Geisler M, Yang M, Sack F D
Department of Plant Biology, Ohio State University, Columbus 43210, USA.
Planta. 1998 Aug;205(4):522-30. doi: 10.1007/s004250050351.
Stomata are consistently patterned so that they are not in contact. This patterning is violated in the too many mouths (tmm) and four lips (flp) mutations of Arabidopsis thaliana (L.) Heynh. which have stomatal clusters in the first-formed leaves. To clarify the function of both genes in stomatal initiation and patterning, the phenotypes of many different organs were quantified. The flp mutation affects dorsiventral and cylindrical organs differentially with respect to the frequency of clustering. The tmm mutation has a more complex region-specific phenotype in that some regions lack stomata entirely, other regions have excess stomata, and the flower stalk exhibits an apex-to-base gradient from excess to no stomata. This suggests that TMM represents an unusual type of gene regulating plant cell development in that it can either influence stomatal initiation in a positive or negative fashion depending on region. Since the frequencies of initiation and clustering can be uncoupled in tmm, these two functions are under separate region-specific control. Analysis of double mutants shows that tmm and flp in some cases show region-specific interactions in both cluster formation and initiation, and that there may be subpopulations of stomata under different genetic control.
气孔呈规则排列，彼此不接触。在拟南芥的“多嘴”（tmm）和“四唇”（flp）突变体中，这种排列模式被打破，其第一片形成的叶子上出现了气孔簇。为了阐明这两个基因在气孔起始和排列中的功能，对许多不同器官的表型进行了量化。flp突变对背腹型和圆柱形器官的簇生频率影响不同。tmm突变具有更复杂的区域特异性表型，即一些区域完全没有气孔，其他区域气孔过多，而花茎则呈现出从顶部到基部由气孔过多到没有气孔的梯度变化。这表明TMM代表了一种调节植物细胞发育的特殊类型基因，因为它可以根据区域以正向或负向方式影响气孔起始。由于在tmm中起始频率和簇生频率可以分离，这两种功能受不同的区域特异性控制。对双突变体的分析表明，tmm和flp在某些情况下在簇生形成和起始方面都表现出区域特异性相互作用，并且可能存在受不同遗传控制的气孔亚群。
