Abstract
Strigolactone is a phytohormone which suppresses the outgrowth of axillary buds. Currently, little is known about its perception and signaling.
dwarf 14(d14), is insensitive to strigolactone. D14 encodes an alpha/beta-hydrolase protein. Rice genome has a D14 paralogous gene, D14like, and its orthologues are conserved more widely in land plants than D14 orthologues.
To reveal the function of D14like we produced D14like RNAi lines, and compared its phenotypes with d14 mutant. Both d14-1 and D14like RNAi plants exhibited an elongation of the mesocotyl, while enhancement of bud outgrowth and suppression of root growth were observed only in d14 mutant. These results indicate that D14 and D14like have common and unique functions.
We examined mRNA and protein localizations of D14 and D14like. RNA in situ hybridization showed that D14 and D14like mRNA are expressed in meristems, young leaves, companion cells, and xylem parenchyma.D14 promoter::D14-GFP plants were produced to analyze D14 protein localization. GFP fluorescence was observed not only in tissues where mRNA was observed but also in sieve tubes. This indicates a possibility that D14 protein is transported in phloem sap.
