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Wang X, Yuan Y, Charrier L, Deng Z, Geisler M, Deng XW, Chen H. Light-stabilized GIL1 suppresses PIN3 activity to inhibit hypocotyl gravitropism. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024. [PMID: 38990128 DOI: 10.1111/jipb.13736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 06/23/2024] [Indexed: 07/12/2024]
Abstract
Light and gravity coordinately regulate the directional growth of plants. Arabidopsis Gravitropic in the Light 1 (GIL1) inhibits the negative gravitropism of hypocotyls in red and far-red light, but the underlying molecular mechanisms remain elusive. Our study found that GIL1 is a plasma membrane-localized protein. In endodermal cells of the upper part of hypocotyls, GIL1 controls the negative gravitropism of hypocotyls. GIL1 directly interacts with PIN3 and inhibits the auxin transport activity of PIN3. Mutation of PIN3 suppresses the abnormal gravitropic response of gil1 mutant. The GIL1 protein is unstable in darkness but it is stabilized by red and far-red light. Together, our data suggest that light-stabilized GIL1 inhibits the negative gravitropism of hypocotyls by suppressing the activity of the auxin transporter PIN3, thereby enhancing the emergence of young seedlings from the soil.
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Affiliation(s)
- Xiaolian Wang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Yanfang Yuan
- School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Laurence Charrier
- Department of Biology, University of Fribourg, Fribourg, 1700, Switzerland
| | - Zhaoguo Deng
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Markus Geisler
- Department of Biology, University of Fribourg, Fribourg, 1700, Switzerland
| | - Xing Wang Deng
- School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Haodong Chen
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
- School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
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Liu Z, Mao L, Yang B, Cui Q, Dai Y, Li X, Chen Y, Dai X, Zou X, Ou L, Yang S. A multi-omics approach identifies bHLH71-like as a positive regulator of yellowing leaf pepper mutants exposed to high-intensity light. HORTICULTURE RESEARCH 2023; 10:uhad098. [PMID: 37426880 PMCID: PMC10323627 DOI: 10.1093/hr/uhad098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/04/2023] [Indexed: 07/11/2023]
Abstract
Light quality and intensity can have a significant impact on plant health and crop productivity. Chlorophylls and carotenoids are classes of plant pigments that are responsible for harvesting light energy and protecting plants from the damaging effects of intense light. Our understanding of the role played by plant pigments in light sensitivity has been aided by light-sensitive mutants that change colors upon exposure to light of variable intensity. In this study, we conducted transcriptomic, metabolomic, and hormone analyses on a novel yellowing mutant of pepper (yl1) to shed light on the molecular mechanism that regulates the transition from green to yellow leaves in this mutant upon exposure to high-intensity light. Our results revealed greater accumulation of the carotenoid precursor phytoene and the carotenoids phytofluene, antheraxanthin, and zeaxanthin in yl1 compared with wild-type plants under high light intensity. A transcriptomic analysis confirmed that enzymes involved in zeaxanthin and antheraxanthin biosynthesis were upregulated in yl1 upon exposure to high-intensity light. We also identified a single basic helix-loop-helix (bHLH) transcription factor, bHLH71-like, that was differentially expressed and positively correlated with light intensity in yl1. Silencing of bHLH71-like in pepper plants suppressed the yellowing phenotype and led to reduced accumulation of zeaxanthin and antheraxanthin. We propose that the yellow phenotype of yl1 induced by high light intensity could be caused by an increase in yellow carotenoid pigments, concurrent with a decrease in chlorophyll accumulation. Our results also suggest that bHLH71-like functions as a positive regulator of carotenoid biosynthesis in pepper.
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Affiliation(s)
- Zhoubin Liu
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Lianzhen Mao
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Bozhi Yang
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Qingzhi Cui
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Yunhua Dai
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Xueqiao Li
- Institute of Vegetables, Hainan Academy of Agricultural Sciences, Haikou 570100, China
| | - Yisong Chen
- Institute of Vegetables, Hainan Academy of Agricultural Sciences, Haikou 570100, China
| | - Xiongze Dai
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Xuexiao Zou
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Lijun Ou
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
| | - Sha Yang
- Engineering Research Center of Education, Ministry for Germplasm Innovation and Breeding New Varieties of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha 410125, China
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Xin GY, Li LP, Wang PT, Li XY, Han YJ, Zhao X. The action of enhancing weak light capture via phototropic growth and chloroplast movement in plants. STRESS BIOLOGY 2022; 2:50. [PMID: 37676522 PMCID: PMC10441985 DOI: 10.1007/s44154-022-00066-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/11/2022] [Indexed: 09/08/2023]
Abstract
To cope with fluctuating light conditions, terrestrial plants have evolved precise regulation mechanisms to help optimize light capture and increase photosynthetic efficiency. Upon blue light-triggered autophosphorylation, activated phototropin (PHOT1 and PHOT2) photoreceptors function solely or redundantly to regulate diverse responses, including phototropism, chloroplast movement, stomatal opening, and leaf positioning and flattening in plants. These responses enhance light capture under low-light conditions and avoid photodamage under high-light conditions. NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3) and ROOT PHOTOTROPISM 2 (RPT2) are signal transducers that function in the PHOT1- and PHOT2-mediated response. NPH3 is required for phototropism, leaf expansion and positioning. RPT2 regulates chloroplast accumulation as well as NPH3-mediated responses. NRL PROTEIN FOR CHLOROPLAST MOVEMENT 1 (NCH1) was recently identified as a PHOT1-interacting protein that functions redundantly with RPT2 to mediate chloroplast accumulation. The PHYTOCHROME KINASE SUBSTRATE (PKS) proteins (PKS1, PKS2, and PKS4) interact with PHOT1 and NPH3 and mediate hypocotyl phototropic bending. This review summarizes advances in phototropic growth and chloroplast movement induced by light. We also focus on how crosstalk in signaling between phototropism and chloroplast movement enhances weak light capture, providing a basis for future studies aiming to delineate the mechanism of light-trapping plants to improve light-use efficiency.
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Affiliation(s)
- Guang-Yuan Xin
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Lu-Ping Li
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Peng-Tao Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Xin-Yue Li
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Yuan-Ji Han
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Xiang Zhao
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China.
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Serrano AM, Vanhaelewyn L, Vandenbussche F, Boccalandro HE, Maldonado B, Van Der Straeten D, Ballaré CL, Arana MV. Cryptochromes are the dominant photoreceptors mediating heliotropic responses of Arabidopsis inflorescences. PLANT, CELL & ENVIRONMENT 2021; 44:3246-3256. [PMID: 34181245 DOI: 10.1111/pce.14139] [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: 08/10/2020] [Revised: 06/18/2021] [Accepted: 06/20/2021] [Indexed: 06/13/2023]
Abstract
Inflorescence movements in response to natural gradients of sunlight are frequently observed in the plant kingdom and are suggested to contribute to reproductive success. Although the physiological and molecular bases of light-mediated tropisms in vegetative organs have been thoroughly investigated, the mechanisms that control inflorescence orientation in response to light gradients under natural conditions are not well understood. In this work, we have used a combination of laboratory and field experiments to investigate light-mediated re-orientation of Arabidopsis thaliana inflorescences. We show that inflorescence phototropism is promoted by photons in the UV and blue spectral range (≤500 nm) and depends on multiple photoreceptor families. Experiments under controlled conditions show that UVR8 is the main photoreceptor mediating the phototropic response to narrowband UV-B radiation, and phototropins and cryptochromes control the response to narrowband blue light. Interestingly, whereas phototropins mediate bending in response to low irradiances of blue, cryptochromes are the principal photoreceptors acting at high irradiances. Moreover, phototropins negatively regulate the action of cryptochromes at high irradiances of blue light. Experiments under natural field conditions demonstrate that cryptochromes are the principal photoreceptors acting in the promotion of the heliotropic response of inflorescences under full sunlight.
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Affiliation(s)
| | - Lucas Vanhaelewyn
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
| | - Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
| | - Hernán Esteban Boccalandro
- Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Cuyo, Chacras de Coria, Mendoza, Argentina
| | - Belén Maldonado
- Instituto Argentino de Investigación de las Zonas Áridas, Mendoza, Argentina
| | | | - Carlos Luis Ballaré
- Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agronomía (IFEVA), Facultad de Agronomía, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad de Buenos Aires, Argentina
- Instituto de Investigaciones Biotecnológicas (IIBio), Universidad Nacional de San Martín, Buenos Aires, Argentina
| | - María Verónica Arana
- Instituto de Investigaciones Forestales y Agropecuarias Bariloche (Instituto Nacional de Tecnología Agropecuaria-Consejo Nacional de Investigaciones Científicas y Técnicas), San Carlos de Bariloche, Rio Negro, Argentina
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5
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Comprehensive Analysis and Expression Profiling of PIN, AUX/LAX, and ABCB Auxin Transporter Gene Families in Solanum tuberosum under Phytohormone Stimuli and Abiotic Stresses. BIOLOGY 2021; 10:biology10020127. [PMID: 33562678 PMCID: PMC7915614 DOI: 10.3390/biology10020127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary In this study, we provide comprehensive information on auxin transporter gene families in potato, including basic parameters, chromosomal distribution, phylogeny, co-expression network analysis, gene structure, tissue-specific expression patterns, subcellular localization, transcription analysis under exogenous hormone stimuli and abiotic stresses, and cis-regulatory element prediction. The responsiveness of auxin transporter family genes to auxin and polar auxin transport inhibitors implied their possible roles in auxin homoeostasis and redistribution. Additionally, the differential expression levels of auxin transporter family genes in response to abscisic acid and abiotic stresses suggested their specific adaptive mechanisms on tolerance to various environmental stimuli. Promoter cis-regulatory element description analyses indicated that a number of cis-regulatory elements within the promoters of auxin transporter genes in potato were targeted by relevant transcription factors to respond to diverse stresses. We are confident that our results provide a foundation for a better understanding of auxin transporters in potato, as we have demonstrated the biological significance of this family of genes in hormone signaling and adaption to environmental stresses. Abstract Auxin is the only plant hormone that exhibits transport polarity mediated by three families: auxin resistant (AUX) 1/like AUX1 (LAX) influx carriers, pin-formed (PIN) efflux carriers, and ATP-binding cassette B (ABCB) influx/efflux carriers. Extensive studies about the biological functions of auxin transporter genes have been reported in model plants. Information regarding these genes in potato remains scarce. Here, we conducted a comprehensive analysis of auxin transporter gene families in potato to examine genomic distributions, phylogeny, co-expression analysis, gene structure and subcellular localization, and expression profiling using bioinformatics tools and qRT-PCR analysis. From these analyses, 5 StLAXs, 10 StPINs, and 22 StABCBs were identified in the potato genome and distributed in 10 of 18 gene modules correlating to the development of various tissues. Transient expression experiments indicated that three representative auxin transporters showed plasma membrane localizations. The responsiveness to auxin and auxin transport inhibitors implied their possible roles in mediating intercellular auxin homoeostasis and redistribution. The differential expression under abscisic acid and abiotic stresses indicated their specific adaptive mechanisms regulating tolerance to environmental stimuli. A large number of auxin-responsive and stress-related cis-elements within their promoters could account for their responsiveness to diverse stresses. Our study aimed to understand the biological significance of potato auxin transporters in hormone signaling and tolerance to environmental stresses.
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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: 25] [Impact Index Per Article: 6.3] [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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Xu F, He S, Zhang J, Mao Z, Wang W, Li T, Hua J, Du S, Xu P, Li L, Lian H, Yang HQ. Photoactivated CRY1 and phyB Interact Directly with AUX/IAA Proteins to Inhibit Auxin Signaling in Arabidopsis. MOLECULAR PLANT 2018; 11:523-541. [PMID: 29269022 DOI: 10.1016/j.molp.2017.12.003] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 05/04/2023]
Abstract
Light is a key environmental cue that inhibits hypocotyl cell elongation through the blue and red/far-red light photoreceptors cryptochrome- and phytochrome-mediated pathways in Arabidopsis. In contrast, as a pivotal endogenous phytohormone auxin promotes hypocotyl elongation through the auxin receptors TIR1/AFBs-mediated degradation of AUX/IAA proteins (AUX/IAAs). However, the molecular mechanisms underlying the antagonistic interaction of light and auxin signaling remain unclear. Here, we report that light inhibits auxin signaling through stabilization of AUX/IAAs by blue and red light-dependent interactions of cryptochrome 1 (CRY1) and phytochrome B with AUX/IAAs, respectively. Blue light-triggered interactions of CRY1 with AUX/IAAs inhibit the associations of TIR1 with AUX/IAAs, leading to the repression of auxin-induced degradation of these proteins. Our results indicate that photoreceptors share AUX/IAAs with auxin receptors as the same direct downstream signaling components. We propose that antagonistic regulation of AUX/IAA protein stability by photoreceptors and auxin receptors allows plants to balance light and auxin signals to optimize their growth.
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Affiliation(s)
- Feng Xu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shengbo He
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Jingyi Zhang
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Zhilei Mao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Wenxiu Wang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Ting Li
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Jie Hua
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Shasha Du
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Pengbo Xu
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Ling Li
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Hongli Lian
- School of Agriculture and Biology/School of Life Sciences and Biotechnology, Shanghai Jiaotong University, Shanghai 200240, China
| | - Hong-Quan Yang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China.
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Sheerin DJ, Hiltbrunner A. Molecular mechanisms and ecological function of far-red light signalling. PLANT, CELL & ENVIRONMENT 2017; 40:2509-2529. [PMID: 28102581 DOI: 10.1111/pce.12915] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 05/18/2023]
Abstract
Land plants possess the ability to sense and respond to far-red light (700-760 nm), which serves as an important environmental cue. Due to the nature of far-red light, it is not absorbed by chlorophyll and thus is enriched in canopy shade and will also penetrate deeper into soil than other visible wavelengths. Far-red light responses include regulation of seed germination, suppression of hypocotyl growth, induction of flowering and accumulation of anthocyanins, which depend on one member of the phytochrome photoreceptor family, phytochrome A (phyA). Here, we review the current understanding of the underlying molecular mechanisms of how plants sense far-red light through phyA and the physiological responses to this light quality. Light-activated phytochromes act on two primary pathways within the nucleus; suppression of the E3 ubiquitin ligase complex CUL4/DDB1COP1/SPA and inactivation of the PHYTOCHROME INTERACTING FACTOR (PIF) family of bHLH transcription factors. These pathways integrate with other signal transduction pathways, including phytohormones, for tissue and developmental stage specific responses. Unlike other phytochromes that mediate red-light responses, phyA is transported from the cytoplasm to the nucleus in far-red light by the shuttle proteins FAR-RED ELONGATED HYPOCOTYL 1 (FHY1) and FHY1-LIKE (FHL). However, additional mechanisms must exist that shift the action of phyA to far-red light; current hypotheses are discussed.
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Affiliation(s)
- David J Sheerin
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Andreas Hiltbrunner
- Institute of Biology II, Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
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Xu D, Miao J, Yumoto E, Yokota T, Asahina M, Watahiki M. YUCCA9-Mediated Auxin Biosynthesis and Polar Auxin Transport Synergistically Regulate Regeneration of Root Systems Following Root Cutting. PLANT & CELL PHYSIOLOGY 2017; 58:1710-1723. [PMID: 29016906 PMCID: PMC5921505 DOI: 10.1093/pcp/pcx107] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/25/2017] [Indexed: 05/21/2023]
Abstract
Recovery of the root system following physical damage is an essential issue for plant survival. An injured root system is able to regenerate by increases in lateral root (LR) number and acceleration of root growth. The horticultural technique of root pruning (root cutting) is an application of this response and is a common garden technique for controlling plant growth. Although root pruning is widely used, the molecular mechanisms underlying the subsequent changes in the root system are poorly understood. In this study, root pruning was employed as a model system to study the molecular mechanisms of root system regeneration. Notably, LR defects in wild-type plants treated with inhibitors of polar auxin transport (PAT) or in the auxin signaling mutant auxin/indole-3-acetic acid19/massugu2 were recovered by root pruning. Induction of IAA19 following root pruning indicates an enhancement of auxin signaling by root pruning. Endogenous levels of IAA increased after root pruning, and YUCCA9 was identified as the primary gene responsible. PAT-related genes were induced after root pruning, and the YUCCA inhibitor yucasin suppressed root regeneration in PAT-related mutants. Therefore, we demonstrate the crucial role of YUCCA9, along with other redundant YUCCA family genes, in the enhancement of auxin biosynthesis following root pruning. This further enhances auxin transport and activates downstream auxin signaling genes, and thus increases LR number.
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Affiliation(s)
- Dongyang Xu
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan
| | - Jiahang Miao
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan
| | - Emi Yumoto
- Department of Biosciences, Teikyo University, Utsunomiya, 320-8551 Japan
| | - Takao Yokota
- Department of Biosciences, Teikyo University, Utsunomiya, 320-8551 Japan
| | - Masashi Asahina
- Department of Biosciences, Teikyo University, Utsunomiya, 320-8551 Japan
| | - Masaaki Watahiki
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810 Japan
- Faculty of Science, Hokkaido University, Sapporo, 060-0810 Japan
- Corresponding author: E-mail, ; Fax, +81-11-706-4473
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Yu C, Dong W, Zhan Y, Huang ZA, Li Z, Kim IS, Zhang C. Genome-wide identification and expression analysis of ClLAX, ClPIN and ClABCB genes families in Citrullus lanatus under various abiotic stresses and grafting. BMC Genet 2017; 18:33. [PMID: 28388893 PMCID: PMC5384148 DOI: 10.1186/s12863-017-0500-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 03/30/2017] [Indexed: 01/21/2023] Open
Abstract
Background Auxin plays an important role in regulating plant growth and development as well as in the response of plants to abiotic stresses. Auxin is transported by three kinds of major protein families, including the AUXIN RESISTANT 1/LIKE AUX1 (AUX⁄LAX) influx carriers, the PIN-FORMED (PIN) efflux carriers and the ATP binding cassette B/P-glycoprotein/Multidrug-resistance (ABCB/MDR/PGP) efflux/condition carriers. The biological function of several auxin transporter genes has been well characterized in Arabidopsis thaliana. However, their function in response to exogenous auxin and abiotic stresses in watermelon (Citrullus lanatus. L) remained unknown. Results Here, the latest updated watermelon genome was used to characterise the ClLAX, ClPIN and ClABCB family genes from watermelon. The genome-wide analysis of the ClLAX, ClPIN and ClABCB family genes, including chromosome localisation, gene structure, and phylogenic relationships, was carried out. Seven ClLAXs, 11 ClPINs and 15 ClABCBs were mapped on 10 watermelon chromosomes. The expression profiles of the ClLAX, ClPIN and ClABCB genes under exogenous indole-3-acetic acid and various abiotic stresses (salt, drought, and cold stresses) treatments were performed by quantitative real-time PCR (qRT-PCR). The transcriptional level of majority ClLAX, ClPIN and ClABCB genes were changed by abiotic stresses in both shoots and roots. We also analysed the expression levels of ClLAX, ClPIN and ClABCB genes in graft response. Conclusion Analysis of the expression patterns of ClLAX, ClPIN and ClABCB genes under salt, drought, cold treatment and grafting response helps us to understand the possible roles of auxin transporter genes in watermelon adaptation to environmental stresses. Electronic supplementary material The online version of this article (doi:10.1186/s12863-017-0500-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chenliang Yu
- Vegetable Research Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Wenqi Dong
- Vegetable Research Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Yihua Zhan
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Zong-An Huang
- Institute of Vegetable Sciences, Wenzhou Academy of Agricultural Sciences, Wenzhou Vocational College of Science and Technology, Key Lab of Crop breeding in South Zhejiang, Wenzhou, 325014, China
| | - Zhimiao Li
- Vegetable Research Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China
| | - Il Seop Kim
- Dempartment of Horticulture, Kangwon National University, Chuncheon, 200-2071, Korea
| | - Chenghao Zhang
- Vegetable Research Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
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Shade Promotes Phototropism through Phytochrome B-Controlled Auxin Production. Curr Biol 2016; 26:3280-3287. [DOI: 10.1016/j.cub.2016.10.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/25/2016] [Accepted: 10/03/2016] [Indexed: 11/19/2022]
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12
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Geisler M, Bailly A, Ivanchenko M. Master and servant: Regulation of auxin transporters by FKBPs and cyclophilins. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 245:1-10. [PMID: 26940487 DOI: 10.1016/j.plantsci.2015.12.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/14/2015] [Accepted: 12/17/2015] [Indexed: 05/27/2023]
Abstract
Plant development and architecture are greatly influenced by the polar distribution of the essential hormone auxin. The directional influx and efflux of auxin from plant cells depends primarily on AUX1/LAX, PIN, and ABCB/PGP/MDR families of auxin transport proteins. The functional analysis of these proteins has progressed rapidly within the last decade thanks to the establishment of heterologous auxin transport systems. Heterologous co-expression allowed also for the testing of protein-protein interactions involved in the regulation of transporters and identified relationships with members of the FK506-Binding Protein (FKBP) and cyclophilin protein families, which are best known in non-plant systems as cellular receptors for the immunosuppressant drugs, FK506 and cyclosporin A, respectively. Current evidence that such interactions affect membrane trafficking, and potentially the activity of auxin transporters is reviewed. We also propose that FKBPs andcyclophilins might integrate the action of auxin transport inhibitors, such as NPA, on members of the ABCB and PIN family, respectively. Finally, we outline open questions that might be useful for further elucidation of the role of immunophilins as regulators (servants) of auxin transporters (masters).
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Affiliation(s)
- Markus Geisler
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland.
| | - Aurélien Bailly
- University of Zurich, Institute of Plant Biology, CH-8008 Zurich, Switzerland
| | - Maria Ivanchenko
- Oregon State University, Department of Botany and Plant Pathology, 2082 Cordley Hall, Corvallis, OR 97331, USA.
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13
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Okamoto K, Ueda H, Shimada T, Tamura K, Koumoto Y, Tasaka M, Morita MT, Hara-Nishimura I. An ABC transporter B family protein, ABCB19, is required for cytoplasmic streaming and gravitropism of the inflorescence stems. PLANT SIGNALING & BEHAVIOR 2016; 11:e1010947. [PMID: 26337543 PMCID: PMC4883830 DOI: 10.1080/15592324.2015.1010947] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A significant feature of plant cells is the extensive motility of organelles and the cytosol, which was originally defined as cytoplasmic streaming. We suggested previously that a three-way interaction between plant-specific motor proteins myosin XIs, actin filaments, and the endoplasmic reticulum (ER) was responsible for cytoplasmic streaming. (1) Currently, however, there are no reports of molecular components for cytoplasmic streaming other than the actin-myosin-cytoskeleton and ER-related proteins. In the present study, we found that elongated cells of inflorescence stems of Arabidopsis thaliana exhibit vigorous cytoplasmic streaming. Statistical analysis showed that the maximal velocity of plastid movements is 7.26 µm/s, which is much faster than the previously reported velocities of organelles. Surprisingly, the maximal velocity of streaming in the inflorescence stem cells was significantly reduced to 1.11 µm/s in an Arabidopsis mutant, abcb19-101, which lacks ATP BINDING CASSETTE SUBFAMILY B19 (ABCB19) that mediates the polar transport of the phytohormone auxin together with PIN-FORMED (PIN) proteins. Polar auxin transport establishes the auxin concentration gradient essential for plant development and tropisms. Deficiency of ABCB19 activity eventually caused enhanced gravitropic responses of the inflorescence stems and abnormally flexed inflorescence stems. These results suggest that ABCB19-mediated auxin transport plays a role not only in tropism regulation, but also in cytoplasmic streaming.
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Affiliation(s)
- Keishi Okamoto
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- These authors contributed equally to this work.
| | - Haruko Ueda
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- These authors contributed equally to this work.
| | - Tomoo Shimada
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kentaro Tamura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yasuko Koumoto
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Masao Tasaka
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0101, Japan
| | - Miyo Terao Morita
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0101, Japan
- Current address: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Ikuko Hara-Nishimura
- Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
- Correspondence to: Ikuko Hara-Nishimura;
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14
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Zhu J, Geisler M. Keeping it all together: auxin-actin crosstalk in plant development. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4983-98. [PMID: 26085676 DOI: 10.1093/jxb/erv308] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Polar auxin transport and the action of the actin cytoskeleton are tightly interconnected, which is documented by the finding that auxin transporters reach their final destination by active movement of secretory vesicles along F-actin tracks. Moreover, auxin transporter polarity and flexibility is thought to depend on transporter cycling that requires endocytosis and exocytosis of vesicles. In this context, we have reviewed the current literature on an involvement of the actin cytoskeleton in polar auxin transport and identify known similarities and differences in its structure, function and dynamics in comparison to non-plant organisms. By describing how auxin modulates actin expression and actin organization and how actin and its stability affects auxin-transporter endocytosis and recycling, we discuss the current knowledge on regulatory auxin-actin feedback loops. We focus on known effects of auxin and of auxin transport inhibitors on the stability and organization of actin and examine the functionality of auxin and/or auxin transport inhibitor-binding proteins with respect to their suitability to integrate auxin/auxin transport inhibitor action. Finally, we indicate current difficulties in the interpretation of organ, time and concentration-dependent auxin/auxin transport inhibitor treatments and formulate simple future experimental guidelines.
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Affiliation(s)
- Jinsheng Zhu
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland
| | - Markus Geisler
- University of Fribourg, Department of Biology-Plant Biology, CH-1700 Fribourg, Switzerland
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15
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Žádníková P, Smet D, Zhu Q, Straeten DVD, Benková E. Strategies of seedlings to overcome their sessile nature: auxin in mobility control. FRONTIERS IN PLANT SCIENCE 2015; 6:218. [PMID: 25926839 PMCID: PMC4396199 DOI: 10.3389/fpls.2015.00218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 03/19/2015] [Indexed: 05/21/2023]
Abstract
Plants are sessile organisms that are permanently restricted to their site of germination. To compensate for their lack of mobility, plants evolved unique mechanisms enabling them to rapidly react to ever changing environmental conditions and flexibly adapt their postembryonic developmental program. A prominent demonstration of this developmental plasticity is their ability to bend organs in order to reach the position most optimal for growth and utilization of light, nutrients, and other resources. Shortly after germination, dicotyledonous seedlings form a bended structure, the so-called apical hook, to protect the delicate shoot meristem and cotyledons from damage when penetrating through the soil. Upon perception of a light stimulus, the apical hook rapidly opens and the photomorphogenic developmental program is activated. After germination, plant organs are able to align their growth with the light source and adopt the most favorable orientation through bending, in a process named phototropism. On the other hand, when roots and shoots are diverted from their upright orientation, they immediately detect a change in the gravity vector and bend to maintain a vertical growth direction. Noteworthy, despite the diversity of external stimuli perceived by different plant organs, all plant tropic movements share a common mechanistic basis: differential cell growth. In our review, we will discuss the molecular principles underlying various tropic responses with the focus on mechanisms mediating the perception of external signals, transduction cascades and downstream responses that regulate differential cell growth and consequently, organ bending. In particular, we highlight common and specific features of regulatory pathways in control of the bending of organs and a role for the plant hormone auxin as a key regulatory component.
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Affiliation(s)
- Petra Žádníková
- Department of Plant Systems Biology, Flanders Institute for Biotechnology, GhentBelgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, GhentBelgium
| | - Dajo Smet
- Department of Physiology, Laboratory of Functional Plant Biology, Ghent University, GhentBelgium
| | - Qiang Zhu
- Institute of Science and Technology Austria, KlosterneuburgAustria
| | | | - Eva Benková
- Institute of Science and Technology Austria, KlosterneuburgAustria
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16
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Haga K, Hayashi KI, Sakai T. PINOID AGC kinases are necessary for phytochrome-mediated enhancement of hypocotyl phototropism in Arabidopsis. PLANT PHYSIOLOGY 2014; 166:1535-45. [PMID: 25281709 PMCID: PMC4226372 DOI: 10.1104/pp.114.244434] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/02/2014] [Indexed: 05/18/2023]
Abstract
Several members of the AGCVIII kinase subfamily, which includes PINOID (PID), PID2, and WAVY ROOT GROWTH (WAG) proteins, have previously been shown to phosphorylate PIN-FORMED (PIN) auxin transporters and control the auxin flow in plants. PID has been proposed as a key component of the phototropin signaling pathway that induces phototropic responses, although the responses were not significantly impaired in the pid single and pid wag1 wag2 triple mutants. This raises questions about the functional roles of the PID family in phototropic responses. Here, we investigated hypocotyl phototropism in the pid pid2 wag1 wag2 quadruple mutant in detail to clarify the roles of the PID family in Arabidopsis (Arabidopsis thaliana). The pid quadruple mutants exhibited moderate responses in continuous light-induced phototropism with a decrease in growth rates of hypocotyls and normal responses in pulse-induced phototropism. However, they showed serious defects in enhancements of pulse-induced phototropic curvatures and lateral fluorescent auxin transport by red light pretreatment. Red light pretreatment significantly reduced the expression level of PID, and the constitutive expression of PID prevented pulse-induced phototropism, irrespective of red light pretreatment. This suggests that the PID family plays a significant role in phytochrome-mediated phototropic enhancement but not the phototropin signaling pathway. Red light treatment enhanced the intracellular accumulation of PIN proteins in response to the vesicle-trafficking inhibitor brefeldin A in addition to increasing their expression levels. Taken together, these results suggest that red light preirradiation enhances phototropic curvatures by up-regulation of PIN proteins, which are not being phosphorylated by the PID family.
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Affiliation(s)
- Ken Haga
- Department of Human Science and Common Education, Nippon Institute of Technology, Saitama 345-8501, Japan (K.H.);Department of Biochemistry, Okayama University of Science, Okayama 700-0005, Japan (K.-i.H.); andGraduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan (T.S.)
| | - Ken-ichiro Hayashi
- Department of Human Science and Common Education, Nippon Institute of Technology, Saitama 345-8501, Japan (K.H.);Department of Biochemistry, Okayama University of Science, Okayama 700-0005, Japan (K.-i.H.); andGraduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan (T.S.)
| | - Tatsuya Sakai
- Department of Human Science and Common Education, Nippon Institute of Technology, Saitama 345-8501, Japan (K.H.);Department of Biochemistry, Okayama University of Science, Okayama 700-0005, Japan (K.-i.H.); andGraduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan (T.S.)
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17
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Sato A, Sasaki S, Matsuzaki J, Yamamoto KT. Light-dependent gravitropism and negative phototropism of inflorescence stems in a dominant Aux/IAA mutant of Arabidopsis thaliana, axr2. JOURNAL OF PLANT RESEARCH 2014; 127:627-39. [PMID: 24938853 DOI: 10.1007/s10265-014-0643-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/09/2014] [Indexed: 05/20/2023]
Abstract
Gravitropism and phototropism of the primary inflorescence stems were examined in a dominant Aux/IAA mutant of Arabidopsis, axr2/iaa7, which did not display either tropism in hypocotyls. axr2-1 stems completely lacked gravitropism in the dark but slowly regained it in light condition. Though wild-type stems showed positive phototropism, axr2 stems displayed negative phototropism with essentially the same light fluence-response curve as the wild type (WT). Application of 1-naphthaleneacetic acid-containing lanolin to the stem tips enhanced the positive phototropism of WT, and reduced the negative phototropism of axr2. Decapitation of stems caused a small negative phototropism in WT, but did not affect the negative phototropism of axr2. p-glycoprotein 1 (pgp1) pgp19 double mutants showed no phototropism, while decapitated double mutants exhibited negative phototropism. Expression of auxin-responsive IAA14/SLR, IAA19/MSG2 and SAUR50 genes was reduced in axr2 and pgp1 pgp19 stems relative to that of WT. These suggest that the phototropic response of stem is proportional to the auxin supply from the shoot apex, and that negative phototropism may be a basal response to unilateral blue-light irradiation when the levels of auxin or auxin signaling are reduced to the minimal level in the primary stems. In contrast, all of these treatments reduced or did not affect gravitropism in wild-type or axr2 stems. Tropic responses of the transgenic lines that expressed axr2-1 protein by the endodermis-specific promoter suggest that AXR2-dependent auxin response in the endodermis plays a more crucial role in gravitropism than in phototropism in stems but no significant roles in either tropism in hypocotyls.
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Affiliation(s)
- Atsuko Sato
- Division of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
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18
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Kami C, Allenbach L, Zourelidou M, Ljung K, Schütz F, Isono E, Watahiki MK, Yamamoto KT, Schwechheimer C, Fankhauser C. Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:393-403. [PMID: 24286493 DOI: 10.1111/tpj.12395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/24/2013] [Accepted: 11/20/2013] [Indexed: 05/05/2023]
Abstract
Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution.
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Affiliation(s)
- Chitose Kami
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Genopode Building, 1015, Lausanne, Switzerland
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19
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Wang Y, M Folta K. Phototropin 1 and dim-blue light modulate the red light de-etiolation response. PLANT SIGNALING & BEHAVIOR 2014; 9:e976158. [PMID: 25482790 PMCID: PMC4623486 DOI: 10.4161/15592324.2014.976158] [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: 08/05/2014] [Revised: 08/23/2014] [Accepted: 08/25/2014] [Indexed: 06/04/2023]
Abstract
Light signals regulate seedling morphological changes during de-etiolation through the coordinated actions of multiple light-sensing pathways. Previously we have shown that red-light-induced hypocotyl growth inhibition can be reversed by addition of dim blue light through the action of phototropin 1 (phot1). Here we further examine the fluence-rate relationships of this blue light effect in short-term (hours) and long-term (days) hypocotyl growth assays. The red stem-growth inhibition and blue promotion is a low-fluence rate response, and blue light delays or attenuates both the red light and far-red light responses. These de-etiolation responses include blue light reversal of red or far-red induced apical hook opening. This response also requires phot1. Cryptochromes (cry1 and cry2) are activated by higher blue light fluence-rates and override phot1's influence on hypocotyl growth promotion. Exogenous application of auxin transport inhibitor naphthylphthalamic acid abolished the blue light stem growth promotion in both hypocotyl growth and hook opening. Results from the genetic tests of this blue light effect in auxin transporter mutants, as well as phytochrome kinase substrate mutants indicated that aux1 may play a role in blue light reversal of red light response. Together, the phot1-mediated adjustment of phytochrome-regulated photomorphogenic events is most robust in dim blue light conditions and is likely modulated by auxin transport through its transporters.
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Affiliation(s)
- Yihai Wang
- Horticultural Sciences Department; University of Florida, Gainesville, FL USA
- The Graduate Program in Plant Molecular and Cellular Biology; University of Florida, Gainesville, FL USA
| | - Kevin M Folta
- Horticultural Sciences Department; University of Florida, Gainesville, FL USA
- The Graduate Program in Plant Molecular and Cellular Biology; University of Florida, Gainesville, FL USA
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20
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Mazzella MA, Casal JJ, Muschietti JP, Fox AR. Hormonal networks involved in apical hook development in darkness and their response to light. FRONTIERS IN PLANT SCIENCE 2014; 5:52. [PMID: 24616725 PMCID: PMC3935338 DOI: 10.3389/fpls.2014.00052] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 02/04/2014] [Indexed: 05/19/2023]
Abstract
In darkness, the dicot seedlings produce an apical hook as result of differential cell division and extension at opposite sides of the hypocotyl. This hook protects the apical meristem from mechanical damage during seedling emergence from the soil. In darkness, gibberellins act via the DELLA-PIF (PHYTOCHROME INTERACTING FACTORs) pathway, and ethylene acts via the EIN3/EIL1 (ETHYLENE INSENSITIVE 3/EIN3 like 1)-HLS1 (HOOKLESS 1) pathway to control the asymmetric accumulation of auxin required for apical hook formation and maintenance. These core pathways form a network with multiple points of connection. Light perception by phytochromes and cryptochromes reduces the activity of PIFs and (COP1) CONSTITUTIVE PHOTOMORPHOGENIC 1-both required for hook formation in darkness-, lowers the levels of gibberellins, and triggers hook opening as a component of the switch between heterotrophic and photoautotrophic development. Apical hook opening is thus a suitable model to study the convergence of endogenous and exogenous signals on the control of cell division and cell growth.
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Affiliation(s)
- Maria A. Mazzella
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, “Dr. Héctor Torres” (INGEBI-CONICET)Buenos Aires, Argentina
- *Correspondence: Maria A. Mazzella, INGEBI, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, “Dr. Héctor Torres”, 2490 Vuelta de Obligado, Buenos Aires, 1428, Argentina e-mail:
| | - Jorge J. Casal
- Facultad de Agronomía, Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura, Universidad de Buenos Aires and CONICETBuenos Aires, Argentina
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICETBuenos Aires, Argentina
| | - Jorge P. Muschietti
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, “Dr. Héctor Torres” (INGEBI-CONICET)Buenos Aires, Argentina
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos AiresBuenos Aires, Argentina
| | - Ana R. Fox
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, “Dr. Héctor Torres” (INGEBI-CONICET)Buenos Aires, Argentina
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21
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Effendi Y, Jones AM, Scherer GFE. AUXIN-BINDING-PROTEIN1 (ABP1) in phytochrome-B-controlled responses. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:5065-74. [PMID: 24052532 PMCID: PMC3830486 DOI: 10.1093/jxb/ert294] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The auxin receptor ABP1 directly regulates plasma membrane activities including the number of PIN-formed (PIN) proteins and auxin efflux transport. Red light (R) mediated by phytochromes regulates the steady-state level of ABP1 and auxin-inducible growth capacity in etiolated tissues but, until now, there has been no genetic proof that ABP1 and phytochrome regulation of elongation share a common mechanism for organ elongation. In far red (FR)-enriched light, hypocotyl lengths were larger in the abp1-5 and abp1/ABP1 mutants, but not in tir1-1, a null mutant of the TRANSPORT-INHIBITOR-RESPONSE1 auxin receptor. The polar auxin transport inhibitor naphthylphthalamic acid (NPA) decreased elongation in the low R:FR light-enriched white light (WL) condition more strongly than in the high red:FR light-enriched condition WL suggesting that auxin transport is an important condition for FR-induced elongation. The addition of NPA to hypocotyls grown in R- and FR-enriched light inhibited hypocotyl gravitropism to a greater extent in both abp1 mutants and in phyB-9 and phyA-211 than the wild-type hypocotyl, arguing for decreased phytochrome action in conjunction with auxin transport in abp1 mutants. Transcription of FR-enriched light-induced genes, including several genes regulated by auxin and shade, was reduced 3-5-fold in abp1-5 compared with Col and was very low in abp1/ABP1. In the phyB-9 mutant the expression of these reporter genes was 5-15-fold lower than in Col. In tir1-1 and the phyA-211 mutants shade-induced gene expression was greatly attenuated. Thus, ABP1 directly or indirectly participates in auxin and light signalling.
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Affiliation(s)
- Yunus Effendi
- Leibniz Universität Hannover, Institut für Zierpflanzenbau und Gehölzforschung, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
| | - Alan M. Jones
- Departments of Biology and Pharmacology, University of North Carolina, Chapel Hill, NC 27516, USA
| | - Günther F. E. Scherer
- Leibniz Universität Hannover, Institut für Zierpflanzenbau und Gehölzforschung, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany
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22
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Goyal A, Szarzynska B, Fankhauser C. Phototropism: at the crossroads of light-signaling pathways. TRENDS IN PLANT SCIENCE 2013; 18:393-401. [PMID: 23562459 DOI: 10.1016/j.tplants.2013.03.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/28/2013] [Accepted: 03/08/2013] [Indexed: 05/11/2023]
Abstract
Phototropism enables plants to orient growth towards the direction of light and thereby maximizes photosynthesis in low-light environments. In angiosperms, blue-light photoreceptors called phototropins are primarily involved in sensing the direction of light. Phytochromes and cryptochromes (sensing red/far-red and blue light, respectively) also modulate asymmetric hypocotyl growth, leading to phototropism. Interactions between different light-signaling pathways regulating phototropism occur in cryptogams and angiosperms. In this review, we focus on the molecular mechanisms underlying the co-action between photosensory systems in the regulation of hypocotyl phototropism in Arabidopsis thaliana. Recent studies have shown that phytochromes and cryptochromes enhance phototropism by controlling the expression of important regulators of phototropin signaling. In addition, phytochromes may also regulate growth towards light via direct interaction with the phototropins.
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Affiliation(s)
- Anupama Goyal
- Centre for Integrative Genomics, University of Lausanne, Genopode Building, CH 1015 Lausanne, Switzerland
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23
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Hohm T, Preuten T, Fankhauser C. Phototropism: translating light into directional growth. AMERICAN JOURNAL OF BOTANY 2013; 100:47-59. [PMID: 23152332 DOI: 10.3732/ajb.1200299] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Phototropism allows plants to align their photosynthetic tissues with incoming light. The direction of incident light is sensed by the phototropin family of blue light photoreceptors (phot1 and phot2 in Arabidopsis), which are light-activated protein kinases. The kinase activity of phototropins and phosphorylation of residues in the activation loop of their kinase domains are essential for the phototropic response. These initial steps trigger the formation of the auxin gradient across the hypocotyl that leads to asymmetric growth. The molecular events between photoreceptor activation and the growth response are only starting to be elucidated. In this review, we discuss the major steps leading from light perception to directional growth concentrating on Arabidopsis. In addition, we highlight links that connect these different steps enabling the phototropic response.
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Affiliation(s)
- Tim Hohm
- Department of Medical Genetics, Faculty of Biology and Medicine, University of Lausanne, Rue du Bugnon 27, CH-1005 Lausanne, Switzerland
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24
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Haga K, Sakai T. PIN auxin efflux carriers are necessary for pulse-induced but not continuous light-induced phototropism in Arabidopsis. PLANT PHYSIOLOGY 2012; 160:763-76. [PMID: 22843667 PMCID: PMC3461554 DOI: 10.1104/pp.112.202432] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 07/26/2012] [Indexed: 05/18/2023]
Abstract
Auxin efflux carrier PIN-FORMED (PIN) proteins are thought to have central roles in regulating asymmetrical auxin translocation during tropic responses, including gravitropism and phototropism, in plants. Although PIN3 is known to be involved in phototropism in Arabidopsis (Arabidopsis thaliana), no severe defects of phototropism in any of the pin mutants have been reported. We show here that the pulse-induced, first positive phototropism is impaired partially in pin1, pin3, and pin7 single mutants, and severely in triple mutants. In contrast, such impairment was not observed in continuous-light-induced second positive phototropism. Analysis with an auxin-reporter gene demonstrated that PIN3-mediated auxin gradients participate in pulse-induced phototropism but not in continuous-light-induced phototropism. Similar functional separation was also applicable to PINOID, a regulator of PIN localization. Our results strongly suggest the existence of functionally distinct mechanisms i.e. a PIN-dependent mechanism in which transient stimulation is sufficient to induce phototropism, and a PIN-independent mechanism that requires continuous stimulation and does not operate in the former phototropism process. Although a previous study has proposed that blue-light photoreceptors, the phototropins, control PIN localization through the transcriptional down-regulation of PINOID, we could not detect this blue-light-dependent down-regulation event, suggesting that other as yet unknown mechanisms are involved in phototropin-mediated phototropic responses.
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Affiliation(s)
- Ken Haga
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
| | - Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan
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Sakai T, Haga K. Molecular genetic analysis of phototropism in Arabidopsis. PLANT & CELL PHYSIOLOGY 2012; 53:1517-34. [PMID: 22864452 PMCID: PMC3439871 DOI: 10.1093/pcp/pcs111] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Plant life is strongly dependent on the environment, and plants regulate their growth and development in response to many different environmental stimuli. One of the regulatory mechanisms involved in these responses is phototropism, which allows plants to change their growth direction in response to the location of the light source. Since the study of phototropism by Darwin, many physiological studies of this phenomenon have been published. Recently, molecular genetic analyses of Arabidopsis have begun to shed light on the molecular mechanisms underlying this response system, including phototropin blue light photoreceptors, phototropin signaling components, auxin transporters, auxin action mechanisms and others. This review highlights some of the recent progress that has been made in further elucidating the phototropic response, with particular emphasis on mutant phenotypes.
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Affiliation(s)
- Tatsuya Sakai
- Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata, 950-2181 Japan.
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Phytochrome Kinase Substrate 4 is phosphorylated by the phototropin 1 photoreceptor. EMBO J 2012; 31:3457-67. [PMID: 22781128 DOI: 10.1038/emboj.2012.186] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/11/2012] [Indexed: 11/08/2022] Open
Abstract
Phototropism allows plants to redirect their growth towards the light to optimize photosynthesis under reduced light conditions. Phototropin 1 (phot1) is the primary low blue light-sensing receptor triggering phototropism in Arabidopsis. Light-induced autophosphorylation of phot1, an AGC-class protein kinase, constitutes an essential step for phototropism. However, apart from the receptor itself, substrates of phot1 kinase activity are less clearly established. Phototropism is also influenced by the cryptochromes and phytochromes photoreceptors that do not provide directional information but influence the process through incompletely characterized mechanisms. Here, we show that Phytochrome Kinase Substrate 4 (PKS4), a known element of phot1 signalling, is a substrate of phot1 kinase activity in vitro that is phosphorylated in a phot1-dependent manner in vivo. PKS4 phosphorylation is transient and regulated by a type 2-protein phosphatase. Moreover, phytochromes repress the accumulation of the light-induced phosphorylated form of PKS4 showing a convergence of photoreceptor activity on this signalling element. Our physiological analyses suggest that PKS4 phosphorylation is not essential for phototropism but is part of a negative feedback mechanism.
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Henrichs S, Wang B, Fukao Y, Zhu J, Charrier L, Bailly A, Oehring SC, Linnert M, Weiwad M, Endler A, Nanni P, Pollmann S, Mancuso S, Schulz A, Geisler M. Regulation of ABCB1/PGP1-catalysed auxin transport by linker phosphorylation. EMBO J 2012; 31:2965-80. [PMID: 22549467 PMCID: PMC3395086 DOI: 10.1038/emboj.2012.120] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 04/02/2012] [Indexed: 01/12/2023] Open
Abstract
Polar transport of the plant hormone auxin is controlled by PIN- and ABCB/PGP-efflux catalysts. PIN polarity is regulated by the AGC protein kinase, PINOID (PID), while ABCB activity was shown to be dependent on interaction with the FKBP42, TWISTED DWARF1 (TWD1). Using co-immunoprecipitation (co-IP) and shotgun LC-MS/MS analysis, we identified PID as a valid partner in the interaction with TWD1. In-vitro and yeast expression analyses indicated that PID specifically modulates ABCB1-mediated auxin efflux in an action that is dependent on its kinase activity and that is reverted by quercetin binding and thus inhibition of PID autophosphorylation. Triple ABCB1/PID/TWD1 co-transfection in tobacco revealed that PID enhances ABCB1-mediated auxin efflux but blocks ABCB1 in the presence of TWD1. Phospho-proteomic analyses identified S634 as a key residue of the regulatory ABCB1 linker and a very likely target of PID phosphorylation that determines both transporter drug binding and activity. In summary, we provide evidence that PID phosphorylation has a dual, counter-active impact on ABCB1 activity that is coordinated by TWD1-PID interaction.
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Affiliation(s)
- Sina Henrichs
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Bangjun Wang
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
- Department of Biology—Plant Biology, University of Fribourg, Fribourg, Switzerland
- Department of Plant Biology and Biotechnology, University of Copenhagen, Frederiksberg, Denmark
| | - Yoichiro Fukao
- Plant Global Educational Project, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan
| | - Jinsheng Zhu
- Department of Biology—Plant Biology, University of Fribourg, Fribourg, Switzerland
| | - Laurence Charrier
- Department of Biology—Plant Biology, University of Fribourg, Fribourg, Switzerland
| | - Aurélien Bailly
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
- Department of Biology—Plant Biology, University of Fribourg, Fribourg, Switzerland
| | - Sophie C Oehring
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Miriam Linnert
- Signaltransduktion, Max-Planck-Forschungsstelle für Enzymologie der Proteinfaltung, Halle (Saale), Germany
| | - Matthias Weiwad
- Signaltransduktion, Max-Planck-Forschungsstelle für Enzymologie der Proteinfaltung, Halle (Saale), Germany
| | - Anne Endler
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
| | - Paolo Nanni
- Functional Genomics Center Zurich, UZH/ETH Zürich, Zürich, Switzerland
| | - Stephan Pollmann
- Ruhr-Universität Bochum, Lehrstuhl für Pflanzenphysiologie, Bochum, Germany
| | - Stefano Mancuso
- Department of Plant, Soil and Environmental Science, University of Florence, Sesto Fiorentino, Italy
| | - Alexander Schulz
- Department of Plant Biology and Biotechnology, University of Copenhagen, Frederiksberg, Denmark
| | - Markus Geisler
- Molecular Plant Physiology, Institute of Plant Biology, University of Zurich and Zurich-Basel Plant Science Center, Zurich, Switzerland
- Department of Biology—Plant Biology, University of Fribourg, Fribourg, Switzerland
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Lewandowska-Sabat AM, Winge P, Fjellheim S, Dørum G, Bones AM, Rognli OA. Genome wide transcriptional profiling of acclimation to photoperiod in high-latitude accessions of Arabidopsis thaliana. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 185-186:143-155. [PMID: 22325875 DOI: 10.1016/j.plantsci.2011.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 09/28/2011] [Accepted: 10/03/2011] [Indexed: 05/31/2023]
Abstract
Three Arabidopsis thaliana accessions originating from the northernmost boundary of the species distribution in Norway (59-68°N) were used to study global wide transcriptional responses to 16 and 24 h photoperiods during flower initiation. Significant analysis of microarrays (SAM), analyses of statistically overrepresented gene ontologies (GOstat) and gene set enrichment analyses (GSEA) were used to identify candidate genes and genetic pathways underlying phenotypic adaptations of accessions to different photoperiods. Statistical analyses identified 732 and 258 differentially expressed genes between accessions in 16 and 24 h photoperiod, respectively. Among significantly expressed genes, ethylene mediated signaling pathway was significantly overrepresented in 16 h photoperiod, while genes involved in response to auxin stimulus were found to be significantly overrepresented in 24 h photoperiod. Several gene sets were found to be differentially expressed among accessions, e.g. cold acclimation, dehydration response, phytochrome signaling, vernalization response and circadian clock regulated flowering time genes. These results revealed several candidate genes and pathways likely involved in transcriptional control of photoperiodic response. In particular, ethylene and auxin signaling pathway may represent candidate genes contributing to local adaptation of high-latitude accessions of A. thaliana.
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Liu H, Liu B, Zhao C, Pepper M, Lin C. The action mechanisms of plant cryptochromes. TRENDS IN PLANT SCIENCE 2011; 16:684-91. [PMID: 21983106 PMCID: PMC3277817 DOI: 10.1016/j.tplants.2011.09.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 08/01/2011] [Accepted: 09/05/2011] [Indexed: 05/12/2023]
Abstract
Cryptochromes (CRY) are blue-light receptors that mediate various light responses in plants. The photoexcited CRY molecules undergo several biophysical and biochemical changes, including electron transfer, phosphorylation and ubiquitination, resulting in conformational changes to propagate light signals. Two modes of CRY signal transduction have recently been discovered: the cryptochrome-interacting basic-helix-loop-helix 1 (CIB)-dependent CRY2 regulation of transcription; and the SUPPRESSOR OF PHYA1/CONSTITUTIVELY PHOTOMORPHOGENIC1 (SPA1/COP1)-dependent cryptochrome regulation of proteolysis. Both CRY signaling pathways rely on blue light-dependent interactions between the CRY photoreceptor and its signaling proteins to modulate gene expression changes in response to blue light, leading to altered developmental programs in plants.
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Affiliation(s)
- Hongtao Liu
- Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA
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Christie JM, Yang H, Richter GL, Sullivan S, Thomson CE, Lin J, Titapiwatanakun B, Ennis M, Kaiserli E, Lee OR, Adamec J, Peer WA, Murphy AS. phot1 inhibition of ABCB19 primes lateral auxin fluxes in the shoot apex required for phototropism. PLoS Biol 2011; 9:e1001076. [PMID: 21666806 PMCID: PMC3110179 DOI: 10.1371/journal.pbio.1001076] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 04/26/2011] [Indexed: 11/18/2022] Open
Abstract
It is well accepted that lateral redistribution of the phytohormone auxin underlies the bending of plant organs towards light. In monocots, photoreception occurs at the shoot tip above the region of differential growth. Despite more than a century of research, it is still unresolved how light regulates auxin distribution and where this occurs in dicots. Here, we establish a system in Arabidopsis thaliana to study hypocotyl phototropism in the absence of developmental events associated with seedling photomorphogenesis. We show that auxin redistribution to the epidermal sites of action occurs at and above the hypocotyl apex, not at the elongation zone. Within this region, we identify the auxin efflux transporter ATP-BINDING CASSETTE B19 (ABCB19) as a substrate target for the photoreceptor kinase PHOTOTROPIN 1 (phot1). Heterologous expression and physiological analyses indicate that phosphorylation of ABCB19 by phot1 inhibits its efflux activity, thereby increasing auxin levels in and above the hypocotyl apex to halt vertical growth and prime lateral fluxes that are subsequently channeled to the elongation zone by PIN-FORMED 3 (PIN3). Together, these results provide new insights into the roles of ABCB19 and PIN3 in establishing phototropic curvatures and demonstrate that the proximity of light perception and differential phototropic growth is conserved in angiosperms. Plants depend on sunlight for photosynthesis and adapt their growth to optimize light capture. Phototropism, the reorientation of growth towards light, is one important adaptive response. Modern studies of phototropism began with experiments in monocotyledonous grasses by Charles Darwin and led ultimately to the discovery of the plant growth hormone auxin, establishing the concept that light perception at the shoot apex triggers differential bending in the tissues below. In the past two decades, molecular-genetic analysis in the model flowering plant Arabidopsis thaliana has identified the principle photoreceptor for phototropism, phot1, as well as the major auxin transporters. Despite extensive efforts, how the photoreceptor regulates auxin transport so as to establish differential growth is still poorly understood, as is whether this process is conserved between monocots and dicots. Here, we introduce a new approach to the study of Arabidopsis phototropism in the absence of developmental events associated with seedling photomorphogenesis. In doing so, we show that the proximity of light perception and differential growth is conserved between monocots and dicots: in both plant types, differential growth is a consequence of lateral auxin movements across the shoot apex. Moreover, we identify two auxin transporters, PIN3 and ABCB19, that contribute to these movements, the latter serving to prime lateral auxin fluxes in the shoot apex. ABCB19 function is regulated by phot1, identifying it as a substrate for this class of photoreceptor kinase.
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Affiliation(s)
- John M. Christie
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
- * E-mail: (JMC); (ASM)
| | - Haibing Yang
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Gregory L. Richter
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Stuart Sullivan
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Catriona E. Thomson
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Jinshan Lin
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Boosaree Titapiwatanakun
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Margaret Ennis
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Eirini Kaiserli
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Ok Ran Lee
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Jiri Adamec
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, United States of America
| | - Wendy A. Peer
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
| | - Angus S. Murphy
- Department of Horticulture, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (JMC); (ASM)
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Peer WA, Blakeslee JJ, Yang H, Murphy AS. Seven things we think we know about auxin transport. MOLECULAR PLANT 2011; 4:487-504. [PMID: 21505044 DOI: 10.1093/mp/ssr034] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Polar transport of the phytohormone auxin and the establishment of localized auxin maxima regulate embryonic development, stem cell maintenance, root and shoot architecture, and tropic growth responses. The past decade has been marked by dramatic progress in efforts to elucidate the complex mechanisms by which auxin transport regulates plant growth. As the understanding of auxin transport regulation has been increasingly elaborated, it has become clear that this process is involved in almost all plant growth and environmental responses in some way. However, we still lack information about some basic aspects of this fundamental regulatory mechanism. In this review, we present what we know (or what we think we know) and what we do not know about seven auxin-regulated processes. We discuss the role of auxin transport in gravitropism in primary and lateral roots, phototropism, shoot branching, leaf expansion, and venation. We also discuss the auxin reflux/fountain model at the root tip, flavonoid modulation of auxin transport processes, and outstanding aspects of post-translational regulation of auxin transporters. This discussion is not meant to be exhaustive, but highlights areas in which generally held assumptions require more substantive validation.
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Affiliation(s)
- Wendy Ann Peer
- Department of Horticulture, 625 Agriculture Mall Drive, Purdue University, West Lafayette, IN 47907, USA.
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32
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Ding Z, Galván-Ampudia CS, Demarsy E, Łangowski Ł, Kleine-Vehn J, Fan Y, Morita MT, Tasaka M, Fankhauser C, Offringa R, Friml J. Light-mediated polarization of the PIN3 auxin transporter for the phototropic response in Arabidopsis. Nat Cell Biol 2011; 13:447-52. [DOI: 10.1038/ncb2208] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 01/11/2011] [Indexed: 12/15/2022]
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Cole B, Kay SA, Chory J. Automated analysis of hypocotyl growth dynamics during shade avoidance in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 65:991-1000. [PMID: 21288269 PMCID: PMC3076959 DOI: 10.1111/j.1365-313x.2010.04476.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plants that are adapted to environments where light is abundant are especially sensitive to competition for light from neighboring vegetation. As a result, these plants initiate a series of changes known as the shade avoidance syndrome, during which plants elongate their stems and petioles at the expense of leaf development. Although the developmental outcomes of exposure to prolonged shade are known, the signaling dynamics during the initial exposure of seedlings to shade is less well studied. Here, we report the development of a new software-based tool, called HyDE (Hypocotyl Determining Engine) to measure hypocotyl lengths of time-resolved image stacks of Arabidopsis wild-type and mutant seedlings. We show that Arabidopsis grows rapidly in response to the shade stimulus, with measurable growth after just 45 min shade exposure. Similar to other mustard species, this growth response occurs in multiple distinct phases, including two phases of rapid growth and one phase of slower growth. Using mutants affected in shade avoidance phenotypes, we demonstrate that most of this early growth requires new auxin biosynthesis via the indole-3-pyruvate pathway. When activity of this pathway is reduced, the first phase of elongation growth is absent, and this is correlated with reduced activity of auxin-regulated genes. Finally, we show that varying shade intensity and duration can affect the shape and magnitude of the growth response, indicating a broad range of the elongation response to shade.
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Affiliation(s)
- Benjamin Cole
- Plant Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA 92037 U.S.A
- Division of Biological Sciences, University of California - San Diego, 9500 Gillman Dr. La Jolla, CA 92037 U.S.A
| | - Steve A. Kay
- Division of Biological Sciences, University of California - San Diego, 9500 Gillman Dr. La Jolla, CA 92037 U.S.A
| | - Joanne Chory
- Plant Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA 92037 U.S.A
- Howard Hughes Medical Institute, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd., La Jolla, CA 92037 U.S.A
- For correspondence: Tel (858)-453-4100 x1690, Fax (858)-453-558-6379,
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Phytochromes inhibit hypocotyl negative gravitropism by regulating the development of endodermal amyloplasts through phytochrome-interacting factors. Proc Natl Acad Sci U S A 2011; 108:1729-34. [PMID: 21220341 DOI: 10.1073/pnas.1011066108] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Phytochromes are red and far-red light photoreceptors that regulate various aspects of plant development. One of the less-understood roles of phytochromes is the inhibition of hypocotyl negative gravitropism, which refers to the loss of hypocotyl gravitropism and resulting random growth direction in red or far-red light. This light response allows seedlings to curve toward blue light after emergence from the soil and enhances seedling establishment in the presence of mulch. Phytochromes inhibit hypocotyl negative gravitropism by inhibiting four phytochrome-interacting factors (PIF1, PIF3, PIF4, PIF5), as shown by hypocotyl agravitropism of dark-grown pif1 pif3 pif4 pif5 quadruple mutants. We show that phytochromes inhibit negative gravitropism by converting starch-filled gravity-sensing endodermal amyloplasts to other plastids with chloroplastic or etioplastic features in red or far-red light, whereas PIFs promote negative gravitropism by inhibiting the conversion of endodermal amyloplasts to etioplasts in the dark. By analyzing transgenic plants expressing PIF1 with an endodermis-specific SCARECROW promoter, we further show that endodermal PIF1 is sufficient to inhibit the conversion of endodermal amyloplasts to etioplasts and hypocotyl negative gravitropism of the pif quadruple mutant in the dark. Although the functions of phytochromes in gravitropism and chloroplast development are normally considered distinct, our results indicate that these two functions are closely related.
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Knöller AS, Murphy AS. ABC Transporters and Their Function at the Plasma Membrane. THE PLANT PLASMA MEMBRANE 2011. [DOI: 10.1007/978-3-642-13431-9_16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Tsuda E, Yang H, Nishimura T, Uehara Y, Sakai T, Furutani M, Koshiba T, Hirose M, Nozaki H, Murphy AS, Hayashi KI. Alkoxy-auxins are selective inhibitors of auxin transport mediated by PIN, ABCB, and AUX1 transporters. J Biol Chem 2010; 286:2354-64. [PMID: 21084292 DOI: 10.1074/jbc.m110.171165] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polar auxin movement is a primary regulator of programmed and plastic plant development. Auxin transport is highly regulated at the cellular level and is mediated by coordinated transport activity of plasma membrane-localized PIN, ABCB, and AUX1/LAX transporters. The activity of these transporters has been extensively analyzed using a combination of pharmacological inhibitors, synthetic auxins, and knock-out mutants in Arabidopsis. However, efforts to analyze auxin-dependent growth in other species that are less tractable to genetic manipulation require more selective inhibitors than are currently available. In this report, we characterize the inhibitory activity of 5-alkoxy derivatives of indole 3-acetic acid and 7-alkoxy derivatives of naphthalene 1-acetic acid, finding that the hexyloxy and benzyloxy derivatives act as potent inhibitors of auxin action in plants. These alkoxy-auxin analogs inhibit polar auxin transport and tropic responses associated with asymmetric auxin distribution in Arabidopsis and maize. The alkoxy-auxin analogs inhibit auxin transport mediated by AUX1, PIN, and ABCB proteins expressed in yeast. However, these analogs did not inhibit or activate SCF(TIR1) auxin signaling and had no effect on the subcellular trafficking of PIN proteins. Together these results indicate that alkoxy-auxins are inactive auxin analogs for auxin signaling, but are recognized by PIN, ABCB, and AUX1 auxin transport proteins. Alkoxy-auxins are powerful new tools for analyses of auxin-dependent development.
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Affiliation(s)
- Etsuko Tsuda
- Department of Biochemistry, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan
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Shen C, Bai Y, Wang S, Zhang S, Wu Y, Chen M, Jiang D, Qi Y. Expression profile of PIN, AUX/LAX and PGP auxin transporter gene families in Sorghum bicolor under phytohormone and abiotic stress. FEBS J 2010; 277:2954-69. [PMID: 20528920 DOI: 10.1111/j.1742-4658.2010.07706.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Auxin is transported by the influx carriers auxin resistant 1/like aux1 (AUX/LAX), and the efflux carriers pin-formed (PIN) and P-glycoprotein (PGP), which play a major role in polar auxin transport. Several auxin transporter genes have been characterized in dicotyledonous Arabidopsis, but most are unknown in monocotyledons, especially in sorghum. Here, we analyze the chromosome distribution, gene duplication and intron/exon of SbPIN, SbLAX and SbPGP gene families, and examine their phylogenic relationships in Arabidopsis, rice and sorghum. Real-time PCR analysis demonstrated that most of these genes were differently expressed in the organs of sorghum. SbPIN3 and SbPIN9 were highly expressed in flowers, SbLAX2 and SbPGP17 were mainly expressed in stems, and SbPGP7 was strongly expressed in roots. This suggests that individual genes might participate in specific organ development. The expression profiles of these gene families were analyzed after treatment with: (a) the phytohormones indole-3-acetic acid and brassinosteroid; (b) the polar auxin transport inhibitors 1-naphthoxyacetic acids, 1-naphthylphthalamic acid and 2,3,5-triiodobenzoic acid; and (c) abscissic acid and the abiotic stresses of high salinity and drought. Most of the auxin transporter genes were strongly induced by indole-3-acetic acid and brassinosteroid, providing new evidence for the synergism of these phytohormones. Interestingly, most genes showed similar trends in expression under polar auxin transport inhibitors and each also responded to abscissic acid, salt and drought. This study provides new insights into the auxin transporters of sorghum.
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Affiliation(s)
- ChenJia Shen
- State Key Laboratory of Plant Physiology and Biochemistry, Zhejiang University, Hangzhou, China
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38
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Kim JY, Henrichs S, Bailly A, Vincenzetti V, Sovero V, Mancuso S, Pollmann S, Kim D, Geisler M, Nam HG. Identification of an ABCB/P-glycoprotein-specific inhibitor of auxin transport by chemical genomics. J Biol Chem 2010; 285:23309-17. [PMID: 20472555 DOI: 10.1074/jbc.m110.105981] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Plant development and physiology are widely determined by the polar transport of the signaling molecule auxin. This process is controlled on the cellular efflux level catalyzed by members of the PIN (pin-formed) and ABCB (ATP-binding cassette protein subfamily B)/P-glycoprotein family that can function independently and coordinately. In this study, we have identified by means of chemical genomics a novel auxin transport inhibitor (ATI), BUM (2-[4-(diethylamino)-2-hydroxybenzoyl]benzoic acid), that efficiently blocks auxin-regulated plant physiology and development. In many respects, BUM resembles the functionality of the diagnostic ATI, 1-N-naphtylphtalamic acid (NPA), but it has an IC(50) value that is roughly a factor 30 lower. Physiological analysis and binding assays identified ABCBs, primarily ABCB1, as key targets of BUM and NPA, whereas PIN proteins are apparently not directly affected. BUM is complementary to NPA by having distinct ABCB target spectra and impacts on basipetal polar auxin transport in the shoot and root. In comparison with the recently identified ATI, gravacin, it lacks interference with ABCB membrane trafficking. Individual modes or targets of action compared with NPA are reflected by apically shifted root influx maxima that might be the result of altered BUM binding preferences or affinities to the ABCB nucleotide binding folds. This qualifies BUM as a valuable tool for auxin research, allowing differentiation between ABCB- and PIN-mediated efflux systems. Besides its obvious application as a powerful weed herbicide, BUM is a bona fide human ABCB inhibitor with the potential to restrict multidrug resistance during chemotherapy.
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Affiliation(s)
- Jun-Young Kim
- Laboratory of Plant Systems Bio-Dynamics, Pohang University of Science and Technology, 790-784 Pohang, Korea
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Tsuchida-Mayama T, Sakai T, Hanada A, Uehara Y, Asami T, Yamaguchi S. Role of the phytochrome and cryptochrome signaling pathways in hypocotyl phototropism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 62:653-62. [PMID: 20202166 DOI: 10.1111/j.1365-313x.2010.04180.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Unilateral blue-light irradiation activates phototropin (phot) photoreceptors, resulting in asymmetric distribution of the phytohormone auxin and induction of a phototropic response in higher plants. Other photoreceptors, including phytochrome (phy) and cryptochrome (cry), have been proposed as modulators of phototropic responses. We show here that either phy or cry is required for hypocotyl phototropism in Arabidopsis thaliana under high fluence rates of blue light, and that constitutive expression of ROOT PHOTOTROPISM 2 (RPT2) and treatment with the phytohormone gibberellin (GA) biosynthesis inhibitor paclobutrazol partially and independently complement the non-phototropic hypocotyl phenotype of the phyA cry1 cry2 mutant under high fluence rates of blue light. Our results indicate that induction of RPT2 and reduction in the GA are crucial for hypocotyl phototropic regulation by phy and cry. We also show that GA suppresses hypocotyl bending via destabilization of DELLA transcriptional regulators under darkness, but does not suppress the phototropic response in the presence of either phyA or cryptochromes, suggesting that these photoreceptors control not only the GA content but also the GA sensing and/or signaling that affects hypocotyl phototropism. The metabolic and signaling regulation of not only auxin but also GA by photoreceptors therefore appears to determine the hypocotyl growth pattern, including phototropic and gravitropic responses and inhibition of hypocotyl elongation, for adaptation to various light environments.
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Wu G, Cameron JN, Ljung K, Spalding EP. A role for ABCB19-mediated polar auxin transport in seedling photomorphogenesis mediated by cryptochrome 1 and phytochrome B. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 62:179-91. [PMID: 20088903 DOI: 10.1111/j.1365-313x.2010.04137.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
During seedling establishment, blue and red light suppress hypocotyl growth through the cryptochrome 1 (cry1) and phytochrome B (phyB) photosensory pathways, respectively. How these photosensory pathways integrate with growth control mechanisms to achieve the appropriate degree of stem elongation was investigated by combining cry1 and phyB photoreceptor mutations with genetic manipulations of a multidrug resistance-like membrane protein known as ABCB19 that influenced auxin distribution within the plant, as evidenced by a combination of reporter gene assays and direct auxin measurements. Auxin signaling and ABCB19 protein levels, hypocotyl growth rates, and apical hook opening were measured in mutant and wild-type seedlings exposed to a range of red and blue light conditions. Ectopic/overexpression of ABCB19 (B19OE) greatly increased auxin in the hypocotyl, which reduced the sensitivity of hypocotyl growth specifically to blue light in long-term assays and red light in high-resolution, short-term assays. Loss of ABCB19 partially suppressed the cry1 hypocotyl growth phenotype in blue light. Hypocotyl growth of B19OE seedlings in red light was very similar to phyB mutants. Altered auxin distribution in B19OE seedlings also affected the opening of the apical hook. The cry1 and phyB photoreceptor mutations both increased ABCB19 protein levels at the plasma membrane, as measured by confocal microscopy. The B19OE plant proved to be a useful tool for determining aspects of the mechanism by which light, acting through cry1 or phyB, influences the auxin transport process to control hypocotyl growth during de-etiolation.
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Affiliation(s)
- Guosheng Wu
- Department of Botany, University of Wisconsin, 430 Lincoln Drive, Madison, WI 53706, USA
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de Carbonnel M, Davis P, Roelfsema MRG, Inoue SI, Schepens I, Lariguet P, Geisler M, Shimazaki KI, Hangarter R, Fankhauser C. The Arabidopsis PHYTOCHROME KINASE SUBSTRATE2 protein is a phototropin signaling element that regulates leaf flattening and leaf positioning. PLANT PHYSIOLOGY 2010; 152:1391-405. [PMID: 20071603 PMCID: PMC2832238 DOI: 10.1104/pp.109.150441] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 01/09/2010] [Indexed: 05/18/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana), the blue light photoreceptor phototropins (phot1 and phot2) fine-tune the photosynthetic status of the plant by controlling several important adaptive processes in response to environmental light variations. These processes include stem and petiole phototropism (leaf positioning), leaf flattening, stomatal opening, and chloroplast movements. The PHYTOCHROME KINASE SUBSTRATE (PKS) protein family comprises four members in Arabidopsis (PKS1-PKS4). PKS1 is a novel phot1 signaling element during phototropism, as it interacts with phot1 and the important signaling element NONPHOTOTROPIC HYPOCOTYL3 (NPH3) and is required for normal phot1-mediated phototropism. In this study, we have analyzed more globally the role of three PKS members (PKS1, PKS2, and PKS4). Systematic analysis of mutants reveals that PKS2 (and to a lesser extent PKS1) act in the same subset of phototropin-controlled responses as NPH3, namely leaf flattening and positioning. PKS1, PKS2, and NPH3 coimmunoprecipitate with both phot1-green fluorescent protein and phot2-green fluorescent protein in leaf extracts. Genetic experiments position PKS2 within phot1 and phot2 pathways controlling leaf positioning and leaf flattening, respectively. NPH3 can act in both phot1 and phot2 pathways, and synergistic interactions observed between pks2 and nph3 mutants suggest complementary roles of PKS2 and NPH3 during phototropin signaling. Finally, several observations further suggest that PKS2 may regulate leaf flattening and positioning by controlling auxin homeostasis. Together with previous findings, our results indicate that the PKS proteins represent an important family of phototropin signaling proteins.
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Kami C, Lorrain S, Hornitschek P, Fankhauser C. Light-regulated plant growth and development. Curr Top Dev Biol 2010; 91:29-66. [PMID: 20705178 DOI: 10.1016/s0070-2153(10)91002-8] [Citation(s) in RCA: 428] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Plants are sessile and photo-autotrophic; their entire life cycle is thus strongly influenced by the ever-changing light environment. In order to sense and respond to those fluctuating conditions higher plants possess several families of photoreceptors that can monitor light from UV-B to the near infrared (far-red). The molecular nature of UV-B sensors remains unknown, red (R) and far-red (FR) light is sensed by the phytochromes (phyA-phyE in Arabidopsis) while three classes of UV-A/blue photoreceptors have been identified: cryptochromes, phototropins, and members of the Zeitlupe family (cry1, cry2, phot1, phot2, ZTL, FKF1, and LKP2 in Arabidopsis). Functional specialization within photoreceptor families gave rise to members optimized for a wide range of light intensities. Genetic and photobiological studies performed in Arabidopsis have shown that these light sensors mediate numerous adaptive responses (e.g., phototropism and shade avoidance) and developmental transitions (e.g., germination and flowering). Some physiological responses are specifically triggered by a single photoreceptor but in many cases multiple light sensors ensure a coordinated response. Recent studies also provide examples of crosstalk between the responses of Arabidopsis to different external factors, in particular among light, temperature, and pathogens. Although the different photoreceptors are unrelated in structure, in many cases they trigger similar signaling mechanisms including light-regulated protein-protein interactions or light-regulated stability of several transcription factors. The breath and complexity of this topic forced us to concentrate on specific aspects of photomorphogenesis and we point the readers to recent reviews for some aspects of light-mediated signaling (e.g., transition to flowering).
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Affiliation(s)
- Chitose Kami
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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Abstract
Light is vital for plant growth and development: It provides energy for photosynthesis, but also reliable information on seasonal timing and local habitat conditions. Light sensing is therefore of paramount importance for plants. Thus, plants have evolved sophisticated light receptors and signaling networks that detect and respond to changes in light intensity, duration, and spectral quality. Environmental light signals can drive developmental transitions such as germination and flowering, but they also continuously shape development to allow adaptation to the local habitat and microclimate. The ability to respond to a changing and sometimes unfavorable environment underlies the huge success of plants. Much of this growth and developmental plasticity is achieved by light modulation of auxin signaling systems. In this article, we examine the connections between light and auxin that elicit local responses, long distance signaling, and coordinated growth between the shoot and root.
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Affiliation(s)
- Karen J Halliday
- Institute of Molecular Plant Sciences, Edinburgh University, Edinburgh, UK.
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Abstract
The differential distribution of the plant signaling molecule auxin is required for many aspects of plant development. Local auxin maxima and gradients arise as a result of local auxin metabolism and, predominantly, from directional cell-to-cell transport. In this primer, we discuss how the coordinated activity of several auxin influx and efflux systems, which transport auxin across the plasma membrane, mediates directional auxin flow. This activity crucially contributes to the correct setting of developmental cues in embryogenesis, organogenesis, vascular tissue formation and directional growth in response to environmental stimuli.
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Affiliation(s)
- Jan Petrásek
- Institute of Experimental Botany, ASCR, Prague 6, Czech Republic
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Titapiwatanakun B, Murphy AS. Post-transcriptional regulation of auxin transport proteins: cellular trafficking, protein phosphorylation, protein maturation, ubiquitination, and membrane composition. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:1093-107. [PMID: 18824505 DOI: 10.1093/jxb/ern240] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Auxin concentration gradients, established by polar transport of auxin, are essential for the establishment and maintenance of polar growth and morphological patterning. Three families of cellular transport proteins, PIN-formed (PIN), P-glycoprotein (ABCB/PGP), and AUXIN RESISTANT 1/LIKE AUX1 (AUX1/LAX), can independently and co-ordinately transport auxin in plants. Regulation of these proteins involves intricate and co-ordinated cellular processes, including protein-protein interactions, vesicular trafficking, protein phosphorylation, ubiquitination, and stabilization of the transporter complexes on the plasma membrane.
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Yazaki K, Shitan N, Sugiyama A, Takanashi K. Chapter 6 Cell and Molecular Biology of ATP‐Binding Cassette Proteins in Plants. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 276:263-99. [DOI: 10.1016/s1937-6448(09)76006-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Titapiwatanakun B, Blakeslee JJ, Bandyopadhyay A, Yang H, Mravec J, Sauer M, Cheng Y, Adamec J, Nagashima A, Geisler M, Sakai T, Friml J, Peer WA, Murphy AS. ABCB19/PGP19 stabilises PIN1 in membrane microdomains in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:27-44. [PMID: 18774968 DOI: 10.1111/j.1365-313x.2008.03668.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Auxin transport is mediated at the cellular level by three independent mechanisms that are characterised by the PIN-formed (PIN), P-glycoprotein (ABCB/PGP) and AUX/LAX transport proteins. The PIN and ABCB transport proteins, best represented by PIN1 and ABCB19 (PGP19), have been shown to coordinately regulate auxin efflux. When PIN1 and ABCB19 coincide on the plasma membrane, their interaction enhances the rate and specificity of auxin efflux and the dynamic cycling of PIN1 is reduced. However, ABCB19 function is not regulated by the dynamic cellular trafficking mechanisms that regulate PIN1 in apical tissues, as localisation of ABCB19 on the plasma membrane was not inhibited by short-term treatments with latrunculin B, oryzalin, brefeldin A (BFA) or wortmannin--all of which have been shown to alter PIN1 and/or PIN2 plasma membrane localisation. When taken up by endocytosis, the styryl dye FM4-64 labels diffuse rather than punctuate intracellular bodies in abcb19 (pgp19), and some aggregations of PIN1 induced by short-term BFA treatment did not disperse after BFA washout in abcb19. Although the subcellular localisations of ABCB19 and PIN1 in the reciprocal mutant backgrounds were like those in wild type, PIN1 plasma membrane localisation in abcb19 roots was more easily perturbed by the detergent Triton X-100, but not other non-ionic detergents. ABCB19 is stably associated with sterol/sphingolipid-enriched membrane fractions containing BIG/TIR3 and partitions into Triton X-100 detergent-resistant membrane (DRM) fractions. In the wild type, PIN1 was also present in DRMs, but was less abundant in abcb19 DRMs. These observations suggested a rationale for the observed lack of auxin transport activity when PIN1 is expressed in a non-plant heterologous system. PIN1 was therefore expressed in Schizosaccharomyces pombe, which has plant-like sterol-enriched microdomains, and catalysed auxin transport in these cells. These data suggest that ABCB19 stabilises PIN1 localisation at the plasma membrane in discrete cellular subdomains where PIN1 and ABCB19 expression overlaps.
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Mravec J, Kubeš M, Bielach A, Gaykova V, Petrášek J, Skůpa P, Chand S, Benková E, Zažímalová E, Friml J. Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development. Development 2008; 135:3345-54. [DOI: 10.1242/dev.021071] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The signalling molecule auxin controls plant morphogenesis via its activity gradients, which are produced by intercellular auxin transport. Cellular auxin efflux is the rate-limiting step in this process and depends on PIN and phosphoglycoprotein (PGP) auxin transporters. Mutual roles for these proteins in auxin transport are unclear, as is the significance of their interactions for plant development. Here, we have analysed the importance of the functional interaction between PIN- and PGP-dependent auxin transport in development. We show by analysis of inducible overexpression lines that PINs and PGPs define distinct auxin transport mechanisms: both mediate auxin efflux but they play diverse developmental roles. Components of both systems are expressed during embryogenesis, organogenesis and tropisms, and they interact genetically in both synergistic and antagonistic fashions. A concerted action of PIN- and PGP-dependent efflux systems is required for asymmetric auxin distribution during these processes. We propose a model in which PGP-mediated efflux controls auxin levels in auxin channel-forming cells and, thus, auxin availability for PIN-dependent vectorial auxin movement.
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Affiliation(s)
- Jozef Mravec
- Department of Plant Systems Biology, VIB, and Department of Molecular Genetics, Ghent University, 9052 Gent, Belgium
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
| | - Martin Kubeš
- Institute for Experimental Botany, Academy of Sciences of the Czech Republic,Rozvojová 263, 165 02 Praha 6, Czech Republic
- Department of Plant Physiology, Faculty of Science, Charles University,Viničná 5, 128 44 Praha 2, Czech Republic
| | - Agnieszka Bielach
- Department of Plant Systems Biology, VIB, and Department of Molecular Genetics, Ghent University, 9052 Gent, Belgium
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
| | - Vassilena Gaykova
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
| | - Jan Petrášek
- Institute for Experimental Botany, Academy of Sciences of the Czech Republic,Rozvojová 263, 165 02 Praha 6, Czech Republic
- Department of Plant Physiology, Faculty of Science, Charles University,Viničná 5, 128 44 Praha 2, Czech Republic
| | - Petr Skůpa
- Institute for Experimental Botany, Academy of Sciences of the Czech Republic,Rozvojová 263, 165 02 Praha 6, Czech Republic
- Department of Plant Physiology, Faculty of Science, Charles University,Viničná 5, 128 44 Praha 2, Czech Republic
| | - Suresh Chand
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
| | - Eva Benková
- Department of Plant Systems Biology, VIB, and Department of Molecular Genetics, Ghent University, 9052 Gent, Belgium
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
| | - Eva Zažímalová
- Institute for Experimental Botany, Academy of Sciences of the Czech Republic,Rozvojová 263, 165 02 Praha 6, Czech Republic
| | - Jiří Friml
- Department of Plant Systems Biology, VIB, and Department of Molecular Genetics, Ghent University, 9052 Gent, Belgium
- Center for Plant Molecular Biology (ZMBP), University of Tübingen,D-72076 Tübingen, Germany
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Nagashima A, Uehara Y, Sakai T. The ABC subfamily B auxin transporter AtABCB19 is involved in the inhibitory effects of N-1-naphthyphthalamic acid on the phototropic and gravitropic responses of Arabidopsis hypocotyls. PLANT & CELL PHYSIOLOGY 2008; 49:1250-5. [PMID: 18556728 DOI: 10.1093/pcp/pcn092] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
N-1-Naphthylphthalamic acid (NPA) causes the abnormal growth and development of plants by suppressing polar auxin transport. The mechanisms underlying this inhibition, however, have remained elusive. In Arabidopsis, we show that a defect in the ABC subfamily B auxin transporter AtABCB19 suppresses the inhibitory effects of NPA on hypocotyl phototropism and gravitropism, but not on hypocotyl elongation. Expression analysis using the auxin reporter gene DR5:GUS further suggests that NPA partially inhibits the asymmetric distribution of auxin in an AtABCB19-dependent manner. These data thus suggest that AtABCB19 plays an important role in the inhibitory effects of NPA on hypocotyl tropism induced by auxin.
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Affiliation(s)
- Akitomo Nagashima
- Genetic Regulatory Systems Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
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