Burssens S, de Almeida Engler J, Beeckman T, Richard C, Shaul O, Ferreira P, Van Montagu M, Inzé D
Vakgroep Moleculaire Genetica en Departement Plantengenetics, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, KL, Belgium.
Planta. 2000 Oct;211(5):623-31. doi: 10.1007/s004250000333.
The associations of cyclins with highly conserved cyclin-dependent kinases are key events in the regulation of cell cycle progression. The spatio-temporal expression of an Arabidopsis thaliana (L.) Heynh. mitotic cyclin, Arath;CycA2;1, was studied by histochemical beta-glucuronidase (GUS) analysis and in-situ hybridizations. The CycA2,1] promoter was active in the egg apparatus before fertilization. During embryogenesis, CycA2;1:gus expression was found in the embryo and the developing endosperm. Throughout plant development, CycA2;1 transcripts were found in both dividing and non-dividing cells, indicating that the expression of this cyclin is not a limiting factor for cell division. In the pericycle and stelar parenchyma, CycA2;1 transcripts were located at the xylem poles, a position that can be correlated with competence for lateral root formation. In addition, CycA2;1:gus expression was upregulated in roots by auxins and in the shoot apex by cytokinins. Transcription of CycA2;1 was shown by reverse transcription-polymerase chain reaction to be strongly induced by sucrose in A. thaliana cell suspensions.
细胞周期蛋白与高度保守的细胞周期蛋白依赖性激酶的结合是调控细胞周期进程的关键事件。通过组织化学β-葡萄糖醛酸酶（GUS）分析和原位杂交研究了拟南芥（L.）Heynh.有丝分裂细胞周期蛋白Arath;CycA2;1的时空表达。CycA2,1]启动子在受精前的卵器中具有活性。在胚胎发生过程中，在胚胎和发育中的胚乳中发现了CycA2;1:gus表达。在整个植物发育过程中，在分裂和不分裂的细胞中都发现了CycA2;1转录本，这表明这种细胞周期蛋白的表达不是细胞分裂的限制因素。在中柱鞘和中柱薄壁组织中，CycA2;1转录本位于木质部极，该位置与侧根形成能力相关。此外，CycA2;1:gus表达在根中被生长素上调，在茎尖被细胞分裂素上调。通过逆转录-聚合酶链反应表明，在拟南芥细胞悬浮液中，蔗糖强烈诱导CycA2;1的转录。
