McAbee Jessica Messmer, Hill Theresa A, Skinner Debra J, Izhaki Anat, Hauser Bernard A, Meister Robert J, Venugopala Reddy G, Meyerowitz Elliot M, Bowman John L, Gasser Charles S
Section of Molecular Biology, University of California, 1 Shields Ave., Davis, CA 95616, USA.
Plant J. 2006 May;46(3):522-31. doi: 10.1111/j.1365-313X.2006.02717.x.
The Arabidopsis aberrant testa shape (ats) mutant produces a single integument instead of the two integuments seen in wild-type ovules. Cellular anatomy and patterns of marker gene expression indicate that the single integument results from congenital fusion of the two integuments of the wild type. Isolation of the ATS locus showed it to encode a member of the KANADI (KAN) family of putative transcription factors, previously referred to as KAN4. ATS was expressed at the border between the two integuments at the time of their initiation, with expression later confined to the abaxial layer of the inner integument. In an inner no outer (ino) mutant background, where an outer integument does not form, the ats mutation led to amorphous inner integument growth. The kan1kan2 double mutant exhibits a similar amorphous growth of the outer integument without affecting inner integument growth. We hypothesize that ATS and KAN1/KAN2 play similar roles in the specification of polarity in the inner and outer integuments, respectively, that parallel the known roles of KAN proteins in promoting abaxial identity during leaf development. INO and other members of the YABBY gene family have been hypothesized to have similar parallel roles in outer integument and leaf development. Together, these two hypotheses lead us to propose a model for normal integument growth that also explains the described mutant phenotypes.
拟南芥异常种皮形状（ats）突变体产生单个珠被，而非野生型胚珠中的两个珠被。细胞解剖结构和标记基因表达模式表明，单个珠被是野生型两个珠被先天性融合的结果。ATS基因座的分离显示，它编码一个假定的转录因子KANADI（KAN）家族的成员，以前称为KAN4。ATS在两个珠被起始时的边界处表达，随后表达局限于内珠被的远轴层。在一个没有外珠被形成的内无外（ino）突变体背景中，ats突变导致内珠被无定形生长。kan1kan2双突变体表现出类似的外珠被无定形生长，而不影响内珠被生长。我们假设，ATS和KAN1/KAN2分别在内珠被和外珠被的极性特化中发挥相似作用，这与KAN蛋白在叶片发育过程中促进远轴特性的已知作用平行。INO和YABBY基因家族的其他成员被假设在外珠被和叶片发育中具有类似的平行作用。总之，这两个假设使我们提出了一个正常珠被生长的模型，该模型也解释了所描述的突变体表型。
