Differential gene expression in developing grains of two tropical indica rice genotypes differing in grain iron concentration through RNA-seq

ABSTRACT: Rice (Oryza sativa L.) is the main staple food for nearly half of the world’s population. Cereals, especially rice is deficient in micronutrients such as Fe. However, rice genotypes differ in grain Fe concentration (Panda B, et.al. Am J Plant Sci. 2014;5:2829-41. doi: 10.4236/ajps.2014.518299). The present study is focused on identification of gene(s) involved in Fe accumulation in developing rice grain through high throughput RNA-seq technology and to understand the basis of differential Fe accumulation in developing rice grain. Two cultivars of rice viz. Sharbati (high Fe) and Lalat (low Fe) differing in grain iron concentration were used in the study. Root and grain transcriptome sequences of these two cultivars (at mid-grain filling stage) were generated using RNA-Seq (Illumina Hiseq 2000 platform). For each genotype, on an average 9.7 and 7 Gb data was generated for grain and root samples, respectively. The short reads were aligned against the Nipponbare reference genome (IRGSP build 5.0), thereby successfully mapping 95% and 67% of the reads from grain and root samples, respectively. Genes known to be involved in Fe metabolism were analyzed for expression. Among the genes coding for phytosiderophore synthesizing enzymes, OsNAS1 and OsNAAT2 showed higher expression in the grains of Sharbati while OsDMAS1 had higher expression in its root. Of the 18 yellow-stripe like (YSL) genes in rice, only 11 were found to be expressed in the two cultivars. Out of these, 2 (OsYSL2 and OsYSL 8) were up-regulated in the grains of Sharbati highlighting their importance in the uptake of Fe from soil and its accumulation in the developing grain. Two other genes (OsFRO1 and OsIRT1) known to be involved in Fe uptake by the root were also found to be highly expressed in the root of Sharbati. Our findings suggest that higher grain iron concentration of cv. Sharbati might be due to higher expression of key Fe transporters (viz. OsYSL2, OsYSL8 and OsITR1) and root membrane bound OsFRO1, which give an advantage in terms of absorption, transport and assimilation of Fe by this cultivar as compared to the low iron containing cultivar, Lalat.

ORGANISM(S): Oryza sativa

PROVIDER: GSE70093 | GEO | 2016/12/31

SECONDARY ACCESSION(S): PRJNA287628

REPOSITORIES: GEO