稻壳炭表面有机小分子缓解人参连作障碍机理的研究

In order to understand the mechanism in the mall organic molecules from rice husk biochar to rice husk carbon surface which can alleviate continuous cropping obstacles of ginseng, the standard substance of the mall organic molecules is added into the continuous and un-continuous cropping soil and then potted ginseng. And the untreated continuous and uncontinuous were considered as CK. The agronomic trait from ginseng was employed to filtrate the organic compound which could alleviate the continuous cropping obstacles in ginseng.And then the metagenome, 16S rRNA,18S rRNA and ITS were analyzed in ginseng. At the same time, the incidence of soil borne diseases was surveyed. The two data indicated that the organic compound could continuous cropping obstacles though change the microbial population and inhibit the growth of pathogenic bacteria.Besides, there were the organic compounds which couldimprovement of plant stress resistance and promote the plant growth. So the transcriptome and proteome were tested in ginseng in order to understand gene and protein expression difference. And the qPCR and immunohistochemistry were employed to prove the result from transcriptome and proteome. and then indicators of antiretroviral and endogenous hormone levels were studyed on ginseng. All data described the organic compound could alleviate continuous cropping obstacles of ginseng though ginseng strengthening plant resistance responses, promote plant growth . Ultimately, the research understood the mechanism which can alleviate continuous cropping obstacles of ginseng.

为明确稻壳炭表面有机小分子缓解人参连作障碍机理，将稻壳炭表面有机小分子标准品分别添加到连作及非连作土壤，盆栽人参。通过不同处理条件下，人参农艺性状分析，筛选具有缓解人参连作障碍稻壳炭表面有机小分子。然后，对土壤样品进行宏基因组、16S rRNA、18S rRNA及真菌ITS分析，结合土传病害发病率数据，明确表面有机小分子是否通过改变土壤微生物种群，抑制某些致病菌的生长，以达缓解人参连作障碍的目的。此外，本课题对人参植株进行转录组及蛋白质组分析，明确与抗逆及生长通路上相关基因及蛋白表达差异。之后，利用荧光定量PCR及免疫组织化学法验证转录组及蛋白质组结果，同时结合人参抗逆、内源生长激素及农艺性状等数据，阐明稻壳炭表面有机小分子是否通过提高人参抗逆性，促进生长，从而缓解了人参连作障碍。最终，阐明何种稻壳炭表面小分子通过何种途径缓解了人参连作障碍。

农业生产中，常采用破坏森林、施用大量农药等方式缓解人参连作障碍，对环境及地下水源破坏严重。本课题前期研究表明稻壳炭对缓解人参连作障碍有良好效果，机理尚不明确。基于此，本课题通过土壤代谢组、微生物组及植株转录组等分析结果阐明稻壳炭表面有机小分子2,2-diethylacetamide通过调节Steroid hormone biosynthesis、Vitamin B6、Pyrimidine、Cysteine和methionine、Arginine和Proline等5条代谢通路影响Fusarum solani丰度，从而降低障碍性参田根腐病发病率。此外，稻壳炭表面有机小分子Eugenol，Salicyl alcohol和1,2,3-trimethylcyclopentane通过调控L-型组氨酸限速酶HisG活性，促进土壤微生物产生大量L-型组氨酸，进而也降低根腐病发病率。另一方面，稻壳炭表面有机小分子促进人参植株及根系生长。这一现象主要源于稻壳炭表面有机小分子2,2-Diethylacetamide通过调控葡萄糖代谢通路上的限速酶活性影响AOB和NOB丰度，提高土壤氮素转化效率，为人参提供可利用氮源。同时，稻壳炭表面有机小分子Salicyl alcohol、Orcinol及Testosterone与氮素相关受体蛋白OsNRT1.1B和OsNLP4间相互作用，促进人参对氮素的吸收与利用，进而提高植株及根系的快速生长。最后，通过不同原料及工艺制备的生物炭与土壤化感物质苯甲酸标准品的吸附动力学及热力学曲线筛选得到最适降低土壤化感物质的炭基材料，并在障碍性参田试验中得到验证，从针对降低障碍性土壤中化感物质的角度缓解人参连作障碍提供数据。本研究为生物炭缓解人参连作障碍提供新思路。在将生物炭应用于土壤改良的同时缓解参田连作障碍的影响，最大限度降低大量农药施用及森林破坏所带来的环境问题。