Expression of SDP1 in vegetative tissues of Arabidopsis. A, SDP1 promoter activity in leaf, stem, and root of 4-week-old plants monitored using a transgenic line carrying an SDP1p:GUS construct. Values are means ± se of values from four separate plants. B, SDP1-HA protein content in leaf, stem, and root of 4-week-old plants monitored by western blot using a transgenic sdp1-5 line carrying an SDP1p:SDP1-HA fusion construct.