Participation of annexin 1 in the response of Arabidopsis thaliana to lead exposure: potential for phytoremediation

• Main Authors: Phang, Ing Chia, Leung, David W. M., Clark, Gregory B., Taylor, Harry H., Garrill, Ashley, Song, Jason, Roux, Stanley J.
• Format: Conference or Workshop Item
• Language: English
• Published: 2009
• Subjects: Q Science (General)
• Online Access: http://irep.iium.edu.my/309/1/Participation_of_annexin_1_in_the_response_of_Arabidopis_thaliana_sedlings.pdf; http://irep.iium.edu.my/309/; http://phyto.mst.edu/2009_conference/Poster_Sessions.html

Heavy metal pollution has become a serious public health and environmental concern. Lead (Pb) is one of the heavy metals known to bioaccumulate in plants. Phytoremediation is an emerging technology based on the ability of green plants to remove Pb from the environment in a cost-efficient and ecologically sound manner. Currently, an important research focus is to seek a better understanding of the mechanisms of Pb tolerance by plant cells, with the aim of genetically engineering plants with improved tolerance to Pb, and hence better phytoremediation capabilities in the near future. Annexin, a calcium-dependent membrane-binding protein is believed to play a role in many essential cellular processes. It has been shown that expression of annexin genes from Arabidopsis thaliana are differentially regulated in response to a variety of abiotic stresses. Thus annexins are likely be involved in the response of plants to heavy metal stress. This study aimed to obtain new insights into whether annexin 1 (AnnAt1), is involved in Pb tolerance in plant cells. Message levels of AnnAt1 were assessed in response to Pb treatments using quantitative real-time PCR. Expression results were analysed using REST 2008 and normalized against the mitosis protein YLS8. We found that Pb effect on AnnAt1 expression in plants exposed to lower Pb concentrations (25 µM, 50 µM, and 75 µM) was not significantly different from the controls. However, AnnAt1 message levels doubled (2.12-fold, S.E. range is 1.77 - 2.61, p < 0.001) in seedlings treated with 100 µM Pb, in comparison to the control plants. The relative contribution of AnnAt1 in defence against Pb stress will be discussed.