酸化茶园茶树根际土壤微生物蛋白质代谢图谱构建

Construction of the microbial protein metabolism map of tea rhizosphere soil in acidified plantations

土壤是茶树生长的载体,在我国茶园普遍存在土壤酸化现象,但是土壤微生物如何响应土壤酸化以及如何影响茶树生长还鲜有报道.本研究以不同酸度的铁观音茶树种植土壤为材料,分别提取茶树根际土壤微生物蛋白质,采用数据依赖采集(data dependent acquisition, DDA)技术建立茶树根际土壤微生物蛋白质数据库,并采用数据非依赖采集(data independent acquisition, DIA)技术定量分析土壤微生物蛋白质,获得不同酸度茶树根际土壤丰度降低的蛋白质并对其进行功能分析,构建了茶树根际土壤蛋白质组代谢调控图谱.结果表明,茶树根际土壤共检测到微生物蛋白质2741种,分子量主要分布在2.64~338.33 kD之间, pI主要分布在3.78~12.15之间.蛋白质定量分析结果表明,不同酸度茶树根际土壤中共有54种微生物蛋白质丰度下降,按其功能主要可分为遗传信号蛋白、能量代谢信号蛋白、土壤抗氧化信号蛋白、土壤养分循环信号蛋白.基于此结果构建的土壤微生物蛋白质组代谢调控图谱表明,随着茶园土壤酸化加剧,土壤微生物为了生存,释放群体感应蛋白质,激发信号蛋白质的表达;在信号通路蛋白质的调控下,信号蛋白质激发不同代谢途径的特定信号蛋白质表达,进而调控不同代谢途径中的蛋白质表达,而这种表达是下调式的;最终导致微生物能量代谢循环能力下降,繁殖能力降低,数量减少.微生物数量及功能的变化导致土壤养分循环能力减弱,茶树在养分吸收上受阻,进而引起茶树生长受阻,以及茶叶产量和品质下降.

Soil plays a crucial role in tea tree growth, however, only few studies have reported the responses of soil microorganisms to soil acidification in tea plantations and the negative regulation of soil acidification on tea tree growth. In this study, the soil samples from Tieguanyin tea tree plantation with different acidities were used as a material for rhizosphere soil microbial protein extraction. Data dependent acquisition(DDA) was used to establish the soil microbial protein data, whereas Data independent acquisition(DIA) was used for quantitative analyses to obtain the reduced abundance of soil protein in tea rhizosphere soil. Furthermore, the functional analysis of the obtained proteins was conducted, and the regulation map of microbial protein metabolism of rhizosphere soil was constructed. The results showed that a total of 2,741 microbial proteins were detected in the tea tree rhizosphere soil, and the molecular weight ranged from 2.64 to 338.33 kD, whereas the range of pI was from 3.78 to 12.15. Quantitative analyses of soil proteins showed that the abundance of 54 microbial proteins, including genetic signaling proteins, energy metabolism signaling proteins, soil antioxidant signaling proteins, and soil nutrient cycling signaling proteins, which are named according to their functions,was decreased. Based on these analyses, a metabolic regulation map of soil microbial proteomes was constructed, and the results suggested that as tea soil acidity increased, soil microbes released quorum-sensing proteins to trigger signaling proteins for survival.Under the regulation of signaling pathway proteins, signaling proteins activated the expression of specific signaling proteins in different metabolic pathways and then regulated the expression of proteins in different metabolic pathways, demonstrating a downregulated expression trend. Finally, this regulation resulted in a decrease of microbial energy metabolism and circulation capacity as well as the reproduction capacity and quantity. The change in microbial quantity and function led to the weakening of soil nutrient cycling capacity, the blocking of the absorption of nutrients in tea trees, and the stunting of the growth and the declining of the yield and quality of tea trees.