Effect of spraying with 5-aminolevulinic acid and nano-zinc oxide on enhancing floral traits of seedlings dwarf pink Bougainvillea ‘Jewel Pink’

Bushra Alawi  HUSSAIN KHALAF; Zeyad Mohammed  ABDULRAZZAQ

doi:10.14720/aas.2026.122.3.29883

Authors

Bushra Alawi HUSSAIN KHALAF Department of Horticulture and Landscaping, College of Agriculture, University of Anbar, Iraq
Zeyad Mohammed ABDULRAZZAQ Department of Horticulture and Landscaping, College of Agriculture, University of Anbar, Iraq

DOI:

https://doi.org/10.14720/aas.2026.122.3.29883

Keywords:

Seedling Dwarf, 5-Aminolevulinic, ZnO-PNs, Floral growth

Abstract

The research sought to examine the impact of foliar application of 5-Aminolevulinic Acid and Nano-Zinc Oxide on mitigating flower drop, prolonging blooming duration of dwarf pink Bougainvillea ‘Jewel Pink’, in addition to promoting growth characteristics. The experiment included administering four doses of 5-ALA and three concentrations of ZnO-NPs at four separate times. A 4 × 3 factorial experiment was conducted using a RCBD. Means were analysed using the LSD0.05. The results demonstrated that the application of 5-ALA 50 mg l^-1 and ZnO-NPs 75 mg l^-1 to Bougainvillea seedlings significantly improved flowering characteristics, evidenced by an extended flowering duration and decreased flower drop at multiple intervals compared. Furthermore, there were substantial enhancements in vegetative and root development traits; in contrast, the control treatment (0 mg l^-1) had the lowest significant values for both growth metrics. The findings indicated that the concurrent application of 50 mg l^-1 5-ALA and 75 mg l^-1 ZnO-NPs exhibited considerable superiority in most evaluated growth parameters, with the exception of seedling height, branch diameter, and the length of the longest lateral root.

Downloads

Download data is not yet available.

References

Abdel-Azim, M., A.A. Sayed, A.I. Abou-Sreea, A.R. Maray, K.E. Mazrou, A. Elkelish, and N.M. Abdou. (2026). Improving water productivity and drought resilience in caraway plants: The effect of foliar application of nano-zinc oxide on physio-biochemical responses, growth, yield, and oil quality. Fayoum Journal of Agricultural Research and Development, 40(1), 94-119. https://doi.org/10.21608/fjard.2026.470823.1147

Abdulrazzaq, Z.M., and A.H. Abdulmajeed. (2025). Effect of seaweed extract and fertilization NPK on the growth of Bougainvillea ‘Dwarf Pink’ plant. Basrah Journal of Agricultural Sciences, 38(Special Issue), 231-239. https://doi.org/10.37077/25200860.2025.38.sp.21

Abegunde, S.M., H.O. Adubiaro and F.A. Ishaya. (2026). Zinc oxide nanoparticles in smart agricultural fertilization: Current developments and future perspectives. Hybrid Advances, 100637. https://doi.org/10.1016/j.hybadv.2026.100637

Ahmad, I.K. and Z.M. Abdulrazzaq. (2025). Effect of spraying with nano zinc and salicylic acid on the chemical traits and dry matter content of dwarf Tecoma stans seedlings. Euphrates Journal of Agricultural Science, 17(2), 1029-1039.

Ahmad, I.K. and Z.M. Abdulrazzaq. (2026). Effect of foliar application with nano zinc (ZnO NPs) and salicylic acid (SA) on the phenotypic growth traits (vegetative, root, and floral) of dwarf Tecoma stans L. plant. IOP Conference Series: Earth and Environmental Science, 1596(1), 012024. https://doi.org/10.1088/1755-1315/1596/1/012024

Ahmed, M., K. Decsi and Z. Tóth. (2022). Different tactics of synthesized zinc oxide nanoparticles, homeostasis ions, and phytohormones as regulators and adaptatively parameters to alleviate the adverse effects of salinity stress on plants. Life, 13(1), 73. https://doi.org/10.3390/life13010073

Al-Abassi, A.A.A., W.A. Al-Shamary, K.A. Kareem and A.S. Kahlei. (2022). Effect of plant density and foliar spray of zinc on vegetative growth of corn (Zea mays L.). Research on Crops, 23(4), 776–780. http://dx.doi.org/10.31830/2348-7542.2022.ROC-827

Al-Budeiri, M., Z.K.K. Al-Salihi and Y.A.Q. Al-Shami. (2025). Impact of zinc oxide nanoparticles (ZnO-NPs) levels on soil properties, productivity, and nutrient uptake of pomegranate (Punica granatum L.). Sarhad Journal of Agriculture, 41(5), 110-117. https://dx.doi.org/10.17582/journal.sja/2025/41.5.110.117

Ali, A.A. and S.M. Emam. (2025). Effect of foliar application of zinc nanoparticles on growth and yield of grain sorghum (Sorghum bicolor L Moench) under drought conditions. Labyrinth: Fayoum Journal of Science and Interdisciplinary Studies. https://doi.org/10.21608/ifjsis.2025.405976.1121

An, Y., D. Cheng, Z. Rao, Y. Sun, Q. Tang and L. Wang. (2019). 5-Aminolevulinic acid (ALA) promotes primary root elongation through modulation of auxin transport in Arabidopsis. Acta Physiologiae Plantarum, 41(6), 85. https://doi.org/10.1007/s11738-019-2878-x

Anwar, A., Y. Yan, Y. Liu, Y. Li and X. Yu. (2018). 5-aminolevulinic acid improves nutrient uptake and endogenous hormone accumulation, enhancing low-temperature stress tolerance in cucumbers. International Journal of Molecular Sciences, 19(11), 3379. https://doi.org/10.3390/ijms19113379

Arooj, A., N.H. Khan, F. Rasul, S. Gulzar, T.U. Rahman, M.A.B. Hayat and M. Sajid. (2025). 5-Aminolevulinic acid: Key frontier amino acid in confirming abiotic stress tolerance in plants. In Amino Acids in Plant Protection (pp. 235-256). Academic Press. https://doi.org/10.1016/B978-0-443-26793-2.00016-0

Ashokkumar, K., P. Sasikala, M. Murugan, S. Muthukrishnan and M.K. Dhanya. (2026). Insights into green synthesized zinc oxide nanoparticles for abiotic stress tolerance, crop growth and development. Discover Plants, 3(1), 39. https://doi.org/10.1007/s44372-026-00504-4

Bagheri, H., D. Hashemabadi, B. Pasban Eslam and S. Sedaghathoor. (2021). Effects of nano-zinc oxide, salicylic acid, and sodium nitroprusside on physiological and enzymatic traits of sweet violets under different water regimes. Journal of Ornamental Plants, 11(2), 135-151. https://sid.ir/paper/1053499/en

Bagheri, H., D. Hashemabadi, B. Pasban Eslam and S. Sedaghathoor. (2023). Effects of zinc-nano oxide, salicylic acid and sodium nitroprusside on physiological properties, antioxidant enzyme activities and secondary metabolites of Viola odorata under drought stress. Acta Scientiarum Polonorum Hortorum Cultus, 22(6), 29-41. https://doi.org/10.24326/asphc.2023.4778

Chen, H., Y. Song, Y. Wang, H. Wang, Z. Ding and K. Fan. (2024). ZnO nanoparticles: improving photosynthesis, shoot development, and phyllosphere microbiome composition in tea plants. Journal of Nanobiotechnology, 22(1), 389. https://doi.org/10.1186/s12951-024-02667-2

Chen, J., R. Li, J. Wang, J. Feng, Y. He, P. Bai and J. Lyu. (2025). Exogenous ALA promotes tomato fruit quality and pigment metabolism: physiological mechanisms. Frontiers in Nutrition, 12, 1729358. https://doi.org/10.3389/fnut.2025.1729358

Chen, Z., J. Zhang and L. Wang. (2023). ALA induces stomatal opening through regulation among PTPA, PP2AC, and SnRK2.6. Frontiers in Plant Science, 14, 1206728. https://doi.org/10.3389/fpls.2023.1206728

Collins, C., N.M. Maruthi and C.E. Jahn. 2015. CYCD3 D-type cyclins regulate cambial cell proliferation and secondary growth in Arabidopsis. Journal of Experimental Botany, 66(15):4595-4606. https://doi.org/10.1093/jxb/erv218

Daler, S. and Y. Özkol. (2024). Effects of 5-aminolevulinic acid (5-ALA) on morphological and physiological characteristics of grapevine against salt stress. Turkish Journal of Agriculture-Food Science and Technology, 12(4), 575-585. https://doi.org/10.24925/turjaf.v12i4.575-585.6711

Djanaguiraman, M., V. Anbazhagan, O.P. Dhankher and P.V. Prasad. (2024). Uptake, translocation, toxicity, and impact of nanoparticles on plant physiological processes. Plants, 13(22), 3137. https://doi.org/10.3390/plants13223137

Dubey, D. and G.C. Pathak. 2024. Zinc: A critical micronutrient for growth and development of plants. Journal of Applied Bioscience, 50(2), 95-102. https://9vom.in/journals/index.php/joab/article/view/460

El-Metwally, I.M., M.S. Sadak and H.S. Saudy. (2022). Stimulation effects of glutamic and 5-aminolevulinic acids on photosynthetic pigments, physio-biochemical constituents, antioxidant activity, and yield of peanut. Gesunde Pflanzen, 74(4), 915-924. https://doi.org/10.1007/s10343-022-00663-w

Fahad Almulhim, B., F.E. Sherif, N.S. Younis, Y. Safwat and S. Khattab. (2025). Foliar spraying with zinc oxide nanoparticles enhances the anti-osteoporotic efficacy of the fruit extracts of Silybum marianum L. by stimulating silybin production. Frontiers in Plant Science, 15, 1421485. https://doi.org/10.3389/fpls.2024.1421485

Freeman, W.H. and D.C. Harris. (2015). Quantitative chemical analysis. 9th Ed. Analytical and Bioanalytical Chemistry, 407, 8943-8944. https://doi.org/10.1007/s00216-015-9059-6

Garza-Alonso, C.A., A. Juárez-Maldonado, S. González-Morales, M. Cabrera-De la Fuente, G. Cadenas-Pliego and A. Benavides-Mendoza. (2023). ZnO nanoparticles as potential fertilizer and biostimulant for lettuce. Heliyon, 9(1), e12787. https://doi.org/10.1016/j.heliyon.2022.e12787

Gupta, A., R. Bharati, J. Kubes, D. Popelkova, L. Praus, X. Yang and M. Brestic. (2024). Zinc oxide nanoparticles application alleviates salinity stress by modulating plant growth, biochemical attributes and nutrient homeostasis in Phaseolus vulgaris L. Frontiers in Plant Science, 15, 1432258. https://doi.org/10.3389/fpls.2024.1432258

Hamaiel, A.F., E.A. El-Boraie and N.F.A. El-Habashi. (2022). Impact of foliar spraying with boron, zinc, salicylic acid and their combinations on growth and flowering of Jasminum sambac L. plant. Damietta Journal of Agricultural Sciences, 1(2), 1-8.

Hara, M., I. Takahashi, M. Yamori, T. Tanaka, S. Funada and K. Watanabe. (2011). Effects of 5-aminolevulinic acid on growth and amylase activity in the radish taproot. Plant Growth Regulation, 64(3), 287-291. https://doi.org/10.1007/s10725-010-9542-1

Harish, V., D. Tewari, M. Gaur, A.B. Yadav, S. Swaroop, M. Bechelany and A. Barhoum. (2022). Review on nanoparticles and nanostructured materials: Bioimaging, biosensing, drug delivery, tissue engineering, antimicrobial, and agro-food applications. Nanomaterials, 12(3), 457. https://doi.org/10.3390/nano12030457

Hu, Y., L. Zhi, P. Li, J. Hancock and X. Hu. (2022). The role of salicylic acid signal in plant growth, development and abiotic stress. Phyton, 91(12), 2591. https://doi.org/10.32604/phyton.2022.023733

Huang, H., H. Ji, S. Ju, W. Lin, J. Li, X. Lv and X. Ma. (2022). Pantranscriptome combined with phenotypic quantification reveals germplasm kinship and regulation network of bract color variation in Bougainvillea. Frontiers in Plant Science, 13, 1018846.‏ https://doi.org/10.3389/fpls.2022.1018846

Hussain Khalaf, B.A. and Abdulrazzaq, Z.M. (2026), Effect of spraying with 5-aminolevulinic acid and nano-zinc oxide on enhancing floral traits of seedlings dwarf pink Bougainvillea ‘Jewel Pink’. https://doi.org/10.7910/DVN/SAEZBK, Harvard Dataverse.

John, L.H., S.L. Tisdale, W.L. Nelson and J.D. Beaton. (2021). Soil Fertility and Fertilizers: An Introduction to Nutrient Management. 8th ed. Publisher Pearson. 528 p.

Kabata-Pendias, A. and A.B. Mukherjee. (2007). Trace Elements of Group 12 (Previously Group IIb). In: Trace Elements from Soil to Human. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-32714-1_19

Kalefa, A.E., S.A. Salim, N.H. Ateya and H.M. Mahmoud. (2025). Impact of zinc oxide nanoparticles on callus growth, antioxidant activity, and secondary metabolite content in Moringa oleifera, International Journal of Innovative Research and Scientific Studies, 8(3), 4418-4426. https://doi.org/10.53894/ijirss.v8i3.7516

Kumari, M., D. Singh, P. Singh and S. Sahay. (2022). Boungainvillea: An ideal ornamental plant for landscaping and pollution control. Indian Horticulture, 67(4), 25-28. https://epubs.icar.org.in/index.php/IndHort/article/view/123598

Lalarukh, I., N. Zahra, A. Shahzadi, M.B. Hafeez, S. Shaheen, A. Kausar and A. Raza. (2023). Role of aminolevulinic acid in mediating salinity stress tolerance in sunflower (Helianthus annuus L.). Journal of Soil Science and Plant Nutrition, 23(4), 5345-5359. https://doi.org/10.1007/s42729-023-01406-0

Li, S.W. (2021). Molecular bases for the regulation of adventitious root generation in plants. Frontiers in Plant Science, 12, 614072. https://doi.org/10.3389/fpls.2021.614072

Lin, X., H. Chen, M. Sun, X. Du, S. Zeng, B. Guo and G. Liu. (2025). Comparative transcriptome analysis provides insight into the effect of 6-BA on flower development and flowering in Bougainvillea. Plants, 14(22), 3442. https://doi.org/10.3390/plants14223442

Liu, H., D. Liu, S. Lv, S.M. Alam, T. Zhou and Y. Liu. (2025a). Auxin promotes stem secondary growth of Poncirus trifoliata seedling through ARF7 modulating xylem development. Plant Science, 358, 112574. https://doi.org/10.1016/j.plantsci.2025.112574

Liu, P., S. Zhang, X. Wang, Y. Du, Q. He, Y. Zhang and X. Li. (2025b). Adventitious root formation in cuttings: Insights from Arabidopsis and prospects for woody plants. Biomolecules, 15(8), 1089. https://doi.org/10.3390/biom15081089

Liu, X., Y. Peng, Q. Zeng, Y. Ma, J. Liu, Y. Huang and F. Cao. (2024). Transcriptomic profiling and gene network analysis revealed regulatory mechanisms of bract development in Bougainvillea glabra. BMC Plant Biology, 24(1), 543. https://doi.org/10.1186/s12870-024-05246-7

Ma, J., M. Sun, L. Qiu, Y. Xie, Y. Ma and W. Liang. (2022). The 5-aminolevulinic acid (5-ALA) supplement enhances PSII photochemical activity and antioxidant activity in the late growth promotion of Pseudostellaria heterophylla. Plants, 11(22), 3035. https://doi.org/10.3390/plants11223035

Mali, S. and S. Tiwari. (2022). Zinc fractions under different crop management practices. Current Research in Soil Fertility, p.15.

Manzoor, M., K. Korolev and A. Riaz. (2025). Zinc oxide nanoparticles: abiotic stress tolerance in fruit crops focusing on sustainable production. Phyton, 94(5), 1401.

Mazaheri-Tirani, M. and S. Dayani. (2022). Growth, flowering and physiological response of Trachyspermum ammi L. to zinc oxide micro-and nanoparticles. Russian Journal of Plant Physiology, 69(1), 14. https://doi.org/10.1134/S1021443722010125

Mazaheri-Tirani, M., S. Dayani and M.I. Mobarakeh. (2024). Application of machine learning algorithms for predicting the life-long physiological effects of zinc oxide micro/nano particles on Carum copticum. BMC Plant Biology, 24(1), 970. https://doi.org/10.1186/s12870-024-05662-9

Mohammadi, H., P. Ezati, S. Hazrati and M. Ghorbanpour. (2023). Exogenously applied 5-aminolevulinic acid modulates growth, yield, and physiological parameters in lentil (Lens culinaris Medik.) under rain-fed and supplemental irrigation conditions. Scientific Reports, 13(1), 21312. https://doi.org/10.1038/s41598-023-48732-y

Mori, S., Y. Kaji, and R. Degai. (2021). Effects of CO2 enrichment and 5-aminolevulinic acid-based fertilizer application on cut flower yield of Alstroemeria in low light conditions during winter. In III Asian Horticultural Congress-AHC2020 1312 (pp. 255-260). https://doi.org/10.17660/ActaHortic.2021.1312.37

MouliCKs, D., K.L. Bhutia, S. Sarkar, A. Roy, U.M. Mishra and A. Hossain. (2023). The intertwining of Zn-finger motifs and abiotic stress tolerance in plants: Current status and future prospects. Frontiers in Plant Science, 13, 1083960.https://doi.org/10.3389/fpls.2022.1083960

Ochoa-Chaparro, E.H., L.U. Castruita-Esparza and E. Sánchez. (2026). Eco-physiological and molecular roles of zinc oxide nanoparticles (ZnO-NPs) in mitigating abiotic stress: A comprehensive review. Plants, 15(1), 147. https://doi.org/10.3390/plants15010147

Paciolla, C., S. Fortunato, N. Dipierro, A. Paradiso, S.D. Leonardis and M.C. Pinto. (2019). Vitamin C in plants: from functions to biofortification. Antioxidants (Basel), 8(11), 519. https://doi.org/10.3390/antiox8110519

Prabawati, S., N. Sjafrina, A. Sulistyaningrum, E. Rahayu, S.M. Widayanti and A.B. Arif. (2023). Increasing the vase life of chrysanthemum cut flowers by using silver and zinc nanoparticles. The Scientific World Journal, (1), 8871491. https://doi.org/10.1155/2023/8871491

Qian, J., R. Shan, Y. Shi, H. Li, L. Xue, Y. Song and M. Jiang. (2024). Zinc oxide nanoparticles alleviate salt stress in cotton (Gossypium hirsutum L.) by adjusting Na+/K+ ratio and antioxidative ability. Life, 14(5), 595. https://doi.org/10.3390/life14050595

Ramadan, K.M., H. Mohamed, M. Munir, S.M. Youssef, H.S. El-Beltagi, H.S. Saudy and O.A. AlElwany. (2025). Sustainable modeling and optimization of green-synthesized ZnO nanoparticles and humic-citric amendments: enhancing growth, nutrient uptake, and flowering of Solidago in saline soils. Journal of Soil Science and Plant Nutrition, 25(4), 9363-9380. https://doi.org/10.1007/s42729-025-02730-3

Ravishankar, L.V., N. Puranik, V.V. Lekkala, D. Lomada, M.C. Reddy and A.K. Maurya. (2025). ZnO nanoparticles: advancing agricultural sustainability. Plants, 14(15), 2430. https://doi.org/10.3390/plants14152430

Razmjou, J., M. Mardani-Talaee and P. Vivekanandhan. (2025). Investigating the alleviatory ability of bio-synthesized zinc oxide nanoparticles from Sargassum ilicifolium (Turner) C. Agardh on the tomato plants exposed to whitefly infestation. Scientific Reports, 15(1), 44206. https://doi.org/10.1038/s41598-025-27906-w

Rhaman, M.S., S. Imran, M.M. Karim, J. Chakrobortty, M.A. Mahamud, P. Sarker and M. Hasanuzzaman. (2021). 5-aminolevulinic acid-mediated plant adaptive responses to abiotic stress. Plant Cell Reports, 40, 1451-1469. https://doi.org/10.1007/s00299-021-02690-9

Roy, T.K., M.S. Islam, N.A. Mahiddin, S.A. Hossain, T. Biswas, U.B. Antu and Z. Ismail. (2025). Application of nanoparticles (NPs) to ameliorate abiotic stress in economically important crop species: a potential review. Journal of Crop Health, 77(1), 19. https://doi.org/10.1007/s10343-024-01069-6

Rudani, K., V. Patel and K. Prajapati. (2018). The importance of zinc in plant growth: A review. International Research Journal of Natural and Applied Sciences, 5(2), 38-47. https://doi.org/18.A003.aarf.J14I01.200001.887683

Salinas Ruíz, J., O.A. Montesinos López and J. Crossa. (2024). Randomized Complete Block Design. In Introduction to Experimental Designs with PROC GLIMMIX of SAS: Applications in Food Science and Agricultural Science, 75-98. Cham: Springer. https://doi.org/10.1007/978-3-031-65575-3_4

Seydmohammadi, Z., Z. Roein and S. Rezvanipour. (2020). Accelerating the growth and flowering of Eustoma grandiflorum by foliar application of nano - ZnO and nano - CaCO₃. Plant Physiology Reports, 2, 148-140. https://doi.org/10.1007/s40502-019-00473-9

Shi, Y., Z. Jin, J. Wang, G. Zhou, F. Wang and Y. Peng. (2024). 5-aminolevulinic acid (5-ALA)-induced drought resistance in maize seedling root at physiological and transcriptomic levels. International Journal of Molecular Sciences, 25(23), 12963. https://doi.org/10.3390/ijms252312963

Singh, A., R.S. Sengar, V.D. Rajput, T. Minkina and R.K. Singh. (2022). Zinc oxide nanoparticles improve salt tolerance in rice seedlings by improving physiological and biochemical indices. Agriculture, 12(7), 1014. https://doi.org/10.3390/agriculture12071014

SS Ahmed, A., M.E. El-Sayed, O. M Fekry and H. S Ahmed. (2025). Influence of pectic oligosaccharides and 5-aminolevulinic acid along with abscisic acid on growth, yield and quality attributes of crimson seedless grape cultivar. Alexandria Science Exchange Journal, 46(3), 841-847. https://doi.org/10.21608/asejaiqjsae.2025.461304

Tan, S., J. Cao, X. Xia and Z. Li. 2022. Advances in 5-aminolevulinic acid priming to enhance plant tolerance to abiotic stress. International Journal of Molecular Sciences, 23(2), 702. https://doi.org/10.3390/ijms23020702

Thounaojam, T.C., T.T. Meetei, Y.B. Devi, S.K. Panda and H. Upadhyaya. (2021). Zinc oxide nanoparticles (ZnO-NPs): a promising nanoparticle in renovating plant science. Acta Physiologiae Plantarum, 43(136), 1-21. https://doi.org/10.1007/s11738-021-03307-0

Tran, T.L.C., L. Kong, W. Yang and D. Cahill. (2026). Nanoparticle-enabled enhancement of plant photosynthesis: Mechanisms and applications. Nano Today, 68, 103003. https://doi.org/10.1016/j.nantod.2026.103003

Ugwu, E.I. and J.C. Agunwamba. (2020). A review on the applicability of activated carbon derived from plant biomass in adsorption of chromium, copper, and zinc from industrial wastewater. Environmental Monitoring and Assessment, 192(4), 240. https://doi.org/10.1007/s10661-020-8162-0

Wang, L., J. Zhang, Q. Zhao and L. Zhang. (2025). Humboldt review: 5-aminolevulinic acid: from pyrrole biosynthetic precursor to multifunctional plant growth regulator. Journal of Plant Physiology, 310, 154524. https://doi.org/10.1016/j.jplph.2025.154524

Wang, S., R. Fang, X. Yuan, J. Chen, K. Mi, R. Wang and H. Zhang. (2023c). Foliar spraying of ZnO nanoparticles enhanced the yield, quality, and zinc enrichment of rice grains. Foods, 12(19), 3677. https://doi.org/10.3390/foods12193677

Wang, X., H. Xie, P. Wang and H. Yin. (2023b). Nanoparticles in plants: uptake, transport and physiological activity in leaf and root. Materials, 16(8), 3097. https://doi.org/10.3390/ma16083097

Waseem, M., M.M. Hasan, Y. Hazzazi, B.M. Alharbi, M.U. Ghani, P. Ahmad and M. Carriquí. (2025). Potential mechanisms for the rapid post-drought reversal of ABA-induced stomatal closure by melatonin, 5-aminolevulinic acid, and brassinosteroids. Photosynthetica, 63(2), 104. https://doi.org/10.32615/ps.2025.011

Weng, J., L. Xu, P. Li, W. Xing, S. Rahman, N. Ahmad and A. Rehman. (2025). Interactions of Fe and Zn nanoparticles at physiochemical, biochemical, and molecular level in horticultural crops under salt stress: A review. Horticulturae, 11(4), 442. https://doi.org/10.3390/horticulturae11040442

Wu, H. and Z. Li. (2022). Nano-enabled agriculture: How do nanoparticles cross barriers in plants? Plant Communications, 3(6), 100346. https://doi.org/10.1016/j.xplc.2022.100346

Wu, L., L. Song, L. Cao and L. Meng. (2023). Alleviation of shade stress in Chinese Yew (Taxus chinensis) seedlings with 5-aminolevulinic acid (ALA). Plants, 12(12), 2333. https://doi.org/10.3390/plants12122333

Wu, Y., W. Liao, M.M. Dawuda, L. Hu and J. Yu. (2019). 5-aminolevulinic acid (ALA) biosynthetic and metabolic pathways and its role in higher plants: a review. Plant Growth Regulation, 87(2), 357-374. https://doi.org/10.1007/s10725-018-0463-8

Wu, Y., X. Jin, W. Liao, L. Hu, M.M. Dawuda, X. Zhao and J. Yu. (2018). 5-aminolevulinic acid (ALA) alleviated salinity stress in cucumber seedlings by enhancing chlorophyll synthesis pathway. Frontiers in Plant Science, 9, 635. https://doi.org/10.3389/fpls.2018.00635

Xie, L., Z.H. Wang, X.H. Cheng, j.j. Gao, ZhangZ.P. and L.J. Wang. (2013). 5-aminolevulinic acid promotes anthocyanin accumulation in Fuji apples. Plant Growth Regulation, 69, 295-303. https://doi.org/10.1007/s10725-012-9772-5

Xu, L., L. Yuan, Y. Che, F. Tan, D. Wang, Z. Zhang and Y. Zhao. (2024). 5-aminolevulinic acid regulates the grain morphology, carbohydrate and hormone contents, increasing grain yield of maize in field land. Plant Growth Regulation, 102(3), 633-646. https://doi.org/10.1007/s10725-023-01076-z

Yang, H., J. Zhang, H. Zhang, Y. Xu, Y. An and L. Wang. (2021). Effect of 5-aminolevulinic acid (5-ALA) on leaf chlorophyll fast fluorescence characteristics and mineral element content of Buxus megistophylla grown along urban roadsides. Horticulturae, 7(5), 95. https://doi.org/10.3390/horticulturae7050095

Yang, Y., J. Xia, X. Fang, H. Jia, X. Wang, Y. Lin and L. Shangguan. (2023). Drought stress in ‘Shine Muscat’grapevine: Consequences and a novel mitigation strategy–5-aminolevulinic acid. Frontiers in Plant Science, 14, 1129114. https://doi.org/10.3389/fpls.2023.1129114

Zaghdoud, C., Y. Yahia, K. Nagaz and M.D.C. Martinez-Ballesta. (2024). Foliar spraying of zinc oxide nanoparticles improves water transport and nitrogen metabolism in tomato (Solanum lycopersicum L.) seedlings mitigating the negative impacts of cadmium. Environmental Science and Pollution Research, 31(25), 37428-37443. https://doi.org/10.1007/s11356-024-33738-4

Zarifi, M., L. Vojodi Mehrabani, R. Valizadeh Kamran, L. Khoshmaram and M. Pessarakli. (2025). Growth enhancement and physiological responses of Tanacetum balsamita L. by cerium oxide, zinc oxide, and activated carbon nanoparticles foliar treatment under salinity stress. Communications in Soil Science and Plant Analysis, 56(6), 966-983. https://doi.org/10.1080/00103624.2024.2439308

Zhai, J., X. Xian, Z. Zhang and Y. Wang. (2025). Nano-zinc oxide can enhance the tolerance of apple rootstock M9-T337 seedlings to saline alkali stress by initiating a variety of physiological and biochemical pathways. Plants, 14(2), 233. https://doi.org/10.3390/plants14020233

Zhang, L. and C. Ambrose. (2024). Beauty is more than epidermis deep: How cell division and expansion sculpt the leaf spongy mesophyll. Current Opinion in Plant Biology, 79, 102542. https://doi.org/10.1016/j.pbi.2024.102542

Zhang, W., Q. Zhou, J. Lin, X. Ma, F. Dong, H. Yan and R. Ming. (2022). Transcriptome analyses shed light on floral organ morphogenesis and bract color formation in Bougainvillea. BMC Plant Biology, 22(1), 97. https://doi.org/10.1186/s12870-022-03478-z

Zulfiqar, F., J. Chen, P.M. Finnegan, M. Nafees, A. Younis, N. Shaukat and K.B. Hamed. (2021). Foliar application of trehalose or 5-aminolevulinic acid improves photosynthesis and biomass production in drought stressed Alpinia zerumbet. Agriculture, 11(10), 908. https://doi.org/10.3390/agriculture11100908