TAG encodes an adenine nucleotide transport protein that regulates leaf color in rice

Leaf is an important organ of photosynthesis in plants, and leaf color has an important influence on photosynthesis. However, the molecular mechanisms of leaf color regulation are still unclear. In this study, we identified a rice ( Oryza sativa ) temperature sensitive albino trans-green ( tag ) mutant, which showed albino leaves at the seedling stage, and gradually turned green. Map-based cloning showed that TAG is a Novel allele gene of OsBT3 , encoding an adenine nucleotide transport protein. Compared with the allele mutants of sla and wsl2 , tag displayed some new phenotypes, such as it was a low-temperature-sensitive albino trans-green mutant with serious DNA damage in the albino leaves, and the PSI photosynthetic efficiency and photosynthesis of it were enhanced significantly in mature stage. Besides, we also found TAG was also localized in chloroplasts and played an important role on chloroplast development. Moreover, we newly discovered that TAG is highly expressed in L3U, which is induced by low temperature, and in situ hybridization results showed TAG expressed in the shoot apical meristem, leaf primordium and vascular bundle. Taken together, the above new results provide deeper clues to explain the molecular mechanisms by which TAG regulates chloroplast development.