Expression Analysis Of Arabidopsis Heterotrimeric G Protein Genes And CNGC13/17 Channel Genes

Heterotrimeric G protein（G protein for short）is an important signal transduction molecule that is conserved in eukaryotic cells.It mediates the interaction between G protein-coupled receptors（GPCR）on the outer side of the cell membrane and effectors on the inner side of the membrane.Transmembrane signal transduction is composed of three subunits:α,β and γ.In the classic G protein signal transduction model,when the extracellular signal molecule binds to the GPCR,it causes the G protein to dissociate into activated Gα and Gβγ dimers,which each interact with downstream effector molecules to transmit and amplify signal.Studies in animal cells have shown that an important type of downstream effector directly regulated by G protein is plasma membrane ion channels,including Ca2+channels.In plants,the phenotypic analysis of mutants with loss of function of each subunit of G protein has revealed that they are widely involved in plant growth and development and signal transduction in response to biotic and abiotic stresses,as well as in the regulation of plant cell Ca2+channel activity.However,there are few studies on the expression patterns of G protein subunit genes in different plant organs,different growth and development stages and different stimuli.The mechanism of plant G protein regulating the activity of Ca2+channels is even less known.Cyclic Nucleotide Gated Channel（CNGC）is an important calcium ion permeability channel in plants.It affects stomatal movement,polar growth of pollen tubes and root hairs,leaf senescence,and plant resistance by regulating cytoplasmic Ca2+levels.Various physiological processes such as disease.Preliminary studies in this laboratory have shown that G protein a and y subunits physically interact with CNGC 13 and CNGC 17 calcium channels,suggesting that G protein may directly regulate the channel activity of CNGC 13/17,but the current position of CNGC 13/17 expression and its participation The biological process is not clear.In order to further analyze the biological significance of the interaction between G protein and CNGC13/17,this paper systematically analyzed the expression of G protein subunits and CNGC 13 and CNGC 17 genes in different organs,different growth and development stages and different stress stimuli in Arabidopsis.mode.The results are as follows:1.In 5-day-old seedlings,GPA1 is expressed in root tips,roots,hypocotyls,leaves and guard cells,but the expression in root tips and roots is higher than that in hypocotyls and leaves,and the hypocotyl and The expression of vascular tissue in the root is higher than that in surrounding tissues.In 12-day,three-week-old and five-week-old plants,GPA1 was also expressed in root tips,roots,hypocotyls,leaves and guard cells.At the five-week-old reproductive stage,GPA1 is expressed in the sepals,petals,stamens and pistils of flowers.After comparing different developmental stages,it was found that with the development of plants,the expression of GPA1 in hypocotyls and roots showed an upward trend,and the expression of vascular tissues in hypocotyls and root elongation zone and mature zone was always higher than that in surrounding tissues.And the expression in root tips and leaves showed a downward trend.Salicylic acid（SA）,NaCl and polyethylene glycol（PEG）treatments inhibited the expression of GPA1 in the roots and root tips of 5-day and 3-week-old plants to varying degrees,and had different expressions in other parts of the plant.Effect:The effect of abscisic acid（ABA）treatment on the expression of GPA1 in different parts is related to the developmental stage,and the degree of influence is different.2.In 5-day-old seedlings,AGB1 is expressed in leaves,hypocotyls,roots and root tips.The expression in hypocotyls is higher than that in other parts.At 12 days old,AGB1 is still in leaves and hypocotyls.Root and root tip,the expression increased in leaves,while the expression in other parts decreased;in three-week-old plants,AGB1 was only expressed in leaves,and the expression level was higher than that of 12-day-old;at five-week-old,AGB1 is expressed in the pistil of flowers and also expressed in hypocotyl cortex tissues.ABA treatment inhibited the expression of AGB1 in the middle leaves and hypocotyls of 5-day-old seedlings,and promoted the expression of AGB1 in roots and root tips;SA,NaCl and PEG had an effect on the AGB1 expression in 5-day-old and 3-week-old plants.The expression has a certain degree of inhibition.3.In 5-day-old seedlings,AGG1 is expressed in leaves,hypocotyls and roots,and the expression in leaves is significantly higher than that in hypocotyls and roots.Similarly,it was expressed in 12-day-old leaves,hypocotyls and roots,but the expression levels were all decreased.At three and five weeks of age,AGG1 is expressed in leaves and root tips.With the development of plants,the expression of AGG1 in leaves,hypocotyls and roots showed a downward trend.ABA,NaCl and PEG treatments have inhibitory effects on the expression of AGG1 in various parts of 5-day and 3-week-old plants;SA has different effects on the expression of AGG1 in different developmental stages and different parts.4.In 5-day-old seedlings,AGG2 is expressed in root tips,roots and leaves,and the expression in leaves is higher than that in roots and root tips;at 12 days old,AGG2 is expressed in leaves and roots,and the amount of expression Compared with the age of 5 days,the expression of AGG2 was not detected in all organs at the age of three weeks,but at the age of five weeks,the expression of AGG2 appeared in the hypocotyls and roots,and the expression level was extremely higher than that in the seedling stage.Big improvement.With the development of the plant,the expression of AGG2 in the leaves gradually decreased,while the expression in the roots first decreased and then increased.ABA,NaCl and PEG treatments promote the expression of AGG2 in the leaves of 5-day and 3-week-old plants,while SA treatment has an inhibitory effect on it;SA and PEG treatments have a significant effect on the expression of AGG2 in the hypocotyls of 5-day-old plants.Promoting,but inhibiting the expression in the hypocotyls of three-week-old plants;ABA,SA,NaCl and PEG treatments inhibited the expression of AGG2 in the roots and root tips of 5-day-old and three-week-old plants.5.In 5-day-old seedlings,AGG3 is expressed in root tips,roots,hypocotyls,leaves and guard cells,but the expression in leaves and roots is higher than that in hypocotyls and root tips,and the hypocotyl and root tips The expression of vascular tissue in the root is higher than that in surrounding tissues.In 12-day,three-week-old and five-week-old plants,AGG3 is also expressed in root tips,roots,hypocotyls,leaves and guard cells.AGG3 is expressed in the sepals,petals,stamens and pistils of flowers.Moreover,with the development of plants,the expression of AGG3 in hypocotyls and roots first decreased and then increased,and the expression of AGG3 in root tips and leaves always showed a downward trend.ABA,NaCl and PEG treatments can promote the expression of AGG3 in the leaves and hypocotyls of 5-day-old and 3-week-old plants;SA,NaCl and PEG treatments can promote the expression of AGG3 in the roots and root tips of 5-day-old and 3-week-old plants.The expression has an inhibitory effect.6.In 5-day-old and 12-day-old seedlings,CNGC13 is only expressed in leaves;in three-week-old plants,CNGC13 is expressed in leaves and hypocotyls;in five-week-old plants,CNGC13 is expressed in hypocotyls and roots expression.And with the development of the plant,the expression of CNGC13 in the leaves showed a downward trend,while it was only expressed in the hypocotyl and roots in the later stages of plant development.CNGC13 is not expressed in guard cells,but is expressed in the pistils of five-week-old flowers.ABA and SA treatments promoted the expression of CNGC13 in the leaves,hypocotyls and roots of 5-day and 3-week-old plants,while NaCl treatment had an inhibitory effect on it;PEG treatment had an effect on CNGC13 in 5-day-old and 3-week-old plants’ hypocotyls.The expression of is promoted,and it has an inhibitory effect on the expression at three weeks of age.7.In 5-day-old and 12-day-old seedlings,CNGC17 was only expressed in the central veins and roots;CNGC17 was not detected in any vegetative organs at the age of three and five weeks,but in five-week-old plants Specific expression in anthers.ABA and SA treatments promoted the expression of CNGC17 in three-week-old leaves and roots,but ABA,SA,NaCl and PEG all inhibited the expression of CNGC17 in 5-day-old leaves and roots.