| The legume Arachis hypogaea, commonly known as peanut or groundnut, is a very important economic crop and food source throughout the tropics and subtropics. It occupies a rank of major oilseed crop in the world because of its nutrition and taste. China is the biggest peanut producer and exporter in the world, accounting for more than90%peanut production along with other countries in Asia. In China, peanut is cultivated mainly in arid and semi-arid regions. Therefore, research in peanut salt and drought stress responses is of great value.Annexin is a ubiquitous calcium binding protein, accounting for1%of total plant proteins. It can be bound to membrane and endomembrane system in a reversible manner under specific circumstances. Emerging evidence shows that, unlike animal annexins, plant annexins have some unique features and play a role in stress responses, usually conferring stress resistance in tansgenic plants. Researchers believe that they may function through calcium and ABA signal transduction pathways.People in our group cloned two peanut annexin genes, named AnnAhland AnnAh2. Expression profile in peanut leaves revealed that both of them were down regulated under seven different abiotic stresses. According to this, we created transgenic tabacoo lines expressing peanut annexin genes AnnAhland AnnAh2respectively to further research their roles in salt stress responses. Results showed that both of the transgenic lines were salt sensitive compared to the wild type. Therefore, we speculated that peanut annexins may function different stress response mechanism.We also obtained onion epidermal cells transiently expressing peanut annexin genes respectively. The fluorescence signals were found in membrane, cytoplasm and nucleus, indicating a role in nuclues calcium signal transduction. These results provided new evidence for the exsistance of plant annexins in nucleus and new materials for the research of their roles in nucleus signal transduction pathways. |
PDF Full Text Request