野生二粒小麦根中干旱响应蛋白的分离与鉴定

为了解野生二粒小麦响应干旱胁迫的调控机制,分析了干旱胁迫下小麦根的相对含水量、丙二醛、脯氨酸和过氧化氢含量,采用双向电泳(2-DE)结合MALDI-TOF-TOF-MS方法分离和鉴定了野生二粒小麦根中干旱响应蛋白的变化。结果表明,随着干旱处理时间的延长,野生二粒小麦根的相对含水量下降,脯氨酸含量先上升后降低,过氧化氢含量和丙二醛含量上升;复水后的野生二粒小麦根的相对含水量、脯氨酸含量有所升高,但未达到对照的水平。通过对干旱处理6d后根系的总蛋白进行双向电泳分离和MALDI-TOFTOF生物质谱鉴定,成功鉴定出26个差异表达蛋白,13个上调表达,13个下调表达。26个差异表达蛋白的功能主要涉及信号传导、氧化解毒、碳代谢、能量代谢、蛋白质生物合成及细胞骨架稳定。推测野生二粒小麦为适应干旱胁迫,通过根部感应胁迫信号,并传导至细胞内,影响小麦根中蛋白质的生物合成、氨基酸代谢、碳水化合物代谢、细胞骨架形成;通过抗氧化酶系统和抗氧化物质的作用,将过多活性氧加以清除;通过增加胞内脯氨酸含量,降低根中水分损失。

Isolation and Identification of Drought Stress Responsive Proteins in Root of Triticum Dicoccoides

To understand the complex drought response mechanism in Triticum Dicoccoides,the relative water,malondialdehyde(MDA),proline and hydrogen peroxide content changes in the root under drought stress were analyzed. 2-dimentional electrophoresis(2-DE) combined with MALDI-TOF-TOF analysis were adopted to isolate and identify drought responsive proteins in root of Triticum Dicoccoides. The results showed that the relative water content of roots was inhibited with the stress time prolonged. The proline content in root increased firstly,and then decreased while the increase of stress time. On the other hand,the H₂O₂ and MDA content in root under drought stress were increased,indicating reactive oxygen species(ROS) resulted in the membrane lipid peroxidation or membrane breakup,thereafter lead to the increase of MDA,and the decrease of proline. Although the relative water content and proline content in root under rewatering was increased,it still could not recover to the control level. About 26 protein spots were successfully identified by 2-DE and MALDI-TOF-TOF analyses between control and stressed samples,including 13 up-regulated and 13 down-regulated proteins. Further analysis of these differential expressed proteins revealed that these proteins were mainly associated with signal transduction,oxidative detoxification,carbon metabolism,energy metabolism,protein synthesis and cytoskeleton stable. It was speculated that to response the drought,the root of Triticum Dicoccoides firstly sensed the drought signal,and then affected protein synthesis,amino metabolism,carbohydrate metabolism and cell cytoskeleton. The plus reactive oxygen species were eliminated by oxidative detoxification associated proteins. The water loss in root was decreased by enhancing proline content.