[Kazue Kanehara] A pair of DUF538 domain-containing proteins modulates plants growth and trichome development through the transcriptional regulation of GLABRA1 in Arabidopsis thalianaPOST:
SMALLER TRICHOMES WITH VARIABLE BRANCHES (SVB) belongs to the land plant-specific DUF538 domain-containing protein family and acts as a plant regulator in trichome development, endoplasmic reticulum stress response, and phosphoinositide signaling. Despite its multifaceted roles, functions of the DUF538 protein family are poorly understood in plant growth and development. Here, we report that SVB-like (SVBL), the closest homolog of SVB, modulates plant growth and trichome development with SVB in Arabidopsis thaliana. The svb svbl double mutant exhibited dwarfed plant growth and defective trichome development. The double mutation reduced the transcript level of a central hub gene for trichome development, GLABRA1 (GL1), which in turn affects several downstream genes, GLABRA2 (GL2), TRANSPARENT TESTA GLABRA2 (TTG2), TRIPTYCHON (TRY), CAPRICE (CPC), and ENHANCER OF TRY AND CPC1 (ETC1). The current study suggests that SVB and SVBL play a pivotal role in plant growth and trichome development by affecting a specific subset of known trichome developmental regulators, which features the importance of the DUF538 protein family in higher plants.