| Litchi(Litchi chinensis Sonn.)originating in southern China,is widely cultivated in southern China special fruit,with high economic value,is China’s most competitive in the international market,one of the fruit.The rapid browning of litchi fruit greatly shortened the shelf life of litchi and lowered its commodity value,which was the main factor restricting the development of litchi trade and industry.Fresh litchi water content of up to 75 ~ 95%,which is to maintain the normal physiological metabolism of litchi fruit and fresh quality of the necessary conditions.Litchi fruit outer skin covered with a very fine layer of film to protect the water running out of the fruit.The preliminary study showed that the waxy content of the kiwi litchi peel was much lower than that of the sub-litchi litchi,and the expression of the waxy synthesis-related gene in the litchi fruit was studied mode.In this paper,the full length of Lc WIN1 and Lc LACS4,two key genes related to waxy synthesis of litchi,were further cloned.By observing the wild type lines and overexpressing the phenotype of the target gene plants,the expression level of the target gene in waxy synthesis was Change,identify the function of these two genes.The results show:(1)Cloning of two key genes related to waxy synthesis Lc WIN1 and Lc LACS4 full length.Lc WIN1 was located in the nucleus and Lc LACS4 was localized in the endoplasmic reticulum.(2)The p B2GW7-35s-Lc WIN1/Lc LACS4 overexpression vector was constructed and transferred into wild-type Micro Tom tomato.Wild-type Micro Tom tomato fruit showed round,while the transgenic tomato fruit showed gourd-shaped,placental and other deformities.This may be due to thickening of the waxy layer on the surface of the transgenic tomato fruit.(3)The total amount of wax in the leaves and fruits of transgenic tomato was significantly higher than that of wild type tomato.And the density and length of the epidermis were significantly higher than those of the control.The stomatal density of the transgenic tomato leaves and the lenticole density of the transgenic tomato were all lower than the control.Meanwhile,the stomata of the transgenic lines As well as the surface of the fruit lacquer are covered with thick waxy crystals.Waxy components also change.Mainly for the alkanes,aldehydes increased,while the primary alcohol,keto acid content decreased.(4)After the drought treatment,the transgenic tomato had more proline content than the wild type Micro Tom tomato plant,the content of malondialdehyde was low,the relative conductivity was low,the relative water content was more,and the weight loss of transgenic tomato than wild type tomato fruit The rate was significantly reduced.Multiple physiological indexes indicate that overexpression of Lc WIN1 and Lc LACS4 can significantly improve the drought resistance of plants.In conclusion,Lc WIN1 and Lc LACS4,which express the waxy synthesis genes of litchi fruit in the model plants,can improve the total wax content of the transgenic lines and change the structure and composition of the leaves and peel waxes.Plant wax content increased,can effectively enhance their own drought resistance.The results indicated that Lc WIN1 and Lc LACS4 were the key genes in the waxy synthesis of litchi fruit.Overexpression of Lc WIN1 and Lc LACS4 could significantly increase the content of wax in plant epidermis,and enhanced the drought resistance of plants. |
