Department of Botany, Savitribai Phule Pune University, Pune, 411 007, Maharashtra, India; Department of Biotechnology, Yashavantrao Chavan Institute of Science, Satara, 415 001, Maharashtra, India.
Department of Botany, Yashavantrao Chavan Institute of Science, Satara, 415 001, Maharashtra, India.
Plant Physiol Biochem. 2021 May;162:677-689. doi: 10.1016/j.plaphy.2021.03.033. Epub 2021 Mar 20.
Over the last decade, silicon (Si) has been widely accepted as a beneficial element for plant growth. The advantages plant derives from the Si are primarily based on the uptake and transport mechanisms. In the present study, the Si uptake regime was studied in finger millet (Eleusine coracana (L). Gaertn.) under controlled and stress conditions. The finger millet can efficiently uptake Si and accumulate it by more than 1% of dry weight in the leaf tissues, thus categorized as a Si accumulator. Subsequent evaluation with the single root assay revealed a three-fold higher Si uptake under osmatic stress than control. These results suggest that Si alleviated the PEG-induced stress by regulating the levels of osmolytes and antioxidant enzymes. Further, to understand the molecular mechanism involved in Si uptake, the Si influx (EcoLsi1 and EcoLsi6) and efflux transporters (EcoLsi2 and EcoLsi3) were identified and characterized. The comparative phylogenomic analysis of the influx transporter EcoLsi1 with other monocots revealed conserved features like aromatic/arginine (Ar/R) selectivity filters and pore morphology. Similarly, Si efflux transporter EcoLsi3 is highly homologous to other annotated efflux transporters. The transcriptome data revealed that the expression of both influx and efflux Si transporters was elevated due to Si supplementation under stress conditions. These findings suggest that stress elevates Si uptake in finger millet, and its transport is also regulated by the Si transporters. The present study will be helpful to better explore Si derived benefits in finger millet.
在过去的十年中，硅（Si）已被广泛认为是植物生长的有益元素。植物从 Si 中获得的优势主要基于吸收和运输机制。在本研究中，在受控和胁迫条件下研究了手指小米（Eleusine coracana（L）。Gaertn。）中的 Si 吸收情况。手指小米可以有效地吸收 Si，并在叶片组织中积累超过干重的 1％，因此被归类为 Si 积累器。随后用单根分析进行的评估表明，在渗透胁迫下 Si 的吸收比对照高三倍。这些结果表明，Si 通过调节渗透物和抗氧化酶的水平来缓解 PEG 诱导的胁迫。此外，为了了解 Si 吸收涉及的分子机制，鉴定并表征了 Si 流入（EcoLsi1 和 EcoLsi6）和流出转运蛋白（EcoLsi2 和 EcoLsi3）。与其他单子叶植物的流入转运蛋白 EcoLsi1 的比较系统发育分析揭示了保守特征，如芳香族/精氨酸（Ar/R）选择性过滤器和孔形态。同样，Si 流出转运蛋白 EcoLsi3 与其他注释的流出转运蛋白高度同源。转录组数据表明，由于胁迫条件下 Si 的补充，流入和流出 Si 转运蛋白的表达均升高。这些发现表明，胁迫会增加手指小米中的 Si 吸收，其运输也受 Si 转运蛋白的调节。本研究将有助于更好地探索手指小米中 Si 带来的益处。
