AbstractDue to the preeminence of reductionist approaches, our understanding of plant responses to combined stresses is limited. We speculated that light-quality signals of neighboring vegetation might increase susceptibility to heat shocks because shade reduces tissue temperature and hence the likeness of heat shocks. In contrast, plants of Arabidopsis thaliana grown under low red / far-red ratios typical of shade were less damaged by heat stress than plants grown under simulated sunlight. Shade reduces the activity of phytochrome B (phyB) and the phyB mutant showed high tolerance to heat stress even under simulated sunlight. The enhanced heat tolerance under low red / far-red ratios failed in a multiple mutant of PHYTOCHROME INTERACTING FACTORs. The phyB mutant showed reduced expression of several fatty acid desaturase (FAD) genes, proportion of fully unsaturated fatty acids and electrolyte leakage of membranes exposed to a heat shock. Activation of phyB by red light also reduced thermotolerance of dark-grown (etiolated) seedlings but not via changes in FAD gene expression and membrane stability. We propose that the reduced photosynthetic capacity linked to thermotolerant membranes would be less costly under shade, where the light input itself limits photosynthesis.

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PCH1 regulates light, temperature, and circadian signaling as a structural component of phytochrome B-photobodies inArabidopsis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1818217116 ◽

2019 ◽

Vol 116 (17) ◽

pp. 8603-8608 ◽

Cited By ~ 17

Author(s):

He Huang ◽

Katrice E. McLoughlin ◽

Maria L. Sorkin ◽

E. Sethe Burgie ◽

Rebecca K. Bindbeutel ◽

...

Keyword(s):

Structural Component ◽

Genetic Interaction ◽

Red Light ◽

Early Event ◽

Plant Responses ◽

Phytochrome B ◽

Temperature Dependent ◽

Direct Regulator ◽

Unique Ability

The members of the phytochrome (phy) family of bilin-containing photoreceptors are major regulators of plant photomorphogenesis through their unique ability to photointerconvert between a biologically inactive red light-absorbing Pr state and an active far-red light-absorbing Pfr state. While the initial steps in Pfr signaling are unclear, an early event for the phyB isoform after photoconversion is its redistribution from the cytoplasm into subnuclear foci known as photobodies (PBs), which dissipate after Pfr reverts back to Pr by far-red irradiation or by temperature-dependent nonphotochemical reversion. Here we present evidence that PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) functions both as an essential structural component of phyB-containing PBs and as a direct regulator of thermal reversion that is sufficient to stabilize phyB as Pfr in vitro. By examining the genetic interaction between a constitutively active phyBY276H-YFP allele (YHB-YFP) and PCH1, we show that the loss of PCH1 prevents YHB from coalescing into PBs without affecting its nuclear localization, whereas overexpression of PCH1 dramatically increases PB levels. Loss of PCH1, presumably by impacting phyB-PB assembly, compromises a number of events elicited inYHB-YFPplants, including their constitutive photomorphogenic phenotype, red light-regulated thermomorphogenesis, and input of phyB into the circadian clock. Conversely, elevated levels of both phyB and PCH1 generate stable, yet far-red light–reversible PBs that persisted for days. Collectively, our data demonstrate that the assembly of PCH1-containing PBs is critical for phyB signaling to multiple outputs and suggest that altering PB dynamics could be exploited to modulate plant responses to light and temperature.

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PCH1 regulates light, temperature, and circadian signaling as a structural component of phytochrome B-photobodies in Arabidopsis

10.1101/566687 ◽

2019 ◽

Author(s):

He Huang ◽

Katrice E. McLoughlin ◽

Maria L. Sorkin ◽

E. Sethe Burgie ◽

Rebecca K. Bindbeutel ◽

...

Keyword(s):

Circadian Clock ◽

Structural Component ◽

Genetic Interaction ◽

Red Light ◽

Early Event ◽

Plant Responses ◽

Phytochrome B ◽

Thermal Perception ◽

Interacting Protein

AbstractThe phytochrome (phy) family of bilin-containing photoreceptors are major regulators of plant photomorphogenesis through their unique ability to photointerconvert between a biologically inactive red light-absorbing Pr state and an active far-red lightabsorbing Pfr state. While the initial steps in Pfr signaling are unclear, an early event for the phyB isoform after photoconversion is its redistribution from the cytoplasm into subnuclear foci named photobodies (PBs) that dissipate after Pfr reverts back to Pr by far-red irradiation or by temperature-dependent non-photochemical reversion. Here we present evidence that PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) functions both as an essential structural component of phyB-containing PBs and as a direct regulator of thermal reversion that is sufficient to stabilize phyB as Pfr in vitro. By examining the genetic interaction between a constitutively active phyBY276H-YFP allele (YHB-YFP) and PCH1, we show that the loss of PCH1 prevents YHB from coalescing into PBs without affecting its nuclear localization, whereas overexpression of PCH1 dramatically increases PB levels. Loss of PCH1, presumably by impacting phyB-PB assembly, compromises a number of events elicited in YHB-YFP plants, including their constitutive photomorphogenic phenotype, red light-regulated thermomorphogenesis, and input of phyB into the circadian clock. Conversely, elevated levels of both phyB and PCH1 generate stable, yet far red-light reversible PBs that persisted for days. Collectively, our data demonstrate that the assembly of PCHl-containing PBs is critical for phyB signaling to multiple outputs, and suggest that altering PB dynamics could be exploited to modulate plant responses to light and temperature.SignificanceIn Arabidopsis, phytochrome B (phyB) perceives light and temperature signals to regulate various fundamental morphogenic processes in plants through its interconversion between its active Pfr and inactive Pr states. Upon photoconversion from Pr to Pfr, phyB forms subnuclear foci called photobodies, whose composition and molecular function(s) are unclear. We show here that the phyB-interacting protein PCH1 is a structural component of phyB-photobodies and protects Pfr from thermal reversion back to Pr thus helping maintain phyB signaling. Loss of PCH1 compromises photobody formation, which disrupts a number of downstream events including photo- and thermal perception and signaling into the circadian clock. These results demonstrate that forming PCHl-dependent phyB-photobodies is an essential step connecting light and temperature to controls on plant morphogenesis.

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Association between the Polymorphisms of fads2a and fads2b and Poly-Unsaturated Fatty Acids in Common Carp (Cyprinus carpio)

Animals ◽

10.3390/ani11061780 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1780

Author(s):

Yan Zhang ◽

Xiao-Qing Sun ◽

Yu-Qing Ye ◽

Qi Wang ◽

Qing-Song Li ◽

...

Keyword(s):

Common Carp ◽

Unsaturated Fatty Acids ◽

Major Gene ◽

Fatty Acid Desaturase ◽

Mixed Linear Model ◽

Nucleotide Polymorphisms ◽

Single Nucleotide ◽

Food Fish ◽

Rate Limiting ◽

Fatty Acid Desaturase 2

Fatty acid desaturase 2 (fads2) is one of the rate-limiting enzymes in PUFAs biosynthesis. Compared with the diploid fish encoding one fads2, the allo-tetraploid common carp, one most important food fish, encodes two fads2 genes (fads2a and fads2b). The associations between the contents of different PUFAs and the polymorphisms of fads2a and fads2b have not been studied. The contents of 12 PUFAs in common carp individuals were measured, and the polymorphisms in the coding sequences of fads2a and fads2b were screened. We identified five coding single nucleotide polymorphisms (cSNPs) in fads2a and eleven cSNPs in fads2b. Using the mixed linear model and analysis of variance, a synonymous fads2a cSNP was significantly associated with the content of C20:3n-6. One non-synonymous fads2b cSNP (fads2b.751) and one synonymous fads2b cSNP (fads2b.1197) were associated with the contents of seven PUFAs and the contents of six PUFAs, respectively. The heterozygous genotypes in both loci were associated with higher contents than the homozygous genotypes. The fads2b.751 genotype explained more phenotype variation than the fads2b.1197 genotype. These two SNPs were distributed in one haplotype block and associated with the contents of five common PUFAs. These results suggested that fads2b might be the major gene responding to common carp PUFA contents and that fads.751 might be the main effect SNP. These cSNPs would be potential markers for future selection to improve the PUFA contents in common carp.

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Genome-wide identification and analysis of the heat shock transcription factor family in moso bamboo (Phyllostachys edulis)

Scientific Reports ◽

10.1038/s41598-021-95899-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bin Huang ◽

Zhinuo Huang ◽

Ruifang Ma ◽

Jialu Chen ◽

Zhijun Zhang ◽

...

Keyword(s):

Heat Stress ◽

Stress Response ◽

Heat Shock ◽

Gene Family ◽

Regulatory Elements ◽

Moso Bamboo ◽

Naphthalene Acetic Acid ◽

Plant Responses ◽

Heat Stress Response ◽

Regulatory Pathways

AbstractHeat shock transcription factors (HSFs) are central elements in the regulatory network that controls plant heat stress response. They are involved in multiple transcriptional regulatory pathways and play important roles in heat stress signaling and responses to a variety of other stresses. We identified 41 members of the HSF gene family in moso bamboo, which were distributed non-uniformly across its 19 chromosomes. Phylogenetic analysis showed that the moso bamboo HSF genes could be divided into three major subfamilies; HSFs from the same subfamily shared relatively conserved gene structures and sequences and encoded similar amino acids. All HSF genes contained HSF signature domains. Subcellular localization prediction indicated that about 80% of the HSF proteins were located in the nucleus, consistent with the results of GO enrichment analysis. A large number of stress response–associated cis-regulatory elements were identified in the HSF upstream promoter sequences. Synteny analysis indicated that the HSFs in the moso bamboo genome had greater collinearity with those of rice and maize than with those of Arabidopsis and pepper. Numerous segmental duplicates were found in the moso bamboo HSF gene family. Transcriptome data indicated that the expression of a number of PeHsfs differed in response to exogenous gibberellin (GA) and naphthalene acetic acid (NAA). A number of HSF genes were highly expressed in the panicles and in young shoots, suggesting that they may have functions in reproductive growth and the early development of rapidly-growing shoots. This study provides fundamental information on members of the bamboo HSF gene family and lays a foundation for further study of their biological functions in the regulation of plant responses to adversity.

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Heat stress elicits remodeling in the anther lipidome of peanut

Scientific Reports ◽

10.1038/s41598-020-78695-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Zolian S. Zoong Lwe ◽

Ruth Welti ◽

Daniel Anco ◽

Salman Naveed ◽

Sachin Rustgi ◽

...

Keyword(s):

Fatty Acids ◽

Heat Stress ◽

Fatty Acid ◽

Membrane Lipids ◽

Fatty Acid Desaturase ◽

Susceptible Genotype ◽

Unsaturated Lipid ◽

Lipid Species ◽

Lipid Unsaturation ◽

Fatty Acid Amount

AbstractUnderstanding the changes in peanut (Arachis hypogaea L.) anther lipidome under heat stress (HT) will aid in understanding the mechanisms of heat tolerance. We profiled the anther lipidome of seven genotypes exposed to ambient temperature (AT) or HT during flowering. Under AT and HT, the lipidome was dominated by phosphatidylcholine (PC), phosphatidylethanolamine (PE), and triacylglycerol (TAG) species (> 50% of total lipids). Of 89 lipid analytes specified by total acyl carbons:total carbon–carbon double bonds, 36:6, 36:5, and 34:3 PC and 34:3 PE (all contain 18:3 fatty acid and decreased under HT) were the most important lipids that differentiated HT from AT. Heat stress caused decreases in unsaturation indices of membrane lipids, primarily due to decreases in highly-unsaturated lipid species that contained 18:3 fatty acids. In parallel, the expression of Fatty Acid Desaturase 3-2 (FAD3-2; converts 18:2 fatty acids to 18:3) decreased under HT for the heat-tolerant genotype SPT 06-07 but not for the susceptible genotype Bailey. Our results suggested that decreasing lipid unsaturation levels by lowering 18:3 fatty-acid amount through reducing FAD3 expression is likely an acclimation mechanism to heat stress in peanut. Thus, genotypes that are more efficient in doing so will be relatively more tolerant to HT.

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Arabidopsis Phytochrome B Promotes SPA1 Nuclear Accumulation to Repress Photomorphogenesis under Far-Red Light

The Plant Cell ◽

10.1105/tpc.112.107086 ◽

2013 ◽

Vol 25 (1) ◽

pp. 115-133 ◽

Cited By ~ 38

Author(s):

Xu Zheng ◽

Suowei Wu ◽

Huqu Zhai ◽

Peng Zhou ◽

Meifang Song ◽

...

Keyword(s):

Red Light ◽

Nuclear Accumulation ◽

Phytochrome B

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Interactive Effects of Light Quality and Temperature on Arabidopsis Growth and Immunity

Plant and Cell Physiology ◽

10.1093/pcp/pcaa020 ◽

2020 ◽

Vol 61 (5) ◽

pp. 933-941

Author(s):

Xiaoying Liu ◽

Chunmei Xue ◽

Le Kong ◽

Ruining Li ◽

Zhigang Xu ◽

...

Keyword(s):

Disease Resistance ◽

Blue Light ◽

Light Quality ◽

Red Light ◽

Complex Interaction ◽

Hypocotyl Elongation ◽

Interactive Effects ◽

Phytochrome B ◽

Light Conditions ◽

Effects Of Temperature

Abstract We report here the interactive effects of three light qualities (white, red and blue) and three growth temperatures (16�C, 22�C and 28�C) on rosette growth, hypocotyl elongation and disease resistance in Arabidopsis thaliana. While an increase in temperature promotes hypocotyl elongation irrespective of light quality, the effects of temperature on rosette growth and disease resistance are dependent on light quality. Maximum rosette growth rate under white, red and blue light are observed at 28�C, 16�C and 22�C, respectively. The highest disease resistance is observed at 16�C under all three light conditions, but the highest susceptibility is observed at 28�C for white light and 22�C for red and blue light. Interestingly, rosette growth is inhibited by phytochrome B (PHYB) under blue light at 28�C and by cryptochromes (CRYs) under red light at 16�C. In addition, disease resistance is inhibited by PHYB under blue light and promoted by CRYs under red light. Therefore, this study reveals a complex interaction between light and temperature in modulating rosette growth and disease resistance as well as the contribution of PHYB and CRY to disease resistance.

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Light Gradient-Based Screening of Arabidopsis thaliana on a 384-Well Type Plant Array Chip

Micromachines ◽

10.3390/mi11020191 ◽

2020 ◽

Vol 11 (2) ◽

pp. 191

Author(s):

Youn-Hee Park ◽

Je-Kyun Park

Keyword(s):

Arabidopsis Thaliana ◽

White Light ◽

Solid Medium ◽

Red Light ◽

Phytochrome B ◽

Wild Type ◽

Light Gradient ◽

Gradient Based ◽

Light Effects ◽

Germination And Growth

Arabidopsis thaliana (Arabidopsis), as a model for plant research, is widely used for various aspects of plant science. To provide a more sophisticated and microscopic environment for the germination and growth of Arabidopsis, we report a 384-well type plant array chip in which each Arabidopsis seed is independently seeded in a solid medium. The plant array chip is made of a poly(methyl methacrylate) (PMMA) acrylic material and is assembled with a home-made light gradient module to investigate the light effects that significantly affect the germination and growth of Arabidopsis. The light gradient module was used to observe the growth pattern of seedlings according to the intensity of the white light and to efficiently screen for the influence of the white light. To investigate the response to red light (600 nm), which stimulates seed germination, the light gradient module was also applied to the germination test. As a result, the germination results showed that the plant array chip can be used to simultaneously screen wild type seeds and phytochrome B mutant seeds on a single array chip according to the eight red light intensities.

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Ecometabolomics for a Better Understanding of Plant Responses and Acclimation to Abiotic Factors Linked to Global Change

Metabolites ◽

10.3390/metabo10060239 ◽

2020 ◽

Vol 10 (6) ◽

pp. 239 ◽

Cited By ~ 3

Author(s):

Jordi Sardans ◽

Albert Gargallo-Garriga ◽

Otmar Urban ◽

Karel Klem ◽

Tom W.N. Walker ◽

...

Keyword(s):

Amino Acids ◽

Heat Stress ◽

Global Change ◽

Secondary Metabolites ◽

De Novo ◽

Abiotic Factors ◽

Soluble Sugars ◽

Metabolic Responses ◽

Plant Responses ◽

Co2 Concentrations

The number of ecometabolomic studies, which use metabolomic analyses to disentangle organisms’ metabolic responses and acclimation to a changing environment, has grown exponentially in recent years. Here, we review the results and conclusions of ecometabolomic studies on the impacts of four main drivers of global change (increasing frequencies of drought episodes, heat stress, increasing atmospheric carbon dioxide (CO2) concentrations and increasing nitrogen (N) loads) on plant metabolism. Ecometabolomic studies of drought effects confirmed findings of previous target studies, in which most changes in metabolism are characterized by increased concentrations of soluble sugars and carbohydrate derivatives and frequently also by elevated concentrations of free amino acids. Secondary metabolites, especially flavonoids and terpenes, also commonly exhibited increased concentrations when drought intensified. Under heat and increasing N loads, soluble amino acids derived from glutamate and glutamine were the most responsive metabolites. Foliar metabolic responses to elevated atmospheric CO2 concentrations were dominated by greater production of monosaccharides and associated synthesis of secondary metabolites, such as terpenes, rather than secondary metabolites synthesized along longer sugar pathways involving N-rich precursor molecules, such as those formed from cyclic amino acids and along the shikimate pathway. We suggest that breeding for crop genotypes tolerant to drought and heat stress should be based on their capacity to increase the concentrations of C-rich compounds more than the concentrations of smaller N-rich molecules, such as amino acids. This could facilitate rapid and efficient stress response by reducing protein catabolism without compromising enzymatic capacity or increasing the requirement for re-transcription and de novo biosynthesis of proteins.

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Arabidopsis chloroplast J protein DJC75/CRRJ mediates nitrate-promoted seed germination in the dark

Annals of Botany ◽

10.1093/aob/mcaa040 ◽

2020 ◽

Vol 125 (7) ◽

pp. 1091-1099

Author(s):

Huai-Syuan Ciou ◽

Yu-Lun Tsai ◽

Chi-Chou Chiu

Keyword(s):

Arabidopsis Thaliana ◽

Seed Germination ◽

Germination Rate ◽

Red Light ◽

Phytochrome B ◽

Biosynthetic Gene ◽

Unknown Mechanism ◽

J Domain ◽

Domain Protein ◽

J Protein

Abstract Background and Aims Nitrate can stimulate seed germination of many plant species in the absence of light; however, the molecular mechanism of nitrate-promoted seed germination in the dark remains largely unclear and no component of this pathway has been identified yet. Here, we show that a plastid J-domain protein, DJC75/CRRJ, in arabidopsis (Arabidopsis thaliana) is important for nitrate-promoted seed germination in the dark. Methods The expression of DJC75 during imbibition in the dark was investigated. The seed germination rate of mutants defective in DJC75 was determined in the presence of nitrate when light cues for seed germination were eliminated by the treatment of imbibed seeds with a pulse of far-red light to inactivate phytochrome B (phyB), or by assaying germination in the dark with seeds harbouring the phyB mutation. The germination rates of mutants defective in CRRL, a J-like protein related to DJC75, and in two chloroplast Hsp70s were also measured in the presence of nitrate in darkness. Key Results DJC75 was expressed during seed imbibition in the absence of light. Mutants defective in DJC75 showed seed germination defects in the presence of nitrate when light cues for seed germination were eliminated. Mutants defective in CRRL and in two chloroplast Hsp70s also exhibited similar seed germination defects. Upregulation of gibberellin biosynthetic gene GA3ox1 expression by nitrate in imbibed phyB mutant seeds was diminished when DJC75 was knocked out. Conclusions Our data suggest that plastid J-domain protein DJC75 regulates nitrate-promoted seed germination in the dark by upregulation of expression of the gibberellin biosynthetic gene GA3ox1 through an unknown mechanism and that DJC75 may work in concert with chloroplast Hsp70s to regulate nitrate-promoted seed germination. DJC75 is the first pathway component identified for nitrate-promoted seed germination in the dark.

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