Cloning And Analysis Of Gene OsMBL In Rice

Ca2+is a very important second messenger,which participates in a variety of physicalogical responses as a signal vector in plants. Ca2+signal can be generated by almost all extracellular stimuli, including various biotic and abiotic stresses. Ca2+is the indispensable part of plants,which is involved in seed germination, plant growth and development, aging, death, and adaptation to the environment. Calmodulin (CaM) is the most widely distributed member of this family of proteins and is thought to be a primary intracellular Ca+receptor in all eukaryotes. The hallmark of CaM’s mechanism of action is that it transduces second messenger Ca2+signals by binding to and altering the activity of a variety of other proteins.Plant lectin (Lectin) is a class of non-immune origin plant protein, which has the capacity to bind monosaccharide or oligosaccharide reversiblyand specificity.It play an important role in the defense response against invading pathogens and to respond to various stresses,it is able to regulate hormonal biotic and abiotic stresses by interacting with sugar or sugar-protein which can induce the generation of signal molecules.The expression of CaMBPs can be affected by a variety of stresses. We founded that OsCaMBP was induced by chilling and heat, suggesting that it might serve as a common regulatory factor involved in the rice adversity reaction. In this study,we screen a mannose-binding jacalin-related lectin,named OsMBL,from Nipponbare chill cDNA library using Yeast Two-Hybrid Experiments.The main results as following:1.Analyzing the sequence of OsMBL,we found the gene encodes145amino acid residues, and isoelectric point is about4.78, eight stress-inducible cis-elements can be found in its promoter. The result of semi-quantitative PCR shows the OsMBL can be induced by various stresses;2. Subcellular localization confirmed that OsMBL located mainly in the cell membrane and cytoplasm, suggesting that it may participate in the cell membrane of plant defense processes, and can interact with sugar or glycoprotein hormones further involvement of different signaling pathways to regulation of biotic and abiotic stresses; 3.We found that the stress tolerance is enhanced in overexpression plants and the growth period of the knock-downplants is delayed15-20days;4.To verify the protein interaction between OsMBL and OsCaMBP,we constructed the vectors of yeast two-hybrid, bimolecular fluorescence complementary and fusion protein. Prepared and purified OsCaMBP-GST and OsMBL-pET fusion protein for the further research.