Preliminary Study On The Effect And Mechanism Of Acetoallicin On Kiwifruit Bacterial Canker

Kiwi bacterial canker is a disease caused by Pseudomonas syringae pv.actinidiae(Psa),which is mainly replicate and proliferation in the main branches,dendrite,new shoot and leaves of kiwifruit and extremenly easy to lead to widespread death damaging the development of the kiwifruit industry in China.Ethylicin is a broad-spectrum bionic bactericide that has a good prevention effect on multiple plant pathogenic fungi and bacterial diseases.Our previous research results show that ethylicin has a certain prevention effect on kiwi bacterial canker,but its mechanism of action on Psa is unclear.Therefore,based on the good activity of ethylicin to Psa,this study focused on studying the effects of ethylicin on the physiological biochemistry of Psa,and analyzing the effects of ethylicin on Psa gene expression through transcriptome sequencing,and then further speculated the potential mechanism.The specific research results are as follows:(1)The in vivo Psa inhibition activity of ethylicin was tested by turbid metric method,and the results showed that ethylicin had excellent inhibition activity on Psa,and its median effective inhibition concentration(EC₅₀)value was 1.80?g/m L,which was distinctly better than the control drug copper hydroxide(37.72?g/m L)and copper abietate(157.35?g/m L).The results of in vitro pot experiment test showed that the protection and curative activity of ethylicin on the kiwi bacterial canker was82.34%and 43.26%,respectively indicating that ethylicin can effectively prevent kiwi bacterial canker.(2)The impact of Psa's physiological biochemical caused by ethylicin indicates that ethylicin can effectively inhibit the growth of Psa,the formation of its biofilm and the motility of Psa.Furthermore,according to the results of scanning electron microscopy(SEM)and transmission electron microscopy(TEM),ethylicin can not only destroy the cell membrane of the Psa but also inhibit the formation of Psa's flagends.(3)The transcriptome sequencing results of showed that 1793 genes expressed differently after the treatment of ethylicin,of which 839 different genes were up-regulated and 954 genes down-regulated.5 differential genes with related pathway were selected for RT-q PCR experiments,and the results showed that the expression level of these five different genes was consistent with the transcriptional sequencing results.The KEGG analysis results showed that ethylicin up-regulates the gene of Psa's protein export pathway and biofilm formation-copper-green pseudoma pathway,and down-regulates Psa's flagella assembly path-related gene,which indicates that ethylicin inhibit the swimming movement of Psa by repressing the related gene of Psa's flagella assembly pathway.