Magnesium transporter CsMGT10 of tea plants plays a key role in chlorosis leaf vein greening.

Magnesium (Mg2+), as the central atom of chlorophyll, is the most abundant divalent cation for plant growth and development in living cells. MRS2/MGT magnesium transporters play important roles in coping with magnesium stress, chloroplast development and photosynthesis. However, the molecular mechanism of MGT influencing tea plant leaf vein color remains unknown. Here, we demonstrate that CsMGT10 may be a potential transporter influencing leaf vein color. CsMGT10 belongs to Clade A member of MRS2/MGT family. CsMGT10 has the highest expression level in leaves of tea plants. And it is mainly expressed in aboveground parts, especially in vascular bundles. Moreover, CsMGT10 localizes to the chloroplast envelope of tea plants with a high affinity to Mg2+. And the GMN motif is required for its magnesium transport function. Ectopic expression of CsMGT10 in Arabidopsis leaf variegation mutant var5-1 can restore green color of chlorosis leaf veins, and the contents of chlorophyll and carotenoid change significantly, proving its essential role in leaf vein greening. Furthermore, the chlorophyll and carotenoid of tea leaves treated with CsMGT10 antisense oligonucleotides also decrease significantly. Our findings indicate that CsMGT10 mainly acts as Mg2+ transporter in chloroplast envelope of leaf veins, which may play a key role in leaf vein greening of tea plants.

[Identification of six species of medicinal Diospyros plants based on leaf macro- and micro-morphology].

To establish a method for the identification of five species and one variety of medicinal plants from Diospyros, their leaf veins, epidermis, anatomic and powder characters were observed and compared with macro-morphological and microscopic methods. The results indicated the differences of secondary and tertiary veins among those Diospyros species. The single cell non-glandular hair and glandular hair exist in most species' epidermis while stone cells were only found in the leaf powders of two species. Through the study, the main differences of leaf macro- and micro-morphology of these species were obtained and practical keys were also established, which can provide scientific base not only for identification of these species during their vegetative stages, but also for accuracy authentication of the source of Kaki Folium.

Identification of six species of medicinal Diospyros plants based on leaf macro- and micro-morphology / 中国中药杂志

To establish a method for the identification of five species and one variety of medicinal plants from Diospyros, their leaf veins, epidermis, anatomic and powder characters were observed and compared with macro-morphological and microscopic methods. The results indicated the differences of secondary and tertiary veins among those Diospyros species. The single cell non-glandular hair and glandular hair exist in most species' epidermis while stone cells were only found in the leaf powders of two species. Through the study, the main differences of leaf macro- and micro-morphology of these species were obtained and practical keys were also established, which can provide scientific base not only for identification of these species during their vegetative stages, but also for accuracy authentication of the source of Kaki Folium.