García-Hernández M, Murphy A, Taiz L
Biology Department, Sinsheimer Laboratories, University of California, Santa Cruz, California 95064, USA.
Plant Physiol. 1998 Oct;118(2):387-97. doi: 10.1104/pp.118.2.387.
The spatial and temporal expression patterns of metallothionein (MT) isoforms MT1a and MT2a were investigated in vegetative and reproductive tissues of untreated and copper-treated Arabidopsis by in situ hybridization and by northern blotting. In control plants, MT1a mRNA was localized in leaf trichomes and in the vascular tissue in leaves, roots, flowers, and germinating embryos. In copper-treated plants, MT1a expression was also observed in the leaf mesophyll and in vascular tissue of developing siliques and seeds. In contrast, MT2a was expressed primarily in the trichomes of both untreated and copper-treated plants. In copper-treated plants, MT2a mRNA was also expressed in siliques. Northern-hybridization studies performed on developing seedlings and leaves showed temporal variations of MT1a gene expression but not of MT2a expression. The possible implications of these findings for the cellular roles of MTs in plants are discussed.
通过原位杂交和Northern印迹法，研究了金属硫蛋白（MT）亚型MT1a和MT2a在未处理和经铜处理的拟南芥营养组织和生殖组织中的时空表达模式。在对照植物中，MT1a mRNA定位于叶毛状体以及叶、根、花和萌发胚中的维管组织。在经铜处理的植物中，MT1a表达也见于叶肉以及发育中的角果和种子的维管组织。相比之下，MT2a主要在未处理和经铜处理植物的毛状体中表达。在经铜处理的植物中，MT2a mRNA也在角果中表达。对发育中的幼苗和叶片进行的Northern杂交研究表明，MT1a基因表达存在时间变化，而MT2a表达则无时间变化。讨论了这些发现对MTs在植物细胞中作用的可能影响。
