Biochemical and molecular evidences of the presence of a plant natriuretic peptide in garlic (Allium sativum L.) [Evidencias bioquímicas y moleculares de la presencia de un péptido natriurético de plantas en ajo (Allium sativum L.)]

The natriuretic peptides (NP) are vertebrate hormones involved in the regulation of ion and water homeostasis in the cell. In plants, natriuretic peptides (PNP) have been identified by molecular and biochemical methods. It has been suggested that PNPs, have similar functions to the PN, since they mediate (1) ion transport through the cell, (2) the opening and closing of Na%2b and K%2b channels through the stimulation and synthesis of a second messenger such as cGMP, and (3) the aperture of stomata. In this study, a PNPs gene was partially identified by PCR in garlic (Allium sativum L.), which was called AsPNP, and showed a similarity of 96%25 with the AtPNP-A of Arabidopsis thaliana. The deduced amino acid sequence of AsPNP displayed four cysteine and the highly conserved reason (i.e., K [VI] VD) in PNPs. The modelling of AsPNP in amino acids showed a three-dimensional structure similar to AtPNP-A and to the domain I of expansins. The real-time PCR analysis identified at least two possible copies of this gene in garlic. The immunodetection with antibodies directed to human NPs receptors suggests the presence of similar receptors in garlic leaves. It was also found that a protein fraction purified by ion exchange chromatography from garlic leaves was able to stimulate stomatal opening in cuticles of Opuntia ficus-indica. These evidences demonstrate the presence of NP in garlic plants. © 2017, Fundacion Romulo Raggio. All rights reserved.

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