Functional Research Of SlWUS In Abscission Of Tomato Pedicel

Tomato(Solanum lycopersicum)is one of the important Facility vegetable crops in China.Due to various factors in agricultural production,there will be abnormal flower and fruit drop from plants,which will seriously affect the crop yield and damage the economic benefits of growers.To solve this problem,it is necessary to clarify the mechanism that affects the shedding of tomato flower organs.Plant stem cell determinant gene WUSCHEL(WUS)plays a key role in its entire growth and development process.Related reports have shown that the tomato Sl WUS gene is specifically expressed in abscission zone,but its role is unclear.In this study,by studying the role of the Sl WUS gene in the process of tomato pedicel abscission and its downstream genes,it was initially determined that Sl WUS was involved in the process of tomato pedicel abscission.1.Expression analysis showed that the Sl WUS gene was expressed only in abscission zone,but not expressed at the distal region and proximal region.2.After removing flowers induces tomato flower pedicel abscission,the expression of Sl WUS gene decreases rapidly,and no expression is detected in 4 hours after treatment.The use of auxin and 1-MCP to delay the shedding process,we found the expression of Sl WUS was maintained.3.Sl WUS overexpressing transgenic plants delay flower pedicel abscission,and down-regulate the expression of Sl WUS by VIGS to accelerate flower pedicel abscission,suggesting that Sl WUS is a negative regulator of tomato flower pedicel abscission.4.In order to further explore the downstream genes of the Sl WUS,through the transcriptome analysis,the significantly down-regulated genes Solyc09g020190.2.1 and the significantly up-regulated genes Solyc04g072520.2 were selected as candidate genes.Through VIGS,it was found that the above two genes significantly affected the occurrence of shedding.The results of EMSA showed that Sl WUS can directly bind to the promoter of the candidate gene and regulate the expression of the candidate gene.Thus,regulating tomato flower pedicel abscission.Based on the above conclusions,it can be concluded that Sl WUS can regulate tomato flower pedicel abscission by affecting the expression of key downstream genes.