Understanding aquaporin regulation defining metalloid uptake in legume species

Abstract

The current study revealed differential uptake of silicon in warm and cold season legumes. Based on these results the warm season legumes can be classified as highsilicon legumes and cool season legumes can be classified as low silicon legumes. The NIP2 sub family of aquaporin transporters acts as the silicon influx transporters (Lsi1) in plant species, therefore genome wide identification of aquaporins was performed in 35 legume species to represent the warm as well as cold season legumes. Previous studies have identified thestructuralrequirementsofLsi1 transporter for being capable of silicon transport. All these features were studied in legume Lsi1 in 35 species and it was found that both low silicon accumulator and high silicon accumulator legume Lsi1 has similar structural features. As no difference was observed in Lsi1 transporter the genome wide identification of silicon efflux transporter (Lsi2) was carried out in the 35 legume species. It was observed that high silicon legumes group has more than three Lsi2 transporters whereas low silicon group has only one Lsi2 transporter. Current also study investigated the genotypic variation for seed arsenic content in soybean. The GWAS analysis based on this variation identified putative transporters that may be involved in the loading of arsenic to the soybean seeds. The RNA sequencing was employed to investigate the expression dynamics of genes in soybean roots subjected to silicon and arsenic treatments with subsequent identification and enrichment analysis of differentially expressed genes. The DEGs and enrichment analysis provided insights into the biological processes, cellular components and molecular functions affected by arsenic, silicon, and arsenic+silicon. Finally, theroleof silicon in alleviating arsenicstress was studied in soybean, pigeonpea, chickpea and lentil. It was found out that silicon significantly improved the performance of soybean and pigeonpea arsenic stress while minor differences were seen in chickpeas and lentils.