Majeau N., Coleman J. R.
Department of Botany, University of Toronto, Toronto, Ontario, Canada M5S 3B2.
Plant Physiol. 1994 Apr;104(4):1393-1399. doi: 10.1104/pp.104.4.1393.
The enzyme carbonic anhydrase (carbonate dehydratase, EC 4.2.1.1) is an abundant soluble protein in the C3 plant chloroplast; however, its function in photosynthetic carbon assimilation is not well defined. In this study we have examined the relationship between carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) expression during pea (Pisum sativum) development as well as in various tissues and cultivars. Although absolute levels of activity and transcript abundance for the two proteins can vary considerably during development, a relatively constant ratio of CA to Rubisco transcript abundance and enzyme activity appears to be initiated during greening and maintained in mature and senescing photosynthetic tissue. Various pea cultivars, although exhibiting differing amounts of Rubisco and CA, also appear to maintain an invariant CA:Rubisco ratio. These data are discussed with respect to gene copy number, regulation of expression, and the proposed role of CA in photosynthetic carbon fixation.
碳酸酐酶(碳酸盐脱水酶,EC 4.2.1.1)是C3植物叶绿体中一种丰富的可溶性蛋白质;然而,其在光合碳同化中的功能尚未明确界定。在本研究中,我们研究了豌豆(Pisum sativum)发育过程中以及不同组织和品种中碳酸酐酶(CA)与1,5-二磷酸核酮糖羧化酶/加氧酶(Rubisco)表达之间的关系。尽管这两种蛋白质的活性和转录本丰度的绝对水平在发育过程中可能有很大差异,但CA与Rubisco转录本丰度和酶活性的相对恒定比例似乎在绿化过程中开始形成,并在成熟和衰老的光合组织中维持。各种豌豆品种虽然表现出不同数量的Rubisco和CA,但似乎也维持着不变的CA:Rubisco比例。我们将结合基因拷贝数、表达调控以及CA在光合碳固定中的假定作用来讨论这些数据。