| Tomato is known as one of the most important vegetable crops in the world,at present,the annual output of tomatoe in China is increasing year by year.One of the important goals of tomato domestication is the increase of fruit weight,The number of locule in tomato is an important factor affecting the weight and shape of the fruit,The locule is positively correlated with the fruit's size and the incidence of deformed fruit.Therefore,the research of locule's formation has great significance in production.In recent years,studies have found that TOPLESS(TPL),a transcriptional co-repressor,is widely involved in plant growth and development,and there is a certain degree of combined inhibition in hormonal response and resistance to disease.However,there are few studies on the specific molecular mechanism of tomato multi-locule formation.Therefore,we selected three RNAi lines of SlTPL3 as test materials in this study,which performeing the phenotypic identification and quality verification,and studying the expression characteristics and inhibition mechanism of SlTPL3 in tomato by yeast two-hybrid and qRT-PCR.The main results are as follows:1.The statistics of agronomic traits showed that SlTPL3 silencing can significantly reduce the plant height,increase the number of flower organs and locules,and speed up the opening time of flower,besides,also can delay fruit breaker time significantly occasionally showing multi-locule malformed fruit.2.The silencing of SlTPL3 significantly decreased the content of soluble sugar and lycopene,and significantly increased the content of ?-carotene and lutein,but had no significant effect on the amount of the free amino acid in the period of Br+7.3.SlTPL3,SlWUS,SlYABBY,SlIMA,SlFW2.2,SlLTM,SlTAG1,and SlCLV3 genes were respectively constructed on pGAD predator and pGBD decoy carriers for yeast two-hybrid experiments.The results showed that there was protein-protein interaction between SlTPL3 and SlWUS.4.qRT-PCR revealed that the expression levels of SlTPL3 and SlTPL6 were significantly down-regulated in the stem apex of SlTPL3 Rline2,while the expression levels of SlTPL1,SlTPL2,SlTPL4,and SlTPL5 in TOPLESS family did not change significantly;in SlTPL3 Rline2,SlWUS and SlCLV3 were significantly up-regulated at the5 th and 7th tips,but significantly down-regulated at 10 thd.During the shoot tip development,the SlTAG1's expression level in SlTPL3 Rline2 was significantly down-regulated.The expression level of SlFW2.2 in SlTPL3 Rline2 and WT was no significant change during the shoot tip development;In the SlTPL3 Rline2,SlYABBY was significantly up-regulated at the shoot tip on days 5 and 10,but no significant changes on day 7;SlLTM and SlIMA genes were significantly up-regulated on the 7th day of shoot tip development in SlTPL3 RNAi lines,and there was no significant change on the 5th and10 th days.It was shown that the down-regulation of SlTPL3 had a certain effect on the expression of genes related to multi-locule development.In summary,silence of SlTPL3 resulted in a significant increase of locule number in tomato fruits.SlTPL3 regulates the locule formation of tomato through the interaction with SlWUS and the transcriptional co-suppression of locule formation-related genes.SlTPL3 is involved in the growth and development of tomato,in addition,the SlTPL3 gene also regulates fruit ripening.The down-regulation of SlTPL3 gene resulted in the decrease of soluble sugar content and lycopene content,and the up-regulation of the relative expression of key genes in the carotenoid synthesis pathway also had a certain effect on fruit quality. |
PDF Full Text Request