| Potato(Solanum tuberosm L.) is the fourth largest food crop in the world, which plays immutable important role in the agricultural production of the world.As a massive potato-production country, per unit area yield of our country is low. And the constraints behind is the relatively outdated potato cultivation techniques in China. In recent years, Fujian Province greatly popularizes the straw mulching in sandwich cultivation model, which has been proved to be able to enhance the yield and quality of potato significantly.Therefore, the in-depth study on the influence of straw mulching in sandwich model on tuber development and main agronomic traits of potato and revelation of high yield mechanism of straw mulching in sandwich cultivation model, which is of great significance to the further improvement of the practical techniques and theoretical basis of high yield cultivation of potato.In this study, we select the winter potato Zhongshu No.3 of high yield and good quality as the experiment object. Many major agronomic traits of potato plants respectively under the straw mulching in sandwich cultivation model and conventional cultivation model were measured in the period from 40th day to 100th day.In addition, the proteome changes of stolons under these two of cultivation models in the tuberization process (i.e.,four development stage like stolon initiation,stolon elongation,stolon growth cessation and tuber initiation) and tubers under two cultivation models in the tuber bulking process (i.e.,60d,70d,80d,90d and 1OOd) were analyzed. Comparative analysis of main agronomic traits of potato and the proteome changes under two kinds of cultivation models were made as well as the differential proteomics analysis of potato during the development of tuber.And further research were conducted so as to determining the specific proteins that were related to high yield mechanism of the straw mulching in sandwich cultivation model.This study is aimed at revealing high yield mechanism of the straw mulching in sandwich cultivation model and tuber development mechanism at the molecular level.The results are as follows:1. The effect of the straw mulching as sandwich cultivation mode on the main agronomic traits of potatoThe field test showed that the potato yield per 667 m2 in the straw mulching in sandwich cultivation model was increased by 9.07% compared with conventional cultivation. The analysis of three yield components revealed that tuber number of sigle plant,tuber weight per plant and commodity potato rate in the straw mulching in sandwich cultivation model were increased by 5.71%,9.68% and 2.52% compared with conventional cultivation respectively.In addition, plant height, creeping stem weight of single plant, leaves and steam weightof single plant, tuber weight of single plant and root weight of single plant in the straw model were higher than that in conventional cultivation during the growth and development of tuber. These results indicated that high yield in the straw model could be result from the strong root, developed stolon and more exuberant overground part.2. The effect of the straw mulching as sandwich cultivation mode on the proteome expression of stolonThe 2-DE profile of stolons under two kinds of cultivation models in the tuberization process was compared and analyzed, and 29 differentially expressed protein spots (P<0.05,≥2 folds) were identified.These proteins were divided into seven groups by MS analyse and GO functional annotation:ten proteins related to material metabolism, four proteins related to protein synthesis and degradation, four proteins related to energy metabo’ism, three proteins related to resistance, a cell division associated protein, five patatin proteins and two unknown proteins.The straw model might enhance carbon, nitrogen and substance metabolism of stolon, regulated the expression of patatin proteins effectively and promoted protein synthesis and cell division of stolon in the tuberization process, and then promoted growth of stolon and induced tuberization to lay a foundation for the high yield of the straw mulching as sandwich cultivation model.3. The effect of the straw mulching as sandwich cultivation mode on the proteome expression of tuberProteomic analysis showed that the expressions of 42 proteins in the straw model changed significantly compared with conventional cultivation during the expansion of tuber.These proteins were divided into six categories by MS analyse and GO functional annotation:ten material metabolism-related proteins, four protein synthesis and metabolism related proteins, four energy metabolism related proteins, three resistance-related proteins, a cell division related protein, five patatin proteins and two unknown proteins. Among them, the secondary metabolism-related proteins and resistance-related protein in the straw model expression were down-regulated compared with conventional cultivation., which indicated that the straw model could provide a more suitable environment for the growth of potato. Remarkably, fructose kinase 2 and enolase that promote starch biosynthesis and eleven patatin proteins expression were up-regulated in the straw model, suggesting that high yield of the straw mulching as sandwich cultivation model may be related to the mass synthesis of patatin protein and starch.4. The differential proteomic expression during the growth and development of tuberThere are 14 differentially expressed proteins in the tuberization process.These proteins are involved in many physiological processes, such as material metabolism and transport, cell division, protein synthesis and degradation, stress resistance and patatin proteins.The up-regulated expression of glucose phosphate, the accumulation of ferritin-2 and the effective regulation of actin-7 on cell division and elongation may play an important role in the tuberization process. In particular, one of patatin proteins expressionwas up-regulated in the tuberization process, and the other two patatin proteins has increased more than ten times at the tuber initiation stage. It showed that the expression level of patatin proteins were closely related to the development of tuber, and reached the peak value at the tuber initiation stage.There are 17 differentially expressed proteins during the expansion of tuber.These differentially expressed proteins were involved in many physiological processes, such as substance metabolism, energy metabolism, cell division, protc;:. synthesis, stress resistance and patatin proteins. The expression level of most proteins in 60d and 80d were significantly higher than those in the other three stages, indicating that 60d and 80d might be the key stages of tuber development. In addition, patatin proteins expression were up-regulated during the expansion of tuber, which indicated that the expansion of tuber required the accumulation of patatin proteins. |
