A typical Shaker type potassium ion absorption channel gene AmKAT1 was cloned from the leaves of Ammopiptanthus mongolicus. Electrophysiological studies of AmKAT1 show that AmKAT1 is a K+ absorption channel regulated by potassium ion concentration. the system can only input K+ into guard cells when the extracellular potassium ion concentration is high (above 10 mmol/L). This distinctive feature has important physiological significance for xerophytes such as Ammopiptanthus mongolicus: under the condition of low concentration of extracellular potassium ions (no matter how high the concentration of sodium ions), AmKAT1 is difficult to open, potassium ions cannot enter guard cells, the guard cells will not absorb water and expand, and stomata will be difficult to open, thus reducing the transpiration and loss of water in Ammopiptanthus mongolicus and enhancing the viability of Ammopiptanthus mongolicus in arid environment. We have further studied the mechanism of extracellular potassium ion regulating the activity of AmKAT1 and found that at least two sites in AmKAT1 are involved in potassium ion induction, and now one site has been determined to be located in the channel pore region. In addition, we cloned a guard cell export-oriented K+ channel AmGORK and a slow anion channel AmSLAC1. Fluorescence quantitative PCR results showed that AmGORK was mainly expressed in the upper part of the ground, and its transcription level was affected by PEG simulated water stress, ABA, NaCl and osmotic stress treatments to varying degrees. Electrophysiological studies in xenogeneic system of Xenopus laevis oocytes show that AmGORK channel of Mongolian Ammopiptanthus mongolicus guard cells can mediate efficient efflux of K+ when membrane potential is depolarized. The activation of this channel has typical voltage dependence and potassium ion concentration dependence, and is inhibited by potassium ion channel inhibitors TEA and Ba2+; In addition, the activity of AmGORK is regulated by extracellular pH, but not by extracellular calcium concentration. These results show that although Ammopiptanthus mongolicus is an ancient drought-resistant leguminous shrub originated millions of years ago, it is highly similar to the existing common model plant Arabidopsis thaliana in the stomatal closure mechanism dominated by K+. These results provide evidence to preliminarily reveal the functional conservatism of GORK-like stomatal regulatory channels in different species and long-term evolution.
2020-07-28
As determined in mid-august 2013, planting species: bubbly spines (different habitats are mid-range intermountain lowland and gobi), red sand (different habitats are mid-range gobi and downstream gobi). Using the brother company of LI - 6400 Portable Photosynthesis System (Portable Photosynthesis System, LI - COR, USA) and LI - 3100 leaf area meter, etc., to the desert plant photosynthetic physiological characteristics were observed. The symbolic meaning of the observed data is as follows: Obs，observation frequency ； Photo ，net photosynthetic rate，μmol CO2•m–2•s–1； Cond stomatal conductance，mol H2O•m–2•s–1 ; Ci, Intercellular CO2 concentration, μmol CO2•mol-1； Trmmol，transpiration rate，mmol H2O•m–2•s–1； Vpdl，Vapor pressure deficit，kPa； Area，leaf area，cm2； Tair，free air temperature ，℃； Tleaf，Leaf temperature，℃； CO2R，Reference chamber CO2 concentration，μmol CO2•mol-1； CO2S，Sample chamber CO2 concentration，μmol CO2•mol-1； H2OR，Reference chamber moisture，mmol H2O•mol-1； H2OS，Sample chamber moisture，mmol H2O•mol-1； PARo，photon flux density，μmol•m–2•s–1； RH-R，Reference room air relative humidity，%； RH-S，Relative humidity of air in sample room，%； PARi，Photosynthetic effective radiation，μmol•m–2•s–1； Press，barometric pressure，kPa； Others are the state parameters of the instrument at the time of measurement.
2020-03-10
In mid-july 2011, photosynthetic organs (leaves or assimilating branches) of typical desert plants were collected and brought back to the laboratory in a liquid nitrogen tank for determination. The analysis indexes mainly include soluble protein unit: mg/g;Free amino acid unit: g/g;Chlorophyll content unit: mg/g;Superoxide dismutase (SOD) unit: U/g FW;Catalase (CAT) unit: U/(g•min);POD unit: U/(g•min);Proline (Pro) unit: g/g; Soluble sugar unit: g/g;Malondialdehyde (MDA) is given in moles per liter.
2020-03-10
On the basis of physiological and biochemical analysis of photosynthetic organs (leaves or assimilating branches) of typical desert plants in heihe river basin collected in mid-july 2011, some photosynthetic organs of desert plants were collected in mid-july 2012 and put into a liquid nitrogen tank and brought back to the laboratory for determination. Physiological analysis indexes mainly include: soluble protein unit: mg/g;Free amino acid unit: g/g;Chlorophyll content unit: mg/g;Superoxide dismutase (SOD) unit: U/g FW;Catalase (CAT) unit: U/(g•min);POD unit: U/(g•min);Proline (Pro) unit: g/g; Soluble sugar unit: g/g;Malondialdehyde (MDA) is given in moles per liter.
2020-03-10
The data set is the physiological and ecological parameters of the dominant species of each ecosystem in Heihe River Basin. According to the requirements of tesim model, the data set divides Heihe River basin into seven ecosystems: deciduous broad-leaved forest ecosystem (BRD), evergreen coniferous forest ecosystem (CNF), agricultural field ecosystem (CRP), desert ecosystem (DST), meadow grassland ecosystem (MDS) Shrubbery ecosystem (SHB) and grassland ecosystem (STP). Some of the data in this data set are based on the measured data, some are obtained by reference documents, but after verification, they are applied to the Heihe River Basin. For the data in this data, each parameter of each ecosystem has three values, which are the value in the model, the minimum value and the maximum value of this parameter. The data can provide input parameters for the ecological process model, and the data set is still in further optimization.
2020-03-06
In mid July 2011, the photosynthetic organs (leaf or assimilating branches) of typical desert plants were collected and determined by laboratory. The indicators include: leaf water potential, total leaf water content, relative water content, dry weight water content, leaf dry matter content, specific leaf area, specific leaf volume, free water, bound water, etc.
2019-09-15
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