
A homolog of the ALOG family controls corolla tube differentiation in Torenia fournieri
Author(s) -
Wei Xiao,
Shihao Su,
Tetsuya Higashiyama,
Da Luo
Publication year - 2019
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.15
H-Index - 36
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.177410
Subject(s) - biology , botany , microbiology and biotechnology
Flowers of honey plants (Torenia) face various abiotic stressors, including rain, which can damage pollens and dilute nectar. Many Torenia species develop a modified corolla base termed corolla neck to prevent raindrops from contacting the nectar. Although this hypothesis was postulated long ago, direct validation is lacking. Here, we evaluated Torenia fournieri, the corolla tube of which differentiates into distinct regions, a conical tube above that connects to an inflated base through a constriction. This constriction and inflated base is collectively referred to as the corolla neck. Using transcriptomic sequencing and genome editing approaches, we characterized an ALOG gene, TfALOG3, involved in formation of the corolla neck. TfALOG3 was found expressed in the epidermis of the corolla neck. Cells in the corolla bottom differentiated and expanded in wild-type T. fournieri, whereas such cells in TfALOG3 loss-of-function mutants failed to develop into a corolla neck. Water easily contacted the nectary in the absence of the corolla neck. Taken together, our study unveils a novel gene that controls corolla tube differentiation and demonstrates a hypothetical property of the corolla neck.