有机肥对烟叶次生代谢物影响分析
作者: 申树林 李洪勋 黄兰 张昆鹏 朱勇 张龙 陈德慧 尹能文 曲存民 彭华伟 林叶春
摘要 肥料是影响烟叶产量、品质的重要因素之一,其中施用有机肥可促进烟叶增产,改善烟叶品质。为探究增施有机肥对烟叶代谢的影响,以云烟87为材料,通过增施0、900和1 500 kg/hm2 3个不同梯度的炭基(酒糟)有机肥处理后,利用液相色谱质谱方法对打顶后7 d 烟叶中的代谢物进行了非靶向代谢组分析。在烟叶中鉴定了219种次生代谢物,通过代谢物比较分析发现,增施900和1 500 kg/hm2分别有14和26个代谢物相比对照组积累降低;有7种代谢物在2个处理组中均显著降低,其中包含了M780(降烟碱)、M1021(尼古丁)和M1328(可替宁)3种烟碱类代谢物。进一步分析发现,33种差异代谢物中有9种代谢物在增施900和1 500 kg/hm2 2个分组之间具有积累差异;其余差异代谢物在2个分组之间无显著积累差异。差异代谢物相关网络分析发现,山奈酚等苯丙烷途径代谢物与烟碱的积累变化紧密相关,也具有降低的趋势。结果表明,增施有机肥既能显著减少烟叶烟碱类代谢物的积累,也能在一定程度上降低烟叶苯丙烷途径代谢物的积累;增施900和1 500 kg/hm2有机肥对烟碱的影响无明显差异。综上,明确了有机肥对烟叶次生代谢物的影响,为后续烟叶生产中有机肥合理施用提供了一定的理论指导。
关键词 有机肥;烟叶;代谢物;烟碱;类黄酮
中图分类号 S 572 文献标识码 A 文章编号 0517-6611(2024)20-0141-04
doi:10.3969/j.issn.0517-6611.2024.20.035
开放科学(资源服务)标识码(OSID):
Analysis of the Effect of Organic Fertilizer on Secondary Metabolites in Tobacco Leaves
SHEN Shu-lin LI Hong-xun2,3, HUANG Lan4 et al
(1. College of Agronomy and Biotechnology, Southwest University, Chongqing 400715;2. Upland Flue-Cured Tobacco Quality & Ecology Key Laboratory of China Tobacco, Guiyang, Guizhou 550081;3. Guizhou Academy of Tobacco Sciences, Guiyang, Guizhou 550081;4. Bijie Branch of Guizhou Tobacco Company, Bijie, Guizhou 551700)
Abstract Fertilizer is one of the important factors affecting the yield and quality of tobacco leaves, among which the application of organic fertilizer can promote the increase of tobacco leaf yield and improve the quality of tobacco leaves. To explore the effect of increasing the application of organic fertilizers on the metabolism of tobacco leaves, Yunyan 87 was used as the material in this study. After applying three different gradients of carbon-based organic fertilizers at 0, 900 and 1 500 kg/hm2, and by using the liquid chromatography-mass spectrometry method,the metabolites in tobacco leaves 7 days after topping were subjected to untargeted metabolome analysis. A total of 219 secondary metabolites were identified in tobacco leaves. Through comparative analysis of metabolites, it was found that 14 and 26 metabolites were reduced in the accumulation of 900 and 1 500 kg/hm2 respectively compared with the control group;7 metabolites in the two treatments were significantly reduced, which contained three nicotinic metabolites M780 (nornicotine), M1021 (nicotine) and M1328 (cotinine). Further analysis found that 9 of the 33 differential metabolites had accumulation differences between the two groups with additional application of 900 and 1 500 kg/hm2; the rest of the differential metabolites had no significant accumulation differences between the two groups. Correlation network analysis of differential metabolites found that phenylpropane pathway metabolites such as kaempferol were closely related to the accumulation changes of nicotine,and also had decreased trend. The above results showed that increasing the application of organic fertilizers could not only significantly reduce the accumulation of nicotinic metabolites in tobacco leaves, but also reduce the accumulation of metabolites in the phenylpropanoid pathway in tobacco leaves to a certain extent; there was no significant difference between adding 900 and 1 500 kg/hm2 organic fertilizer on nicotine. In summary, this study clarified the effects of organic fertilizers on secondary metabolites of tobacco leaves, and provided certain theoretical guidance for the rational application of organic fertilizers in subsequent tobacco leaf production.
Key words Organic fertilizers;Tobacco leaves;Metabolites;Nicotine;Flavonoids
有机肥是以动植物残体等富含有机质的资源为主要原料,经发酵腐熟后而成的肥料,是我国农业生产的传统肥料[1]。随着现代农业的发展,我国农业施肥体系由以传统的有机肥为主变成以高效、高生产率的化肥为主的施肥体系[2]。然而化肥的过量使用造成了土壤板结、盐碱化等问题[3]。近年来,以化肥配施有机肥的施肥体系成为趋势,大量试验研究和长期农业生产实践证明:两类肥料的混合使用可在保证土壤肥力稳定的同时兼顾土壤的保护,是保证作物稳产高产的基本措施[4-5]。因此,探究有机肥对烟叶代谢的影响,可为合理施肥提供理论依据,具有较高的研究意义与价值。在烟草种植中,有机肥具有提高烤烟产量,提升烟叶品质和改善土壤环境等多种效果[6]。同时,通过调整有机肥配方还可以降低烟草花叶病、青枯病、赤星病的发生率[7]。上述研究表明,施用有机肥对烟叶种植具有多种益处,但目前增施有机肥后烟叶生理变化机理了解较少,特别是烟叶的代谢变化尚不清楚。
烟草作为重要的经济作物,也是一种重要的模式植物,在研究植物遗传、生长发育和防御反应方面发挥重要作用[8-9]。次生代谢物是植物生长的重要物质,广泛参与植物的生命活动,其差异变化能反映植物对基因或环境改变的最终响应[10]。随着代谢组检测技术的日益成熟,近年来非靶向代谢组在烟叶研究中得到广泛应用[11]。如:向海英等[12]基于非靶向代谢组学对红花大金元不同生育期烟叶代谢图谱进行了差异分析,揭示了不同生育期烟草代谢物变化规律。李楠芬等[13]进行了不同品种雪茄烟叶晾制后代谢组的差异分析,鉴定出楚雪10号和楚雪14号2个品种烟叶晾制后的叶色差异主要与脯氨酸、水杨酸、黄酮类和生物碱的含量差异有关。因此,为明确有机肥处理对烟叶代谢物的影响,该研究以云烟87为对象,基于非靶向代谢组学,解析了增施炭基(酒糟)有机肥处理后烟叶次生代谢物的积累变化,为烟叶生产中通过合理施用有机肥提高烟叶质量提供理论依据。
1 材料与方法
1.1 仪器、试剂与材料
受试烟草种植于贵州省毕节市大风科技园,采取小区种植。在正常烟草管理条件下,设置0、900和1 500 kg/hm2 3个不同梯度的当地生产用炭基(酒糟)有机肥施肥处理,分别命名为CK、T1和T2。每组3次重复。于打顶后7 d,选取每组6株植株中部健康烟叶混合,将烟叶样品放入冻存管中并立即放入液氮中保存,在实验室放入-80 ℃超低温冰箱保存用于后续试验。
1.2 试验方法和条件
1.2.1 烟叶代谢物的提取。
参照Yin等[14]方法,略有改动:将冻存新鲜烟叶研磨成粉末状,称取50 mg粉末,加入1 mL 80%甲醇水溶液。使用超声仪(KQ-100E,昆山,中国)常温(25 ℃)超声提取1 h,期间涡旋3次。10 200 r/min离心15 min,吸取上清液,经0.22 μm尼龙微孔过滤样本后,转置上样瓶中,进行代谢组上机检测。
1.2.2 LC-MS/MS条件。
参照Yin等[14]方法,略有改动:液相色谱分析使用the Dionex UltiMateTM 3 000 UHPLC system(Thermo Fisher Scientific,USA);ACQUITY UPLC BEH C18 VanGuard预柱(孔径:1.7 μm,2.1 mm×5.0 mm,Waters,Ireland);Acquity UPLCBEH C18色谱柱(孔径:1.7 μm,2.1 mm×150.0 mm,Waters,Ireland)。流动相为0.1%甲酸水溶液(A)和0.1%甲酸乙腈水溶液(B)。流速为0.3 mL/min,柱温40 ℃,流动相梯度为0~2 min,5%~10% B;2~10 min,10%~25% B;10~15 min,25%~50% B;15~20 min,50%~95% B;20~23 min,95% B;23.0~23.5 min,95%~5% B;23.5~28.0 min,5% B。流速为0.3 mL/min,进样量为5 μL。
质谱分析系统为Thermo ScientificTM Q-ExactiveTM,具体参数为:正离子模式,加热电喷雾电离源(HESI),离子源电压为3.5 kV,毛细管温度为350 ℃,扫描范围为100~1 200 m/z。气流参数设置:鞘气(sheath gas)35;辅助气(auxiliary gas)10;反吹气(sweep gas)0。
1.3 数据分析
使用MS-Dail软件进行离子峰提取,对齐,得到离子峰信息,包括质核比、保留时间、二级质谱、峰面积等[15]。注释数据库由MS-Dail软件提供,具体数据库见网站http://prime.psc.riken.jp/compms/msdial/main.html#MSP。差异代谢物统计分析使用Metaboanalyst 5.0(https://www.metaboanalyst.ca/)网站进行[16]。使用 TBtools软件绘制差异代谢物热图[17]。相关性分析使用R语言psych包corr.test函数计算,并使用Gephi软件进行代谢网络的构建[18]。
2 结果与分析
2.1 烟叶代谢物的提取与鉴定
利用MS-Dail软件对所测样本原始离子峰进行提取,从提取的5 047个离子峰中筛选了219个高质量的注释离子峰用于后续分析(图1A、表1)。为检测代谢组数据的可靠性,对质控样本进行相关性计算,其相关系数大于0.99,符合质控要求(图1B)。对所有样本进行无监督的PCA分析(图1C),施肥量1 500 kg/hm2组(T2)与对照有着显著的区分,施肥量900 kg/hm2组(T1)与对照组无显著区分。PCA分析表明,所检测离子峰能反映施肥处理后烟草叶片的代谢差异,且随着施肥量的增加,烟叶次生代谢差异越大。