Root microbiome changes associated with cadmium exposure and/or overexpression of a transgene that reduces Cd content in rice
Root microbiome changes associated with cadmium exposure and/or overexpression of a transgene that reduces Cd content in rice
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DOI：
10.1016/j.ecoenv.2022.113530
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发表时间：
2022-04-21
影响因子：
6.8
通讯作者：
Ow, David W.
中科院分区：
文献类型：
--
作者：
Li, Kangjia;Wang, Changhu;Ow, David W.
镉(Cd)是一种有毒的重金属，可在农作物中积累。我们以前报道过通过过表达一个截短的OsO3L2基因来培育水稻低镉积累系(2B)。由于该转基因基因在植物根中的表达水平最高，因此利用扩增和转录组测序的方法研究了其表达对根相关微生物的影响。根据细菌16S rRNA的扩增序列，而真菌ITS的扩增序列较少，OTUS(操作分类单位)在紧密(根面)的土壤中的多样性低于与植物根联系的松散的(根际)。发现低Cd积累植物2B、Cd处理或两者都能引起OTUS的显著变化，在Cd处理2B样品中富集的13个OTUS中，有10个(77%)先前被描述为与Cd或其他重金属的耐受性有关。对根际微生物组进行转录组测序发现，细菌占微生物RNA的70-75%。Cd处理和植物2B共培养的土壤微生物中，光合作用天线蛋白和氮代谢途径最活跃。相应地，蓝藻的相对丰度仅为Cd处理根际细菌的1%，但占Cd处理2B根际转录物的13%。这些通过转基因和Cd富集的微生物是未来应用于减少作物对Cd吸收的有价值的候选。
Cadmium (Cd) is a toxic heavy metal that can accumulate in crop plants. We reported previously the engineering of a low cadmium-accumulating line (2B) of rice through overexpression of a truncated OsO3L2 gene. As expression of this transgene was highest in plant roots, amplicon and metatranscriptome sequencing were used to investigate the possibility that its expression affects root associated microbes. Based on amplicon sequencing of bacterial 16S rRNA, but less so from fungal ITS, the OTUs (operational taxonomic units) showed less diversity in soil tightly (rhizoplane) than loosely (rhizosphere) associated with plant roots. Significantly changed OTUs caused by the low-Cd accumulating plant 2B, Cd treatment or both were found, and 10 of the 13 OTUs (77%) that were enriched in Cd treated 2B samples over the wild type counterpart have been previously described as involved in tolerance to Cd or other heavy metals. Metatranscriptome sequencing of rhizosphere microbiome found that bacteria accounted for 70-75% of the microbial RNA. Photosynthesis-antenna proteins and nitrogen metabolism pathways were most active in soil microbes treated with Cd and grown with plant 2B. Correspondingly, the relative abundance of Cyanobacteria was enriched to < 1% of Cd treated rhizosphere bacteria, yet accounted for up to 13% of Cd treated 2B rhizospheric transcripts. These enriched microbes by transgene and Cd are worthy candidates for future application on reducing crop uptake of Cd.