Phosphoproteomics of Cold Stress-Responsive Mechanisms in Rhododendron Chrysanthum

As an alpine plant，Rhododendron chrysanthum (R. chrysanthum) has evolved cold resistance mechanisms and become a valuable plant resource with the responsive mechanism of cold stress. In my study, we adopt the phosphoproteomic and proteomic analysis combining with physiological measurement to illustrate the responsive mechanism of R. chrysanthum seedling under cold (4℃) stress. After chilling for 12 h, 350 significantly changed proteins and 274 significantly changed phosphoproteins were detected. Clusters of Orthologous Groups（COG）analysis showed that significantly changed proteins and phosphoproteins were mainly involved in signal transduction and energy production and conversion under cold stress. The results indicated photosynthesis was inhibited under cold stress, but cold induced calcium-mediated signaling, reactive oxygen species (ROS) homeostasis and other transcription regulation factors could protect plants from the destruction caused by cold stress. These results provide a detailed insight into the cold stress response and defense mechanisms of R. chrysanthum leaves at the phosphoproteome level.

Phosphoproteomics of Cold Stress-Responsive Mechanisms in Rhododendron Chrysanthum

Background: As an alpine plants，Rhododendron chrysanthum (R. chrysanthum) has evolved cold resistance mechanisms and become a valuable plant resource with the responsive mechanism of cold stress. Results: In my study, we adopt the phosphoproteomic and proteomic analysis combining with physiological measurement to illustrate the responsive mechanism of R. chrysanthum seedling under cold (4℃) stress. After chilling for 12 h, 350 significantly changed proteins and 274 significantly changed phosphoproteins were detected. COG analysis showed that significantly changed proteins and phosphoproteins were mainly involved in signal transduction and energy production and conversion under cold stress. The results indicated photosynthesis was inhibited under cold stress, but cold induced calcium-mediated signaling, reactive oxygen species (ROS) homeostasis and other transcription regulation factors could protect plants from destruction caused by cold stress. Conclusions: These data constitute a cold stress-responsive metabolic atlas in R. chrysanthum, which will springboard further investigations into the complex molecular mechanisms of plant cold adaptation.

UPLC–MS Triglyceride Profiling in Sunflower and Rapeseed Seeds

Sunflower and rapeseed are among the most important sources of vegetable oil for food and industry. The main components of vegetable oil are triglycerides (TAGs) (about 97%). Ultra- performance liquid chromatography coupled with mass spectrometry (UPLC–MS) profiling of TAGs in sunflower and rapeseed has been performed and the TAG profiles obtained for these species have been compared. It has been identified that 34 TAGs are shared by sunflower and rapeseed. It was demonstrated that TAGs 52:2, 52:5, 52:6, 54:3; 54:4, 54:7, 56:3, 56:4, and 56:5 had the highest variability levels between sunflower and rapeseed with the higher presence in rapeseed. TAGs 50:2, 52:3, 52:4, 54:5, and 54:6 also showed high variability, but were the most abundant in sunflower. Moreover, the differences in TAG composition between the winter-type and spring-type rapeseed have been revealed, which may be associated with freezing tolerance. It was shown that winter-type rapeseed seeds contain TAGs with a lower degree of saturation, while in spring-type rapeseed highly saturated lipids are the most abundant. These findings may give new insights into the cold resistance mechanisms in plants the understanding of which is especially important in terms of global climate changes.