Plant hormone crosstalk mediated by humic acids

Abstract

Background The reliance on chemical inputs to support high yields is the Achilles’ heel of modern crop production. The soil organic matter management is as old as agriculture itself. Recently, the use of soluble humic substances as plant growth promoters has been brought to attention due to their effects on nutrient uptake and water use efficiency. Humic substances applied directly at low concentrations can trigger different molecular, biochemical, and physiological processes in plants. However, how humic substances exert this plethoric regulatory action remains unclear. The objective of this study was to evaluate changes in the transcription level of genes coding cell receptors, phosphatases, synthesis, and function of different plant hormones and transcription factors. Materials and methods After seven days of humic acid treatment, we used RNAseq in maize root seedlings. The level of gene transcription was compared with control plants. Results Plant kinase receptors and different phosphatases were regulated by humic acids. Likewise, genes related to plant hormones (auxin, gibberellin, ethylene, cytokinin, abscisic acid, brassinosteroids, jasmonic and salicylic acids) were transcript in differential levels in maize root seedlings as well as the expression of a hundred of transcription factors modifying the signal transduction pathway via alterations of the subsequent gene response. Conclusion We showed a general mechanism for simultaneously regulating the activity of several hormones where humic acids act as a key regulatory hub in plant responses integrating hormonal signalling and response pathways.

Protein Profiling of Psittacanthus calyculatus during Mesquite Infection

“…DNA replication licensing factor MCM2 [ 77 ] and WEB family proteins [ 78 , 79 ] are synchronized and prepare the cell cycle progression, respectively, while leucine-rich repeat-containing protein DDB is involved in chromatin and DNA dynamics [ 79 ]. On the other hand, DeSI-like (peptidase-like) protein is a protein involved in nitrogen catabolism [ 52 , 80 , 81 ], and these nitrogen derivates could be translocated and transformed into nitrogen reserves in seeds or be responsible for the emergence of seedlings [ 82 ].…”

“…However, in P. calyculatus , that infects mesquite trees, there are no reports indicating that it secretes lignocellulolytic and peptidase enzymes. In that sense, we detected a group of proteins that were accumulated in the main infective stages such as pectinesterase 15 and DeSI-like (peptidase-like) protein that are likely cell wall-degrading and peptidase enzymes, respectively [ 52 , 53 , 54 , 80 , 81 , 116 ]. A pectin methylesterase enzyme was secreted from calli and seedlings of Orobranche aegyptiaca and O. cumana and it was speculated that the enzyme may have a function in host infection [ 51 , 117 , 118 ].…”

Application of biostimulant products and biological control agents in sustainable viticulture: A review

“…It is suggested that some biostimulant effects of HS originate from their impact on structural and physiological modifications in roots and shoots related to nutrient assimilation and soil distribution ( Canellas et al., 2015 ). Also, HS can simultaneously regulate the transcription and activity of some plant hormones following addition to the rhizosphere ( Souza et al., 2022 ). Recently, it has been demonstrated that HS can alter the plant microbiome by favoring the recruitment of beneficial microorganisms after application ( da Silva et al., 2021 ).…”

Molecular characteristics of humic substances from different origins and their effects on growth and metabolism of Pinus laricio callus

“…HS are extracted from soils, sediments, composted biomasses, or agro-industrial residues and might be regarded as supramolecular associations of small, heterogeneous molecules held together in metastable structures by non-covalent interactions (van de Waals, p-p, H-bonds; metal bridges) [34,53]]. The molecular heterogeneity and conformational complexity of HS explains the range of different effects on plant metabolism [29,30,47]. Numerous experimental evidence showed that humified organic matter stimulates plant growth and is capable of significantly improving crops yields [1,8].…”