Preliminary Proteomic Analysis Of Cassava Leaves Under Drought Stress

Cassava(Manihot esculenta Crantz) is the only cultivated crop of Euphorbiaceae. In southern China, cassava is an important industrial materials for starch and alcohol production. Cassava has some excellent characteristics including high drought tolerance, wide adaptability and high starch yield, and so on. In this study, cassava (SC5) was taken as experimental materials. Using proteomic methods, the cassava leaf proteomic profiles were analyzed in condition of different drought stress periods. The biological functions of differentially expressed proteins were also analyzed to facilitate the study of drought adaptive molecular mechanisms in cassava. Preliminary results were obtained as the following:1. Analysis of MDA content, proline content and SOD activity between control and drought stress (6d,12d,16d) of cassava leaves, the results were found as following:①Leaf wilting appears with the deepening of the stress level, leaves gradually dried up and die off from bottom.②In the drought stress periods (6d,12d), MDA content in leaves were higher than the control. However, MDA content was lower than in the control in16d.③The content of proline is greatly improved as drought stress level goes up.④The SOD activity gradually increases while drought stress time becomes longer.2.55differentially expressed protein spots between control and drought stress were found by2-D electrophoresis analysis. By MALDI-TOF-MS analysis,33proteins were identified and their amino acid sequences were presented by database searching, including22known proteins as follows:15photosynthetic carbon metabolism-related proteins;2energy metabolism pathway-related proteins;1signal conditioning-related proteins;1resistance-related protein;1cell structure protein;1oxynitrilases;1alcohol dehydrogenase.This study found a lot of differentially expressed cassava leaf proteins under drought stress by the application of proteomics methods. The results would provide data supports to study the drought-resistant molecular mechanisms in cassava and create new cassava germplasms with high drought-tolerance.