Oil induces chlorophyll deficient propagules in mangroves.

Abstract

In Australia, some trees of the mangrove, Avicennia marina, growing in a chronic oil polluted site, produce chlorophyll deficient (albino) propagules. We tested the hypothesis that albinism was due to an oil-induced mutant allele that controls photosynthesis. We determined whether there are genetic differences between normal and chlorophyll deficient propagules. Four gene regions (nuclear 18S-26S cistron; chloroplast - trnH-psbA, rsp16 and matK) were sequenced and analysed for normal and albino propagules. Mutations occurred in both nuclear (ITS) and coding chloroplast (matK) genes of albino propagules. There were 10 mutational differences between normal and albino propagules in the matK samples. Analysis of molecular variation (AMOVA) of the matK dataset indicated highly significant genetic differentiation between normal and albino propagules. Our study suggests for the first time that PAHs from a chronic oil polluted site resulted in mutations in both nuclear and chloroplast genes, resulting in the production of albino propagules.