Study On The Effect Mechanism Of Aluminum Stress On Flower Color Of Hydrangea Cultivar ’Meihong Mother’

Hydrangea is a well-known horticultural plant with high economic efficiency and ornamental value.One of the main ornamental characteristics of hydrangea is its gorgeous and changeable flower color,and its flower color will turn to a unique blue color with changes in environmental conditions.,Attracted much attention.In this study,the hydrangea cultivar’Meihong Mama’was divided into S1,S2 and S3 according to the developmental stage of the calyx.Exogenous aluminum stress treatment was applied when the flower bud was about 2cm,and the flower color phenotype,soluble sugar and soluble protein content,anthocyanin The composition and content,metal ion content,and anthocyanin transport-related gene expression levels were determined,and correlation analysis was carried out by combining relevant indicators with the color value of the calyx to further explore the response mechanism of hydrangea flower color under aluminum stress.The cultivation of the stable blue-purple hydrangea that the market demands provides a reference.The main conclusions are as follows:（1）The color of the calyx of hydrangea under different aluminum stress treatments has a significant effect.The calyx of the control group was red from beginning to end,and with the gradual opening of the calyx,the L*value,a*value and C*value all increased,and the flower color became brighter and brighter;the calyx of the aluminum treatment group all turned blue to varying degrees.And as the concentration increases,the degree of blue becomes deeper,the L*value gradually decreases,the a*value,b*value,and C*value also all decrease,the brightness of the calyx and the saturation of the color are significantly reduced,the red is reduced,and the red is more and more blue.development of.The red-green degree a*value has a significant positive correlation with the blue-yellow degree b*value,and the color saturation C*value.The formation of blue means the disappearance of red,and the lightness L*value is not greatly affected by aluminum stress.（2）The results of this experiment show that the calyx of Hydrangea flowers under the treatment of the three concentrations of Al Cl₃solution has accumulated different contents of anthocyanin and aluminum ion,and the content of anthocyanin glycoside has a significant positive correlation with the content of aluminum ion.Compared with the control,10μM/L Al Cl₃solution and 50μM/L Al Cl₃solution treatments promote the accumulation of hydrangea anthocyanin and aluminum ion,while 100μM/L Al Cl₃solution treatment can promote the accumulation of hydrangea anthocyanin and aluminum ion.Promote first and then inhibit,there is a significant difference in the accumulation of anthocyanin between different treatments;soluble sugar and soluble protein content both increase with the increase of the applied Al Cl₃solution concentration,showing a significant positive correlation,soluble sugar and soluble The protein also has a significant negative correlation with the chromaticity value a*value,b*value and C*value,which has a great influence on the formation of flower color.（3）In this experiment,the HmABCC1 gene of Hydrangea was analyzed by bioinformatics,and it was found that this gene was highly conserved.Through homology comparison,it was found that the HmABCC1 gene has high homology with genes in the same family of other plant species.It is predicted to be a tonoplast transporter related to anthocyanin transport.The color of the flowers under the treatment of the three concentrations of Al Cl₃solution changed to a certain extent and was accompanied by changes in the expression of anthocyanin transport related genes,but the relative expression of HmABCC1 gene did not increase with the increase of aluminum stress concentration.Combining the accumulation of anthocyanin content and aluminum ion content during flower development,as well as changes in calyx color and HmABCC1 gene expression,it is believed that a certain concentration of exogenous Al Cl₃solution treatment can induce the expression of anthocyanin transport related genes.Increase the accumulation of anthocyanin glycosides,increase the accumulation of aluminum ions in the calyx of the hydrangea,and change the flower color of the hydrangea.However,the high concentration of Al Cl₃solution may cause the hydrangea to absorb aluminum ions and chelate the anthocyanin glycosides and store them in After reaching saturation,the mechanism within the cell will have an inhibitory effect,resulting in aluminum toxicity.