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Gao F, Dubos C. The arabidopsis bHLH transcription factor family. TRENDS IN PLANT SCIENCE 2023:S1360-1385(23)00381-3. [PMID: 38143207 DOI: 10.1016/j.tplants.2023.11.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/26/2023]
Abstract
Basic helix-loop-helices (bHLHs) are present in all eukaryotes and form one of the largest families of transcription factors (TFs) found in plants. bHLHs function as transcriptional activators and/or repressors of genes involved in key processes involved in plant growth and development in interaction with the environment (e.g., stomata and root hair development, iron homeostasis, and response to heat and shade). Recent studies have improved our understanding of the functioning of bHLH TFs in complex regulatory networks where a series of post-translational modifications (PTMs) have critical roles in regulating their subcellular localization, DNA-binding capacity, transcriptional activity, and/or stability (e.g., protein-protein interactions, phosphorylation, ubiquitination, and sumoylation). Further elucidating the function and regulation of bHLHs will help further understanding of the biology of plants in general and for the development of new tools for crop improvement.
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Affiliation(s)
- Fei Gao
- College of Agronomy, Hunan Agricultural University, Changsha 410128, China; Yuelushan Laboratory, Changsha 410128, China.
| | - Christian Dubos
- IPSiM, University of Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France.
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2
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Sharma A, Pridgeon AJ, Liu W, Segers F, Sharma B, Jenkins GI, Franklin KA. ELONGATED HYPOCOTYL5 (HY5) and HY5 HOMOLOGUE (HYH) maintain shade avoidance suppression in UV-B. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 115:1394-1407. [PMID: 37243898 PMCID: PMC10953383 DOI: 10.1111/tpj.16328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/17/2023] [Accepted: 05/23/2023] [Indexed: 05/29/2023]
Abstract
Reductions in red to far-red ratio (R:FR) provide plants with an unambiguous signal of vegetational shade and are monitored by phytochrome photoreceptors. Plants integrate this information with other environmental cues to determine the proximity and density of encroaching vegetation. Shade-sensitive species respond to reductions in R:FR by initiating a suite of developmental adaptations termed shade avoidance. These include the elongation of stems to facilitate light foraging. Hypocotyl elongation is driven by increased auxin biosynthesis promoted by PHYTOCHROME INTERACTING FACTORs (PIF) 4, 5 and 7. UV-B perceived by the UV RESISTANCE LOCUS 8 (UVR8) photoreceptor rapidly inhibits shade avoidance, in part by suppressing PIF4/5 transcript accumulation and destabilising PIF4/5 protein. Here, we show that longer-term inhibition of shade avoidance is sustained by ELONGATED HYPOCOTYL 5 (HY5) and HY5 HOMOLOGUE (HYH), which regulate transcriptional reprogramming of genes involved in hormone signalling and cell wall modification. HY5 and HYH are elevated in UV-B and suppress the expression of XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE (XTH) genes involved in cell wall loosening. They additionally increase expression GA2-OXIDASE1 (GA2ox1) and GA2ox2, encoding gibberellin catabolism enzymes that act redundantly to stabilise the PIF-inhibiting DELLA proteins. UVR8 therefore regulates temporally distinct signalling pathways to first rapidly inhibit and subsequently maintain suppression of shade avoidance following UV-B exposure.
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Affiliation(s)
- Ashutosh Sharma
- School of Biological Sciences, Life Sciences BuildingUniversity of BristolBristolBS8 1TQUK
| | - Ashley J. Pridgeon
- School of Biological Sciences, Life Sciences BuildingUniversity of BristolBristolBS8 1TQUK
| | - Wei Liu
- School of Molecular Biosciences, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowG12 8QQUK
| | - Francisca Segers
- School of Biological Sciences, Life Sciences BuildingUniversity of BristolBristolBS8 1TQUK
| | - Bhavana Sharma
- School of Biological Sciences, Life Sciences BuildingUniversity of BristolBristolBS8 1TQUK
| | - Gareth I. Jenkins
- School of Molecular Biosciences, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowG12 8QQUK
| | - Keara A. Franklin
- School of Biological Sciences, Life Sciences BuildingUniversity of BristolBristolBS8 1TQUK
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3
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Zhao J, Bo K, Pan Y, Li Y, Yu D, Li C, Chang J, Wu S, Wang Z, Zhang X, Gu X, Weng Y. Phytochrome-interacting factor PIF3 integrates phytochrome B and UV-B signaling pathways to regulate gibberellin- and auxin-dependent growth in cucumber hypocotyls. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4520-4539. [PMID: 37201922 DOI: 10.1093/jxb/erad181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/11/2023] [Indexed: 05/20/2023]
Abstract
In Arabidopsis, the photoreceptors phytochrome B (PhyB) and UV-B resistance 8 (UVR8) mediate light responses that play a major role in regulating photomorphogenic hypocotyl growth, but how they crosstalk to coordinate this process is not well understood. Here we report map-based cloning and functional characterization of an ultraviolet (UV)-B-insensitive, long-hypocotyl mutant, lh1, and a wild-type-like mutant, lh2, in cucumber (Cucumis sativus), which show defective CsPhyB and GA oxidase2 (CsGA20ox-2), a key gibberellic acid (GA) biosynthesis enzyme, respectively. The lh2 mutation was epistatic to lh1 and partly suppressed the long-hypocotyl phenotype in the lh1lh2 double mutant. We identified phytochrome interacting factor (PIF) CsPIF3 as playing a critical role in integrating the red/far-red and UV-B light responses for hypocotyl growth. We show that two modules, CsPhyB-CsPIF3-CsGA20ox-2-DELLA and CsPIF3-auxin response factor 18 (CsARF18), mediate CsPhyB-regulated hypocotyl elongation through GA and auxin pathways, respectively, in which CsPIF3 binds to the G/E-box motifs in the promoters of CsGA20ox-2 and CsARF18 to regulate their expression. We also identified a new physical interaction between CsPIF3 and CsUVR8 mediating CsPhyB-dependent, UV-B-induced hypocotyl growth inhibition. Our work suggests that hypocotyl growth in cucumber involves a complex interplay of multiple photoreceptor- and phytohormone-mediated signaling pathways that show both conservation with and divergence from those in Arabidopsis.
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Affiliation(s)
- Jianyu Zhao
- Horticulture Department, University of Wisconsin, Madison WI 53706, USA
| | - Kailiang Bo
- Horticulture Department, University of Wisconsin, Madison WI 53706, USA
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yupeng Pan
- Horticulture Department, University of Wisconsin, Madison WI 53706, USA
- College of Horticulture, Northwest A& F University, Yangling 712100, China
| | - Yuhong Li
- College of Horticulture, Northwest A& F University, Yangling 712100, China
| | - Daoliang Yu
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Chuang Li
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jiang Chang
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shuang Wu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhongyi Wang
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaolan Zhang
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xingfang Gu
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yiqun Weng
- Horticulture Department, University of Wisconsin, Madison WI 53706, USA
- USDA-ARS Vegetable Crops Research Unit, Madison, WI 53705, USA
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4
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Fang F, Lin L, Zhang Q, Lu M, Skvortsova MY, Podolec R, Zhang Q, Pi J, Zhang C, Ulm R, Yin R. Mechanisms of UV-B light-induced photoreceptor UVR8 nuclear localization dynamics. THE NEW PHYTOLOGIST 2022; 236:1824-1837. [PMID: 36089828 PMCID: PMC9825989 DOI: 10.1111/nph.18468] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
Light regulates the subcellular localization of plant photoreceptors, a key step in light signaling. Ultraviolet-B radiation (UV-B) induces the plant photoreceptor UV RESISTANCE LOCUS 8 (UVR8) nuclear accumulation, where it regulates photomorphogenesis. However, the molecular mechanism for the UV-B-regulated UVR8 nuclear localization dynamics is unknown. With fluorescence recovery after photobleaching (FRAP), cell fractionation followed by immunoblotting and co-immunoprecipitation (Co-IP) assays we tested the function of UVR8-interacting proteins including CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 in the regulation of UVR8 nuclear dynamics in Arabidopsis thaliana. We showed that UV-B-induced rapid UVR8 nuclear translocation is independent of COP1, which previously was shown to be required for UV-B-induced UVR8 nuclear accumulation. Instead, we provide evidence that the UV-B-induced UVR8 homodimer-to-monomer photo-switch and the concurrent size reduction of UVR8 enables its monomer nuclear translocation, most likely via free diffusion. Nuclear COP1 interacts with UV-B-activated UVR8 monomer, thereby promoting UVR8 nuclear retention. Conversely, RUP1and RUP2, whose expressions are induced by UV-B, inhibit UVR8 nuclear retention via attenuating the UVR8-COP1 interaction, allowing UVR8 to exit the nucleus. Collectively, our data suggest that UV-B-induced monomerization of UVR8 promotes its nuclear translocation via free diffusion. In the nucleus, COP1 binding promotes UVR8 monomer nuclear retention, which is counterbalanced by the major negative regulators RUP1 and RUP2.
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Affiliation(s)
- Fang Fang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Li Lin
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
- Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai Jiao Tong UniversityShanghai200240China
- Joint Center for Single Cell BiologyShanghai Jiao Tong UniversityShanghai200240China
| | - Qianwen Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Min Lu
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China
| | - Mariya Y. Skvortsova
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
| | - Roman Podolec
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3)University of GenevaCH‐1211Geneva 4Switzerland
| | - Qinyun Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Jiahao Pi
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Chunli Zhang
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of SciencesUniversity of GenevaCH‐1211Geneva 4Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3)University of GenevaCH‐1211Geneva 4Switzerland
| | - Ruohe Yin
- School of Agriculture and BiologyShanghai Jiao Tong University800 Dongchuan Road, Minhang DistrictShanghai200240China
- Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai Jiao Tong UniversityShanghai200240China
- Joint Center for Single Cell BiologyShanghai Jiao Tong UniversityShanghai200240China
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5
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Qin W, Wang N, Yin Q, Li H, Wu AM, Qin G. Activation tagging identifies WRKY14 as a repressor of plant thermomorphogenesis in Arabidopsis. MOLECULAR PLANT 2022; 15:1725-1743. [PMID: 36155833 DOI: 10.1016/j.molp.2022.09.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 09/06/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
Increases in recorded high temperatures around the world are causing plant thermomorphogenesis and decreasing crop productivity. PHYTOCHROME INTERACTING FACTOR 4 (PIF4) is a central positive regulator of plant thermomorphogenesis. However, the molecular mechanisms underlying PIF4-regulated thermomorphogenesis remain largely unclear. In this study, we identified ABNORMAL THERMOMORPHOGENESIS 1 (ABT1) as an important negative regulator of PIF4 and plant thermomorphogenesis. Overexpression of ABT1 in the activation tagging mutant abt1-D caused shorter hypocotyls and petioles under moderately high temperature (HT). ABT1 encodes WRKY14, which belongs to subgroup II of the WRKY transcription factors. Overexpression of ABT1/WRKY14 or its close homologs, including ABT2/WRKY35, ABT3/WRKY65, and ABT4/WRKY69in transgenic plants caused insensitivity to HT, whereas the quadruple mutant abt1 abt2 abt3 abt4 exhibited greater sensitivity to HT. ABTs were expressed in hypocotyls, cotyledons, shoot apical meristems, and leaves, but their expression were suppressed by HT. Biochemical assays showed that ABT1 can interact with TCP5, a known positive regulator of PIF4, and interrupt the formation of the TCP5-PIF4 complex and repress its transcriptional activation activity. Genetic analysis showed that ABT1 functioned antagonistically with TCP5, BZR1, and PIF4 in plant thermomorphogenesis. Taken together, our results identify ABT1/WRKY14 as a critical repressor of plant thermomorphogenesis and suggest that ABT1/WRKY14, TCP5, and PIF4 may form a sophisticated regulatory module to fine-tune PIF4 activity and temperature-dependent plant growth.
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Affiliation(s)
- Wenqi Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Ning Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Qi Yin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Huiling Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China
| | - Ai-Min Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China.
| | - Genji Qin
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
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6
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Sun G, Yang L, Zhan W, Chen S, Song M, Wang L, Jiang L, Guo L, Wang K, Ye X, Gou M, Zheng X, Yang J, Yan Z. HFR1, a bHLH Transcriptional Regulator from Arabidopsis thaliana, Improves Grain Yield, Shade and Osmotic Stress Tolerances in Common Wheat. Int J Mol Sci 2022; 23:ijms231912057. [PMID: 36233359 PMCID: PMC9569703 DOI: 10.3390/ijms231912057] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/16/2022] Open
Abstract
Common wheat, Triticum aestivum, is the most widely grown staple crop worldwide. To catch up with the increasing global population and cope with the changing climate, it is valuable to breed wheat cultivars that are tolerant to abiotic or shade stresses for density farming. Arabidopsis LONG HYPOCOTYL IN FAR-RED 1 (AtHFR1), a photomorphogenesis-promoting factor, is involved in multiple light-related signaling pathways and inhibits seedling etiolation and shade avoidance. We report that overexpression of AtHFR1 in wheat inhibits etiolation phenotypes under various light and shade conditions, leading to shortened plant height and increased spike number relative to non-transgenic plants in the field. Ectopic expression of AtHFR1 in wheat increases the transcript levels of TaCAB and TaCHS as observed previously in Arabidopsis, indicating that the AtHFR1 transgene can activate the light signal transduction pathway in wheat. AtHFR1 transgenic seedlings significantly exhibit tolerance to osmotic stress during seed germination compared to non-transgenic wheat. The AtHFR1 transgene represses transcription of TaFT1, TaCO1, and TaCO2, delaying development of the shoot apex and heading in wheat. Furthermore, the AtHFR1 transgene in wheat inhibits transcript levels of PHYTOCHROME-INTERACTING FACTOR 3-LIKEs (TaPIL13, TaPIL15-1B, and TaPIL15-1D), downregulating the target gene STAYGREEN (TaSGR), and thus delaying dark-induced leaf senescence. In the field, grain yields of three AtHFR1 transgenic lines were 18.2–48.1% higher than those of non-transgenic wheat. In summary, genetic modification of light signaling pathways using a photomorphogenesis-promoting factor has positive effects on grain yield due to changes in plant architecture and resource allocation and enhances tolerances to osmotic stress and shade avoidance response.
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Affiliation(s)
- Guanghua Sun
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Luhao Yang
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Weimin Zhan
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Shizhan Chen
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Meifang Song
- Institute of Radiation Technology, Beijing Academy of Science and Technology, Beijing 100875, China
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Lijian Wang
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Liangliang Jiang
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Lin Guo
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Ke Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xingguo Ye
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Mingyue Gou
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Xu Zheng
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
| | - Jianping Yang
- State Key Laboratory of Wheat and Maize Crop Science, Center for Crop Genome Engineering, Longzi Lake Campus, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, China
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Correspondence: (J.Y.); (Z.Y.)
| | - Zehong Yan
- Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, China
- Correspondence: (J.Y.); (Z.Y.)
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Tie D, Guo Y, Zhu C, Quan J, Liu S, Zhou Z, Chai Y, Yue M, Liu X. Parental UV-B radiation regulates the habitat selection of clonal Duchesnea indica in heterogeneous light environments. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:600-612. [PMID: 35272763 DOI: 10.1071/fp21253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Habitat selection behaviour is an effective strategy adopted by clonal plants in heterogeneous understorey light environments, and it is likely regulated by the parental environment's ultraviolet-B radiation levels (UV-B) due to the photomorphogenesis of UV-B and maternal effects. Here, parental ramets of Duchesnea indica were treated with two UV-B radiation levels [high (UV5 group) and low (UV10 group)], newborn offspring were grown under a heterogeneous light environment (ambient light vs shade habitat), and the growth and DNA methylation variations of parents and offspring were analysed. The results showed that parental UV-B affected not only the growth of the parent but also the offspring. The offspring of different UV-B-radiated parents showed different performances. Although these offspring all displayed a tendency to escape from light environments, such as entering shade habitats earlier, and allocating more biomass under shade (33.06% of control, 42.28% of UV5 and 72.73% of UV10), these were particularly obvious in offspring of the high UV-B parent. Improvements in epigenetic diversity (4.77 of control vs 4.83 of UV10) and total DNA methylation levels (25.94% of control vs 27.15% of UV10) and the inhibition of shade avoidance syndrome (denser growth with shorter stolons and internodes) were only observed in offspring of high UV-B parents. This difference was related to the eustress and stress effects of low and high UV-B, respectively. Overall, the behaviour of D. indica under heterogeneous light conditions was regulated by the parental UV-B exposure. Moreover, certain performance improvements helped offspring pre-regulate growth to cope with future environments and were probably associated with the effects of maternal DNA methylation variations in UV-B-radiated parents.
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Affiliation(s)
- Dan Tie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China; and Linyou Branch of Baoji Tobacco Company, Linyou County, Baoji, China
| | - Yuehan Guo
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Chunrui Zhu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Jiaxin Quan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Shiqiang Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Zhe Zhou
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Yongfu Chai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Ming Yue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
| | - Xiao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
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8
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Zhang C, Wu Y, Liu X, Zhang J, Li X, Lin L, Yin R. Pivotal roles of ELONGATED HYPOCOTYL5 in regulation of plant development and fruit metabolism in tomato. PLANT PHYSIOLOGY 2022; 189:527-540. [PMID: 35312008 PMCID: PMC9157105 DOI: 10.1093/plphys/kiac133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
The transcription factor ELONGATED HYPOCOTYL5 (HY5) plays critical roles in plant photomorphogenesis. Previous studies on HY5 have mainly focused on the seedling stage in Arabidopsis (Arabidopsis thaliana), and its functions in other plant species have not been well characterized, particularly at adult stages of development. In this report, we investigated the functions of tomato (Solanum lycopersicum) HY5 (SlHY5) from seedlings to adult plants with a focus on fruits. Genome-edited slhy5 mutants exhibited typical compromised photomorphogenesis in response to various light conditions. The slhy5 mutants showed reduced primary root length and secondary root number, which is associated with altered auxin signaling. SlHY5 promoted chlorophyll biosynthesis from seedling to adult stages. Notably, the promotive role of SlHY5 on chlorophyll accumulation was more pronounced on the illuminated side of green fruits than on their shaded side. Consistent with this light-dependent effect, we determined that SlHY5 protein is stabilized by light. Transcriptome and metabolome analyses in fruits revealed that SlHY5 has major functions in the regulation of metabolism, including the biosynthesis of phenylpropanoids and steroidal glycoalkaloids. These data demonstrate that SlHY5 performs both shared and distinct functions in relation to its Arabidopsis counterpart. The manipulation of SlHY5 represents a powerful tool to influence the two vital agricultural traits of seedling fitness and fruit quality in tomato.
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Affiliation(s)
- Chunli Zhang
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yujie Wu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaorui Liu
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiayi Zhang
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xin Li
- Instrumental Analysis Center of Shanghai Jiao Tong University, Shanghai 200240, China
| | - Li Lin
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ruohe Yin
- Shanghai Collaborative Innovation Center of Agri-Seeds/School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
- Key Laboratory of Urban Agriculture Ministry of Agriculture, Shanghai Jiao Tong University, Shanghai 200240, China
- Joint Center for Single Cell Biology, Shanghai Jiao Tong University, Shanghai 200240, China
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9
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Tsurumoto T, Fujikawa Y, Onoda Y, Ochi Y, Ohta D, Okazawa A. Transcriptome and metabolome analyses revealed that narrowband 280 and 310 nm UV-B induce distinctive responses in Arabidopsis. Sci Rep 2022; 12:4319. [PMID: 35279697 PMCID: PMC8918342 DOI: 10.1038/s41598-022-08331-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 02/28/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractIn plants, the UV-B photoreceptor UV RESISTANCE LOCUS8 (UVR8) perceives UV-B and induces UV-B responses. UVR8 absorbs a range of UV-B (260–335 nm). However, the responsiveness of plants to each UV-B wavelength has not been intensively studied so far. Here, we performed transcriptome and metabolome analyses of Arabidopsis using UV light emitting diodes (LEDs) with peak wavelengths of 280 and 310 nm to investigate the differences in the wavelength-specific UV-B responses. Irradiation with both UV-LEDs induced gene expression of the transcription factor ELONGATED HYPOCOTYL 5 (HY5), which has a central role in the UVR8 signaling pathway. However, the overall transcriptomic and metabolic responses to 280 and 310 nm UV-LED irradiation were different. Most of the known UV-B-responsive genes, such as defense-related genes, responded only to 280 nm UV-LED irradiation. Lipids, polyamines and organic acids were the metabolites most affected by 280 nm UV-LED irradiation, whereas the effect of 310 nm UV-LED irradiation on the metabolome was considerably less. Enzymatic genes involved in the phenylpropanoid pathway upstream in anthocyanin biosynthesis were up-regulated only by 280 nm UV-LED irradiation. These results revealed that the responsivenesses of Arabidopsis to 280 and 310 nm UV-B were significantly different, suggesting that UV-B signaling is mediated by more complex pathways than the current model.
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Petrella DP, Breuillin-Sessoms F, Watkins E. Layering contrasting photoselective filters improves the simulation of foliar shade. PLANT METHODS 2022; 18:16. [PMID: 35135559 PMCID: PMC8822638 DOI: 10.1186/s13007-022-00844-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 01/12/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Neutral density shade cloth is commonly used for simulating foliar shade, in which it reduces light intensity without altering spectral quality. However, foliar shade also alters spectral quality, reducing the ratio of red to far-red (R:FR) light, altering the ratio of blue to green (B:G) light, and reducing ultraviolet light. Unlike shade cloth, photoselective filters can alter spectral quality, but the filters used in previous literature have not simulated foliar shade well. We examined the spectral quality of sunlight under color temperature blue (CTB), plus green (PG), and neutral density (ND) filters from LEE Filters, Rosco e-colour + and Cinegel brands either alone or layered, hypothesizing that the contrasting filter qualities would improve simulations. As a proof-of-concept, we collected spectral data under foliar shade to compare to data collected under photoselective filters. RESULTS Under foliar shade reductions in the R:FR ratio ranged from 0.11 to 0.54 (~ 1.18 in full sun), while reductions in the B:G ratio were as low as 0.53 in deep shade, or were as high as 1.11 in moderate shade (~ 0.87 in full sun). Neutral density filters led to near-neutral reductions in photosynthetically active radiation and reduced the R:FR ratio similar to foliar shade. Color temperature blue filters simulated the increased B:G ratio observed under moderate foliar shade, but did not reduce the R:FR ratio low enough. On their own, PG filters did not simulate any type of foliar shade. Different brands of the same filter type also had disparate effects on spectral quality. Layered CTB and ND filters improved the accuracy of moderate foliar shade simulations, and layering CTB, PG, and ND filters led to accurate simulations of deep foliar shade. CONCLUSIONS Layering photoselective filters with contrasting effects on the spectral quality of sunlight results in more accurate simulations of foliar shade compared to when these filters are used separately. Layered filters can re-create the spectral motifs of moderate and deep foliar shade; they could be used to simulate shade scenarios found in different cropping systems. Photoselective filters offer numerous advantages over neutral density shade cloth and could be a direct replacement for researchers currently using neutral density shade cloth.
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Affiliation(s)
- Dominic P Petrella
- Department of Horticultural Science, Univ. of Minnesota, 1970 Folwell Ave., St. Paul, MN, 55108, USA.
| | | | - Eric Watkins
- Department of Horticultural Science, Univ. of Minnesota, 1970 Folwell Ave., St. Paul, MN, 55108, USA
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11
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He R, Li Y, Ou S, Gao M, Zhang Y, Song S, Liu H. Regulation of Growth and Main Health-Promoting Compounds of Chinese Kale Baby-Leaf by UV-A and FR Light. FRONTIERS IN PLANT SCIENCE 2021; 12:799376. [PMID: 34975989 PMCID: PMC8719463 DOI: 10.3389/fpls.2021.799376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/19/2021] [Indexed: 05/27/2023]
Abstract
Chinese kale baby leaves were hydroponically cultured under the basal light (Red: white LEDs = 2:3 at PPFD of 250 μmol·m-2·s-1) with different supplemental lighting, including individual ultraviolet-A (UV-A, 380 ± 10 nm, 20 μmol·m-2·s-1), far-red (FR, 735 ± 10 nm, 30 μmol·m-2·s-1) light, and their combination (UF) radiation in an artificial light plant factory. Effects of supplemental light qualities on morphology and physiology as well as health-promoting compounds of Chinese kale baby leaves were investigated. Application of UV-A and FR presented a positive effect on biomass, with a pronounced increase in petiole length, stem diameter, main stem length, and leaf area. Notably, plants under UF grew more vigorously than under other treatments. Higher levels of FRAP, vitamin C, total phenolic, and flavonoid were observed in plants under UV-A, while no striking changes or a decreasing trend recorded under FR and UF. Moreover, UV-A enhanced the glucosinolates (GLs) accumulation in Chinese kale baby leaves by increasing the predominant GLs (glucoraphanin and glucobrassicin) contents. RT-qPCR results indicated that UV-A upregulated the gene expressions of transcription factors and core structure genes related to GLs biosynthesis. However, downregulated or unchanged gene expressions of GLs biosynthesis-related genes in Chinese kale baby leaves were observed in FR and UF. Therefore, UV-A was benefited for the production of functional substances, while FR was conducive to a significant increase in crop yield. The combination of UV-A and FR, as a balance between yield and production of secondary metabolite, provided a new perspective for the application of artificial light in horticultural crop production.
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Podolec R, Demarsy E, Ulm R. Perception and Signaling of Ultraviolet-B Radiation in Plants. ANNUAL REVIEW OF PLANT BIOLOGY 2021; 72:793-822. [PMID: 33636992 DOI: 10.1146/annurev-arplant-050718-095946] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Ultraviolet-B (UV-B) radiation is an intrinsic fraction of sunlight that plants perceive through the UVR8 photoreceptor. UVR8 is a homodimer in its ground state that monomerizes upon UV-B photon absorption via distinct tryptophan residues. Monomeric UVR8 competitively binds to the substrate binding site of COP1, thus inhibiting its E3 ubiquitin ligase activity against target proteins, which include transcriptional regulators such as HY5. The UVR8-COP1 interaction also leads to the destabilization of PIF bHLH factor family members. Additionally, UVR8 directly interacts with and inhibits the DNA binding of a different set of transcription factors. Each of these UVR8 signaling mechanisms initiates nuclear gene expression changes leading to UV-B-induced photomorphogenesis and acclimation. The two WD40-repeat proteins RUP1 and RUP2 provide negative feedback regulation and inactivate UVR8 by facilitating redimerization. Here, we review the molecular mechanisms of the UVR8 pathway from UV-B perception and signal transduction to gene expression changes and physiological UV-B responses.
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Affiliation(s)
- Roman Podolec
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
| | - Emilie Demarsy
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland; , ,
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva, Switzerland
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13
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Lee S, Zhu L, Huq E. An autoregulatory negative feedback loop controls thermomorphogenesis in Arabidopsis. PLoS Genet 2021; 17:e1009595. [PMID: 34061850 PMCID: PMC8195427 DOI: 10.1371/journal.pgen.1009595] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/11/2021] [Accepted: 05/11/2021] [Indexed: 12/13/2022] Open
Abstract
Plant growth and development are acutely sensitive to high ambient temperature caused in part due to climate change. However, the mechanism of high ambient temperature signaling is not well defined. Here, we show that HECATEs (HEC1 and HEC2), two helix-loop-helix transcription factors, inhibit thermomorphogenesis. While the expression of HEC1 and HEC2 is increased and HEC2 protein is stabilized at high ambient temperature, hec1hec2 double mutant showed exaggerated thermomorphogenesis. Analyses of the four PHYTOCHROME INTERACTING FACTOR (PIF1, PIF3, PIF4 and PIF5) mutants and overexpression lines showed that they all contribute to promote thermomorphogenesis. Furthermore, genetic analysis showed that pifQ is epistatic to hec1hec2. HECs and PIFs oppositely control the expression of many genes in response to high ambient temperature. PIFs activate the expression of HECs in response to high ambient temperature. HEC2 in turn interacts with PIF4 both in yeast and in vivo. In the absence of HECs, PIF4 binding to its own promoter as well as the target gene promoters was enhanced, indicating that HECs control PIF4 activity via heterodimerization. Overall, these data suggest that PIF4-HEC forms an autoregulatory composite negative feedback loop that controls growth genes to modulate thermomorphogenesis.
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Affiliation(s)
- Sanghwa Lee
- Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Ling Zhu
- Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Enamul Huq
- Department of Molecular Biosciences and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
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14
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Liu Y, Jafari F, Wang H. Integration of light and hormone signaling pathways in the regulation of plant shade avoidance syndrome. ABIOTECH 2021; 2:131-145. [PMID: 36304753 PMCID: PMC9590540 DOI: 10.1007/s42994-021-00038-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/24/2021] [Indexed: 11/25/2022]
Abstract
As sessile organisms, plants are unable to move or escape from their neighboring competitors under high-density planting conditions. Instead, they have evolved the ability to sense changes in light quantity and quality (such as a reduction in photoactive radiation and drop in red/far-red light ratios) and evoke a suite of adaptative responses (such as stem elongation, reduced branching, hyponastic leaf orientation, early flowering and accelerated senescence) collectively termed shade avoidance syndrome (SAS). Over the past few decades, much progress has been made in identifying the various photoreceptor systems and light signaling components implicated in regulating SAS, and in elucidating the underlying molecular mechanisms, based on extensive molecular genetic studies with the model dicotyledonous plant Arabidopsis thaliana. Moreover, an emerging synthesis of the field is that light signaling integrates with the signaling pathways of various phytohormones to coordinately regulate different aspects of SAS. In this review, we present a brief summary of the various cross-talks between light and hormone signaling in regulating SAS. We also present a perspective of manipulating SAS to tailor crop architecture for breeding high-density tolerant crop cultivars.
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Affiliation(s)
- Yang Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Fereshteh Jafari
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 China
| | - Haiyang Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642 China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642 China
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15
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González CV, Prieto JA, Mazza C, Jeréz DN, Biruk LN, Jofré MF, Giordano CV. Grapevine morphological shade acclimation is mediated by light quality whereas hydraulic shade acclimation is mediated by light intensity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 307:110893. [PMID: 33902854 DOI: 10.1016/j.plantsci.2021.110893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 05/27/2023]
Abstract
Plants acclimate to shade by sensing light signals such as low photosynthetic active radiation (PAR), low blue light (BL) levels and low red-to-far red ratios (R:FR) trough plant photoreceptors cross talk. We previously demonstrated that grapevine is irresponsive to variations in R:FR and that BL-attenuation mediates morphological and architectural responses to shade increasing light interception and absorption efficiencies. However, we wondered if grapevine respond to low R:FR when BL is attenuated at the same time. Our objective was to evaluate if morphological, architectural and hydraulic acclimation to shade is mediated by low R:FR ratios and BL attenuation. To test this, we carried out experiments under natural radiation, manipulating light quality by selective sunlight exclusion and light supplementation. We grew grapevines under low PAR (LP) and four high PAR (HP) treatments: HP, HP plus FR supplementation (HP + FR), HP with BL attenuation (HP-B) and HP with BL attenuation plus FR supplementation (HP-B + FR). We found that plants grown under HP-B and HP-B + FR had similar morphological (stem and petiole length, leaf thickness and area), architectural (laminae' angles) and anatomical (stomatal density) traits than plants grown under LP. However, only LP plants presented lower stomata differentiation, lower δ13C and hence lower water use efficiency. Therefore, even under a BL and R:FR attenuated environment, morphological and architectural responses were modulated by BL but not by variation in R:FR. Meanwhile water relations were affected by PAR intensity but not by changes in light quality. Knowing grapevine responses to light quantity and quality are indispensable to adopt tools or design new cultural management practices that manipulate irradiance in the field intending to improve crop performance.
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Affiliation(s)
- Carina V González
- IBAM (Instituto de Biología Agrícola de Mendoza), FCA UNCuyo - CONICET, Almirante Brown 500, Chacras de Coria, 5505, Luján de Cuyo, Mendoza, Argentina; FCEN (Facultad de Ciencias Exactas y Naturales), Universidad Nacional de Cuyo, Padre Contreras 1300, 5500, Mendoza, Argentina.
| | - Jorge A Prieto
- Estación Experimental Agropecuaria Mendoza, Instituto Nacional de Tecnología Agropecuaria (INTA), San Martin 3853, Mayor Drummond, 5507, Luján de Cuyo, Mendoza, Argentina
| | - Carlos Mazza
- IFEVA (Instituto de Investigaciones Fisiológicas y Ecológicas vinculadas a la Agricultura), CONICET - Universidad de Buenos Aires, Facultad de Agronomía, Av. San Martín 4453 (1417), Buenos Aires, Argentina
| | - Damián Nicolás Jeréz
- IBAM (Instituto de Biología Agrícola de Mendoza), FCA UNCuyo - CONICET, Almirante Brown 500, Chacras de Coria, 5505, Luján de Cuyo, Mendoza, Argentina
| | - Lucía N Biruk
- IADIZA (Instituto Argentino de Investigaciones en Zonas Áridas), CONICET, UNCuyo. Av. Ruiz Leal s/n, Parque General San Martín, 5500, Mendoza, Argentina
| | - María Florencia Jofré
- IBAM (Instituto de Biología Agrícola de Mendoza), FCA UNCuyo - CONICET, Almirante Brown 500, Chacras de Coria, 5505, Luján de Cuyo, Mendoza, Argentina
| | - Carla V Giordano
- IADIZA (Instituto Argentino de Investigaciones en Zonas Áridas), CONICET, UNCuyo. Av. Ruiz Leal s/n, Parque General San Martín, 5500, Mendoza, Argentina
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Fernández-Milmanda GL, Ballaré CL. Shade Avoidance: Expanding the Color and Hormone Palette. TRENDS IN PLANT SCIENCE 2021; 26:509-523. [PMID: 33461868 DOI: 10.1016/j.tplants.2020.12.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/05/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Major strides have been made over the past decade in elucidating the mechanisms that mediate shade-avoidance responses. The canonical PHYTOCHROME INTERACTING FACTOR (PIF)-auxin pathway that begins with inactivation of phytochrome B (phyB) by a low red:far-red (R:FR) ratio, and that leads to increased elongation, has been thoroughly characterized in arabidopsis (Arabidopsisthaliana) seedlings. Nevertheless, studies in other life stages and plant species have demonstrated the role of other wavelengths, photoreceptors, and hormones in the orchestration of shade-avoidance responses. We highlight recent developments that illustrate how canopy light cues regulate signaling through auxin, gibberellins (GAs), jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), and strigolactones (SLs) to modulate key aspects of plant growth, metabolism, and defense.
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Affiliation(s)
- Guadalupe L Fernández-Milmanda
- Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE, Buenos Aires, Argentina
| | - Carlos L Ballaré
- Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires, Avenida San Martín 4453, C1417DSE, Buenos Aires, Argentina; Instituto de Investigaciones Biotecnológicas (IIBIO), CONICET, Universidad Nacional de San Martín, B1650HMP Buenos Aires, Argentina.
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17
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A constitutively monomeric UVR8 photoreceptor confers enhanced UV-B photomorphogenesis. Proc Natl Acad Sci U S A 2021; 118:2017284118. [PMID: 33542100 PMCID: PMC8017708 DOI: 10.1073/pnas.2017284118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Coping with UV-B is crucial for plant survival in sunlight. The UV-B photoreceptor UVR8 regulates gene expression associated with photomorphogenesis, acclimation, and UV-B stress tolerance. UV-B photon reception by UVR8 homodimers results in monomerization, followed by interaction with the key signaling protein COP1. We have discovered a UV-B hypersensitive UVR8 photoreceptor that confers strongly enhanced UV-B tolerance and generated a UVR8 variant based on the underlying mutation that shows extremely enhanced constitutive signaling activity. Our findings provide key mechanistic insight into how plants respond and acclimate to UV-B radiation. The plant ultraviolet-B (UV-B) photoreceptor UVR8 plays an important role in UV-B acclimation and survival. UV-B absorption by homodimeric UVR8 induces its monomerization and interaction with the E3 ubiquitin ligase COP1, leading ultimately to gene expression changes. UVR8 is inactivated through redimerization, facilitated by RUP1 and RUP2. Here, we describe a semidominant, hyperactive allele, namely uvr8-17D, that harbors a glycine-101 to serine mutation. UVR8G101S overexpression led to weak constitutive photomorphogenesis and extreme UV-B responsiveness. UVR8G101S was observed to be predominantly monomeric in vivo and, once activated by UV-B, was not efficiently inactivated. Analysis of a UVR8 crystal structure containing the G101S mutation revealed the distortion of a loop region normally involved in stabilization of the UVR8 homodimer. Plants expressing a UVR8 variant combining G101S with the previously described W285A mutation exhibited robust constitutive photomorphogenesis. This work provides further insight into UVR8 activation and inactivation mechanisms and describes a genetic tool for the manipulation of photomorphogenic responses.
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18
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Pierik R, Ballaré CL. Control of Plant Growth and Defense by Photoreceptors: From Mechanisms to Opportunities in Agriculture. MOLECULAR PLANT 2021; 14:61-76. [PMID: 33276158 DOI: 10.1016/j.molp.2020.11.021] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/19/2020] [Accepted: 11/26/2020] [Indexed: 06/12/2023]
Abstract
Plants detect and respond to the proximity of competitors using light signals perceived by photoreceptor proteins. A low ratio of red to far-red radiation (R:FR ratio) is a key signal of competition that is sensed by the photoreceptor phytochrome B (phyB). Low R:FR ratios increase the synthesis of growth-related hormones, including auxin and gibberellins, promoting stem elongation and other shade-avoidance responses. Other photoreceptors that help plants to optimize their developmental configuration and resource allocation patterns in the canopy include blue light photoreceptors, such as cryptochromes and phototropins, and UV receptors, such as UVR8. All photoreceptors act by directly or indirectly controlling the activity of two major regulatory nodes for growth and development: the COP1/SPA ubiquitin E3 ligase complex and the PIF transcription factors. phyB is also an important modulator of hormonal pathways that regulate plant defense against herbivores and pathogens, including the jasmonic acid signaling pathway. In this Perspective, we discuss recent advances on the studies of the mechanisms that link photoreceptors with growth and defense. Understanding these mechanisms is important to provide a functional platform for breeding programs aimed at improving plant productivity, stress tolerance, and crop health in species of agronomic interest, and to manipulate the light environments in protected agriculture.
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Affiliation(s)
- Ronald Pierik
- Plant Ecophysiology, Department of Biology, Utrecht University, Padualaan 8, Utrecht 3584 CH, the Netherlands.
| | - Carlos L Ballaré
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Ave. San Martín 4453, C1417DSE, Buenos Aires, Argentina; IIBIO-INTECH, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de San Martín, B1650HMP, Buenos Aires, Argentina.
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Favero DS, Lambolez A, Sugimoto K. Molecular pathways regulating elongation of aerial plant organs: a focus on light, the circadian clock, and temperature. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:392-420. [PMID: 32986276 DOI: 10.1111/tpj.14996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/11/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
Organs such as hypocotyls and petioles rapidly elongate in response to shade and temperature cues, contributing to adaptive responses that improve plant fitness. Growth plasticity in these organs is achieved through a complex network of molecular signals. Besides conveying information from the environment, this signaling network also transduces internal signals, such as those associated with the circadian clock. A number of studies performed in Arabidopsis hypocotyls, and to a lesser degree in petioles, have been informative for understanding the signaling networks that regulate elongation of aerial plant organs. In particular, substantial progress has been made towards understanding the molecular mechanisms that regulate responses to light, the circadian clock, and temperature. Signals derived from these three stimuli converge on the BAP module, a set of three different types of transcription factors that interdependently promote gene transcription and growth. Additional key positive regulators of growth that are also affected by environmental cues include the CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and SUPPRESSOR OF PHYA-105 (SPA) E3 ubiquitin ligase proteins. In this review we summarize the key signaling pathways that regulate the growth of hypocotyls and petioles, focusing specifically on molecular mechanisms important for transducing signals derived from light, the circadian clock, and temperature. While it is clear that similarities abound between the signaling networks at play in these two organs, there are also important differences between the mechanisms regulating growth in hypocotyls and petioles.
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Affiliation(s)
- David S Favero
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Alice Lambolez
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
| | - Keiko Sugimoto
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan
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Küpers JJ, Oskam L, Pierik R. Photoreceptors Regulate Plant Developmental Plasticity through Auxin. PLANTS 2020; 9:plants9080940. [PMID: 32722230 PMCID: PMC7463442 DOI: 10.3390/plants9080940] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/13/2022]
Abstract
Light absorption by plants changes the composition of light inside vegetation. Blue (B) and red (R) light are used for photosynthesis whereas far-red (FR) and green light are reflected. A combination of UV-B, blue and R:FR-responsive photoreceptors collectively measures the light and temperature environment and adjusts plant development accordingly. This developmental plasticity to photoreceptor signals is largely regulated through the phytohormone auxin. The phytochrome, cryptochrome and UV Resistance Locus 8 (UVR8) photoreceptors are inactivated in shade and/or elevated temperature, which releases their repression of Phytochrome Interacting Factor (PIF) transcription factors. Active PIFs stimulate auxin synthesis and reinforce auxin signalling responses through direct interaction with Auxin Response Factors (ARFs). It was recently discovered that shade-induced hypocotyl elongation and petiole hyponasty depend on long-distance auxin transport towards target cells from the cotyledon and leaf tip, respectively. Other responses, such as phototropic bending, are regulated by auxin transport and signalling across only a few cell layers. In addition, photoreceptors can directly interact with components in the auxin signalling pathway, such as Auxin/Indole Acetic Acids (AUX/IAAs) and ARFs. Here we will discuss the complex interactions between photoreceptor and auxin signalling, addressing both mechanisms and consequences of these highly interconnected pathways.
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