2个不同耐旱性甘薯品种的苗期根系蛋白组差异分析

Proteomic Analysis of Roots in Seedling Stage of Two Sweetpotato Varieties With Different Drought Tolerance

为从蛋白水平明确不同耐旱性甘薯品种苗期根系对干旱的应答机制,促进甘薯耐旱相关基因发掘,以耐旱性强的济薯21(JS)和耐旱性弱的济紫薯1(JZ)为材料,采用PEG-6000模拟田间梯度干旱胁迫过程,进行苗期根系蛋白的双向电泳和质谱分析。结果表明,基于60个不同耐旱性甘薯苗期根系的差异蛋白点分析,共鉴定出32个蛋白,其中有明确生理功能的有12个。在JZ中,下调表达的有3个肌动蛋白,上调表达的有2个60S核糖体蛋白,受体类蛋白激酶和真核翻译起始因子各1个;在JS中,下调表达的有1个类甜蛋白,上调表达的有2个过氧化物酶蛋白、1个磷酸果糖激酶家族蛋白和1个赤霉素调控蛋白。基因本体(GO)分析发现,干旱对甘薯苗期根系细胞质中糖和能量代谢过程影响较大,耐旱性强的品种苗期根系在抗氧化防御、能量代谢和信号转导方面占据优势。综上,不同耐旱性甘薯苗期根系在蛋白组学水平上响应干旱的生理调控途径存在明显差异,本研究结果为甘薯耐旱性品种选育提供了理论依据。

Drought tolerant sweetpotato variety Jishu21 （JS） and sensitive variety Jizishul （JZ） were chosen to reveal the drought-response mechanism of seedling roots from protein level and explore drought tolerance related genes. Two- dimensional gel electrophoresis and mass spectrometry were used to analysis the proteins in seedling roots by hydroponic with PEG-6000 to simulate gradient drought stress in the field. The results showed that based on the 60 differential protein spots in seedling roots of sweetpotato with different drought tolerance, 32 proteins were identified, among which 12 had definite physiological functions. In JZ, three actin proteins were down-regulated, while two 60S ribosomal proteins, one eukaryotic translation initiation factor 5A and one receptor-like protein kinase were up-regulated. In comparison, one thaumatin-like protein was down-regulated, two peroxidase proteins, one phosphofructokinase family protein and gibberellin-regulated protein 6 - like showed up-regulated in JS. Gene ontology analysis showed that the processes of sugar and energy metabolism in cytoplasm of seedling roots could be significantly influenced by drought, and the seedling root of drought tolerant variety had stronger ability of antioxidant defense, energy metabolism and signal transduction. In conclusion, the physiological regulation sweetpotato markedly, and the study can provide theoretical on proteomic level responded to drought varied between basis for drought tolerance breeding.