Penetration Of Phenazine-1-carboxylic Acid Amino Acid Conjugate In Plants

Phenazine-1-carboxylic acid is a microbial bactericide.It has good antibacterial activity against a variety of plant pathogens,low toxicity and good compatibility with the environment.However,it can not control soil borne diseases,because Phenazine-1-carboxylic acid has no conductivity in phloem and can not reach plant roots by spraying.In order to improve the phloem transport of Phenazine-1-carboxylic acid,a series of Phenazine-1-carboxylic acid amino acid conjugates were obtained by coupling amino acids with it.Among them,Phenazine-1-carboxylic acid has the best phloem conductance in castor,and some of the other Phenazine-1-carboxylic acid amino acid conjugates have phloem conductance and some do not.Apart from the difference in the configuration of L and D,other reasons are not clear.The factors affecting the entry of Phenazine-1-carboxylic acid amino acid conjugate into castor cells were studied in this paper.In this paper,the oil-water partition coefficient of Phenazine-1-carboxylic acid and its amino acid coupling was measured by shaking flask method.The results showed that there was a great difference between the actual measured value and the software estimated value.According to the prediction of kleier model,Phenazine-1-carboxylic acid amino acid coupling should have a medium degree of phloem transport.According to the preliminary test in our laboratory,the phloem transport of Phenazine-1-carboxylic acid amino acid coupling did not accord with the model.Therefore,it is speculated whether Phenazine-1-carboxylic acid amino acid conjugate is affected when entering castor.Through the absorption content of Phenazine-1-carboxylic acid amino acid conjugate in castor leaves,judge whether it is affected when Phenazine-1-carboxylic acid amino acid conjugate initially contacts and begins to enter castor leaves.The absorption of Phenazine-1-carboxylic acid amino acid conjugate in castor leaves was detected by liquid-liquid extraction and liquid chromatography-mass spectrometry.The results showed that at the six time points of 10 min,20 min,30 min,40 min,60 min and120 min,the absorption of Phenazine-1-carboxylic acid increased with time,and the absorption of Phenazine-1-carboxylic acid-L-valine conjugate and Phenazine-1-carboxylic acid-L-phenylalanine conjugate first increased,then decreased and then increased with time.The absorption of Phenazine-1-carboxylic acid-L-asparagine conjugate increased with time,and the increase was small.With the increase of time,the absorption of Phenazine-1-carboxylic acid-D-valine conjugate first increased slowly,then increased rapidly and then decreased.A liquid phase detection method was established by detecting the absorption of castor cells and protoplasts.In the experiment of castor protoplast,the absorption of Phenazine-1-carboxylic acid in castor protoplast decreased with the increase of time from 0.5 min to 10 min.With the increase of time,the absorption of Phenazine-1-carboxylic acid-L-valine conjugate first increased,then decreased,and then basically remained in equilibrium.The absorption of Phenazine-1-carboxylic acid-D-valine conjugate first increased and then decreased with time.Under the same conditions,the absorption of Phenazine-1-carboxylic acid-L-valine conjugate was higher than that of Phenazine-1-carboxylic acid-D-valine conjugate.The absorption of Phenazine-1-carboxylic acid-L-phenylalanine increased significantly at 1.5 min,reached the maximum at 2 min,and decreased significantly from 2.5 min.The absorption of Phenazine-L-carboxylic acid-L-asparagine in protoplasts increased significantly in 2 minutes and began to decrease in 2.5 minutes.Uncoupler CCCP was added in the protoplast absorption test.After adding uncoupler,the absorption of Phenazine-1-carboxylic acid-L-valine conjugate in castor protoplast decreased significantly,indicating that Phenazine-1-carboxylic acid-L-valine entering castor protoplast is a process requiring energy,and the way of entering castor protoplast includes active transportation.The results show that the entry of Phenazine-1-carboxylic acid amino acid conjugate into castor is a complex process.In addition to its physical and chemical properties,there are also active absorption components.Especially for the Phenazine-1-carboxylic acid amino acid conjugate that can conduct in the phloem of castor,the content of the tested agent increased rapidly in the initial stage of contact with castor plant,and the absorption decreased significantly when adding uncoupler,indicating that the transport carrier on castor cells participated in the absorption,which is an active absorption process.However,due to the limited transport capacity of the carrier,passive diffusion becomes the main absorption mode when the concentration of exogenous Phenazine-1-carboxylic acid amino acid conjugate increases.Therefore,the absorption of Phenazine-1-carboxylic acid amino acid conjugate on castor is a process of both active absorption and passive diffusion,which is affected by many factors at the same time.