Faria de Souza Andressa Fabiane, Calderín García Andrés, Nivaldo de Oliveira Sátiro José, Ribeiro de Lima Brisa, Silvestre Fernandes Manlio, Louro Berbara Ricardo Luiz, Azevedo Santos Leandro
Plant Nutrition Laboratory, Department of Soils, Federal Rural University of Rio de Janeiro (UFRRJ), Seropédica 23890-000, Rio de Janeiro, Brazil.
Soil Biological Chemistry Laboratory, Department of Soils, Federal Rural University of Rio de Janeiro (UFRRJ), Seropédica 23890-000, Rio de Janeiro, Brazil.
J Agric Food Chem. 2025 Aug 13;73(32):20081-20093. doi: 10.1021/acs.jafc.5c06288. Epub 2025 Jul 31.
Humic acid (HA) enhances plant development, but the integration between reactive oxygen species (ROS) and hormone signaling in HA-induced root growth remains unclear. This study investigated the mechanisms of HA extracted from vermicompost on rice root development using ROS scavengers, hormone pathway inhibitors, and gene expression analyses. HA application increased root dry weight by 27% and lateral root length by 20%. ROS staining revealed higher O accumulation in root tips and HO in the elongation zone. Treatments with SB, TIRON, DMTU, DPI, PCIB, and FLD suppressed HA-induced growth, indicating redox and hormonal modulation. HA also upregulated genes related to ROS signaling () and hormone signaling (). These findings support the idea that HA triggers a controlled oxidative signal that interacts with hormone pathways to regulate gene expression and root development. This ROS-hormone crosstalk reveals a key mechanism underlying HA bioactivity and reinforces its potential as a biostimulant for sustainable crop production.
腐殖酸（HA）可促进植物生长，但其诱导根系生长过程中活性氧（ROS）与激素信号之间的整合关系尚不清楚。本研究利用ROS清除剂、激素途径抑制剂和基因表达分析，探究了从蚯蚓堆肥中提取的HA对水稻根系发育的作用机制。施用HA使根干重增加了27%，侧根长度增加了20%。ROS染色显示根尖处O积累更多，伸长区HO更多。用SB、TIRON、DMTU、DPI、PCIB和FLD处理可抑制HA诱导的生长，表明存在氧化还原和激素调节。HA还上调了与ROS信号（）和激素信号（）相关的基因。这些发现支持了HA触发可控氧化信号的观点，该信号与激素途径相互作用以调节基因表达和根系发育。这种ROS-激素相互作用揭示了HA生物活性的关键机制，并增强了其作为可持续作物生产生物刺激剂的潜力。
