Downregulation of endo-polygalacturonase in sesame (Sesamum indicum L.) delayed capsule opening and caused changes in gene expression patterns in capsule false septa tissues.

Sesame (Sesamum indicum L.) is one of the oldest cultivated oil crops worldwide and has a low yield, which could be partially attributed to capsule dehiscence and seed dispersal just before and during full maturation. Using a nontissue culture-based technique, we successfully produced transgenic sesame plants with impaired endopolygalacturonase gene expression. T0 and T1 sesame plants (from one family, on the basis of seed availability) were subjected to PCR, RT-PCR, and real-time PCR to confirm the transfer and incorporation of the transgene into the next generation. T0 and T1 were treated with BASTA "leaf painting and spraying over mature plants." The transgenic sesame plants presented significantly lower endo-PG levels than nontransgenic controls. They also presented a noticeable delay in leaf and organ senescence and a decrease in capsule opening, even after two weeks of incubation in a 37C incubator. Comparative transcriptome analysis of false septa tissues "excised at different developmental stages" from transgenic and nontransgenic capsules revealed that 25,174 unigenes were identified, with 514 DEGs detected. Among the 514 DEGs, 349 were upregulated, and 165 were downregulated. Nineteen DEGs were chosen on the basis of their fold changes and were found to be involved in plant hormonal balance, cell wall modification, fruit maturation, and transcription factor expression. Our results suggest that the endo-PG gene might regulate the expression of an extensive array of genes involved in false septa tissue degradation, leading to capsule opening and adding another layer of complexity to false septa tissue degradation and capsule opening in sesame.