Effects Of Post-harvest Ferulic Acid Treatment On Storage Quality And Control Of Blue Mold Caused By Penicillium Expansum In Tomato Fruit

Tomato fruit(Lycopersicon esculentum Mill.)is unique in flavor and rich in nutrition,but it is susceptible to pathogen infection and highly perishable.The most common disease of tomato fruit is gray mold,while Penicillium expansum,the causal pathogen caused blue mold decay,is prone to infect the mechanical wounds of tomato.Ferulic acid(FA),an ubiquitous phenolic compound in natural,has exhibited wide variety of biological properties such as antioxidant,antimicrobial and so on.In this paper,the effects of FA on tomato fruits at mature green stage were investigated.The tomato fruits'Jinpeng 218,were harvested in Jiaxing,Zhejiang province and then transported to the laboratory in Hangzhou immediately.The fruits were dipped in 5,10mmol/L solution of FA or water(as control)for 10 min and then stored at room temperature(20±2)?.The effects of post-harvest FA treatments on storage quality and control of blue mold caused by P.expansum in tomato were measured.Furthermore,The effects of FA treatment on P.expansum growth,the resistance-related physiological and biochemical reactions and gene expression in tomato fruit were evaluated to preliminarily determine the FA resistance mechanism.The main research results were as follows:1.FA treatment was effective in decreasing the weight loss and soluble solids content,delaying the color development,maintaining a high level of titratable acid,ascorbic acid and lycopene content in tomato.The results showed that FA treatment delayed the ripening and maintained the quality of tomato in storage.2.In vitro results indicated that FA had a direct inhibitory effect on P.expansum growth.5 and 10 mM FA could significantly inhibit the spore germination and colony growth.In vivo results indicated that FA treatment could decrease the disease incidence and lesion diameter of tomato.It was showed that 10 mM FA treatment could efficiently control the disease in tomato fruits.3.Post-harvest FA treatment was effective in enhancing the activities of defense enzymes,including peroxidase(POD),chitinase(CHI),?-1,3-glucanase(GLU),phenylalanine ammonia-lyase(PAL)and 4-coumarate CoA ligase(4CL)in tomato.Contents of total phenol,flavonoids,lignin and hydroxyproline-rich glycoprotein(HRGP)were also increased.Moreover,FA treatment enhanced the activities of catalase(CAT),superoxide dismutase(SOD),ascorbic peroxidase(APX),and inhibited the increase of H2O2 content.Furthermore,FA treatment could reduce the cell wall damage of P.expansum to tomato and MDA content at later storage period.The results showed that the involved mechanism of FA on disease resistance was related to the stimulation of defense enzymes and increasing of the contents of defense substances.4.Using Real-Time PCR to obtain an overall view on gene expression difference of tomato after inoculation of P.expansum in storage.The results showed that FA treatment could upregulate genes related defense resistance,such as PpGLU,PpCHI9,PpPODl and PpPAL5.Therefore,Theses results further explained that FA induced resistance by regulating gene expression in tomato fruit at the molecular level.