FRIZZLE PANICLE (FZP) and RFL/ABERRANT PANICLE ORGANIZATION 2 (APO2) play important roles in regulating the ABCDE floral organ identity genes. However, the relationships among FZP and these floral identity genes in the regulation of panicle formation remain unclear. Here, we used the novel mutant fzp-11, wild-type and FZP-overexpressing plants to compare the expression of these genes during panicle development by real-time PCR and in situ hybridization. The results indicate that FZP is a major negative regulator of RFL/APO2 and determines the transition from panicle branching to spikelet formation. Moreover, overexpression of FZP severely represses axillary meristem formation in both the vegetative and reproductive phases and the outgrowth of secondary branches in panicle. FZP overexpression positively regulates the expression of a subset of the class B genes, AGL6 genes (OsMADS6 and OsMADS17) as well as class E genes (OsMADS1, OsMADS7 and OsMADS8) in floral meristem (FM). Thus, it suggested that FZP could specify floral organ identity by regulating the related OsMADS-box genes.
FZP和APO2在ABCDE花器官特性基因的調(diào)控中發(fā)揮重要作用。但是在調(diào)控穗形成時(shí)，F(xiàn)ZP和這些花特性基因之間的關(guān)系仍不清楚。本文我們利用新突變體fzp-11、野生型以及FZP過表達(dá)植株，通過實(shí)時(shí)熒光定量PCR和原位雜交比較這些基因在穗發(fā)育過程中的表達(dá)。結(jié)果表明FZP是RFL/APO2的主要負(fù)調(diào)控因子，決定穗分枝向小穗形成的轉(zhuǎn)化。此外，過表達(dá)FZP會(huì)嚴(yán)重抑制營養(yǎng)階段和生殖階段腋芽原基的形成以及穗上二級(jí)枝梗的生長。過表達(dá)FZP會(huì)正向調(diào)控花分生組織一系列B類基因、AGL6基因（OsMADS6、OsMADS17）以及E類基因（OsMADS1、OsMADS7、OsMADS8）表達(dá)。因而，這些結(jié)果表明FZP通過調(diào)控相關(guān)OsMADS盒基因，進(jìn)而決定花器官特性。