Page 93 - 《广西植物》2024年第11期
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11 期 简少芬等: 氮素形态对穿心莲氮吸收、分配和内酯成分积累的影响 2 0 7 7
( 1. National Center for TCM Inheritance and Innovationꎬ Guangxi Botanical Garden of Medicinal Plantsꎬ Nanning 530023ꎬ Chinaꎻ 2. Guangxi Key
Laboratory of Medicinal Resource Protection and Genetic Improvementꎬ Guangxi Botanical Garden of Medicinal Plantsꎬ Nanning 530023ꎬ Chinaꎻ
3. Guangxi Engineering Research Centre of TCM Intelligent Creationꎬ Guangxi Botanical Garden of Medicinal Plantsꎬ Nanning 530023ꎬ China )
Abstract: Nitrogen (N) is a mineral nutrient with the highest demand for plantsꎬ and it is also a vital abiotic factor
that limits plant yield and quality. In order to clarify the utilization characteristics of different N forms of Andrograhis
paniculata and its relationship with the accumulation of andrographolide contentꎬ with nitrate nitrogen ( NN)ꎬ
ammonium nitrogen (AN)ꎬ amide nitrogen (ureaꎬ UN) and amino acid nitrogen ( glycineꎬ GN) as sole nitrogen
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source and combining N isotope tracing and physiological and biochemical analysisꎬ the effects of nitrogen form on N
uptake and distribution and andrographolide content at different growth stages ( rapid growth stageꎬ jointing stageꎬ
budding stageꎬ flowering stage) of A. paniculata were studied. The results were as follows: (1) N contents in leaf and
root decreased gradually with the growth stageꎬ and it was lower in the NN treatment. (2) The uptake rate of N was
higher in the vegetative growth stageꎬ and rapidly decreased in the reproductive growth stage. The uptake rates of ANꎬ
UN and GN were higher than that of NN in A. paniculata. (3) The allocation ratio of N in leaf was decreasedꎬ while
the allocation ratio of N in stem was increased at budding stage. In comparison to the NN treatmentꎬ ANꎬ UNꎬ and GN
treatments reduced N allocation ratio in leafꎬ but increased the ratios in stem and root at this growth stage. (4) At
rapid growth stageꎬ the maximum carboxylation rate and maximum electron transport rate of photosynthesis were lower
in the NN treatmentꎬ as well as the proportion of leaf N allocation in the carboxylation system and bioenergetics
components. The allocation of leaf N in the carboxylation system in UN and AN treatments were reduced at budding
and flowering stagesꎬ respectively. ( 5) ANꎬ UN and GN increased andrographolide and dehydroandrographolide
contentsꎬ and decreased 14 ̄deoxyandrographolide content at budding and flowering stagesꎬ while neoandrographolide
was slightly affected by N forms. ( 6) The contents of andrographolide and neoandrographolide were significantly
negatively correlated with N contents in leafꎬ stem and rootꎬ N uptake rateꎬ and N allocation ratios in leaf and rootꎬ
while they were significantly positively correlated with N allocation ratio in stem. The opposite was true for 14 ̄
deoxyandrographolide. Taken togetherꎬ the results indicate that the vegetative growth stage is the main stage for N
uptake in A. paniculataꎬ and that A. paniculata can better utilize ANꎬ UNꎬ and GNꎬ and promote the accumulation of
andrographolide components by optimizing N allocation. The results provide a theoretical reference for N management
of A. paniculata.
Key words: nitrogen formꎬ nitrogen uptakeꎬ nitrogen allocationꎬ andrographolideꎬ Andrographis paniculata
氮是植物需求量最大的矿质营养元素ꎬ也是 (Camellia sinensis)(Yang et al.ꎬ 2018)、天门冬(梁
限制植物产量和品质的关键非生物因子ꎮ 植物所 娟等ꎬ2018)、菘蓝( 唐晓清等ꎬ2017) 等植物中ꎬ较
需的 氮 主 要 来 源 于 土 壤ꎬ 以 无 机 态 的 硝 酸 根 高比例的铵态氮更有利于次生代谢物质的积累ꎮ
(NO )和铵根(NH )离子为主ꎬ也包括一些小分 不同氮素形态可能通过调控药用植物初生代谢
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+
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子的氨基酸和多肽等有机态氮( 曹小闯等ꎬ2015)ꎮ (如氨基酸合成、三羧酸循环和糖酵解) 和次生代
不同的氮素形态不仅对植物生长和生理特征有较 谢的关系以及次生代谢通路酶编码基因的表达影
大影响( Guo et al.ꎬ 2007)ꎬ也是影响药用植物次 响次生代谢物的积累( 张强等ꎬ2018ꎻ罗佳琪和付
生代谢物积累的关键因子ꎮ 不同氮素形态对植物 立忠ꎬ2020ꎻChen et al.ꎬ 2023)ꎮ 然而ꎬ其具体的影
次生代谢物积累的影响有很大差别ꎬ与次生代谢 响机制还缺乏系统研究ꎮ 不同氮形态对植物体内
物种类、植物对氮素形态的偏好性及氮形态的组 活性成分影响的差异在一定程度上与植物对不同
成有关ꎮ 如荨麻多酚物质( Biesiada et al.ꎬ 2009)、 形态氮的吸收利用差异有关( 晏枫霞等ꎬ2010)ꎮ
甜叶菊的甜菊苷(Sun et al.ꎬ 2021)、医用大麻的大 但目前为止ꎬ关于药用植物对不同氮素形态的吸
麻素和萜类物质( Saloner & Bernsteinꎬ 2022) 等在 收利用特征及其对次生代谢物积累的影响还鲜有
硝态氮条件下积累较铵态氮条件下高ꎬ而在茶树 报道ꎮ