Salt,Drought Stress...

Salt,Drought Stresses etc.

Specific Areas:

• Study of plant response to stress conditions, physiological regulation mechanisms of signal transduction pathways
• Screening of the stress-resistant varieties of crops,

Drought, cold, high temperature, waterlogging, salinity, pests and diseases, and chemical pollutants etc. are just partial of adverse factors the plants has to cope with.NMT presents a new way to study how the plants is adjusting themselves with monitoring flux activities of H⁺ , Ca²⁺, K⁺, of Na⁺, Cl^-, and O₂ etc.

Examples

（1）NMT reveals the mechanism why one plant specie has higher salt resistance than the other.

Sun J, et al. NaCl-Induced Alternations of Cellular and Tissue Ion Fluxes in Roots of Salt-Resistant and Salt-Sensitive Poplar Species. Plant Physiology, 2009, 149: 1141-1153

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（2）Direct measurement of PM H⁺-ATPase activities via H⁺ fluxes

Yang YQ, et al. The Arabidopsis Chaperone J3 Regulates the Plasma Membrane H⁺-ATPase through Interaction with the PKS5 Kinase. Plant Cell, 2010, 22: 1313 - 1332.

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Photosynthesis/Respiration

 Photosynthesis and Respiration in Plants

Specific Areas:

• Mechanism of Photosynthesis
• Mechanism of Respiration in Plants
• Screening of Plants with High Photosynthesis Efficiency

Plant leaf morphology, mesophyll cell growth conditions, lights and other factors have direct impacts on the efficiency of photosynthesis. Meanwhile, in order to maintain the fundamental functions of all cells, exchanges of ions and/or molecules, e.g. K⁺,H⁺,Cl^-,O₂ etc. with external environments are crucial.

Respiration is an essential process for both animals and plants by consuming O₂ and producing energy while the energy is stored in the form of maintaining a proton (H⁺) gradient across the plasma membrane.
Therefore, being able to measure ionic/molecular fluxes of K⁺,H⁺,Cl^-,O₂ etc. directly, non-invasively, in situ, in vivo and in real time, NMT is an ideal tool to study both photosynthesis and respiration in plants.

Examples:

（1）Using the NMT, extracellular oxygen and proton fluxes from Spirogyra grevilleana were measured. When the cell was illuminated, oxygen showed a net efflux and protons showed a net influx . These measurements provided a new insight in our understanding of basic cellular physiology in plant photosynthesis.

PorterfieldDM and Smith PJS. Single-cell, real-time measurements of extracellular oxygen and proton fluxes fromSpirogyra grevilleana. Protoplasma, 2000, 212: 80-88

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（2）Using the NMT, extracellular oxygen and proton fluxes from pollen tube were measured. O₂ influxes and H⁺ effluxes were detected in the region of condensed mitochodria.

Xu Y, et al. Application of non-invasive microsensing system to simultaneously measure both H⁺ and O₂ fluxes around the pollen tube. Journal of integrative plant biology, 2006, 48: 823-831.

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Development and its Regulations

Development and its Regulations

Specific Areas:

• Study the mechanisms of regulation of plant development
• Study the roles of auxin, gibberellin, abscisic acid, ethylene and other plant hormones
• Study stress phenomena in plant development
• Signal transduction
• Looking for mechanisms to promote the rapid growth and development of crops

Plant growth and development is a complex process, accompanied by active metabolism and exchanges of various substances with the outside world, it starts from seed germination, root, leave differentiations, growth and maturation, flowering, reproduction and finally aging and death. Therefore, detection of fluxes of H⁺, Ca²⁺, K⁺, Cl^- and Mg²⁺, O₂ etc. provides a indispensable way to understand the plant growth and development and how they are regulated.

Examples

（1）Ca²⁺ influxes were affected by NO stimulator or suppressor

Wang Yuhua, et al. Nitric oxide modulates the influx of extracellular Ca²⁺and actin filament organization during cell wall construction in Pinus bungeana pollen tubes. New Phytologist, 2009, 182: 851-862.

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（2）Cl^- fluxes are correlated with pollen tube growth

Laura Zonia, et al. Oscillatory Chloride Efflux at the Pollen Tube Apex Has a Role in Growth and Cell Volume Regulation and Is Targeted by Inositol 3,4,5,6-Tetra kis phosphate. Plant Cell, 2002, 14: 2233-2249

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Microbial Interactions

Microbial Interactions

Specific Areas:

• Mechanism of plant and microbial interactions
• Plant signal transduction in fungal infection process
• Plant mycorrhizal study
• Plant nitrogen fixation
• Allelopathy
• Fungal development

To study the interactions between microbes and plants, microbes and microbes, microbes and other organisms etc. is crucial to understand symbiotic, antagonistic and parasitic etc. Since most of the interactions are mediated by activities of various ions and molecules, NMT, which can detect minute dynamic fluxes of these ions/molecules in real time and non-invasively, provides a innovative tools to uncover these interaction processes.

Examples:

（1）Characteristics of H⁺ fluxes during fungal development, and are subject to the regulation of nutrient absorption

Ramos AC,et al. Proton (H⁺) flux signature for the presymbiotic development of the arbuscular mycorrhizal fungi. New Phytologist, 2008, 178: 177-188.

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（2）Ca²⁺effluxes present after infected by P. syringae pv syringae

Nemchinov LG, et al. Calcium Efflux as a Component of the Hypersensitive Response of Nicotiana benthamiana to Pseudomonas syringae. Plant Cell and Physiology, 2008, 49: 40-46.

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Plant Nutrition

Plant Nutrition

Specific Areas:

• Mechanism of crop nutrient absorption
• Looking for substances that can regulate nutrient absorption
• Screening crops
• Evaluation of the effect of fertilizer
• Develop guidance of rational fertilization process

In order to survive and grow, Plants need a large number of N, P and K and other nutrients from the environment, these nutrients are often in the forms of NH₄⁺, of NO₃^-, K,⁺ influxes near the surface of the roots. Meanwhile, fluxes of other ions and/or molecules, such as Ca^{2 +}, H⁺ and O₂ etc. are also important to regulate those nutrients absorption process.

Therefore, NMT is a vital tool to study plant nutrition absorption and regulation mechanisms because not only it can measure NH₄⁺, NO₃^-, of K⁺, Ca^{2 +} , O₂ and H⁺ etc. but also it provides a way to study them in situ, in vivo, in real time and theoretically no restrictions to the size of your samples.

Examples：

(1)Periodical oscillations of H⁺, K⁺ and Ca²⁺ absorptions have been found in the roots of wheat

ShabalaS, et al. Rhythmic patterns of nutrient acquisition by wheat roots. Functional Plant Biology, 2002, 29, 595–605.

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(2)NH₄⁺ and NO₃^- absorptions are regulated by pH

Garnett TP, et al. Trevor P. Garnett et al.Simultaneous measurement of ammonium, nitrate and proton fluxes along the length of eucalypt roots. Plant and Soil, 2001, 236: 55–62.

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(3)Different effects on NO₃^- and NH₄⁺absorptions by increase of external on NO₃^- and NH₄⁺

Fang YY, et al. Ammonium and Nitrate Uptake by the Floating Plant Landoltia punctata. Annals of Botany, 2007, 99: 365–370.

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