Heavy metal transporters play a key role in regulating metal accumulation and transport in plants. These are important candidate genes to study in metal tolerant and accumulator plants for their potential use in environmental clean up. We coupled a degenerate primer-based RT-PCR approach with a molecular fingerprinting technique based on amplified rDNA restriction analysis (ARDRA) to identify novel ESTs corresponding to heavy metal transporters from metal accumulator Brassica juncea. We utilized this technique to clone several family members of natural resistance-associated macrophage proteins (NRAMP) and yellow stripe-like proteins (YSL) in a high throughput manner to distinguish between closely related isoforms and/or allelic variants from the allopolyploid B. juncea. Partial clones of 23 Brassica juncea NRAMPs and 27 YSLs were obtained with similarity to known Arabidopsis thaliana and Noccaea (Thlaspi) caerulescens NRAMP and YSL genes. The cloned transporters showed Brassica-specific changes in domains, which can have important functional consequences. Semi-quantitative RT-PCR-based expression analysis of chosen members indicated that even closely related isoforms/allelic variants of BjNRAMP and BjYSL have distinct tissue-specific and metal-dependent expressions which might be essential for adaptive fitness and heavy metal tolerance. Consistent to this, BjYSL6.1 and BjYSL5.8 were found to show elevated expressions specifically in cadmium-treated shoots and lead-treated roots of B. juncea, respectively.

Typha angustifolia is a metal hypertolerant grass that predominates the wetlands of uranium tailings in Jaduguda, India, contaminated with extreme levels of iron (Fe) and manganese (Mn). In the paper investigations were carried out to understand the molecular mechanism of metal tolerance in this tolerant macrophyte. Metal analysis was coupled with fluorescent differential display (FDD) and reverse northern to compare the metal profile and transcriptome between Typha plants growing in the tailings versus a control wetland. The expressions of the validated transcripts in Mn and Fe stress were confirmed using reverse northern and semiquantitaive RT-PCR. Typha selectively accumulated and stored Mn in shoots but excluded/restricted Fe both in the field and in vitro. Differential expressions of 23 ESTs were validated among 118 FDD genes. Although Typha behaved as a Mn accumulator, these transcripts were found to be regulated in a complex fashion not only by Mn accumulated in the shoots but also by Fe excluded from the shoots. Our results provide the first report in the molecular understanding of metal tolerance in Typha angustifolia and indicate a Plant Soil (2011) 342:301-317

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In modern days, sand dune stabilization works are very common in desert areas globally. The purpose is multifaceted; developmental needs, soil moisture conservation works, and prevention of desert spread being the main among them. In the Indian state of Rajasthan, the same works have been ongoing for a long in the Thar desert, primarily by the forest department. This study was aimed as a non replicated administrative study, which has reflected on the possible correlation between the stabilization work by afforestation and gradual loss of native shrub species of desert ecosystem as found from the pilot sites. The preliminary findings of this study were then verified against previous research and findings in other arid regions of the world. Simple counting of standing tree and shrub species was done from 1 sq. m. sample plots of both forest department plantation sites and non-forest land areas. It was found that area with matured grown Acacia tortilis has less ground coverage than other areas. Arid ecosystem has unique survival adaptations, the fast growth of an introduced foreign species impacting the native ground cover can be due to multiple ecological reasons. A much broader replicated study is necessary to ascertain this fact and thereby take necessary measures for preserving both the desert ecosystem and enhance the sand stabilization works