中国农业科学 ›› 2022, Vol. 55 ›› Issue (2): 378-389.doi: 10.3864/j.issn.0578-1752.2022.02.012

• 园艺 • 上一篇    下一篇

氮素水平及形态对娃娃菜根系特征及生理指标的影响

马玉峰1(),周忠雄3,李雨桐1,高雪琴1,乔亚丽1,张文斌1,颉建明1,胡琳莉1,2(),郁继华1,2()   

  1. 1甘肃农业大学园艺学院,兰州 730070
    2甘肃省干旱生境作物学重点实验室,兰州 730070
    3湖北凯龙楚兴化工集团有限公司,湖北钟祥 431900
  • 收稿日期:2020-03-17 接受日期:2021-05-31 出版日期:2022-01-16 发布日期:2022-01-26
  • 通讯作者: 胡琳莉,郁继华
  • 作者简介:马玉峰,E-mail: mayf@st.gsau.edu.cn
  • 基金资助:
    甘肃农业大学科技创新基金公招博士科研启动基金(GSAU-RCZX201713);中央引导地方科技发展专项(ZCYD-2020-5);甘肃农业大学科技创新基金盛彤笙创新基金(GSAU-STS-1746)

Effects of Nitrogen Level and Form on Root Morphology of Mini Chinese Cabbage and Its Physiological Index

MA YuFeng1(),ZHOU ZhongXiong3,LI YuTong1,GAO XueQin1,QIAO YaLi1,ZHANG WenBin1,XIE JianMing1,HU LinLi1,2(),YU JiHua1,2()   

  1. 1College of Horticulture, Gansu Agricultural University, Lanzhou Gansu,730070
    2Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou 730070
    3Hubei Kailong Chuxing Chemical Group Co., Ltd, Zhongxiang 431900, Hubei
  • Received:2020-03-17 Accepted:2021-05-31 Online:2022-01-16 Published:2022-01-26
  • Contact: LinLi HU,JiHua YU

摘要:

【目的】所有高等植物均会调控其根系形态,以便能更好地在土壤环境中获得充足的养分和水分,其中,氮素是调控根系形态的一个关键因子。探究氮素水平及形态对娃娃菜根系形态的影响及其生理机制,明确参与根系形态塑造的关键因子,为进一步研究氮素调控植物根系形态的分子机制奠定基础。【方法】以娃娃菜(品种‘惠农金娃娃’)为试材,设置两个氮素浓度(0.1和1 mmol·L-1)及两种氮素形态(NO3-和NH4+)共4个处理组合,使用根系扫描仪以及生理试验等方法,测定娃娃菜根系形态指标:总根长、总根体积、总根表面积和根尖数;生理指标:NO3-含量、NH4+含量、糖、一氧化氮(NO)和过氧化氢(H2O2)以及生根相关酶过氧化物酶(POD)、多酚氧化酶(PPO)以及吲哚乙酸氧化酶(IAAO)活性,采用同位素内标法,对内源激素细胞分裂素类(CTK)、茉莉酸类(JA)、生长素(IAA)、水杨酸(SA)、1-氨基环丙基-1-羧酸(ACC)和脱落酸(ABA)含量进行LC-MS/SM绝对定量分析,并分析根系形态与各生理指标之间的相关性。【结果】相同形态下,不同氮素水平对娃娃菜根系形态和生理作用不同。低浓度(0.1 mmol·L-1)的NO3-(LN)与高浓度(1.0 mmol·L-1)的NO3-(HN)相比,可分别显著提高根系总根长、表面积、根尖数43%、24%和50%;LN处理与HN处理相比,还原糖含量提高了55.81%,NO含量提高了18.3%,H2O2降低了20.44%;低浓度(0.1 mmol·L-1)的NH4+(LA)与高浓度(1.0 mmol·L-1)的NH4+(HA)相比,分别提高了根系总根长、总根体积、总根表面积和根尖数96%、73%、85%和45%,LA处理比HA处理的还原糖含量提高了200%,NO与H2O2均有所降低,分别降低74.59%和13.58%。相同水平下,不同氮素形态影响娃娃菜根系形态以及生理指标,与LA处理相比,LN处理提高了娃娃菜总根长和总根表面积,降低了总根体积和总根尖数,同时提高了还原糖含量,LA处理比LN处理的NO和H2O2含量分别降低73.68%和40.98%;与HA处理相比,HN处理提高总根长、总根体积和总根表面积,但降低了根系总根尖数,HA处理比HN处理NO和H2O2含量分别降低82.16%和58.66%。根系激素中十二氧植物二烯酸(12-OPDA)含量以LA处理最大,高于HA处理55.18%,各处理下12-OPDA含量高低为LA>LN>HA>HN;吲哚乙酸(IAA)含量以HN最大,比LN高44.10%,LA比HA高93.79%,各处理下IAA含量高低为HN>LA>LN>HA。根系形态指标与生理指标之间的相关分析结果表明,根长与还原糖呈极显著正相关(P<0.01),根尖数与12-OPDA呈显著正相关(P<0.05)。【结论】低浓度硝态氮影响根系还原糖,对娃娃菜主根和侧根的伸长产生促进作用;低浓度铵态氮调控娃娃菜根系12-OPDA,可使娃娃菜根系的侧根数量增多。

关键词: 娃娃菜, 氮素营养, 根系发育, 内源激素

Abstract:

【Objective】 All higher plants regulate their root morphology to obtain sufficient nutrients and moisture from the soil environment, of which nitrogen is a critical factor in regulating root morphology. The purpose of this study was to explore the effects of nitrogen levels and forms on root morphology of mini Chinese cabbage and its physiological mechanism and to identify the key factors involved in root morphology shaping, which laid a foundation for further research on the molecular mechanism of nitrogen regulation on plant root morphology. 【Method】 Mini Chinese cabbage (variety ‘Hui nong jin wawa’) were used as test material, four combinations including two nitrogen concentrations (0.1 mmol∙L -1 and 1 mmol∙L-1) and two nitrogen forms (NO3- and NH4+) were set up. The root morphological parameters, including total root length, root volume, root surface area and root tip number, and root physiological indicators, including NO3- content, NH4+ content, sugar, nitric oxide (NO), hydrogen peroxide (H2O2), as well as the activities of rooting related enzymes such as peroxidase (POD), polyphenol oxidase (PPO) and indole acetic acid oxidase (IAAO), were evaluated by root scanner and physiological experiment methods. The contents of endogenous hormones, including cytokinins (CTK), jasmonic acids (JA), auxin (IAA), salicylic acid (SA), 1-aminocyclopropyl-1-carboxylic acid (ACC) and abscisic acid (ABA), were determined by LC-MS/SM absolute quantitative analysis using isotope internal standard method. The correlation between root morphology and physiological indexes were also analyzed. 【Result】Under the same nitrogen form, the different nitrogen levels had different effects on the root morphology and physiology of mini Chinese cabbage. Compared with higher concentration (1.0 mmol∙L-1) NO3- (HN), low concentration (0.1 mmol∙L-1) NO3- (LN) significantly increased the total root length, surface area and number of root tips by 43%, 24% and 50%, respectivley. Compared with HN treatment, the content of reducing sugar increased by 55.81%, the content of NO increased by 18.3%, while the content of H2O2 decreased by 20.44% in LN-treated plants. Compared with higher concentration (1.0 mmol∙L-1) of NH4+ (HA), the low concentration (0.1 mmol∙L-1) of NH4+ (LA) increased the total root length, total root volume, total root surface area and root tips by 96%, 73%, 85%, and 45%, respectively. Compared with HA treatment, LA treatment increased the reducing sugar content by 200%, and both NO and H2O2 decreased to 74.59% and 13.58%, respectively. Under the same nitrogen level, the different nitrogen forms affected the root morphology and physiological indexes of mini Chinese cabbage. Compared with LA treatment, LN treatment increased the total root length and total root surface area, decreased the total root volume and total root tip number, and increased the content of reducing sugars. The contents of NO and H2O2 under LA treatment were 73.68% and 40.98% lower than that under LN treatment, respectively. Compared with HA treatment, HN treatment increased total root length, total root volume and total root surface area, and decreased the total number of root tips. Compared with HN treatment, HA treatment reduced NO and H2O2 content by 82.16%, and 58.66%, respectively. The content of 12-oxo- phytodienoic acid (12-OPDA) in root hormones was the highest under LA treatment, which was 55.18% higher than that under HA treatment. Under each treatment, the content of 12-OPDA was LA>LN>HA>HN; the content of indole acetic acid (IAA) was the largest in HN, which was 44.10% higher than LN, and the IAA content of LA was 93.79% higher than that of HA. The content of IAA under each treatment was HN> LA>LN>HA. The results of correlation analysis between root morphology and physiological indexes showed that root length was significantly positively correlated with reducing sugar (P<0.01), and the number of root tips was positively correlated with 12-OPDA (P<0.05). 【Conclusion】The low concentration of nitrate nitrogen affected root reducing sugar and promotesd the elongation of the main root and lateral roots of mini Chinese cabbage. The low concentration of ammonium nitrogen regulated the 12-OPDA content, which could increase the number of lateral roots of mini Chinese cabbage root system.

Key words: mini Chinese cabbage, nitrogen nutrient, root development, endogenous hormone