Schneeberger R G, Becraft P W, Hake S, Freeling M
Department of Plant Biology, University of California, Berkeley 94720, USA.
Genes Dev. 1995 Sep 15;9(18):2292-304. doi: 10.1101/gad.9.18.2292.
Rough sheath1 (Rs1) is a dominant mutation that alters cell fate and causes unregulated cell division and expansion in the maize leaf. A knox (Kn1 like-homeo box gene) sequence closely linked to the Rs1-O mutation was cloned and shown by transposon mutagenesis to encode the rs1 gene. The deduced amino acid sequence of the RS1 protein is highly similar to KN1 in the homeo domain but contains a unique amino-terminal region. rs1 is expressed in the shoot apical meristem in a circular pattern preceding leaf initiation, but is not detectable in leaf primordia or mature leaves in normal plants. Rings of rs1 expression subtend leaf insertion sites in the shoot, and lateral organ primordia in inflorescence and floral meristems. The timing and position of rs1 expression in meristems suggests a possible role for rs1 in patterning the placement of lateral organs along the axis of the shoot. In contrast to wild type, rs1 is expressed in early leaf primordia of Rs1 mutant plants, suggesting that ectopic expression causes the mutant phenotype. Ectopic expression in Rs1-O plants suggests the ligular [corrected] region is more competent to respond to rs1 than blade or sheath tissues.
粗糙叶鞘1（Rs1）是一种显性突变，它改变细胞命运并导致玉米叶片中细胞分裂和扩展不受调控。一个与Rs1 - O突变紧密连锁的knox（类Kn1同源盒基因）序列被克隆出来，通过转座子诱变表明它编码rs1基因。推导的RS1蛋白氨基酸序列在同源结构域与KN1高度相似，但包含一个独特的氨基末端区域。rs1在叶原基形成之前以环状模式在茎尖分生组织中表达，但在正常植株的叶原基或成熟叶片中检测不到。rs1表达环对着茎中叶片插入位点、花序和花分生组织中的侧生器官原基。rs1在分生组织中表达的时间和位置表明rs1在沿茎轴确定侧生器官位置的模式形成中可能发挥作用。与野生型相反，rs1在Rs1突变植株的早期叶原基中表达，这表明异位表达导致了突变表型。Rs1 - O植株中的异位表达表明叶舌[校正后]区域比叶片或叶鞘组织对rs1的反应更敏感。
