Photos of representatives from the T
generations showing the aberrant phenotypes observed in
(A, B,C) and
(D,E,F) plants. (A) T1
35S:HvCesA4 plants and wild-type (WT) Golden promise on the far left. Dwarfism (d) persisted in most plants grown from parents with an aberrant phenotype except for one or two plants within the same line (e.g. plant NP, normal phenotype). The ratio of plants displaying dwarf: normal phenotype (including nulls & revertants) in T1 is 58%: 42%. (B) Many T2, 35S:HvCesA4 progeny were dwarfed with “brittle nodes” (d,B). About 25% of T2 plants from each line exhibited a severe reduction in stature, was sterile (S) and some died. The plants with a severe phenotype may be homozygotes. (C) Close up view of necrosis found at the leaf-tips of a 1 month old plant that further developed into a dwarf plant with few viable grains. (D) T1
35S:HvCesA8 plants. Aberrant phenotypes observed were “brittle node” (B) and severely stunted plants that died young (S) (~1 month old). Plants with a “brittle node” phenotype had no reduction in stature but when pressure was applied manually, the stems snapped at the nodes. (E) T2
35S:HvCesA8 plants. About 25% of T2 plants from each line were stunted and died young (S). Many were only brittle at the node (B) with no compromise in stature. (F) Comparison of two wild-type (left) and two transgenic “brittle node” stems (right). One stem each from wild-type and transgenic plant were sliced in half to reveal the stem’s internal anatomy. The bracket indicates the nodal region of the stem and at closer inspection the break-point was often found to be at the “nodal plate” (arrow).