Research On Physiological Indeces And Differences In Protein Expression Of Banana Seedling Leaves Under Cold Stress

The banana native to Southeast Asia which is Musaceae) Musa is the world’s largest one of the three major fruit production and an important crop in many developing countries, in addition to rice, wheat and corn.Low temperature is a pretty adverse one of many kinds of stresses. The yield and quality of banana due to the serious impact perennially.In this study, physiological indexes in the process of the continuous low temperature stress on seedlings of Gui Jiao No.6 and two dimensional electrophoresis technology were be used to research the response of Gui Jiao No.6 seedlings to low temperature stress combined with the biological information analysis of mass spectrometry data.The main results are as follows:(1)The seedling leaves of Gui Jiao No.6 got morphological changes and cold brown spots while tip of leaves crinkled and edge of leaves lost water,became withering and yellowing at the same time.The content of MDA of the leaves got a middle part of the stress while overall increased firstly and then decreased. The content of proline increased continuously and the increase rate reduced in the middle part of the stress.The content of soluble sugar increased continuously and the increase is more significant with the increase of stress time.The content of soluble protein increased overall which reduced in the middle part of the stress time.Visibly,Gui Jiao No.6 is sensitive to low temperature and is vulnerable to the effects of low temperature stress.In addition,the content of soluble sugar and the content of soluble protein are suitable to study the physiological changes of banana seedlings under low temperature stress.(2) Improved TCA/acetone method and phenol extraction method respectively were used to extract total protein of Gui Jiao No.6 seedling leaves under low temperature stress.The results showed that phenol extraction method was more suitable to extract the total protein of banana leaves by comparing the extraction efficiency and the effect of vertical electrophoresis of two kinds of methods.(3)9 spots were successfully identified after discovering 16 obviously differential expressed protein spots including 8 spots up,7 spots down and one unique spot for the seedling leaves under low temperature stress by establishing differential protein electrophoresis of 2-DE of Gui Jiao No.6 seedling leaves.Protein functions with different expression of No.6 seedlings under low temperature stress involve the various aspects of by bioinformatics analysis.From the view of biological process,protein functions with different expression are the most involved in energy metabolism, photosynthesis and carbohydrate and are the second involved in the stress response, protein modification etc.From the view of molecular function, these proteins mainly combine with ATP and catalysis activity of enzyme.From the cellular level, these differentially expressed proteins are mainly related to support of cell structure and changes of the structure of related cell membrane.