Enhancement of Heavy Metal Accumulation by Tissue Specific Co-expression of iaaaM and Acc Deaminase Genes in Plant

Tan, Mark Chin Seong (2011) Enhancement of Heavy Metal Accumulation by Tissue Specific Co-expression of iaaaM and Acc Deaminase Genes in Plant. Final Year Project (Other), Tunku Abdul Rahman University College.

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Abstract

The use of phytoremediation showed to be a promising way to remediate polluted soil non distruptively and cost effectively. However, progress in phytoremediation technology has always been hindered by the slow growth rate and high mortality of plants used for phytoremediation. Reserchers have proposed many possible ways in creating transgenic plants targeting the enhancement of different functions involved in metal accumulation transport and tolerance. Two of the enzymes, ACC deaminase and iaaM are particularly favorable as they show promising features of solving two of the most common problems of phytoremediation plants which are low accumulation rate and low accumulation rate. ACC deaminase reduces the main stress hormone of the plant which is ethylene, by metabolizing its precursor which is ACC into α-ketobutarate and ammonium. iaaM gene promote auxin synthesis by actively participating in the auxin synthesis pathway. By co-expressing these two enzymes, low ethylene and high auxin condition in plants are achievable which will induce high shoot biomass and high root proliferation. Such features will induce better absorption and accumulation of metals with the increased coverage of roots and higher biomass to accumulate the metals.