A splicing switch enables SR45a-driven thermotolerance in plants.

Heat stress reshapes plant transcriptomes through alternative splicing, yet the regulatory logic governing isoform switching remains poorly understood. Recently, a heat-activated, branch-point-dependent splicing switch in Serine/arginine-rich splicing factor 45a (SR45a) was uncovered by Xu et al. This switch couples transcriptional activation to isoform remodeling, driving thermotolerance.