Zhu Qian-Hao, Dennis Elizabeth S, Upadhyaya Narayana M
CSIRO Plant Industry, Australian Capital Territory, 2601, Canberra, Australia.
Plant Cell Rep. 2007 Apr;26(4):421-7. doi: 10.1007/s00299-006-0259-6. Epub 2006 Nov 17.
The shoot apical meristem (SAM) produces lateral organs in a regular spacing (phyllotaxy) and at a regular interval (phyllochron) during the vegetative phase. In a Dissociation (Ds) insertion rice population, we identified a mutant, compact shoot and leafy head 1 (csl1), which produced massive number of leaves (~70) during the vegetative phase. In csl1, the transition from the vegetative to the reproductive phase was delayed by about 2 months under long-day conditions. With a reduced leaf size and severe dwarfism, csl1 failed to produce a normal panicle after the transition to reproductive growth. Instead, it produced a leafy panicle, in which all primary rachis-branches were converted to vegetative shoots. Phenotypically csl1 resembled pla mutants in short plastochron but was more severe in the conversion of the reproductive organs to vegetative organs. In addition, neither the expression nor the coding region of PLA1 or PLA2 was affected in csl1. csl1 is most likely a dominant mutation because no mutant segregant was observed in progeny of 67 siblings of the csl1 mutant. CSL1 may represent a novel gene, which functions downstream of PLA1 and/or PLA2, or alternatively functions in a separate pathway, involved in the regulation of leaf initiation and developmental transition via plant hormones or other mobile signals.
在营养生长阶段，茎尖分生组织（SAM）以规则的间距（叶序）和规则的间隔（叶龄期）产生侧生器官。在一个解离（Ds）插入水稻群体中，我们鉴定出一个突变体，紧凑型茎和多叶穗1（csl1），它在营养生长阶段产生大量叶片（约70片）。在csl1中，在长日照条件下，从营养生长阶段到生殖生长阶段的转变延迟了约2个月。由于叶片尺寸减小和严重矮化，csl1在转变为生殖生长后未能产生正常的穗。相反，它产生了一个多叶穗，其中所有的一级枝梗都转化为营养枝。从表型上看，csl1在短叶龄期方面类似于pla突变体，但在生殖器官向营养器官的转化方面更为严重。此外，csl1中PLA1或PLA2的表达和编码区均未受影响。csl1很可能是一个显性突变，因为在csl1突变体的67个同胞后代中未观察到突变分离体。CSL1可能代表一个新基因，它在PLA1和/或PLA2的下游起作用，或者在一个独立的途径中起作用，通过植物激素或其他移动信号参与叶片起始和发育转变的调控。
