Insights into plant annexins function in abiotic and biotic stress tolerance

Abstract

Crop productivity depends heavily on several biotic and abiotic factors. Plant annexins are a multigene family of calcium-dependent phospholipid-binding proteins that function in response to environmental stresses and signaling during growth and development of plants. We recently isolated and characterized a Triticum durum annexin, called TdANN12, which is upregulated by different abiotic stresses. Overexpression of TdANN12 in transgenic tobacco improves stress tolerance through ROS removal. This mini-review outlines the functional characterization of plant annexin genes and suggests how these features could be exploitated to improve stress tolerance in plants. Furthermore, transgenic overexpression of plant annexin genes in crops (tobacco, tomato, rice, alfalfa, cotton, and potato) will be discussed as a promising approach to acquire abiotic and biotic stress tolerance.

Advanced Microscopy Reveals Complex Developmental and Subcellular Localization Patterns of ANNEXIN 1 in Arabidopsis

“…ANNEXIN genes encode calcium-dependent phospholipid-binding proteins and represent a multigene family in both plants and animals ( Mortimer et al., 2008 ; Divya et al., 2010 ). They can function as Ca 2+ -binding and regulating channels or participate in diverse cellular processes including responses to environmental stresses and signaling during plant growth and development ( Jami et al., 2012 ; Yadav et al., 2018 ; He et al., 2019 ; Saad et al., 2020 ).…”

“…Annexins represent an evolutionary highly conserved superfamily of phospholipid-binding proteins, abundant in all eukaryotes ( Lizarbe et al., 2013 ). This multifunctional group of proteins is involved in the coordination of fundamental processes, such as cell growth, differentiation, and stress responses ( Clark et al., 2012 ; Yadav et al., 2018 ; He et al., 2020 ; Saad et al., 2020 ). Annexins can likely play roles in intracellular vesicular trafficking (endocytosis and exocytosis) and bind to cytoskeletal components and membrane phospholipids depending on Ca 2+ ions.…”

Overexpression of Cassava MeAnn2 Enhances the Salt and IAA Tolerance of Transgenic Arabidopsis

“…The N-terminal, as a variable region, may have different amino acid sequence lengths in each annexin, containing multiple protein-binding sites, such as for proteolysis and phosphorylation. Therefore, the N-terminal functionally serves as the regulatory region of the annexin molecule and the basis by which members of different annexin families can be distinguished [ 1 , 2 , 3 , 4 ]. The conserved C-terminal homologous domains are generally composed of four highly similar repeats of amino acids (Repeats I–IV), each containing about 70 amino acid residues.…”

“…The conserved C-terminal homologous domains are generally composed of four highly similar repeats of amino acids (Repeats I–IV), each containing about 70 amino acid residues. Generally, only Repeat I and Repeat IV contain the K–G–X–G–T–(38)–D/E motif, which is the type II Ca 2+ -binding site [ 1 , 3 ], while Repeat II and III do not have the above motif [ 1 , 3 , 4 ]. Each repeat has five α-helical folding (helix A–E) secondary structures, which are closely stacked to form a disk-like structure with a convex side and a concave side [ 3 , 4 ].…”

“…The type II Ca 2+ -binding site G–X–G–T locates in the helix A-B loops, while the bidentate acidic side chain is found in the helix D [ 3 ]. In plant cells, the convex side of annexin is oriented toward the biofilm and the concave side is oriented toward the cytoplasm when the annexin as mediated by Ca 2+ , and the N-terminal domain can interact with other proteins or molecules in the cytoplasm as part of the annexin function [ 1 , 3 , 4 ]. The localization of annexin in cells is the key factor in its various functions.…”