Sinha N, Hake S
Plant Biology Department, University of California, Berkeley 94720.
Dev Biol. 1990 Sep;141(1):203-10. doi: 10.1016/0012-1606(90)90115-y.
Knotted (Kn1), a dominant mutation in maize, perturbs normal leaf development. Mutant leaves have localized regions of extra growth called knots and, in addition to the normal ligule, ectopic fringes of ligule are found on the leaf blade. Previous clonal analysis showed that the epidermal genotype was immaterial in knot formation. To establish which inner leaf layer was required for formation of knots and ectopic ligule we used a closely linked albino mutation to mark X-ray-induced clonal sectors of wild type (kn) tissue in Kn1 plants. The sectors examined frequently changed in composition of layers in the leaf both transversely and longitudinally. We present results that show that both mutant characters are determined in the middle mesophyll-bundle sheath (MMBS) layer. We show that a lateral vein can produce a knot when only half the MMBS layer around the lateral vein contains the mutant gene. We also show that the ectopic ligule in Kn1 has contributions from both the adaxial epidermal and adaxial mesophyll layer.
“纽结”（Kn1）是玉米中的一种显性突变，会扰乱叶片的正常发育。突变叶片有称为纽结的局部额外生长区域，并且除了正常叶舌外，在叶片上还发现异位叶舌条纹。先前的克隆分析表明，表皮基因型在纽结形成中无关紧要。为了确定形成纽结和异位叶舌需要哪一层内部叶层，我们使用了一个紧密连锁的白化突变来标记Kn1植株中野生型（kn）组织的X射线诱导克隆区。所检查的区域在叶片中的层组成上经常在横向和纵向上发生变化。我们给出的结果表明，这两个突变性状都是在中叶肉-维管束鞘（MMBS）层中决定的。我们表明，当围绕侧脉的MMBS层只有一半含有突变基因时，一条侧脉就能产生一个纽结。我们还表明，Kn1中的异位叶舌来自近轴表皮层和近轴叶肉层两者。
