Jump to Main Content
Calmodulin Gene Expression in Response to Mechanical Wounding and Botrytis cinerea Infection in Tomato Fruit
- Hui Peng, Tianbao Yang, Wayne M. Jurick II
- Plants 2014 v.3 no.3 pp. 427-441
- Botrytis cinerea, calmodulin, fungal diseases of plants, gene expression, gene expression regulation, genes, host-pathogen relationships, immunity, methyl jasmonate, physiological response, plant damage, plant pathogenic fungi, salicylic acid, tomatoes
- Calmodulin, a ubiquitous calcium sensor, plays an important role in decoding stress-triggered intracellular calcium changes and regulates the functions of numerous target proteins involved in various plant physiological responses. To determine the functions of calmodulin in fleshy fruit, expression studies were performed on a family of six calmodulin genes (SlCaMs) in mature-green stage tomato fruit in response to mechanical injury and Botrytis cinerea infection. Both wounding and pathogen inoculation triggered expression of all those genes, with SlCaM2 being the most responsive one to both treatments. Furthermore, all calmodulin genes were upregulated by salicylic acid and methyl jasmonate, two signaling molecules involved in plant immunity. In addition to SlCaM2, SlCaM1 was highly responsive to salicylic acid and methyl jasmonate. However, SlCaM2 exhibited a more rapid and stronger response than SlCaM1. Overexpression of SlCaM2 in tomato fruit enhanced resistance to Botrytis-induced decay, whereas reducing its expression resulted in increased lesion development. These results indicate that calmodulin is a positive regulator of plant defense in fruit by activating defense pathways including salicylate- and jasmonate-signaling pathways, and SlCaM2 is the major calmodulin gene responsible for this event.