Differential Gene Expressed Study Of Fruit In Tomato Yellow-Mutant

Tomato (Lycopersicon esculenrum Miller) is a kind of vegetable and fruit with important economic position, and also an important model plant in fruit development research. The nutritional quality of tomato fruit highly correlated with pigment content and pigment composition, and research the pigment metabolism molecular mechanism has profound theoretical value and application prospects about exploring the tomato fruit development and varieties preferred. In our research, we choose general red-fruit tomato Lr and the introgression lines yellow-fruit mutant Ly as genetic materials, aim to explore the molecular mechanism of yellow fruit mutation phenotype. We grow Lr and Ly in the field, sampling at the three typical develop stages (green mature, breaker, ripe).In one hand, We extracted the chlorophyll, lycopene and β-carotene from three processes, did the detection by spectrophotometry and did significant analysis by DPS v14.10; in the other hand, did the digital gene expression of two materials, and establish the gene expression profile of Lr and Ly. Comparing the differentially expressed genes between Lr and Ly, and did the function verification of some important genes. The results were as following:1, the pigment comparing research between Lr and Ly show:chlorophyll a and chlorophyll b content peaked in green mature, depend the fruit development, showed gradual decomposition; lycopene and β-carotene were low content in green mature, but did gradual accumulation along with the development. The main difference between Lr and Ly is about the accumulation of lycopene and β-carotene, the content of Lr is4-5times than Ly in ripe.2, The digital gene expression sequencing got21,617,449useful reads. The amount of data is about3.47G. the total reads number about the three stages of Lr respectively were3,578,840,3,592,889,3,600,613; and about Ly were3,594,082,3,527,735,3,723,290. Among those datum, the reads can be mapped to reference genome and reference gene respectively were3,069,640,3,092,308,3,091,126and3,063,416,2,985,670,2,537,770. And the unique mapped reads were2,956,231,2,969,242,2,989,150and2,969,290,2,875,726,2,437,111, with the ratio to total reads as82.60%,82.64%,83.02%and82.62%,81.52%,65.46%.3, After doing the comparing analysis of DGE results, we know about that:the significant differentially expressed genes of the three stages horizontal contrast is292, and the number between green mature stage and breaker stage is698.Combined the special materials in this study, the genes in chromosome6is24, involved with enzyme activity, protein translation prolonging actor, ion transmembrane transportation, cis-acting element, heat shock protein and so on. The significant enrich pathway in three stages simultaneously is metabolic pathways (ko01100), which combined all kinds of biochemical metabolism pathways (e.g.:glycolysis, citric acid cycle and so on), the value is limited. The common significant pathway of green mature and turning stage is photosynthesis (ko00195) and the carbon fixation in photosynthetic organisms (ko00710); the common significant pathway of turning and ripe stage is galactose metabolism (ko000512) and pyruvate metabolism (ko00620).4、The result of RT-PCR experiment appears that the PCR trends of14genes about carotenoid biosynthesis are basic agree with DGE statistics.5、Sum up the results of pigment comparing, DGE and related bioinformatics analysis statistics, we speculate that the possible mechanism of the yellow-fruit phenotype of yellow-fruit mutant lines is some molecular mechanism is triggered to make lycopene and β-carotene in tomato fruit contents of mutant fruit decrease sharply. We guess the possible triggered mechanism happened by some kind of trans-acting factor (e.g. transcription factor).