Principal Investigator
Researcher
Email:yfw@cemps.ac.cn
Personal Web: http://people.ucas.edu.cn/~0012230

Ion nutrients and signaling in plants 

National Key Laboratory of Plant Molecular Genetics

August 2019——Present, Principle Investigator/Group Leader, Shanghai Institute of  Plant Physiology & Ecology, Chinese Academy of Sciences, 200032 Shanghai, China 

January 2003——July 2009, Postdoctoral researcher, University of California, San  Diego, 92093-0116 San Diego, California, USA 

September 2008——December 2003, Ph.D student, China Agricultural University, 100004 Beijing, China September 1995——July 2008, Master student, Hebei Normal University, 050024  

Shijiazhuang, Hebei Province, China  

September 1991——July 1995, Undergraduate student, Hebei Normal University, 050024 Shijiazhuang, Hebei Province,China 

1. Polar growth and guidance regulation 

Root hairs and pollen tubes are typical tip-growing plant cells, and also ideal models for biological study. It has been well-established decades ago that a cytosolic Ca²⁺ gradient is present in the tips of root hairs and pollen tubes, and is required for the tip growth and orientation of the two types of tip-growing cells. External Ca²⁺ influx is the main source of Ca²⁺ for the establishment and dynamic regulation of the cytosolic Ca²⁺ gradients, and inward Ca²⁺ channels localized in the tips of root hair and pollen tubes are believed to be the main tunnels and regulators of Ca²⁺ influx and cytosolic Ca²⁺ signal. But it is largely unknown how Ca²⁺ signaling is involved in this processes.  

Root hairs are essential for the intake of ion nutrient and water, and thus are important for plant growth and development. Root hair initiation and growth are regulated by phytohormone (ethylene and auxin) and the availability of ion nutrients in soil. In this area, we are interested to identify the main Ca²⁺ channels controlling root hair growth and further elucidate the molecular mechanisms of how Ca²⁺ signaling and the Ca²⁺ channels are integrated into the regulating network in root hairs.  

Pollen tubes are responsible for the delivery of sperm cells into ovules for fertilization, and the polar growth of pollen tubes is guided by signaling molecules from female gametophyte by regulating cytosolic Ca²⁺ signal in pollen tubes. The identities of the Ca²⁺ channels as well as the signaling pathway from the external signal from female gametophyte to the tip-growing machinery of pollen tubes are open scientific questions. Our group is interested to address the remaining questions in this area.  

2. Stomata movement regulation 

Multiple stimuli, including Abscisic acid (ABA), light, changes of [CO₂] and ozone, can trigger stomata movement. We are working on diverse ion channels of guard cells to investigate the mechanisms of how ions are involved in stomatal movement regulation as osmotic components and signaling molecules. We are also investigating how guard cells perceive and integrate multiple upstream stimuli to open or close stomata via coordination between diverse ion channels and/or transporters in guard cells.  

3. Ion nutrient intake and crop architecture regulation 

We are interested to explore how to improve the efficiency of diverse ion intake from soil in Arabidopsis and rice, and how ion nutrient condition and ion signaling are involved in plant architecture formation and regulation. 

1. Identification and characterization of regulators of Ca²⁺ signaling 

The elevation and oscillation of cytosolic Ca²⁺ function as important second signaling in plant cells, and are required by almost all biological processes. Ca²⁺ influx mediated and regulated by plasma membrane Ca²⁺ channels are the source of Ca²⁺ signal. Thus plasma membrane Ca²⁺ channels are the “generators” and “encoders” of cytosolic Ca²⁺ signal. But the identities of the plasma membrane Ca²⁺ channels for most of biological processes are largely unknown for decades. 

Research in 1990’s revealed the presence of a cytosolic Ca²⁺ concentration gradient in pollen tube apex, and further found that the Ca²⁺ gradient is required for the elongating growth and orientation of pollen tubes. It has been well-established that inward plasma membrane Ca²⁺ channels localized in the pollen tube tips are the tunnels and regulators for dynamic external Ca²⁺ influx. However the identities of inward Ca²⁺ channels responsible for polar growth and guidance of pollen tubes remain to be addressed for decades. We characterized the ion selectivity and permeability of six cyclic nucleotide-gated channels (CNGCs) expressed in pollen tubes as divalent cation-selective and Ca²⁺-permeable channels. We further found that two point mutations in CNGC18, which is one of the six CNGCs, impaired pollen germination and tube growth, and disrupted ovular guidance of Arabidopsis pollen tubes. Whereas the loss-of-function mutations in other 5 CNGCs and two GLRs failed to obviously affect the ovular guidance of pollen tubes. Thus we identified and characterized CNGC18as the major Ca²⁺ channel essential for pollen germination, elongating growth and guidance of pollen tubes in Arabidopsis (Gao and Gu et al., 2014; Gao and Gu et al., 2016; Gu et al., 2017).   

Root hairs are essential for the intake of ion nutrients and water in plants, and consequently important for plant growth and development. Root hairs are also polar growing plant cells, similar to pollen tubes. A cytosolic Ca²⁺ gradient in root hair tips is required for polar growth and development of root hairs, and the Ca²⁺ channels responsible for the establishment and regulation of the Ca²⁺ gradient in root hairs are also unknown for years. This research growth recently found that CNGC5, CNGC6 and CNGC9 form together the main Ca²⁺ channels essential for the constitutive growth of root hairs, and are also involved in auxin signaling. This work was recently published in a new launched journal Plant Communications (Tan et al., 2019), and highly recommended by Faculty1000 Prime.  

2. Clarification of main osmotic anion for stomata movement via analyzing the selectivity of anion channel SLAC1 

It has been reported that chloride and malate are two main osmotic anions in guard cells for stomata movement regulation, and each of them takes approximate 50% responsibility in balancing the positive charges of K⁺ in 1980’s. The main anion channel SLAC1 for stomata closure has been identified and cloned in the recent ten years in diverse plant species. We recently found that nitrate is the dominant osmotic anion for stomatal closure in rice and maize relative to chloride and malate, and the dominancy of nitrate is significant larger in rice and maize than in Arabidopsis plants. In other words, each plant species choose its dominant osmotic anion for stomata closure via the selectivity and permeability of SLAC1. We conclude that monocots prefer nitrate as the dominant osmotic anion in guard cells relative to chloride, whereas guard cells of dicots show less preference to nitrate relative to monocots (Qi et al., 2018). 

3. Coordinated transmembrane movement of diverse ions 

In natural environments, diverse environmental stimuli are often applied to guard cells simultaneously. Guard cells must perceive and integrate the diverse upstream signals, and consequently determine how to respond to these diverse stimuli. This research group found that drought stress significantly improved the expression level of anion channels SLAC1 and SLAH3 in Arabidopsis guard cells. SLAC1 and SLAH3 dramatically inhibited the activity of inward K⁺ channels KAT1 and AKT2, but not KAT2, via direct protein-protein interaction. We thus revealed not only a novel molecular mechanism of crosstalk between ABA signaling pathway and light-signaling pathway in Arabidopsis guard cells for stomata movement regulation, but also a novel molecular mechanism of transmembrane movement coordination between different ions. We further found that similar coordination between anion channels and Shaker K⁺ channels is also present in root and may be involved in the coordinating transport of anion and K⁺. Those works were published in Plant Cell (Zhang et al., 2016) and Sci Bull (Yao et al., 2017). 

1. Tan Y-Q, Yang Y, Zhang A, Fei C-F, Gu LL, Sun SJ, Xu W, Wang L, Liu H, and Wang Y-F*. (2019). Three CNGC family members, CNGC5, CNGC6, and CNGC9, are required for constitutive growth of Arabidopsis root hairs as Ca²⁺-permeable channels. Plant Com, doi: https://doi.org/10.1016/j.xplc.2019.100001.   

2. Wang J, Liu X, Zhang A, Ren Y, Wu F, Wang G, Xu Y, Lei C, Zhu S, Pan T, Wang Y, Zhang H, Wang F, Tan Y-Q, Wang Y, Jin X, Luo S, Zhou C, Zhang X, Liu J, Wang S, Meng L, Wang Y, Chen X, Lin Q, Zhang X, Guo X, Cheng Z, Wang J, Tian Y, Liu S, Jiang L, Wu C, Wang E, Zhou J-M, Wang Y-F, Wang H, Wan J*. (2019). A cyclic nucldotide-gated channel mediates cytoplasmic calcium elevation and disease resistance in rice. Cell Res, doi: 10.1038/s41422-019-0219-7. 

3. Tan Y-Q, Sun S-J, Xu W, Wang L, and Wang Y-F*. (2019). Advances in plasma membrane ion channels of plant cells. Chin Bull Bot 54(1), 102-118.  

4. Qi G-N, Yao F-Y, Ren H-M, Sun S-J, Hussain J, and Wang Y-F*. (2018). Constitutive activation of calcium-dependent protein kinase 3 confers a drought tolerance by inhibiting inward K⁺ channel KAT1 and stomatal opening in Arabidopsis. Sci Bull 63, 1037-1039.  

5. Yao L, Cheng X, Gu Z, Huang W, Li S, Wang L, Wang Y-F, Xu P, Ma H, and Ge X. (2018). The AWPM-9 family protein OsPM1 mediates abscisic acid influx and drought response in rice. Plant Cell 30(6): 1258-1276.  

6. Qi G-N, Yao F-Y, Ren H-M, Sun S-J, Tan Y-Q, Zhang Z-C, Qiu B-S, and Wang Y-F*. (2018). S-type anion channel ZmSLAC1 plays essential roles in stomatal closure by mediating nitrate efflux in maize. Plant Cell Physiol 59, 614-623. 

7. Yao F-Y, Qi G-N, Ren, H-M, Zhang A, Jamshaid H, and Wang Y-F*. (2017). S-type anion channel SLAC1’s homologues inhibit inward potassium channels AKT2 and KAT2 in Arabidopsis. Sci Bull 62: 464-466. 

8. Zhang A, Ren H-M, Tan Y-Q, Qi G-N, Yao F-Y, Wu G-L, Yang L-W, Hussain J, Sun S-J, Wang Y-F*. (2016). S-type anion channels SLAC1 and SLAH3 function as essential negative regulators for K⁺ channel KAT1 and stomatal opening in Arabidopsis. Plant Cell 28:949-965. 

9. Gao Q-F, Gu L-L, Wang H-Q, Fei C-F, Xiang F, Hussain J, Sun S-J, Dong J-Y, Liu H, Wang Y-F*. (2016). Cyclic nucleotide-gated channel 18 is an essential Ca²⁺ channel in pollen tube tips for pollen tube guidance to ovules in Arabidopsis. Proc Natl Acad Sci USA 113: 3096-3101. 

10. Gu L-L, Gao Q-F, and Wang Y-F*. (2016). Cyclic nucleotide-gated channel 18 is essential for pollen germination and tube growth in Arabidopsis. Plant Signal Behav, doi: 10.1080/15592324.2016.1197999.  

11. Sun S-J, Qi G-N, Gao Q-F, Wang H-Q, Yao F-Y, Hussain J, and Wang Y-F*. (2016). Protein kinase OsSAPK8 functions as an essential activator of S-type anion channel OsSLAC1, which is nitrate-selective in rice. Planta 243: 489-500 

12. Gao Q-F, Fei C-F, Dong J-Y, Gu L-L, and Wang Y-F*. (2014). Arabidopsis CNGC18 is a Ca²⁺-permeable channel. Mol Plant 7: 739-743. 

13. Wang Y-F*, Munemasa S, Nishimura N, Ren H-M, Robert N, Han M, Puzorjova I, Kollist H, Lee S, Mori I, Schroeder JI*. (2013). Identification of cyclic GMP-activated nonselective Ca²⁺-permeable cation channels and associated CNGC5 and CNGC6 genes in Arabidopsis guard cells. Plant Physiol 163: 578-590.