Study Of Transcriptome And Storage Physiological Effect Of Sulfur And Desulfurization Treatment On Longan Fruit

Use longan fruit as material to study the desulphurization effects of desulfurization process to sulfur treatment and Influence of storage physiology.We have analyzed the change of gene expression before and after longan browning and sulfur treatment by using transcriptome technical and then Cloned the lipoxygenase full length and discussed the relationship between LOX and longan pericarp Browning.The main results were as follows:1. After sulfur treatment, sulfite residue in pericarp is higher than that in aril, and then decreases as the storage extension. Different desulfurization material for sulfur smoked longan desulfurization effect is significant difference, among them, the best desulfurizer is jingbailing, followed by chlorine dioxide.2. Sulfur treatment significantly improved the color of longan exocarp, Delay the endocarp Browning and extended fruit storage period. Higher desulphurization processing will reduced the sulfur treatment effects. When decrease the using concentration and processing time, it can be decrease the sulfite residue significant and maintain the effect of sulfur treatment.3. SO activity and SO expression quantity level maintain in stable level in control longan, after sulfur treatment, SO activity and SO expression quantity improved, so as to improve the ability of eliminate of sulfur residue. Then after desulfurization treatment, SO activity and SO expression quantity are not different from sulfur treatment.4. The transcriptome sequencing obtain 8.98 Gb of data, assembly for 45594 genes, 33552（73.6%） genes getting annotation.5. Using RPKM screening difference changes in gene transcription and the contrast between samples, speculated that effect of preservation of SO₂ treatment of longan fruits may be by inhibiting Browning related increase gene expression in the process of implementation, and then SO₂ further inhibit the expression of related genes. GO functional annotations indicate that longan pericarp Browning is likely to be involved in the cell of related genes in catalytic activity under the catalysis of participate in metabolic reactions, participate in longan pericarp Browning.6. We analysis the change of the LOX and sulfur metabolic pathways through KEGG pathway. Enrich the understanding of longan desulfurization and longan pericarp Browning control theory.7. Total RNA extracted from longan fruit was used as template with RACE method to clone the full-length c DNA was named Dl LOX. sequence alignment found that LOX is 9-LOX, N-terminal signal peptide found LOX belong toⅠclass, phylogenetic tree analysis results show that the longan LOX and litchi nearest evolution.8. During longan postharvest storage, Dl LOX expression quantity raise first and then declined, And Dl LOX expression quantity rise before in longan fruit Browning, SO activity also increases, Speculated that there has a close contact between pericarp browning, LOX activity and expression of Dl LOX. But sulfur treatment destroy the cell membrane system seriously. But in the sulfur treatment of longan fruit, LOX changes in membrane far less sulfur handling damage to the cell membrane. Speculated that LOX Participates in the longan pericarp Browning process, but not the decisive factors in longan pericarp Browning.