The Reseach On The Molecular Mechanisms Of CbTPS5 In Respond To Abiotic Stresses

Trehalose accμMulation is generally associated with osmotic stress resistance.Trehalose metabolism has profound effects on plant groColh and metabolism. Trehalose biosynthetic proteins play defined roles in coordinating carbohydrate utilization and developmental signalling and morphogenesis. Although TPS1 (Class Ⅰ) proteins have established TPS activity, respectively, the function of the Class Ⅱ proteins remains elusive. Chorispora bungeana is a kind of typical alpine subnival plant species, which can grow and develop normally under low temperature, high altitude and strong UV light stress.It shows highly stress tolerance without possessing any specific morphostructure.Therefore, abiotic stress signaling can be studied by using it as appropriate species.We have selected and investigated the role of CbTPS5 up-regulated in low temperature in Chorispora bungeana,a kind of typical alpine subnival plant species.We research the gene functions and the molecular mechanisms of CbTPS5 in respond to abiotic stresses by kinds of physiological, biochemical and molecular methods. The suMmary is shown as follows:1. The tissue expression of CbTPS5 is expressed in nutritive organs by real-time PCR, and the expression sare Up-regulated under low temperature stress2. The study indicated CbTPS5 reacts on protecting Chorispora bungeana from abiotic stresses. The expression of CbTPS5 showed obvious increasing under low temperature stress.ABA will induce expression of CbTPS5 within a small range, the seed germination and cotyledon greening rate of transgenic plants of CbTPS5 overexpression is also slightly higher than the wild-type by ABA stress. The expression of CbTPS5 showed a decreasing trend, and the germination rate and cotyledon greening rate CbTPS5 expression plant is also lower than the wild-type under NaCl stress.More ever, under mannitol stress the germination and cotyledon greening rate is much higher than that of wild type, which indicated that CbTPS5 genes involved in plant responses to abiotic stress response, including salt stress low temperature and other different stresses.3. It is sensitive to salt in Chorispora bungeana.However a interesting Phenomenon was found that the expression of CbTPS5 is accμMulated after apoptotic cell death,which showed CbTPS5 may regulate cell apoptosis and tissue death.4. The result indicated that CbTPS5 was localized on cell membrane and cytoplasm after tobacco infiltration, it may maintain the stability of the cell membrane.In conclusion, CbTPS5 plays an important role in the response to abiotic stress, it may also be relevant with apoptosis in Chorispora bungeana. These biological functions of CbTPS5 has a significance is importent to reveal the function of trehalose synthase in the regulation of plant groColh and development, and molecular mechanisms in the stress protection, it also provide theoretical foundation for physiology and molecular biological research of the plant to response to abiotic stresses.