S-RNase Internalisation and Vacuolar Targeting via Clathrin-Dependent Endocytosis Mediate Interspecific Pollen Rejection in Nicotiana.

ABSTRACT: In Nicotiana, the multiallelic S-locus controls self-incompatibility (SI), which encodes S-RNases in the pollen's pistil and S-locus F-box (SLF) proteins. Their interaction mediates S allele-specific pollen rejection, preventing self-fertilisation. Beyond its role in SI, the S-locus also contributes to unilateral interspecific (UI) incompatibility, where self-incompatible pistils reject pollen from self-compatible species. Experimental evidence indicates that S-RNases alone can mediate UI. In transgenic Nicotiana tabacum-a naturally self-compatible species-expression of the S-RNase is sufficient to trigger self-pollen rejection, demonstrating that S-RNases can function independently of a complete SI system. However, the molecular mechanisms underlying S-RNase-mediated factor-independent UI

SUBMITTER: Rios-Carrasco S 

PROVIDER: S-EPMC12279473 | biostudies-literature | 2025 Jul-Aug

REPOSITORIES: biostudies-literature