Interactions between indole-3-acetic acid (IAA) with a lectin from Canavalia maritima seeds reveal a new function for lectins in plant physiology

Abstract

Indole-3-acetic acid (IAA) bound is considered a storage molecule and is inactive. However, some studies have proposed an additional possible regulatory mechanism based on the ability of lectins to form complexes with IAA. We report the first crystal structure of ConM in complex with IAA at 2.15 Å resolution. Based on a tetrameric model of the complex, we hypothesize how the lectin controls the availability of IAA during the early seedling stages, indicating a possible new physiological role for these proteins. A free indole group is also bound to the protein. The ConM interaction with different forms of IAA is a strategy to render the phytohormone unavailable to the cell. Thus, this new physiological role proposed for legume lectins might be a novel mechanism by which IAA levels are decreased in addition to the destruction and formation of new complexes in the later stages of seed germination.

Use of ammonium salts or binary mixtures derived from amino acids, glycine betaine, choline and indole-3-butyric acid as plant regulators

“…Indole-3-butyric acid is known to be the most stable form of natural auxins; however, like tryptophan (Trp), indole-3-acetic acid (IAA), and indole-3-propionic acid (IPA), IBA is degraded aerobically depending on many factors, including the oxygen level and exposure to heat and light. [41][42][43][44] In this study, we determined how light accelerated the abovementioned decomposition (the methodology is described in the ESI †). The intensity of the maximum absorption for IBA in acid or anionic forms (l max ¼ 221 nm) decreased aer only 7 days in prepared water solutions exposed to stable visible light ( Fig.…”

“…As both acidic and ionic forms of IBA degrade, the likely degradation product is 5-(2-formamidophenyl)-5oxopentanoic acid, a KYN derivative. [41][42][43][44] The light stability of the aqueous solutions was strongly correlated with the form of IBA and the type of cation or second binary mixture component in the products. Products 1, 2, and 5 were less stable than IBA and binary mixtures 3 and 4 under light exposure.…”

Ectopic Expression of GsSRK in Medicago sativa Reveals Its Involvement in Plant Architecture and Salt Stress Responses

“…However, the phenotype (dwarf and more branches) of the GsSRK-t transgenic alfalfa is similar to the application of IAA. Furthermore, it is reported that lectins could interact with IAA, and possibly lectin controls the availability of IAA during early seedling stages ( Edelman and Wang, 1978 ; Delatorre et al, 2013 ). Another research also reported that an S-locus LecRLK in Arabidopsis AtARK2 was required for auxin-mediated lateral root development under phosphate-starved conditions ( Deb et al, 2014 ).…”

Metodología Sencilla para Evaluar Bioactividad de Ácidos Húmicos obtenidos de Lignito Mediante Extracción Alcalina y Bacterias Solubilizadoras de Carbón

“…Los AH se han relacionado con la estimulación de la producción y elongación de raíces, lo que a su vez repercute en los procesos que definen la arquitectura de la raíz, la toma de agua, nutrientes y las asociaciones que establece la planta con los microorganismos del suelo en la rizósfera y que adicionalmente, pueden afectar diferentes rutas del metabolismo vegetal e influir sobre la arquitectura total de la planta (Canellas y Olivares, 2014;. Por otra parte se sabe que el ácido indol acético (AIA) puede establecer interacciones hidrofóbicas con otros compuestos (Delatorre et al, 2013), además, a través del proceso de humificación los microorganismos del suelo contribuyen preferencialmente a la formación de SH hidrofóbicas, por lo tanto este hecho podría favorecer la interacción de las SH con el AIA presente en el suelo, que luego podría ser utilizado por la planta. Sobre este aspecto, Nardi et al (2017) señalan la posibilidad de que la bioactividad de las SH se deba a la presencia de moléculas de auxinas atrapadas en la supraestructura húmica.…”