1
|
Zia SF, Berkowitz O, Bedon F, Whelan J, Franks AE, Plummer KM. Direct comparison of Arabidopsis gene expression reveals different responses to melatonin versus auxin. BMC PLANT BIOLOGY 2019; 19:567. [PMID: 31856719 PMCID: PMC6921455 DOI: 10.1186/s12870-019-2158-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/25/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Melatonin (N-acetyl-5-methoxytryptamine) in plants, regulates shoot and root growth and alleviates environmental stresses. Melatonin and the phyto-hormone auxin are tryptophan-derived compounds. However, it largely remains controversial as to whether melatonin and auxin act through similar or overlapping signalling and regulatory pathways. RESULTS Here, we have used a promoter-activation study to demonstrate that, unlike auxin (1-naphthalene acetic acid, NAA), melatonin neither induces Direct repeat 5 DR5 expression in Arabidopsis thaliana roots under normal growth conditions nor suppresses the induction of Alternative oxidase 1a AOX1a in leaves upon Antimycin A treatment, both of which are the hallmarks of auxin action. Additionally, comparative global transcriptome analysis conducted on Arabidopsis treated with melatonin or NAA revealed differences in the number and types of differentially expressed genes. Auxin (4.5 μM) altered the expression of a diverse and large number of genes whereas melatonin at 5 μM had no significant effect but melatonin at 100 μM had a modest effect on transcriptome compared to solvent-treated control. Interestingly, the prominent category of genes differentially expressed upon exposure to melatonin trended towards biotic stress defence pathways while downregulation of key genes related to photosynthesis was observed. CONCLUSION Together these findings indicate that though they are both indolic compounds, melatonin and auxin act through different pathways to alter gene expression in Arabidopsis thaliana. Furthermore, it appears that effects of melatonin enable Arabidopsis thaliana to prioritize biotic stress defence signalling rather than growth. These findings clear the current confusion in the literature regarding the relationship of melatonin and auxin and also have greater implications of utilizing melatonin for improved plant protection.
Collapse
Affiliation(s)
- Sajal F Zia
- Department of Animal, Plant and Soil Sciences, AgriBio, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Oliver Berkowitz
- Department of Animal, Plant and Soil Sciences, AgriBio, La Trobe University, Bundoora, VIC, 3086, Australia
- ARC Centre of Excellence in Plant Energy Biology, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Frank Bedon
- Department of Animal, Plant and Soil Sciences, AgriBio, La Trobe University, Bundoora, VIC, 3086, Australia.
| | - James Whelan
- Department of Animal, Plant and Soil Sciences, AgriBio, La Trobe University, Bundoora, VIC, 3086, Australia
- ARC Centre of Excellence in Plant Energy Biology, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Ashley E Franks
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, VIC, 3086, Australia
- Centre for Future Landscapes, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Kim M Plummer
- Department of Animal, Plant and Soil Sciences, AgriBio, La Trobe University, Bundoora, VIC, 3086, Australia.
| |
Collapse
|
2
|
Shao MR, Kumar Kenchanmane Raju S, Laurie JD, Sanchez R, Mackenzie SA. Stress-responsive pathways and small RNA changes distinguish variable developmental phenotypes caused by MSH1 loss. BMC PLANT BIOLOGY 2017; 17:47. [PMID: 28219335 PMCID: PMC5319189 DOI: 10.1186/s12870-017-0996-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 02/08/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Proper regulation of nuclear-encoded, organelle-targeted genes is crucial for plastid and mitochondrial function. Among these genes, MutS Homolog 1 (MSH1) is notable for generating an assortment of mutant phenotypes with varying degrees of penetrance and pleiotropy. Stronger phenotypes have been connected to stress tolerance and epigenetic changes, and in Arabidopsis T-DNA mutants, two generations of homozygosity with the msh1 insertion are required before severe phenotypes begin to emerge. These observations prompted us to examine how msh1 mutants contrast according to generation and phenotype by profiling their respective transcriptomes and small RNA populations. RESULTS Using RNA-seq, we analyze pathways that are associated with MSH1 loss, including abiotic stresses such as cold response, pathogen defense and immune response, salicylic acid, MAPK signaling, and circadian rhythm. Subtle redox and environment-responsive changes also begin in the first generation, in the absence of strong phenotypes. Using small RNA-seq we further identify miRNA changes, and uncover siRNA trends that indicate modifications at the chromatin organization level. In all cases, the magnitude of changes among protein-coding genes, transposable elements, and small RNAs increases according to generation and phenotypic severity. CONCLUSION Loss of MSH1 is sufficient to cause large-scale regulatory changes in pathways that have been individually linked to one another, but rarely described all together within a single mutant background. This study enforces the recognition of organelles as critical integrators of both internal and external cues, and highlights the relationship between organelle and nuclear regulation in fundamental aspects of plant development and stress signaling. Our findings also encourage further investigation into potential connections between organelle state and genome regulation vis-á-vis small RNA feedback.
Collapse
Affiliation(s)
- Mon-Ray Shao
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE USA
| | | | - John D. Laurie
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE USA
- Sainsbury Laboratory, University of Cambridge, Cambridge, UK
| | - Robersy Sanchez
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE USA
| | - Sally A. Mackenzie
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE USA
| |
Collapse
|
3
|
Pedroza-Garcia JA, Domenichini S, Bergounioux C, Benhamed M, Raynaud C. Chloroplasts around the plant cell cycle. CURRENT OPINION IN PLANT BIOLOGY 2016; 34:107-113. [PMID: 27816816 DOI: 10.1016/j.pbi.2016.10.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 10/19/2016] [Accepted: 10/23/2016] [Indexed: 06/06/2023]
Abstract
Plastids arose from an endosymbiosis between a host cell and free-living bacteria. One key step during this evolutionary process has been the establishment of coordinated cell and symbiont division to allow the maintenance of organelles during proliferation of the host. However, surprisingly little is known about the underlying mechanisms. In addition, due to their central role in the cell's energetic metabolism and to their sensitivity to various environmental cues such as light or temperature, plastids are ideally fitted to be the source of signals allowing plants to adapt their development according to external conditions. Consistently, there is accumulating evidence that plastid-derived signals can impinge on cell cycle regulation. In this review, we summarize current knowledge of the dialogue between chloroplasts and the nucleus in the context of the cell cycle.
Collapse
Affiliation(s)
- José-Antonio Pedroza-Garcia
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Batiment 630, 91405 Orsay, France; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405 Orsay, France
| | - Séverine Domenichini
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Batiment 630, 91405 Orsay, France; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405 Orsay, France
| | - Catherine Bergounioux
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Batiment 630, 91405 Orsay, France; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405 Orsay, France
| | - Moussa Benhamed
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Batiment 630, 91405 Orsay, France; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405 Orsay, France
| | - Cécile Raynaud
- Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Batiment 630, 91405 Orsay, France; Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-Cité, Bâtiment 630, 91405 Orsay, France.
| |
Collapse
|
4
|
Wilson ME, Mixdorf M, Berg RH, Haswell ES. Plastid osmotic stress influences cell differentiation at the plant shoot apex. Development 2016; 143:3382-93. [PMID: 27510974 DOI: 10.1242/dev.136234] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 08/02/2016] [Indexed: 01/05/2023]
Abstract
The balance between proliferation and differentiation in the plant shoot apical meristem is controlled by regulatory loops involving the phytohormone cytokinin and stem cell identity genes. Concurrently, cellular differentiation in the developing shoot is coordinated with the environmental and developmental status of plastids within those cells. Here, we employ an Arabidopsis thaliana mutant exhibiting constitutive plastid osmotic stress to investigate the molecular and genetic pathways connecting plastid osmotic stress with cell differentiation at the shoot apex. msl2 msl3 mutants exhibit dramatically enlarged and deformed plastids in the shoot apical meristem, and develop a mass of callus tissue at the shoot apex. Callus production in this mutant requires the cytokinin receptor AHK2 and is characterized by increased cytokinin levels, downregulation of cytokinin signaling inhibitors ARR7 and ARR15, and induction of the stem cell identity gene WUSCHEL Furthermore, plastid stress-induced apical callus production requires elevated plastidic reactive oxygen species, ABA biosynthesis, the retrograde signaling protein GUN1, and ABI4. These results are consistent with a model wherein the cytokinin/WUS pathway and retrograde signaling control cell differentiation at the shoot apex.
Collapse
Affiliation(s)
- Margaret E Wilson
- Department of Biology, Mailbox 1137, One Brookings Drive, Washington University in Saint Louis, Saint Louis, MO 63130 USA
| | - Matthew Mixdorf
- Department of Biology, Mailbox 1137, One Brookings Drive, Washington University in Saint Louis, Saint Louis, MO 63130 USA
| | - R Howard Berg
- Integrated Microscopy Facility, Donald Danforth Plant Science Center, 975 North Warson Rd., Saint Louis, MO 63132 USA
| | - Elizabeth S Haswell
- Department of Biology, Mailbox 1137, One Brookings Drive, Washington University in Saint Louis, Saint Louis, MO 63130 USA
| |
Collapse
|