*3.2. Functional Classification of Putative Warming Genes*

As shown in Table 2 and Tables S12–S14, most genes belonging to the GO categories "heat acclimation", "response to heat", and "chromosome organization" were upregulated in both inbred lines, but their levels were higher in Kenshin than in Chiifu. These results suggest that the minor differences in expression of these genes in *B. rapa* could result from long-term adaptation to HS or that the genes identified in *Arabidopsis* could be associated with short-term HS adaptation. *BrCYP71B2* (involved in "heat acclimation") was upregulated in Kenshin under both minor-warming and warming conditions; its homolog is also upregulated upon HS in *Arabidopsis* [35], indicating its possible involvement in the HSR in *B. rapa*. Some putative HT adaptation-related genes have well-known functions in *Arabidopsis*. For example, *Mge1* is induced by heat (under the control of HsfA1) and confers thermotolerance under priming conditions [36]. *Arabidopsis* SMP1 and SWC6 are associated with splicing [37] and chromatin remodeling [38], respectively. These findings suggest that these genes might play a role in HT adaptation in Kenshin. Kenshin-specific genes were classified into four categories ("lipid biosynthetic process", "response to hormone stimulus", "intracellular membrane bound organelle", and "signal transduction") (Table 2; Table S12), but none were found to be involved in HT adaptation, except for auxin-responsive genes. Further studies are needed to investigate the roles of these genes in *B. rapa*.
