The effect of natural and artificial fruit dehiscence on floss properties, seed germination and protein expression in Calotropis procera

A method was established, based on artificial fruit dehiscence, to collect seeds and silk fibers of C. procera without any loss. The seeds and floss obtained by this method were compared with those collected naturally. Natural fruit dehiscence caused a marked decrease in seeds and fibers yielded from C. procera. The seeds and fibers obtained under artificial fruit dehiscence were approximately sixfold higher than those obtained under natural fruit dehiscence. Furthermore, the application of artificial fruit dehiscence treatment had further advantages, such as a decrease in fiber diameter, and an increase in fiber density and cellulose content. However, this treatment had a slight negative impact on seed biomass and fiber birefringence. Fiber length, lignin and ash content of fibers were not affected by artificial fruit dehiscence. Seed germinability and seedling biomass were slightly decreased following application of artificial fruit dehiscence in comparison with natural fruit dehiscence. A significant difference was observed between the two treatments in amylase activity, soluble sugars and protein content. Some variation in protein expression was also apparent. Artificial fruit dehiscence lowered the expression of the short chain dehydrogenase, elongation factor 1-alpha, and peptidyl-prolyl cis–trans isomerase in comparison with natural dehiscence. Conversely, the expression of chitinase was enhanced in response to the artificial fruit dehiscence. Two conserved protein regions (prrl and vvet) were also observed.