2016 Fiscal Year Annual Research Report
Roles of strigolactones in rice responses to salinity and arsenic toxicity
| Project/Area Number |
16F16091
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| Research Institution | Institute of Physical and Chemical Research |
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Principal Investigator |
TRAN LamSon・P 国立研究開発法人理化学研究所, 環境資源科学研究センター, ユニットリーダー (10549009)
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| Co-Investigator(Kenkyū-buntansha) |
MOSTOFA MOHAMMAD 国立研究開発法人理化学研究所, 環境資源科学研究センター, 外国人特別研究員
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| Project Period (FY) |
2016-10-07 – 2019-03-31
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| Keywords | Phytohormones / Abiotic stress / Strigolactones / Metal toxicity / Signaling molecules / Stress Tolerance / Oxidative metabolism |
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| Outline of Annual Research Achievements |
We have been studying the roles of various signaling molecules in mitigation of various abiotic stresses, including salinity and heavy metal stress. Below is the summary of our achievements in the last 6 months:
1.We have accomplished the investigation of glutathione in mitigating salt stress tolerance in soybean (Journal of Plant Growth Regulation, 2017, DOI: 10.1007/s00344-017-9691-9). Our findings reveal that exogenous GSH application can minimize oxidative stress and contribute to the improvement of yield-contributing parameters, leading to improved yield in soybean genotypes under salt stress.
2.We have completely analyzed the effects of selenium in inducing phytotoxicity in rice (Chemosphere, 2017, 178:212-223). Our results suggest that excessive Se caused phytotoxic effects on rice plants by inducing chlorosis, reducing sugar, protein and antioxidant contents, and exacerbating oxidative stress and methylglyoxal toxicity.
3.To unravel the regulatory and signaling roles of strigolactones (SLs) in rice adaptation to arsenic (As) toxicity, we have set up several experiments and obtained the following results:
Hydroponically grown 15-day-old rice plants (WT and SL-deficient mutants) were treated with 0, 125 and 250μM Na2AsO4 for a period of 5 days. Assessment of phenotypes, growth parameters, membrane integrity and oxidative stress parameters revealed that WT plants were more able to withstand As-toxicity as compared with SL-deficient mutants.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Currently, metal and micronutrient analyses, biochemical and molecular analyses of root and shoot samples are under investigation for data acquisition.
As and micronutrient quantifications: As uptake and accumulation, and the levels of various micronutrients (Ca, Mg, Mn, Fe, and Zn) in roots and shoots are under determination using ICP-MS.
RNA extraction and cDNA preparation: RNA extraction and purification, and cDNA preparation are going on following the protocol previously described by Ha et al. (2013).
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| Strategy for Future Research Activity |
Transcriptomics: By taking the advantages of RNA sequencing technology, we plan to identify patterns of gene expression and metabolic response in WT and SL-mutants exposed to As-stress. The RNA sequencing results, which will be verified by RT-qPCR, will allow us to gain an insight into how SLs coordinate a network regulating rice responses to As-toxicity.
Metabolomics: To decipher the role of SL in adjusting metabolites under As-stress,a comprehensive metabolite profiling in WT and SL-biosynthetic mutants will be carried out using GC-MS, LC-MS and lipid-LC-MS
Biochemical analysis: To assess As-induced biochemical responses regulated by SLs, oxidative stress parameters, membrane integrity loss, photosynthetic pigments, osmoprotectants, non-enzymatic antioxidants, and the activities of the antioxidant and glyoxalase enzymes, will be determined in leaves and roots of WT and mutant plants according to Mostofa et al. (2014).
Phytohormone profiling: Phytohormones play a central role in signaling networks to regulate almost all phases of plant development. Moreover, hormones are interrelated by synergistic or antagonistic crosstalk so as they are able to modulate each other’s biosynthesis or responses. SLs act coordinately with other phytohormones, and any modulation of SLs might have a profound effect in the regulatory network of plant growth, and responses to abiotic stresses. The levels of various phytohormones will be measured as previously described (Kojima et al. 2009).
Research findings from this project will be summarized and published in international journals.
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