Viroid‐derived small RNA induces early flowering in tomato plants by RNA silencing

• Published in: Molecular plant pathology Vol. 19; no. 11; pp. 2446 - 2458
• Main Authors: Adkar‐Purushothama, Charith Raj, Sano, Teruo, Perreault, Jean‐Pierre
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.11.2018; John Wiley and Sons Inc
• Subjects: Base Sequence; early flowering; Flowering; Flowers - genetics; Flowers - physiology; FRIGIDA‐like protein 3; Gene Expression Regulation, Plant; Host plants; host–pathogen interaction; Infections; Lycopersicon esculentum - genetics; Lycopersicon esculentum - physiology; Lycopersicon esculentum - virology; miRNA; mRNA; Original; Phenotype; Plant Diseases - genetics; Plant Diseases - virology; Plant Proteins - genetics; Plant Proteins - metabolism; Plants (botany); Potatoes; Proteins; PSTVd; Ribonucleic acid; RNA; RNA Interference; RNA ligase; RNA silencing; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Small Interfering - metabolism; RNA, Viral - metabolism; RNA-mediated interference; Tomatoes; vd‐sRNA; viroid; Viroids - genetics; FRIGIDA-like protein 3; host-pathogen interaction; PSTVd; vd-sRNA; viroid; RNA silencing; early flowering
• ISSN: 1464-6722; 1364-3703
• DOI: 10.1111/mpp.12721

Summary Viroid infection often leads to early flowering in the host plant. This report describes the targeting of the FRIGIDA‐like protein 3 (FRL3) mRNA in tomato plants by a small RNA derived from the conserved left terminal region of the potato spindle tuber viroid (PSTVd). This targeting leads to the silencing of the FRL3 mRNA. Viroid infection assays using a severe variant of PSTVd induced early flowering in tomato plants by the down‐regulation of greater amounts of the target than did a mild PSTVd variant. The targeting of the FRL3 mRNA by RNA silencing was validated by both an artificial microRNA experiment transiently expressing viroid‐derived small RNAs in tomato plants, and by 5′ RNA ligase‐mediated rapid amplification of cDNA ends (RACE). These data unambiguously demonstrated the role of small RNAs in the early flowering seen in viroid‐infected plants.