Effects Of Auxin Response Factor SlARF3 On Organic Acids In Tomato Fruit

Tomato(Solanum lyccopersicum)has become one of the indispensable vegetables in people’s lives,and people are more and more fond of tomatoes.Tomato is one of the main types of agricultural vegetables cultivation in the world because of its strong adaptability,diverse cultivation methods,high yield in each season,rich nutritional value and popular special flavor.Tomato fruit development and maturity is a very complex physiological and biochemical process,which needs to be controlled by multiple mechanisms.ARF(auxin response factor)is a transcription factor that responds to auxin signal,which directly affects the transmission of auxin in various parts of plant tissues.ARFs can be combined with the auxin response elements in the promoter region of the target gene,activate the transcription expression of target gene,and play an important role in the growth and development of fruit and fruit quality.Our main test materials are tomato AC varieties.By the physiological index and transcriptional group,observed the effect of SlARF3 on the quality of tomato fruit.Some ARFs have been proved to be involved in the formation and development of plant fruits,and play an important role.In the cultivation of facilities tomato,if the temperature of the fruit stage is too high or the temperature is too low,the tomato will have bad pollination or falling flowers and fruit falling,which will directly affect the tomato yield and the number of malformed fruits,which seriously affects the fruit quality and yield of tomato.Previous studies have shown that ARF4,ARF7,ARF8,ARF9,ARF10 and other genes play an important role in affecting the fruit quality of tomato.For example,the down regulation of the expression of SlARF4 makes a large amount of chlorophyll accumulation in the early stage of tomato fruit development,producing dark green fruit,and plays a key role in the accumulation of sugar in the fruit development process;SlARF7 plays a negative role in the fruit setting of tomato.When the gene of SlARF7 is silent,tomato can form a single fruiting without pollination;The specific expression of slarf8 can promote the fruit single fruiting;The difference of SlARF9 expression in the fruit setting stage and early fruit development of tomato plays a negative role in the cell division of tomato fruit;SlARF10 regulated the accumulation of sugar in tomato fruit by regulating the expression of starch synthesis related enzymes in tomato fruit.According to the evolution tree of tomato,one of the members of ARFs family,it is found that SlARF3 and SlARF4 are highly homologous genes,and the expression of SlARF4 is the highest in tomato fruit,which plays a certain regulatory role in the accumulation of sugar in the fruit.Therefore,it is suggested that slarf3 will also play an important role in the development of tomato fruit.In order to clarify the specific role of SlARF3 gene in fruit development,constructed Crispr-Cas9 transgenic plants of the gene,cultivated and screened,and obtained T3 generation homozygous mutant plants.In observation and experiment,we found that the mature fruit size and sugar acid ratio of mutant plants were significantly different from control plants.Our results suggest that the SlARF3 gene plays an important role in the formation and accumulation of organic acids during tomato fruit development.further analyzed the changes of organic acid content and the differential expression of related genes in tomato fruit by using transcriptome analysis,and screened 21 differentially expressed genes,among which solyc01g106480,solyc06g083790,solyc06g069530 and solyc12g014180 played an important role in the metabolic pathway of organic acid in tomato fruit development,which indicated that SlARF3 gene played an important role in the development of tomato fruit Through affecting the expression of genes related to malic acid metabolism pathway,it promoted the accumulation of organic acids in fruits and affected the flavor quality of tomato.To sum up,this study mainly used tomato AC varieties as the research object,constructed the transgenic plants of SlARF3,and preliminarily analyzed the role of SlARF3 in the process of organic acid metabolism in tomato fruit development.The results showed that as one of the members of tomato ARFs family,SlARF3 played an extremely important role in the change of organic acid content during fruit development The expression of genes related to metabolic pathway promoted the accumulation of organic acids in tomato fruit.Our study explored the molecular mechanism of ARFs regulating tomato fruit quality,and provided an important theoretical basis for solving the problems of tomato quality and taste.