Transcriptional Effects of Rootstock on Scion after Drought: A Case Study of Using MdGH3 RNAi as the Rootstock

Drought stress is an important environmental factor limiting apple yield and fruit quality. Previously, we identified GRETCHEN HAGEN3.6 (GH3.6) as a negative regulator of drought in trees. Using transgenic MdGH3 RNAi (knocking down MdGH3.6 its five homologs) plants rootstock can increase tolerance, water use efficiency, flowering, quality the Fuji scion after stress. However, molecular mechanism behind this phenomenon still unknown. Here, performed transcriptome sequencing grafted (Fuji/GL-3 where was used non-transgenic GL-3 rootstock, Fuji/MdGH3 rootstock) under control conditions. Under conditions, 667 up-regulated genes 176 down-regulated were RNAi, compared to Fuji/GL-3. Moreover, 941 2226 relative GL-3. GO terms these differentially expressed (DEGs) showed associations with plant growth, development, responses. After stress, 220 452 Significantly enriched included response abiotic stimulus, cell division, microtubule-based process, metabolic biosynthetic process flavonoid, pigment, lignin. The comparison between Fuji/GL-3 yielded smaller number DEGs; however, all them significantly stress-related terms. Furthermore, 365 300 mRNAs could potentially move from respectively, including FIDDLEHEAD (FDH), RESPONSIVE TO DESICCATION 26 (RD26), ARS-binding 2 (ABF2), WRKY75, ferritin (FER). Overall, our work demonstrates effects on at transcriptional level provides theoretical support for further understanding utilization plants.