NAC transcription factor SlNOR-like1 plays a dual regulatory role in tomato fruit cuticle formation.

This article focuses on the role of the NAC transcription factor SlNOR-like1 in regulating tomato fruit cuticle development. Using CRISPR/Cas9-generated SlNOR-like1 knockout mutants (nor-like1), the study found that loss of SlNOR-like1 function leads to reduced cutin deposition and cuticle thickness, resulting in microcracking and increased fruit cracking, while simultaneously promoting wax accumulation on the fruit surface. Molecular analyses demonstrated that SlNOR-like1 directly activates key cutin biosynthesis genes SlGPAT6 and SlCD2 by binding their promoters, and represses wax biosynthesis and transport genes SlKCS1, SlCER1-2, SlWAX2, and SlLTPG1-like, thus exerting opposite regulatory effects on cutin and wax accumulation. These findings provide a new model for the transcriptional regulation of fruit cuticle formation, highlighting SlNOR-like1's dual role in maintaining cuticle integrity and post-harvest fruit quality.