A viral induced gene silencing approach to study galactose loss in cell walls during flower development and senescence
D.A. Hunter, C.Z. Jiang, J.M. Labavitch, K. Morris, M.S. Reid and E.M. O'Donoghue
ISHS Acta Horticulturae 880:387-395. 2010.
2010
บทคัดย่อ
Substantial changes in primary cell wall composition and architecture occur in plant organs such as petals as they develop, mature and senesce. In petals of petunia ‘Mitchell’ (Petunia axillaris x P. axillaris x P. hybrida), galactose is the major non-cellulosic neutral sugar present in the primary cell wall polysaccharides. We have previously shown that its abundance doubles in floral buds during the 24 h period when flowers open before declining in petals as they mature and senesce. Changes in galactose levels are due to the activity of a family of β-galactosidases (EC 3.2.1.23) whose mRNA transcripts increase in abundance in floral buds during rapid bud expansion and in petals as they senesce. As a first step towards understanding galactose metabolism in petunia flower development and senescence, we identified 5 putative β-galactosidase gene family members in petunia petals. To assess their function in petunia flowers, approximately 120 bp fragments of the 5 β-galactosidases were linked in tandem into a hybrid DNA construct, inserted into the tobacco rattle virus (TRV) vector, and used to infect petunia plants. Five to six weeks after inoculation, petunia flowers showed up to 6-fold reduced total β-galactosidase activity, indicating that viral-induced gene silencing is a rapid and effective technology for silencing β-galactosidase expression in petunia flowers.