Histochemical Localization And Expression Profiling Analysis Under Abiotic Stresses Of Synaptotagmin Family In Arabidopsis

Snaptotagmin(Syt) is a large protein family widely existed on the endocrin cells and neurons. As a Ca2+ sensor in Ca2+ -dependent neurotransmitter release procedure, Syt can trigger and regulate the fusion process between plasma and vesicle membrane. There are over 16 isoforms of Syt in mammalian and 6 isoforms have been found in Arabidopsis. In the latest research, the mutant Sytl, showed hypersenstivity at high NaCl concentrations. While cold acclimation in plants, Syt1 increased rapidly. Since the Sytl is involved in membrane fusion, and it can play a role in membrane repair, then the other family members could also respond to various abiotic stresses.The realtime PCR was conducted to examine the expression of Syt family in the different vegetative and reproductive tissues. The expression profiling of the Syt gene family in response to the abiotic stresses was also investigated. Through the experiment, we got the following results:1. We found that the Syt gene family exhibited distinct expression patterns. SytA was expressed at moderate levels in all tissues, whereas SytB was expressed strongly in floral tissues. SytC was expressed strongly in the roots, leaves and seedlings. This indicated that different subtypes might play different roles in physiological processes.2. Facing the same stress the expression pattern of each member is different. Such as, under the cold stress, the transcript level of SytA was increased and then decreased, the levels of SytB\D\F, were induced immediately and SytE was suppressed quickly. This showed that, the structure of Syt was similar, but they had different functions.3. The same members under different stress are also different. Such as, the transcript level of SytA was increased and then decreased under the cold stress, but up-regulated under the osmotic stress. The level of SytE was suppressed under the cold stress but not responded to the heat stress. This reveals the members may have different regulatory mechanisms to cope with various stress.This research will help us to study the function of the Syt family, and the mechanism of the membrane fusion and repair.