Abstract
Low temperature is one of the key environmental stresses, which greatly affects global banana production. However, little is known about the global phosphoproteomes in Musa spp. and their regulatory roles in response to cold stress. In this study, we conducted a comparative phosphoproteomic profiling of cold-sensitive Cavendish Banana and relatively cold tolerant Dajiao under cold stress. Phosphopeptide abundances of five phosphoproteins involved in MKK2 interaction network, including MKK2, HY5, CaSR, STN7 and kinesin-like protein, show a remarkable difference between Cavendish Banana and Dajiao in response to cold stress. Western blotting of MKK2 protein and its T31 phosphorylated peptide verified the phosphoproteomic results of increased T31 phosphopeptide abundance with decreased MKK2 abundance in Daojiao for a time course of cold stress. Meanwhile increased expression of MKK2 with no detectable T31 phosphorylation was found in Cavendish Banana. These results suggest that the MKK2 pathway in Dajiao, along with other cold-specific phosphoproteins, appears to be associated with the molecular mechanisms of high tolerance to cold stress in Dajiao. The results also provide new evidence that the signaling pathway of cellular MKK2 phosphorylation plays an important role in abiotic stress tolerance that likely serves as a universal plant cold tolerance mechanism.
Highlights
Musa spp., which originated in tropics are giant perennial herbaceous monocots
These results revealed that low temperature photo-inhibition[26] occurred in both Cavendish Banana and Dajiao, but apparently Dajiao had a stronger ability to recover from cold stress than Cavendish Banana
Our phosphoproteome was measured at 3 h after cold stress while proteome data was collected for 6 h and 24 h after cold stress
Summary
Musa spp., which originated in tropics are giant perennial herbaceous monocots. They are vital staple food in many African countries and the most popular fruits in industrialized countries[8]. Many important crops originated in the tropics and subtropics, www.nature.com/scientificreports/ Such as rice, maize, soybean, cotton, and tomato, lack the cold acclimation mechanism and are sensitive to chilling stress[10], so do Musa spp. Dynamic changes of the phosphoproteome in response to short-term (5 min or less) exposure to 4 °C in radioactive pulse-labelling of Arabidopsis cell suspension cultures and similar experiment on rice roots were identified by 2-dimensional gel electrophoresis (2DGE) analysis[14,15] The results of these two studies reveal that during cold exposure some proteins are phosphorylated by protein kinases, whereas others are dephosphorylated by protein phosphatases. A MS-based comparative phosphoproteomic approach was used to identify and characterize global phosphorylated proteins under cold stress in both Dajiao, which was collected from a subtropical region of China, and Cavendish Banana, a cold-sensitive species utilized as a control. To identify the key phosphoproteins and their signal networks responsible for cold-tolerance in Dajiao, protein-protein interactions among the differentially expressed phosphoproteins were analyzed and mapped using STRING v
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
