Two AP2 family genes, SUPERNUMERARY BRACT (SNB) and OsINDETERMINATE SPIKELET 1 (OsIDS1), synergistically control inflorescence architecture and floral meristem establishment in rice
Two AP2 family genes, SUPERNUMERARY BRACT (SNB) and OsINDETERMINATE SPIKELET 1 (OsIDS1), synergistically control inflorescence architecture and floral meristem establishment in rice
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DOI：
10.1111/j.1365-313x.2011.04804.x
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发表时间：
2012-02-01
期刊：
影响因子：
7.2
通讯作者：
An, Gynheung
中科院分区：
文献类型：
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作者：
Lee, Dong-Yeon;An, Gynheung
分生组织的特性在决定禾本科植物花序结构方面是至关重要的。我们以前报道过，超数苞片（SNB）调节水稻小穗分生组织向花分生组织的转变。在这里，我们证明了SNB和水稻INTRANSPIATE SPIKELET 1（OsIDS1）一起发挥重要作用，花序结构和花分生组织的建立。在snb osids1双突变体中，与snb单突变体相比，穗内分枝和小穗的数目显著减少，并且向花分生组织的转变进一步延迟。表达分析表明，SN B和OsIDS1是浆片中花器官识别基因B和E功能基因时空表达所必需的。此外，AP 2家族基因对于决定分支分生组织的分枝程度、调节小穗分生组织基因如FRIZZY PANICLE（FZP）的时空表达具有重要意义。此外，microRNA172（miR172）的过表达导致SNB和OsIDS1转录水平的降低，并且转基因植物的表型比SNB osids1更严重。这表明另外的基因参与了分支和花分生组织的发育。成熟miR172在小穗分生组织周围区域的优先表达意味着，通过miR172在这些分生组织中耗尽AP 2家族基因是控制花序分枝和花器官形成的重要步骤。
Meristem identity is crucial in determining the inflorescence architecture of grass species. We previously reported that SUPERNUMERARY BRACT (SNB) regulates the transition of spikelet meristems into floral meristems in rice (Oryza sativa). Here we demonstrated that SNB and Oryza sativa INDETERMINATE SPIKELET 1 (OsIDS1) together play important roles in inflorescence architecture and the establishment of floral meristems. In snb osids1 double mutants, the numbers of branches and spikelets within a panicle are significantly decreased, and the transition to a floral meristem is further delayed compared with the snb single mutant. Expression analyses showed that SNB and OsIDS1 are required for spatio-temporal expression of B- and E-function floral organ identity genes in the lodicules. In addition, the AP2 family genes are important for determining the degree of ramification in branch meristems, regulating the spatio-temporal expression of spikelet meristem genes, such as FRIZZY PANICLE (FZP). Furthermore, overexpression of microRNA172 (miR172) causes reductions in SNB and OsIDS1 transcript levels, and phenotypes of the transgenic plants are more severe than for snb osids1. This indicates that additional gene(s) participate in the development of branch and floral meristems. Preferential expression of mature miR172s in the area around the spikelet meristems implies that depletion of the AP2 family genes in those meristems via miR172 is an important step in controlling inflorescence branching and the formation of floral organs.