Klucher K M, Chow H, Reiser L, Fischer R L
Department of Plant Biology, University of California-Berkeley 94720, USA.
Plant Cell. 1996 Feb;8(2):137-53. doi: 10.1105/tpc.8.2.137.
Ovules play a central role in plant reproduction, generating the female gametophyte within sporophytic integuments. When fertilized, the integuments differentiate into the seed coat and support the development of the embryo and endosperm. Mutations in the AINTEGUMENTA (ANT) locus of Arabidopsis have a profound effect on ovule development. Strong ant mutants have ovules that fail to form integuments or a female gametophyte. Flower development is also altered, with a random reduction of organs in the outer three whorls. In addition, organs present in the outer three floral whorls often have abnormal morphology. Ovules from a weak ant mutant contain both inner and outer integuments but generally fail to produce a functional female gametophyte. We isolated the ANT gene by using a mutation derived by T-DNA insertional mutagenesis. ANT is a member of a gene family that includes the floral homeotic gene APETALA2 (AP2). Like AP2, ANT contains two AP2 domains homologous with the DNA binding domain of ethylene response element binding proteins. ANT is expressed most highly in developing flowers but is also expressed in vegetative tissue. Taken together, these results suggest that ANT is a transcription factor that plays a critical role in regulating ovule and female gametophyte development.
胚珠在植物繁殖中起着核心作用，在孢子体珠被内产生雌配子体。受精后，珠被分化为种皮，并支持胚和胚乳的发育。拟南芥的AINTEGUMENTA（ANT）基因座突变对胚珠发育有深远影响。强ant突变体的胚珠无法形成珠被或雌配子体。花的发育也会改变，外三轮器官随机减少。此外，外三轮花器官的形态通常异常。弱ant突变体的胚珠既有内珠被也有外珠被，但通常无法产生功能性雌配子体。我们通过使用T-DNA插入诱变产生的突变分离出了ANT基因。ANT是一个基因家族的成员，该家族包括花同源异型基因APETALA2（AP2）。与AP2一样，ANT含有两个与乙烯反应元件结合蛋白的DNA结合结构域同源的AP2结构域。ANT在发育中的花中表达最高，但也在营养组织中表达。综上所述，这些结果表明ANT是一种转录因子，在调节胚珠和雌配子体发育中起关键作用。
