EFEITOS DO SILÍCIO EM Theobroma cacao L. CRESCENDO EM SUBSTRATOS DEGRADADOS: UMA ANÁLISE DAS RESPOSTAS MORFOFISIOLÓGICAS E DA FLUORESCÊNCIA DA CLOROFILA A
DOI:
https://doi.org/10.56238/arev8n5-131Palavras-chave:
Crescimento, Alumínio, Ferro, Cacau, Teste JIPResumo
O silício (Si) é considerado um elemento benéfico devido aos seus efeitos positivos na mitigação de diversos estresses bióticos e abióticos. Apesar dos resultados promissores relatados para diferentes culturas, os estudos envolvendo a aplicação de Si em Theobroma cacao ainda são incipientes e têm sido mais comumente associados à mitigação de estresses bióticos. Este estudo teve como objetivo avaliar o potencial mitigador do Si em mudas de cacau submetidas à toxicidade por alumínio (Al) e ferro (Fe), por meio de respostas morfofisiológicas. As mudas foram cultivadas em três substratos: substrato orgânico (Sor), substrato com alta saturação por alumínio (SAl) e substrato com alta saturação por ferro (SFe), com ou sem aplicação ao solo de 2 mM de silicato de potássio. Foram avaliadas variáveis de crescimento, parâmetros de fluorescência da clorofila a, teste JIP e índice SPAD. A aplicação de Si reduziu os valores de Fv/Fm e PIabs em SAl e SFe, bem como o PItotal em SFe, em comparação com Sor. Independentemente do substrato, as plantas tratadas com Si apresentaram respostas inferiores às das plantas sem Si em termos de absorção, captura e transferência de energia ao longo da cadeia de transporte de elétrons. Além disso, a toxicidade metálica promoveu reduções no crescimento e na alocação de biomassa. Em T. cacao, o Si não mitigou os efeitos da toxicidade por Al e Fe sobre o desempenho fotoquímico e o crescimento das mudas; entretanto, estudos adicionais são necessários para melhor compreender a resposta do Si sob diferentes condições de solo e genótipos de cacau.
Downloads
Referências
Adamski, J. M., et al. (2011). Excess iron induces changes in the photosynthetic characteristics of sweet potato. Journal of Plant Physiology, 168(17), 2056–2062. DOI: https://doi.org/10.1016/j.jplph.2011.06.003
Adamski, J. M., et al. (2012). Responses to excess iron in sweet potato: Impacts on growth, enzyme activities, mineral concentrations, and anatomy. Acta Physiologiae Plantarum, 34(5), 1827–1836. DOI: https://doi.org/10.1007/s11738-012-0981-3
Agrostat. (2022). Ministério da Agricultura, Pecuária e Abastecimento. https://indicadores.agricultura.gov.br/agrostat/index.htm
Ahmad, F., et al. (2023). Influence of silicon nano-particles on Avena sativa L. to alleviate the biotic stress of Rhizoctonia solani. Scientific Reports, 13(1), 15191. DOI: https://doi.org/10.1038/s41598-023-41699-w
Akaya, M., & Takenaka, C. (2001). Effects of aluminum stress on photosynthesis of Quercus glauca Thumb. Plant and Soil, 237, 137–146. DOI: https://doi.org/10.1023/A:1013369201003
Ali, A. M., & Bijay-Singh. (2025). Silicon: A crucial element for enhancing plant resilience in challenging environments. Journal of Plant Nutrition, 48(3), 486–521. DOI: https://doi.org/10.1080/01904167.2024.2406479
Anwar, T., et al. (2025). Mitigating cadmium toxicity in maize through silicon nanoparticles: Effects on growth, antioxidant activity and metal accumulation. Silicon, 17(10), 2347–2356. DOI: https://doi.org/10.1007/s12633-025-03317-4
Arnon, D. I., & Stout, P. R. (1939). The essentiality of certain elements in minute quantity for plants with special reference to copper. Plant Physiology, 14(2), 371–375. https://academic.oup.com/plphys/article/14/2/371/6092851 DOI: https://doi.org/10.1104/pp.14.2.371
Baligar, V. C., et al. (2015). Iron sources effects on growth, physiological parameters and nutrition of cacao. Journal of Plant Nutrition, 38(11), 1787–1802. DOI: https://doi.org/10.1080/01904167.2015.1061546
Baligar, V. C., & Fageria, N. K. (2005). Soil aluminum effects on growth and nutrition of cacao. Soil Science and Plant Nutrition, 51(5), 709–713. DOI: https://doi.org/10.1111/j.1747-0765.2005.tb00097.x
Christen, D., et al. (2007). Characterization and early detection of grapevine (Vitis vinifera) stress responses to esca disease by in situ chlorophyll fluorescence and comparison with drought stress. Environmental and Experimental Botany, 60, 504–514. DOI: https://doi.org/10.1016/j.envexpbot.2007.02.003
Detmann, K. C., et al. (2012). Silicon nutrition increases grain yield, which, in turn, exerts a feed-forward stimulation of photosynthetic rates via enhanced mesophyll conductance and alters primary metabolism in rice. New Phytologist, 196, 752–762. DOI: https://doi.org/10.1111/j.1469-8137.2012.04299.x
Deus, A. C. F., et al. (2026). Alleviating effect of silicon on aluminum toxicity in plants. Agronomy, 16(4), 471. DOI: https://doi.org/10.3390/agronomy16040471
Du, H., et al. (2026). Silicon enhances rice tolerance to drought and blast disease through modulating ROS accumulation and stress-related genes. Plants, 15(5), 842. DOI: https://doi.org/10.3390/plants15050842
Exley, C. (1998). Silicon in life: A bioinorganic solution to bioorganic essentiality. Journal of Inorganic Biochemistry, 69, 139–144. DOI: https://doi.org/10.1016/S0162-0134(97)10010-1
Faisal, M., et al. (2025). Supplementation of silicon oxide nanoparticles mitigates the damaging effects of arsenic stress on photosynthesis, antioxidant mechanism and nitrogen metabolism in Brassica juncea. Scientific Reports, 15(1), 21476. DOI: https://doi.org/10.1038/s41598-025-04553-9
Fang, L., et al. (2025). Silicon alleviates aluminum toxicity in apple seedlings by enhancing the lignin biosynthesis pathway through MdCOMT9. Journal of Hazardous Materials, 140299. DOI: https://doi.org/10.1016/j.jhazmat.2025.140299
Fantinato, D. E., et al. (2018). Effects of silicon on biochemical and physiological aspects in Theobroma cacao under inoculation with Moniliophthora perniciosa. Revista de Ciências Agrárias, 41(3), 841–848. DOI: https://doi.org/10.19084/RCA18064
Gonçalves, J. F. C., & Santos Jr., U. M. (2005). Utilization of the chlorophyll a fluorescence technique as a tool for selecting tolerant species to environments of high irradiance. Brazilian Journal of Plant Physiology, 17, 307–313. DOI: https://doi.org/10.1590/S1677-04202005000300005
Guerriero, G., et al. (2016). Silicon and the plant extracellular matrix. Frontiers in Plant Science, 7, art. 463. https://www.frontiersin.org/articles/10.3389/fpls.2016.00463/full DOI: https://doi.org/10.3389/fpls.2016.00463
Hunt, R., et al. (2002). A modern tool for classical plant growth analysis. Annals of Botany, 90(4), 485–488. DOI: https://doi.org/10.1093/aob/mcf214
Jaimez, R. E., et al. (2022). Theobroma cacao L. cultivar CCN 51: A comprehensive review on origin, genetics, sensory properties, production dynamics, and physiological aspects. PeerJ, 10. DOI: https://doi.org/10.7717/peerj.12676
Jucoski, G. D. O., et al. (2016). Excess iron on growth and mineral composition in Eugenia uniflora L. Revista Ciência Agronômica, 47, 720–728. DOI: https://doi.org/10.5935/1806-6690.20160086
Krause, G. H., & Weis, E. (1991). Chlorophyll fluorescence and photosynthesis: The basics. Annual Review of Plant Physiology and Plant Molecular Biology, 42, 313–349. https://doi.org/10.1146/annurev.pp.42.060191.001525 DOI: https://doi.org/10.1146/annurev.arplant.42.1.313
Lapaz, A. M., et al. (2020). Response of soybean to soil waterlogging associated with iron excess in the reproductive stage. Physiology and Molecular Biology of Plants, 26, 1635–1648. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7415068/ DOI: https://doi.org/10.1007/s12298-020-00845-8
Larcher, W. (1995). Photosynthesis as a tool for indicating temperature stress events. In E. D. Schulze & M. M. Caldwell (Eds.), Ecophysiology of photosynthesis (pp. 261–277). Springer-Verlag. DOI: https://doi.org/10.1007/978-3-642-79354-7_13
Lavinsky, A. O., et al. (2016). Silicon improves rice grain yield and photosynthesis specifically when supplied during the reproductive growth stage. Journal of Plant Physiology, 206, 125–132. DOI: https://doi.org/10.1016/j.jplph.2016.09.010
Ma, J., et al. (2015). A hemicellulose-bound form of silicon inhibits cadmium ion uptake in rice (Oryza sativa) cells. New Phytologist, 206, 1063–1074. https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.13276 DOI: https://doi.org/10.1111/nph.13276
Ma, J. F., & Takahashi, E. (2002). Soil, fertilizer, and plant silicon research in Japan. Elsevier Science. DOI: https://doi.org/10.1016/B978-044451166-9/50009-9
Maxwell, K., & Johnson, G. N. (2000). Chlorophyll fluorescence: A practical guide. Journal of Experimental Botany, 51(345), 659–668. https://academic.oup.com/jxb/article/51/345/659/652534 DOI: https://doi.org/10.1093/jexbot/51.345.659
Mitani, N., et al. (2011). Isolation and functional characterization of an influx silicon transporter in two pumpkin cultivars contrasting in silicon accumulation. The Plant Journal, 66(2), 231–240. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2011.04483.x DOI: https://doi.org/10.1111/j.1365-313X.2011.04483.x
Mitani, N., & Ma, J. F. (2005). Uptake system of silicon in different plant species. Journal of Experimental Botany, 56(414), 1255–1261. https://academic.oup.com/jxb/article/56/414/1255/551547 DOI: https://doi.org/10.1093/jxb/eri121
Oukarroum, A., et al. (2007). Probing the responses of barley cultivars (Hordeum vulgare L.) by chlorophyll a fluorescence OJIP under drought stress and re-watering. Environmental and Experimental Botany, 60(3), 438–446. DOI: https://doi.org/10.1016/j.envexpbot.2007.01.002
Pereira, E. G., et al. (2013). Iron excess affects rice photosynthesis through stomatal and non-stomatal limitations. Plant Science, 202, 81–89. DOI: https://doi.org/10.1016/j.plantsci.2012.12.003
Pinto, D. G., et al. (2012). Alterações fisiológicas após aplicação de silício em cacau e sua influência na preferência por pulgões. Revista Ceres, 59(3), 360–367. DOI: https://doi.org/10.1590/S0034-737X2012000300010
Pinto, D. G., et al. (2014). Fotossíntese, crescimento e incidência de insetos-praga em genótipos de cacau pulverizados com silício. Bioscience Journal, 30(3), 715–724.
Pinto, S. S., et al. (2016). Oxidative damage and photosynthetic impairment in tropical rice cultivars upon exposure to excess iron. Scientia Agricola, 73(3), 217–226. https://www.scielo.br/j/sa/a/CMm7CW8Z5bZfbZMB7QBbnrb/abstract/?lang=en DOI: https://doi.org/10.1590/0103-9016-2015-0288
Ribeiro, M. A. Q., et al. (2013). Aluminum effects on growth, photosynthesis, and mineral nutrition of cacao genotypes. Journal of Plant Nutrition, 36(8), 1161–1179. https://www.tandfonline.com/doi/abs/10.1080/01904167.2013.766889 DOI: https://doi.org/10.1080/01904167.2013.766889
Sanglard, L. M. V. P., et al. (2014). Silicon nutrition alleviates the negative impacts of arsenic on the photosynthetic apparatus of rice leaves: An analysis of the key limitations of photosynthesis. Physiologia Plantarum, 152, 355–366. DOI: https://doi.org/10.1111/ppl.12178
Santos, M. S. (2017). O papel do silício na redução dos impactos da toxidez de ferro em arroz: Uma abordagem morfo-anatômica, nutricional e fisiológica (Tese de doutorado). Universidade Federal de Viçosa.
Santos, M. S., et al. (2019). Silicon alleviates the impairments of iron toxicity on the rice photosynthetic performance via alterations in leaf diffusive conductance with minimal impacts on carbon metabolism. Plant Physiology and Biochemistry, 143, 275–285. https://www.sciencedirect.com/science/article/abs/pii/S0981942819303559 DOI: https://doi.org/10.1016/j.plaphy.2019.09.011
Santos, M. S., et al. (2020). Silicon nutrition mitigates the negative impacts of iron toxicity on rice photosynthesis and grain yield. Ecotoxicology and Environmental Safety, 189. https://doi.org/10.1016/j.ecoenv.2019.110008 DOI: https://doi.org/10.1016/j.ecoenv.2019.110008
Shi, G., et al. (2010). Silicon alleviates cadmium toxicity in peanut plants in relation to cadmium distribution and stimulation of antioxidative enzymes. Plant Growth Regulation, 61, 45–52. https://doi.org/10.1007/s10725-010-9447-z DOI: https://doi.org/10.1007/s10725-010-9447-z
Sommer, M., et al. (2006). Silicon pools and fluxes in soils and landscapes: A review. Journal of Plant Nutrition and Soil Science, 169, 310–329. DOI: https://doi.org/10.1002/jpln.200521981
Sousa-Santos, C., et al. (2022). Morphophysiological changes in Genipa americana seedlings in response to root deformation and substrate attributes. Journal of Soil Science and Plant Nutrition, 22, 2755–2764. https://link.springer.com/article/10.1007/s42729-022-00842-8 DOI: https://doi.org/10.1007/s42729-022-00842-8
Strasser, R. J., & Govindjee. (1992). On the O-J-I-P fluorescence transient in leaves and D1 mutants of Chlamydomonas reinhardtii. In N. Murata (Ed.), Research in photosynthesis (pp. 29–32). Kluwer Academic Publishers.
Strasser, R. J., Srivastava, A., & Tsimilli-Michael, M. (2000). The fluorescence transient as a tool to characterize and screen photosynthetic samples. In M. Yunus, U. Pathre, & P. Mohanty (Eds.), Probing photosynthesis: Mechanisms, regulation and adaptation (pp. 445–483). Taylor and Francis.
Taiz, L., & Zeiger, E. (2013). Fisiologia vegetal (5. ed.). Artmed.
Wang, Y., et al. (2004). Apoplastic binding of aluminum is involved in silicon-induced amelioration of aluminum toxicity in maize. Plant Physiology, 136(3), 3762–3770. https://academic.oup.com/plphys/article/136/3/3762/6112479 DOI: https://doi.org/10.1104/pp.104.045005
Xing, W., et al. (2010). Antioxidative responses of Elodea nuttallii (Planch.) H. St. John to short-term iron exposure. Plant Physiology and Biochemistry, 48(10–11), 873–878. https://www.sciencedirect.com/science/article/abs/pii/S0981942810001695 DOI: https://doi.org/10.1016/j.plaphy.2010.08.006
Yusuf, M., et al. (2025). Unveiling the protective role of silicon dioxide nanoparticles against copper-induced oxidative damage in soybean plants through altered proline metabolism and antioxidants. Plant Nano Biology, 12, 100149. DOI: https://doi.org/10.1016/j.plana.2025.100149
Zanetti, L. V., et al. (2016). Leaf application of silicon in young cacao plants subjected to water deficit. Pesquisa Agropecuária Brasileira, 51(3), 215–223. DOI: https://doi.org/10.1590/S0100-204X2016000300003
Zhang, C., et al. (2008). Long-term effects of exogenous silicon on cadmium translocation and toxicity in rice (Oryza sativa L.). Environmental and Experimental Botany, 62(3), 300–307. https://www.sciencedirect.com/science/article/abs/pii/S009884720700175X DOI: https://doi.org/10.1016/j.envexpbot.2007.10.024
