Annexin Signaling In Plants

Annexins were named so because of their ability to bind (annex) Ca²⁺ and acidic phospholipids and are known to be involved in carrying out numerous functions in cells. Annexins were first discovered and extensively studied in animal cells. Later they were also reported to be present in plants. Interestingly both plant and animal annexins were shown to be structurally conserved. Comparison of plant and animal annexins has revealed that both of them have evolved from common ancestor from which they later diverged. Plant annexins have now reported to be involved in carrying out diverse functions in plant cell. Some plant annexins have displayed enzyme like activity such as ATPase, GTPase or peroxidases like activity. This has suggested participation of plant annexins in metabolic energy dependent reactions in the cell. Preliminary studies have demonstrated that peroxidase like annexin (AnnAt1) could have some significant role in plant defense through modification of Ca²⁺ or ROS dependent signaling pathway.