| Biography | |
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 Dr. Iqbal Hussain Government College University, Faisalabad, Pakistan |
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| Title: Silicon transporters and their role in plants | |
| Abstract: Transport of silicon from soil to different organs of the above-ground part requires different transporters. Since the first Si transporter, Lsi1 was identified in rice in 2006, a number of Si transporters have been identified in different plant species. Homologs of rice Lsi1 has been isolated and functionally characterized in barley, maize, wheat, pumpkin and horsetail. They function as a silicon influx transporter, which is required for transporting Si from external solution to the root cells. On the other hand, Si efflux transporters (Lsi2) have also been identified in rice, barley, maize and pumpkin. They are also involved in the Si uptake, but are responsible for transporting Si out of the cells towards the root stele. Different plant species show distinct expression pattern and cellular localization of Lsi1 and Lsi2. After Si uptake by the roots, the translocation of Si from the roots to the shoots is mediated by Lsi3, a homolog of Lsi2 in rice. It is localized to the root pericyclic cells. On the other hand, a homolog of Lsi1, Lsi6 mediates xylem unloading of Si. Knockout of this gene resulted in disturbed Si deposition pattern in the leaves. Final distribution of Si to the grain (mainly husk) is mediated by three different transporters, Lsi2, Lsi3 and Lsi6 in rice. All of them show high expression in the nodes, a place for mineral distribution. Lsi6 is localized at the xylem transfer cells of enlarged vascular bundle, whereas Lsi2 is localized at distal side of a parenchyma cell layer surrounding the enlarged vascular bundles, which is the next cell layer of xylem transfer cells and Lsi3 is localized at the parenchyma tissues between enlarged- and diffuse vascular bundles. Knockout of Lsi6, Lsi2 or Lsi3 resulted in decreased Si accumulation on the husk, but increased Si accumulation in the flag leaf, indicating that cooperation of these transporters localized at the different cell layers are required for inter-vascular transfer of Si from enlarged vascular bundles to diffuse vascular bundles for preferential distribution of Si in the husk. Similar system on such inter-vascular transfer of Si in barley was also observed. In my talk, I will introduce recent progress made in Si transporter researches. Keywords: plants, silicon, silicon transporter, stress tolerance • Sumaira Thind, Iqbal Hussain, Shafaqat Ali, Rizwan Rasheed and Muhammad Arslan Ashraf (2021). Silicon application modulates growth, physio-chemicals and antioxidants in wheat (Triticum aestivum L.) exposed to different cadmium regimes. Dose-Response, 19 (2):1-15. • Sumaira Thind, Iqbal Hussain, Shafaqat Ali, Saddam Hussain, Rizwan Rasheed, Basharat Ali, Hafiz Athar Hussain (2020). Physiological and biochemical bases of foliar silicon-induced alleviation of cadmium toxicity in wheat. Journal of Soil Science and Plant Nutrition, 20(4), 2714-2730. • Iqbal Hussain, Abida Parveen, Rizwan Rasheed, Muhammad Arslan Ashraf, Muhammad Ibrahim, Saima Riaz, Zarbhakhat Afzaal, and Muhammad Iqbal (2019). Exogenous silicon modulates growth, physio-chemicals and antioxidants in barley (Hordeum vulgare L.) exposed to different temperature regimes. Silicon, 11, 2753–2762. • Iqbal Hussain, Muhammad Arslan Ashraf, Rizwan Rasheed, Anum Asghar, Muhammad Asim Sajid, Muhammad Iqbal. (2015). Exogenous application of silicon at the boot stage decreases accumulation of cadmium in wheat grains. Brazilian Journal of Botany, 38(2), 223-234. | |
| Biography: Dr. Iqbal Hussain was born on February 10, 1973 at District Layyah (Punjab) Pakistan. He has been working as Tenured Associate Professor in the Department of Botany, Government College University, Faisalabad-38000, Pakistan Since 17-12-2017 to date. Research Interest: Plant Stress Physiology and Molecular Biology, Identification of Physio-biochemical Markers of stress tolerance. Education: PhD (2004-2009): Botany (Plant Stress Physiology and Molecular Biology), University of Agriculture, Faisalabad, Pakistan. Post-Doc (2016-2017): Foreign Fellowship Program of PHEC awarded for one year from Punjab Higher Education Commission (PHEC), under the supervision of Prof. Dr. Atsushi Higashitani Tadashi (Dean), Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Japan. | |
