Cassava (Manihot esculenta) defensins: Prospection, structural analysis and tissue-specific expression under biotic/abiotic stresses

Biochimie. 2021 Mar 28:S0300-9084(21)00082-1. doi: 10.1016/j.biochi.2021.03.012. Online ahead of print.ABSTRACTDefensins are a prominent family of antimicrobial peptides. They play sophisticated roles in the defense against pathogens in all living organisms, but few works address their expression under different conditions and plant tissues. The present work prospected defensins of Manihot esculenta Crantz, popularly known as cassava. Five defensin candidates (MeDefs) were retrieved from the genome sequences and characterized. Considering chromosome distribution, only MeDef1 and 2 occupy adjacent positions in the same chromosome arm. All 3D structures had antiparallel ß-sheets, an α-helix, and amphipathic residues distributed throughout the peptides with a predominance of cationic surface charge. MeDefs expression was validated by RT-qPCR, including two stress types (biotic: fungus Macrophomina pseudophaseolina, and abiotic: mechanical injury) and a combination of both stresses (fungus+injury) in three different tissues (root, stem, and leaf). For this purpose, ten reference genes (RGs) were tested, and three were chosen to characterize MeDef expression. MeDef3 was up-regulated at roots in all stress situations tested. MeDef1 and MeDef5 were induced in leaves under biotic and abiotic stresses, but not in both stress types simultaneously. Only MeDef2 was down-regulated in the stem tissue also with biotic/abiotic combined stresses. These results indicate that although defensi...

Source: Biochimie - March 31, 2021 Category: Biochemistry Authors: Carlos Andr é Dos Santos-Silva L ívia Maria Batista Vilela Roberta Lane de Oliveira Silva J éssica Barboza da Silva Alexandre Reis Machado Jo ão Pacífico Bezerra-Neto Sergio Crovella Ana Maria Benko-Iseppon Source Type: research