在干旱胁迫下有性四倍体木薯叶片的蛋白质组学研究

为了研究木薯（Manihot esculenta Crantz）有性四倍体的抗旱性，笔者以木薯有性四倍体为供试材料，其母本华南5号（SC5）为对照材料，通过比较在干旱胁迫下木薯的叶片形态和叶片中丙二醛含量、游离脯氨酸含量、超氧化物歧化酶活性等生理生化指标，发现有性四倍体较SC5具有更强的抗旱性。对供试木薯材料进行干旱处理后，将其叶片进行蛋白质双向电泳，通过Delta 2D软件分析，筛选出34个表达量符合平均差异表达量要求的差异蛋白点，包括18个上调表达，16个下调表达；上述差异蛋白质点经质谱分析、NCBI数据库比对，发现其中有29个蛋白质与之相匹配，包含光合作用相关蛋白质、无机离子转运与代谢相关蛋白质、碳水化合物和能量代谢相关蛋白质、结合蛋白、解毒和抗氧化相关蛋白质等；核酮糖二磷酸羧化酶和光系统Ⅱ（PSⅡ）放氧增强蛋白1为响应干旱胁迫，表达量均上调，因此，推测木薯有性四倍体材料更能在干旱胁迫下通过有效地维持光合系统的正常结构和功能来迅速适应干旱胁迫。

Proteomics of the Leaves of Sexual Polyploid Cassava under Drought Stress

An attempt was made to analyze the drought resistance of sexual tetraploid cassava. Sexual tetraploid cassava was treated under different levels of drought with its maternal parent as control, and their leaves were sampled and analyzed in terms of leaf morphology, physiology, biochemistry and proteomics. Comparison of the leaf morphology and leaf physiological and biochemical indicators such as the contents of MDA and proline and SOD activity showed that the sexual tetraploid cassava had higher drought resistance than the cassava SC5. The leaves of cassava SC5 and its sexual tetraploid plants under drought stress were run on two-dimensional protein electrophoresis and analyzed by using Delta 2D software., and 34 protein spots with an average differential expression of at least 2.0 fold change in expression were obtained from the leaves under drought stress, of which 18 were up-regulated and 16 down-regulated. The different protein spots were analyzed by using mass spectrometry and matched to the NCBI database, and 29 protein spots were matched to the NCBI database entries. These 29 proteins are mainly related to photosynthesis, inorganic ion transport and metabolism, carbohydrate and metabolism, binding, detoxification and antioxidants, etc. Moreover, the ribulose bishosphate carboxylase and the oxygen-evolving enhancer protein 1 of the Photosystem II (PSII) in response to drought stress were up-regulated in expression, which implies that the sexual tetraploid cassava is more effective than the SC5 in maintaining the normal structure and function of the photosynthesis system, and hence respond more quickly to drought stress.