Effects of Exogenous 2，4-Epibrassinolide on Physiological Characteristics of Daucus carota L. Seedlings under Cadmium Stress

doi:10.13560/j.cnki.biotech.bull.1985.2024-1066

Abstract

Abstract:

Objective This study is aimed to investigate the impact of varying concentrations of 2,4-epibrassinolide on growth indices, physiological parameters, and the expression of cadmium (Cd) uptake and transporter-related genes in carrot (Daucus carota L.) seedlings subjected to Cd stress. The findings provide theoretical insights into Cd resistance research in carrots. Method The "Hongxin 4" carrot cultivar (Daucus carota L.) was selected for the experimental materials. Using a hydroponic system, we examined the effects of different concentrations (0.1, 0.5, 1, and 1.5 μmol/L) of 2,4-epibrassinolide on the growth traits, physiological indicators, and photosynthesis of carrot seedlings under 0.1 mmol/L CdCl₂ stress. Result The growth of carrot seedlings was significantly inhibited under 0.1 mmol/L Cd stress. However, the exogenous application of 1 μmol/L 2,4-epibrassinolide inhibited cadmium ion absorption and transport, promoted the root length and plant height, elevated the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in the leaves, increased the contents of photosynthetic pigments, enhanced the photosynthetic efficiency, and suppressed the expressions of Cd uptake and transport-related genes (DcHMA3, DcHMA4, DcCAX2 and DcCAX4),thereby maintaining the balance of redox metabolic pathways in the plants. Conclusion 2,4-epibrassinolide promoted carrot root growth, enhanced antioxidant enzyme activity, improved photosynthetic efficiency, regulated the glutathione-phytochelatin (GSH-PC) metabolic pathway, and modulated the expressions of related genes to alleviate Cd stress-induced damage in carrot seedlings. The optimal concentration of 2,4-epibrassinolid for carrots was found to be 1 μmol/L.

Key words: cadmium stress, 2,4-epibrassinolide, carrot, physiological characteristics, gene expression

ZHOU Zhi-guo, FAN Shuang-hu, DENG Chen, FENG Xue. Effects of Exogenous 2，4-Epibrassinolide on Physiological Characteristics of Daucus carota L. Seedlings under Cadmium Stress[J]. Biotechnology Bulletin, 2025, 41(5): 165-174.

Figures/Tables 10

References 33

1	谢元, 杨春, 路润峰, 等. 镉污染土壤(农田)原位钝化修复材料研究进展 [J/OL] . 环境科学,2024. DOI: 10.13227/j.hjkx.202404175 .
	Xie Y, Yang C, Lu RF, et al. Research progress of in-situ passivation remediation materials for cadmium-contaminated soil (farmland) [J/OL] . Environmental Science, 2024. DOI: 10.13227/j.hjkx.202404175 .
2	Li YS, Tang H, Hu YX, et al. Enrofloxacin at environmentally relevant concentrations enhances uptake and toxicity of cadmium in the earthworm Eisenia fetida in farm soils [J]. J Hazard Mater, 2016, 308: 312-320.
3	Méndez-Armenta M, Ríos C. Cadmium neurotoxicity [J]. Environ Toxicol Pharmacol, 2007, 23(3): 350-358.
4	余俊琪, 徐一峰, 郭瑶, 等. 沉积物镉污染下苦草与根际微生物群落响应特征 [J]. 水生生物学报, 2023, 47(11): 1787-1797.
	Yu JQ, Xu YF, Guo Y, et al. Response characteristics of Vallisneria natans and rhizosphere microbial community under sediment-cadmium pollution [J]. Acta Hydrobiol Sin, 2023, 47(11): 1787-1797.
5	李孟盈, 胡龙兴, 向佐湘. 镉胁迫对南方苋种子萌发及幼苗生长和生理的影响 [J]. 草地学报, 2024, 32(3): 754-762.
	Li MY, Hu LX, Xiang ZX. Effect of cadmium on the germination, growth and physiology of seedlings of Amaranthus australis [J]. Acta Agrestia Sin, 2024, 32(3): 754-762.
6	Wang SQ, Zhao HH, Zhao LM, et al. Application of brassinolide alleviates cold stress at the booting stage of rice [J]. J Integr Agric, 2020, 19(4): 975-987.
7	王洁, 华一帆, 秦际远, 等. 表油菜素内酯喷施时期对宽幅播种小麦产量和氮素利用率的影响 [J]. 应用生态学报, 2023, 34(1): 99-106.
	Wang J, Hua YF, Qin JY, et al. Effects of the timing of epibrassinolide spraying on yield and nitrogen use efficiency of wide-belt sowing wheat [J]. Chin J Appl Ecol, 2023, 34(1): 99-106.
8	石欣隆, 薛娴, 杨月琴, 等. 2, 4-表油菜素内酯对低温胁迫下花生幼苗生长及生理特性的影响 [J]. 中国油料作物学报, 2023, 45(2): 341-348.
	Shi XL, Xue X, Yang YQ, et al. Effects of 2, 4-epibrassinolide on growth and physiological characteristics of peanut seedlings under low temperature stress [J]. Chin J Oil Crop Sci, 2023, 45(2): 341-348.
9	袁博. 外源表油菜素内酯(2, 4-EBL)对镉(Cd)胁迫下番茄(Lycopersicon esculentum mill.)幼苗的缓解效应 [D]. 哈尔滨: 哈尔滨师范大学, 2018.
	Yuan B. Alleviating effect of exogenous epibrassinolide (2, 4-EBL) on tomato (Lycopersicon esculentum mill.) seedlings under Cd stress [D]. Harbin: Harbin Normal University, 2018.
10	Que F, Hou XL, Wang GL, et al. Advances in research on the carrot, an important root vegetable in the Apiaceae family [J]. Hortic Res, 2019, 6: 69.
11	张宇光. 胡萝卜杂交品系选育与性状鉴定 [D]. 太谷: 山西农业大学, 2022.
	Zhang YG. Breeding and character identification of carrot hybrid lines [D]. Taigu: Shanxi Agricultural University, 2022.
12	何凌枫, 陈晨, 邓元杰, 等. 基质配比对胡萝卜根系生长及生理特性的影响 [J]. 中国农学通报, 2023, 39(16): 12-19.
	He LF, Chen C, Deng YJ, et al. Effects of substrate ratio on root growth and physiological characteristics of carrot [J]. Chin Agric Sci Bull, 2023, 39(16): 12-19.
13	王葆生, 张艳萍, 刘晓蕊, 等. 胡萝卜根腐病病原菌鉴定及品种抗病性评价 [J]. 蔬菜, 2024(4): 54-58.
	Wang BS, Zhang YP, Liu XR, et al. Identification of the pathogen of root rot and evaluation of disease resistant varieties of carrot [J]. Vegetables, 2024(4): 54-58.
14	王涛, 黄语燕, 陈永快, 等. 镉胁迫对生菜生长、生理特性及镉富集转运特征的影响 [J]. 西北农林科技大学学报: 自然科学版, 2024, 52(7): 115-124.
	Wang T, Huang YY, Chen YK, et al. Effects of cadmium stress on growth, physiological characteristics and cadmium enrichment and transport of lettuce [J]. J Northwest A&F Univ Nat Sci Ed, 2024, 52(7): 115-124.
15	王学奎. 植物生理生化实验原理和技术 [M]. 2版. 北京: 高等教育出版社, 2006.
	Wang XK. Principles and techniques of plant physiological biochemical experiment [M]. 2nd ed. Beijing: Higher Education Press, 2006.
16	刘萍, 李明军. 植物生理学实验 [M]. 2版. 北京: 科学出版社, 2016.
	Liu P, Li MJ. Plant physiology experiment [M]. 2nd ed. Beijing: Science Press, 2016.
17	郝建军, 康宗利, 于洋. 植物生理学实验技术[M]. 北京:化学工业出版社, 2007.
	Hao JJ, Kang ZL, Yu Y. Plant Physiology Experiment Technology[M]. Beijing: Chemical Industry Press, 2007.
18	王国帅, 赵嘉诺, 魏昊泰, 等. 硅对盐胁迫下西葫芦幼苗水分代谢及光合特性的影响 [J]. 西北植物学报, 2024, 44(5): 681-690.
	Wang GS, Zhao JN, Wei HT, et al. Effects of silicon on water metabolism and photosynthetic characteristics of Cucurbita pepo L. seedlings under salt stress [J]. Acta Bot Boreali Occidentalia Sin, 2024, 44(5): 681-690.
19	陈晨, 陈虹, 倪铭, 等. 油菜素内酯调控植物生长发育的研究进展 [J]. 林业科学, 2022, 58(7): 144-155.
	Chen C, Chen H, Ni M, et al. Research progress of brassinolide in regulating plant growth and development [J]. Sci Silvae Sin, 2022, 58(7): 144-155.
20	Fan TT, Long T, Lu YY, et al. Meta-analysis of Cd input-output fluxes in agricultural soil [J]. Chemosphere, 2022, 303: 134974.
21	陈镔, 谭淑端, 董方旭, 等. 重金属对植物的毒害及植物对其毒害的解毒机制 [J]. 江苏农业科学, 2019, 47(4): 34-38.
	Chen B, Tan SD Dong FX, et al. Toxic effects of heavy metals on plants and detoxification mechanism of plants [J]. Jiangsu Agric Sci, 2019, 47(4): 34-38.
22	李晓科, 武玉珍, 张义贤. 2, 4-表油菜素内酯对镉胁迫下大麦幼苗生长的影响 [J]. 福建农业学报, 2018, 33(12): 1251-1256.
	Li XK, Wu YZ, Zhang YX. Effect of 2, 4-brassinosteroid on growth of Hordeum vulgare seedlings under Cd-stress [J]. Fujian J Agric Sci, 2018, 33(12): 1251-1256.
23	冯文静. 24-表油菜素内酯对小麦生长及镉吸收、转运和积累的影响 [D]. 郑州: 河南农业大学, 2022.
	Feng WJ. Effects of 24- epibrassinolide on wheat growth and cadmium absorption, transport and accumulation [D]. Zhengzhou: Henan Agricultural University, 2022.
24	关昕昕, 严重玲, 刘景春, 等. 钙对镉胁迫下小白菜生理特性的影响 [J]. 厦门大学学报: 自然科学版, 2011, 50(1): 132-137.
	Guan XX, Yan CL, Liu JC, et al. Effect of calcium on physiological property of Brassica chinensis L. under cadmium stress [J]. J Xiamen Univ Nat Sci, 2011, 50(1): 132-137.
25	闫雷, 孙小贺, 李威, 等. 外源2, 4-表油菜素内酯对镉胁迫下黄瓜幼苗生长及光合生理特性的影响 [J]. 东北农业大学学报, 2022, 53(6): 10-19.
	Yan L, Sun XH, Li W, et al. Effects of exogenous 2, 4-epibrassinolide on growth and photosynthetic physiological characteristics of cucumber seedlings under cadmium stress [J]. J Northeast Agric Univ, 2022, 53(6): 10-19.
26	吴月莹, 邓思情, 刘松芹, 等. 镉胁迫对不同品种玉米幼苗生长及生理特性的影响 [J]. 湖南农业大学学报: 自然科学版, 2023, 49(5): 509-515.
	Wu YY, Deng SQ, Liu SQ, et al. Effects of cadmium stress on the growth and physiological characteristics of maize seedlings from different varieties [J]. J Hunan Agric Univ Nat Sci, 2023, 49(5): 509-515.
27	王芳, 彭云玲, 方永丰, 等. 外源油菜素内酯对玉米幼苗镉毒害耐受性的影响 [J]. 干旱地区农业研究, 2018, 36(5): 21-27.
	Wang F, Peng YL, Fang YF, et al. Effects of exogenous brassinolide on tolerance to cadmium toxicity in maize seedlings [J]. Agric Res Arid Areas, 2018, 36(5): 21-27.
28	王金香, 张阿良, 秦敏, 等. 镉胁迫对玉米幼苗光合特性及活性氧代谢的影响 [J]. 天津农业科学, 2023, 29(1): 1-6.
	Wang JX, Zhang AL, Qin M, et al. Effects of cadmium stress on photosynthetic characteristics and active oxygen metabolism of maize seedling [J]. Tianjin Agric Sci, 2023, 29(1): 1-6.
29	钟文, 张珊, 王传方, 等. 油菜素内酯调控植物生长发育的研究进展 [J]. 山东农业科学, 2024, 56(8): 173-180.
	Zhong W, Zhang S, Wang CF, et al. Research progress on regulatory roles of brassinosteroids in plant growth and development [J]. Shandong Agric Sci, 2024, 56(8): 173-180.
30	鲜靖苹. 外源MeJA对镉胁迫下波斯菊生长及抗氧化系统的影响 [J]. 西北植物学报, 2019, 39(9): 1627-1635.
	Xian JP. Effect of exogenous methyl jasmonate on growth and antioxidant system of Coreopsis under cadmium stress [J]. Acta Bot Boreali Occidentalia Sin, 2019, 39(9): 1627-1635.
31	孙舒畅. 褪黑素在番茄镉胁迫抗性中的功能研究 [D]. 杭州: 浙江大学, 2020.
	Sun SC. Study on the function of melatonin in the resistance of tomato to cadmium stress [D]. Hangzhou: Zhejiang University, 2020.
32	Lu CN, Zhang LX, Tang Z, et al. Producing cadmium-free indica rice by overexpressing OsHMA3 [J]. Environ Int, 2019, 126: 619-626.
33	陈江坡. 拟南芥Ca²⁺/H⁺反向转运体家族(CAXs)相互作用蛋白的筛选及解析 [D]. 哈尔滨: 东北林业大学, 2016.
	Chen JP. Screening and analysis of interacting proteins of Arabidopsis thaliana Ca²⁺/H⁺ reverse transporter family (CAXs) [D]. Harbin: Northeast Forestry University, 2016.

试剂 Reagent	体积 Volume （μL）
cDNA模板 cDNA template	1
正向引物 Forward primer	0.5
反向引物 Reverse primer	0.5
2xGreen qPCR混合物 2xGreen qPCR Mixture	10
DEPC-ddH₂O	8

试剂 Reagent	体积 Volume （μL）
cDNA模板 cDNA template	1
正向引物 Forward primer	0.5
反向引物 Reverse primer	0.5
2xGreen qPCR混合物 2xGreen qPCR Mixture	10
DEPC-ddH₂O	8

基因 Gene	正向引物 Forward primer （5′‒3′）	反向引物 Reverse primer （5′‒3′）
DcHMA3	CAATGGAGCCACTCTCTAACTC	GACCTGCCTTACTTCTGAACTT
DcHMA4	ATTGGGCATCATCACCTACTC	GCAACACTCCTTGCTCAAAC
DcCAX2	GTGAGTCGAAAGCCTCAGAAA	CTTGATCTCCACTCGTTCATCC
DcCAX4	GCCATGGCAAATGGAGAATG	CAACGACGAGGCCGAAATA
DcActin	CGGTATTGTGTTGGACTCTGGTGAT	CAGCAAGGTCAAGACGGAGTAGG

基因 Gene	正向引物 Forward primer （5′‒3′）	反向引物 Reverse primer （5′‒3′）
DcHMA3	CAATGGAGCCACTCTCTAACTC	GACCTGCCTTACTTCTGAACTT
DcHMA4	ATTGGGCATCATCACCTACTC	GCAACACTCCTTGCTCAAAC
DcCAX2	GTGAGTCGAAAGCCTCAGAAA	CTTGATCTCCACTCGTTCATCC
DcCAX4	GCCATGGCAAATGGAGAATG	CAACGACGAGGCCGAAATA
DcActin	CGGTATTGTGTTGGACTCTGGTGAT	CAGCAAGGTCAAGACGGAGTAGG

处理 Treatment	地上部镉含量 Cd content in aerial parts （mg/kg）	地下部镉含量 Cd content in underground （mg/kg）	地上部富集系数 Overground enrichment coefficient	地下部富集系数 Underground enrichment coefficient	转运系数 Transfer coefficient
CK2	65.18±2.80a	319.00±1.78a	2.61±0.11a	12.76±0.07a	0.20±0.01a
T1	56.81±0.91b	267.80±2.07b	2.27±0.04b	10.71±0.08b	0.21±0.00a
T2	45.81±0.93c	250.60±3.75c	1.83±0.04c	10.02±0.15c	0.18±0.00b
T3	31.67±1.62e	233.17±3.73d	1.27±0.06e	9.33±0.15d	0.14±0.01c
T4	41.17±0.90d	246.53±0.95c	1.65±0.04d	9.86±0.04c	0.17±0.00b