Abstract
Glucose 6-phosphate (G6P) transport activity in chloroplasts increases dramatically during induction of Crassulacean acid metabolism (CAM) in Mesembryanthemum crystallinum by salt stress. We previously reported existence of another G6P/phosphate translocator isozyme, GPT2, in M. crystallinum other than GPT1 reported by Hausler et al. (2000) and showed that transcript levels of both GPTs were increased in the leaves during CAM induction.
In C3 plants, GPTs transport G6P into amyloplasts for starch synthesis. Therefore, we examined the transcript levels of GPTs in the roots from C3 and CAM modes of M. crystallinum by using semi-quantitative RT-PCR technique. The transcript level of GPT1 in the roots from C3- and CAM-M. crystallinum was as high as in the CAM leaves. In contrast, the GPT2 transcript was hardly detected in the roots from both mode of plants. It will be also reported their expression patterns in other tissues in M. crystallinum.
