Gene Expression and miRNA Regulation Changes in Leaves of Rice Backcross Introgression Lines

• Main Authors: Aqin Cao, Ruihua Wang, Jianbo Wang
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Agronomy
• Subjects: gene; miRNA; expression; backcross introgression line; rice; Oryza longistaminata
• Online Access: https://www.mdpi.com/2073-4395/10/9/1381

High-throughput sequencing was used to distinguish the gene and miRNA expression profiles in the leaves of three progenies from a rice backcross introgression line (BC₂F₁₂) and their parents (Oryza sativa and wild rice, O. longistaminata). A total of 33,419 genes and 513 miRNAs were identified in two parents and three lines, and the majority of the genes and miRNAs were commonly expressed. The results show that 10.23% to 17.94% of the genes were differentially expressed genes (DEGs) in the progenies compared with those of the two parents, and the majority of them were up-regulated. Of the miRNAs, 12.56% to15.43% were differentially expressed in the progeny/O. sativa comparisons and the majority of which were up-regulated, while 42.02% to 45.21% of miRNAs were differentially expressed in the progeny/O. longistaminata comparisons, of which nearly half were down-regulated. Most of the DEGs and differentially expressed miRNAs showed expression levels close to that of O. sativa, indicating that the expression of genes and miRNAs in progenies was closely related to their chromosome complements and that the miRNAs were more susceptible than the genes to the effects of genomic composition. Furthermore, a larger number of target genes were predicted in the progeny/O. longistaminata comparisons. Finally, we found that the expression of some genes and miRNAs might increase the possibility for abiotic stress responses and adaptation in progenies. Together, our findings increase the understanding of the molecular mechanisms of hybridization and backcrossing on the expression levels of genes and miRNAs in rice leaves.