Transcriptomic Profiling of Two Rice TGMS Lines with Contrasting Seed Storability after Artificial Accelerated Aging Treatment

Seed storability has a great impact on seed vitality and is a key genetic factor determining the maintenance of seed value during seed storage. In this study, seeds of two rice thermo-sensitive genic male sterile (TGMS) lines, S1146S (storage-tolerant) and SD26S (storage-susceptible), with 0 and 7 days of artificial accelerated aging treatment were sequenced. 2658 and 1523 differentially expressed genes (DEGs) were found in S1146S and SD26S, respectively. Among these DEGs, 729 DEGs (G1) had similar regulation patterns in both lines, while 1924 DEGs (G2) were specific to S1146S, 789 DEGs (G3) were specific to SD26S, and 5 DEGs (G4) were specific to contrary differential expressions in both lines. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that 'translation', 'ribosome', and 'oxidative phosphorylation' were shared by both lines, but DEGs related to 'ATP-dependent activity' and 'intracellular protein transport' were specifically enriched in S1146S, whereas 'protein processing in endoplasmic reticulum' were specifically enriched in SD26S. Several genes, like Os01g0937200, Os05g0328632, and Os07g0214300, associated with seed storability were identified in G4. Core genes of the protein-protein interaction (PPI) networks, such as Os03g0100100 (OsPMEI12), Os03g0320900 (V2), and Os02g0494000, were down-regulated in S1146S, while Os02g0152800 and Os03g0710500 (OsBiP2) were up-regulated in SD26S. Seed vitality genes, MKKK62 (Os01g0699600), OsFbx352 (Os10g0127900), FSE6 (Os05g0540000), and RAmy3E (Os08g0473600), related to seed storability were identified. In conclusion, these findings provide novel insights into the molecular response and related genes under artificial aging conditions in rice TGMS lines with different storability, and provide some new ideas for the study of storability of hybrid rice.