Principal Investigator
Researcher
Email:etwang@cemps.ac.cn
Personal Web:

Plant-Microbe Symbioses

National Key Laboratory of Plant Molecular Genetics

Jan. 2013- Present Professor, Shanghai Institute of Plant Physiology and Ecology, CAS. 
Nov. 2008- Dec. 2012 Postdoctoral Researcher, John Innes Centre, UK
Sep. 2003- Nov. 2008 PhD student, Shanghai Institute of Plant Physiology and Ecology, CAS.
Sep. 1999- Jul. 2003 Undergraduate student, Henan University

We focus on the genetics, biochemistry and cell biology of two symbiotic interactions of plants that can help to achieve higher crop yields with less usage of fertilizers: One is the arbuscular mycorrhizal association that helps the host plant to uptake nutrients from the soil and is especially important for plant acquisition of phosphate and nitrogen. The other is the rhizobial symbiosis that provides a source of nitrogen to the host plant. We propose to use diverse model plants including the monocot Oryza sativa and the eudicot Medicago truncatula to probe the complex genetic networks that underlie AM and rhizobial symbiosis. In addition, we propose to transfer our knowledge of the symbiosis into agronomical important food crops such as maize, wheat and rice to increase nutrient and water using efficiency, with the aim of boosting the food supply for future generations.
 

Association with arbuscular mycorrhiza (AM) is ubiquitous in the plant kingdom. Understanding of this mutually beneficial interaction is of interest to basic biology and has the potential to be applied someday to agriculture to reduce reliance on the use of fertilizers. In the past several years, we have made one major breakthrough discovery and several very exciting findings related to two key events of AM symbiosis.

 

1. Symbiotic Nutrient exchange: At the very heart of AM-host interaction is nutrient exchange, which occurs in arbuscule, a specialized subcellular structure that forms in root cells to maximize the host-symbiont membrane interface. Mycorrhizal fungi improve the nutrient status of their host by increasing phosphate absorption, in turn the host provides carbon for fungal growth. It has been widely assumed that this carbon is provided in the form of sugars, as can be seen in any text book or review article on the subject. We have revised this dogma with the discovery that the AM fungus Rhizophagus irregularis is a fatty acid auxotroph that requires fatty acids synthesized in the host plants to sustain colonization. Transfer of the fatty acids is dependent on the glyceraldehyde-3-phosphate acyltransferase and the ABC transporter-mediated lipid export pathway. Our discovery that fatty acids are transferred from host plant to the mutualistic AM fungus and pathogenic fungus Golovinomyces cichoracerum is a paradigm shifting (Jiang, 2017 Science). In further studies, we found that MtAP2-domain transcription factors function as master regulators of lipid transfer and periarbuscular membrane formation through their direct binding to cis-regulatory elements in promoters of the lipid transporter and phosphate transporter (Jiang, 2018 Molecular Plant). We also found that the transfer of nutrients from the AM fungi requires an H+-ATPase which may energize the proton-coupled transporters, particularly phosphate transporters (Wang, 2014 Plant Cell).

 

2. Recognition of microbes: Initial chemical communication between microorganisms in the rhizosphere and the host plant root is essential for AM symbiosis. Recognition of Myc factors released by AM fungi activate intracellular calcium oscillations through a Common Symbiosis Signaling Pathway, which is shared by the nodulation process. The calcium signal is believed to be decoded by CCaMK and its phosphorylation target IPD3/CYCLOPS. However, the plant receptors responsible for the recognition of Myc factors have been elusive. We identified a heteromer of LysM receptor-like kinases consisting of OsMYR1/OsLYK2 and OsCERK1 that mediates the perception of AM fungi in rice. (Zhang, 2015 Plant Journal; He, 2019 Molecular Plant). We further found that phosphorylation of IPD3/CYCLOPS by CCaMK promotes formation of an IPD3/CYCLOPS-DELLA complex, and that DELLAs function as transcriptional activators in the AM symbiosis (Yu, 2014 Cell Research; Jin, 2016 Nature Communications; Jin, 2018 Front Plant Sci). This research revealed a fundamental link between the symbiotic signaling pathway and gibberellic acid signaling to mediate key transcriptional events required for mycorrhizal colonization.

 

3. An amplification-selection model for root microbiota assembly: Plants live in association and interact with a multitude of microorganisms. The prevalent model for rhizosphere recruitment argues that factors produced by root attract the specific bacterial taxa in the rhizosphere and the more specialized bacterial taxa are further enriched within root. Here, we quantified the absolute abundance of root microbiota in Medicago and rice, which revealed that most of the dominant bacterial phyla are significantly elevated in the rhizosphere to different degrees, followed by the recruitment of specific taxa into the root, suggesting an amplification selection model for root microbiome assembly (Wang, 2020 Science Bulletin).

1.  Wang Xiaolin#, et al., Zhang Xuebin*, Yu Nan*, Wang Ertao* (2020). An amplification-selection model for quantified rhizosphere microbiota assembly. Sci. Bull.. 65, 983-986.

2.  Chen Tao#, Nomura Kinya#, et al., Wang Ertao, Xin Xiu-Fang*, He Sheng Yang* (2020). A plant genetic network for preventing dysbiosis in the phyllosphere. Nature. https://doi.org/10.1038/s41586-020-2185-0.

3.  He J, et al., Wang Ertao* (2019). A LysM Receptor Heteromer Mediates Perception of Arbuscular Mycorrhizal Symbiotic Signal in Rice. Molecular Plant. 12, 1561–1576.

4.  Jiang Y, Xie Q, et al., Wang Ertao* (2018). Medicago AP2-domain transcription factor WRI5a is a master regulator of lipid biosynthesis and transfer mycorrhizal symbiosis. Molecular Plant. 11:1344-1359.

5.  Liu H, Zhang C, Yang J, Yu N*, Wang Ertao* (2018). Hormone modulation of legume-rhizobial symbiosis. J Integr Plant Biol. 60: 632-648.

6.  Jin Y, et al., Yu N*, Wang Ertao* (2018). IPD3 and IPD3L Function Redundantly in Rhizobial and Mycorrhizal Symbioses. Front Plant Sci. doi: 10.3389.

7.  Wang W, Shi J, Xie Q, Jiang Y, Yu N*, Wang Ertao* (2017). Nutrient exchange and regulation in arbuscular mycorrhizal symbiosis. Molecular Plant. 10:1147-1158.

8.  Jiang Y, et al., Wang Ertao* (2017). Plants transfer lipids to sustain colonization by mutualistic mycorrhizal and parasitic fungi. Science. 356.1172-1175.

9.  Deng Y, et al., Wang Ertao, Xie H, Tharreau D, He Z* (2017). Epigenetic regulation of antagonistic receptors confers rice blast resistance with yield balance. Science. 355：962~965

10. Wang C, Wang G, et al., Xu L*, Wang Ertao* (2017). OsCERK1-mediated chitin perception and immune signaling requires Receptor-like Cytoplasmic Kinase185 to activate a MAPK cascade in rice. Molecular Plant. doi: 10.1016.

11. Jin Y, Liu H, et al., Wang Ertao* (2016). DELLA proteins are common components of symbiotic rhizobial and mycorrhizal signaling pathways. Nature Communications. 10.1038.

12. Zhang X, Dong W, Sun J, Feng F, Deng Y, He Z, Oldroyd GEO*, Wang Ertao* (2015). The receptor kinase CERK1 has dual functions in symbiosis and immunity signalling. Plant Journal. 81(2):258-67.

13. Wang Ertao*, et al. (2014). A H+-ATPase that Energizes Nutrient Uptake during Mycorrhizal Symbioses in Rice and Medicago. Plant Cell. 26: 1818-1830.

14. Yu N, Luo D, Zhang X, et al., Wang Ertao* (2014). A DELLA protein complex controls the arbuscular mycorrhizal symbiosis in plants. Cell Research. 24:130-133.

15. Wang Ertao, et al. (2012). A common signalling process that promotes mycorrhizal and omycete colonisation of plants. Current Biology. 22: 2242-2246.

16. Wang Ertao, et al. (2008). Control of rice grain-filling and yield by a gene with a potential signature of domestication. Nature Genetics 40: 1370-1374.