地黄连作胁迫响应机制的块根蛋白质组学分析

地黄种植过程中存在严重的连作障碍问题，连作导致块根无法正常膨大、产量品质下降、土传病害严重等。本研究以正、重茬地黄块根为试验材料，通过差异蛋白质组学技术分析连作下地黄块根蛋白质表达谱变化，并进一步采用qRT-PCR技术对锁定的差异蛋白质表达量变化进行验证分析。研究结果发现，连作导致与块根重要生理代谢过程和主要成分合成相关的蛋白质都下调表达，与蛋白质折叠相关的伴侣素(chaperonin)在重茬地黄块根中全部下调表达；连作下与胁迫响应、抵御相关的蛋白质(如pathogenesis-related protein 10, cytochrome P450, Type IIIa membrane protein cp-wap13等)均上调表达。qRT-PCR定量分析证实重茬地黄块根中PR-10基因表达量显著高于正茬地黄；PR-10基因在尖孢镰刀菌病原菌侵染下能够明显被诱导表达，表达量随着侵染时间的增加而逐渐升高，验证了差异蛋白质组学分析的结果。可见连作胁迫对地黄块根蛋白质表达谱有显著影响，导致蛋白质表达紊乱，连作植株生理代谢过程异常，碳水化合物和能量代谢缓慢，产生连作障碍效应。

Comparative Proteomics Analysis of R. glutinosa Tuber Root in Response to Consecutive Monoculture

Rehmannia glutinosa L. is widely applied in Chinese medicine. However, consecutive monocropping of this plant results in serious decline in both biomass and quality of underground tubers, with poor field performance and insufficient resistance to disease and pest. In the present study, the tuber roots from the newly planted (NP) and consecutively monocropped (SM) R. glutinosa were used through comparative proteomics analysis to study the response of R. glutinosa to consecutive monocropping and the underlying mechanisms of replanting disease. Comparative proteomics analysis showed that these proteins involved in important physiological processes and biosynthese of main components in tuber roots were significantly down-regulated under consecutive monocropping regime.It was also found that chaperonins related to protein folding was down-expressed with the extended monocropping. However, these proteins related to stress response/defense such as pathogenesis-related protein 10, cytochrome P450 and Type IIIa membrane protein cp-wap13 were up-regulated in consecutively monocropped R. glutinosa. Quantitative analysis by qRT-PCR confirmed the up-regulation of PR-10 responding to consecutive monocropping or the infection of pathogenic Fusarium oxysporum. Moreover, PR-10 was gradually up-regulated with the increasing days of infection. In conclusion, consecutive monocropping of R. glutinosa greatly affects the expression profile of proteome in tuber roots. These abnormally expressed proteins might lead to the metabolic disturbances and low energy production. Moreover, the limited energy is applied to resist the external environmental stresses, resulting in significant decline in the growth of tuber roots and the accumulation of active ingredients.