Albert S, Després B, Guilleminot J, Bechtold N, Pelletier G, Delseny M, Devic M
Laboratoire de Physiologie et Biologie Moléculaire des Plantes, UMR 5545 du CNRS, Université de Perpignan, France.
Plant J. 1999 Jan;17(2):169-79. doi: 10.1046/j.1365-313x.1999.00361.x.
The EMB 506 gene of Arabidopsis, required for the normal development of the embryo beyond the globular stage, has been cloned. The gene encodes a protein of predicted size 35 kDa that contains five ankyrin (ANK) repeats within the C terminal moiety. ANK repeats are conserved domains of 33 amino acids involved in specific recognition of protein partners. The EMB 506 protein was detected at different stages of silique development but accumulated preferentially in the mature cauline leaves. The rescue of homozygous emb 506 embryos by complementation with the wild-type sequence cDNA demonstrated that the emb mutation is a consequence of the T-DNA insertion and that integration and expression of the transgene occurred during gametogenesis and/or early embryo development. In addition to the drastic effect of the emb 506 mutation during embryo development, complementation experiments revealed another effect of the gene: emb 506 plants transformed with the wild-type EMB 506 sequence were able to produce viable seeds but showed a reduction of apical dominance and the presence of adventitious buds or bracts along the stem. This result supports the idea that genes essential for embryogenesis may also be required at other stages of the plant life cycle.
拟南芥的EMB 506基因已被克隆，该基因是胚胎在球形期之后正常发育所必需的。该基因编码一种预测大小为35 kDa的蛋白质，其C末端部分含有五个锚蛋白（ANK）重复序列。ANK重复序列是由33个氨基酸组成的保守结构域，参与蛋白质伴侣的特异性识别。在角果发育的不同阶段都检测到了EMB 506蛋白，但它在成熟的茎生叶中优先积累。通过用野生型序列cDNA进行互补来拯救纯合的emb 506胚胎，这表明emb突变是T-DNA插入的结果，并且转基因的整合和表达发生在配子发生和/或早期胚胎发育过程中。除了emb 506突变在胚胎发育过程中的显著影响外，互补实验还揭示了该基因 的另一个作用：用野生型EMB 506序列转化的emb 506植株能够产生可育种子，但顶端优势减弱，并且在茎上出现不定芽或苞片。这一结果支持了这样一种观点，即胚胎发生所必需的基因在植物生命周期的其他阶段可能也是必需的。
