Project description:Rhizospheric bacteria play important roles in plant tolerance and activation of heavy metals. Understanding the bacterial rhizobiome of hyperaccumulators may contribute to the development of optimized phytoextraction for metal-polluted soils. We used 16S rRNA gene amplicon sequencing to investigate the rhizospheric bacterial communities of the cadmium (Cd) hyperaccumulating ecotype (HE) Sedum alfredii in comparison to its nonhyperaccumulating ecotype (NHE). Both planting of two ecotypes of S. alfredii and elevated Cd levels significantly decreased bacterial alpha-diversity and altered bacterial community structure in soils. The HE rhizosphere harbored a unique bacterial community differing from those in its bulk soil and NHE counterparts. Several key taxa from Actinobacteria, Bacteroidetes, and TM7 were especially abundant in HE rhizospheres under high Cd stress. The actinobacterial genus Streptomyces was responsible for the majority of the divergence of bacterial community composition between the HE rhizosphere and other soil samples. In the HE rhizosphere, the abundance of Streptomyces was 3.31- to 16.45-fold higher than that in other samples under high Cd stress. These results suggested that both the presence of the hyperaccumulator S. alfredii and Cd exposure select for a specialized rhizosphere bacterial community during phytoextraction of Cd-contaminated soils and that key taxa, such as the species affiliated with the genus Streptomyces, may play an important role in metal hyperaccumulation.IMPORTANCESedum alfredii is a well-known Cd hyperaccumulator native to China. Its potential for extracting Cd relies not only on its powerful uptake, translocation, and tolerance for Cd but also on processes underground (especially rhizosphere microbes) that facilitate root uptake and tolerance of the metal. In this study, a high-throughput sequencing approach was applied to gain insight into the soil-plant-microbe interactions that may influence Cd accumulation in the hyperaccumulator S. alfredii Here, we report the investigation of rhizosphere bacterial communities of S. alfredii in phytoremediation of different levels of Cd contamination in soils. Moreover, some key taxa in its rhizosphere identified in the study, such as the species affiliated with genus Streptomyces, may shed new light on the involvement of bacteria in phytoextraction of contaminated soils and provide new materials for phytoremediation optimization.
Project description:The aim of this study is to investigate whether the known mechanisms of hyperaccumulaion in Brassicaceae hyperaccumulators (Arabidopsis halleri and Noccaea caerulescens) are conserved among different hyperaccumulating species or if there exist unknown mechanismsin other metal hyperaccumulating species.The comparison of transcriptomes between hyperaccumulator Sedum plumbizincicola and non-hyperaccumulator S. alfredii (NHE) was performed by taking advantage of next-generation sequencing.The data suggested that increased active uptake, long-distance transport and efficient chelation of heavy metals might represent common mechanisms occurred in various hyperaccumulators. Moreover, we found that those genes showing constitutively higher expression in S. plumbizincicola shoots are significantly enriched in processes related to cell wall metabolism, including biosynthesis/modification of cellulose, lignin, pectin, glucan, and other cell wall related components.
Project description:The leaf transcriptome of the nickel hyperaccumulator species Psychotria grandis and Psychotria costivenia (Rubiaceae) from Cuba were compared to the closely related non-accumulator Psychotria revoluta, living on Gallery forest on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator Phyllanthus luciliae (Phyllanthaceae) endemic from New Caledonia was compared to the related non-accumulator Phyllanthus conjugatus var. ducosensis, living respectively on ultramafic and sedimentary soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator Leucocroton havanensis (Euphorbiaceae) living on serpentine Cuabal, from Cuba, was compared to the closely related non-accumulator Lasiocroton microphyllus living on Gallery forest on limestone soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator Geissois pruinosa (Rubiaceae) endemic from New Caledonia was compared to the closely related non-accumulator Geissois racemosa, living respectively in serpentine maquis or rainforest on limestone, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator specie Noccaea caerulescens subsp. fimiensis living on serpentine soils were compared to the closely related non-nickel-accumulators Noccaea caerulescens "Viviez" growing on a zinc mining site and Noccaea montana living on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator species Homalium kanaliense (Salicaceae) endemic from New caledonia were compared to the closely related non-accumulator Homalium betulifolium, living on Gallery forest or maquis on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:Comparative analysis the transcriptomes of the hyperaccumulator Sedum plumbizincicola and the non-hyperaccumulator Sedum alfredii (NHE)