Reduction in organ\u2013organ friction is critical for corolla elongation in morning glory

Ayaka Shimoki,Satoru Tsugawa,Seisuke Kimura,Tomoaki Sakamoto,Takashi Nobusawa,Akiteru Maeno,Eiji Nitasaka,Taku Demura,Masahito Toda,Mika Nagao,Kiyotaka Okada,Seiji Takeda,Keiichiro Ohashi

doi:10.1038/s42003-021-01814-x

Abstract

In complex structures such as flowers, organ–organ interactions are critical for morphogenesis. The corolla plays a central role in attracting pollinators: thus, its proper development is important in nature, agriculture, and horticulture. Although the intraorgan mechanism of corolla development has been studied, the importance of organ–organ interactions during development remains unknown. Here, using corolla mutants of morning glory described approximately 200 years ago, we show that glandular secretory trichomes (GSTs) regulate floral organ interactions needed for corolla morphogenesis. Defects in GST development in perianth organs result in folding of the corolla tube, and release of mechanical stress by sepal removal restores corolla elongation. Computational modeling shows that the folding occurs because of buckling caused by mechanical stress from friction at the distal side of the corolla. Our results suggest a novel function of GSTs in regulating the physical interaction of floral organs for macroscopic morphogenesis of the corolla.

Highlights

In complex structures such as flowers, organ–organ interactions are critical for morphogenesis
We found that glandular secretory trichomes (GSTs) on peripheral organs play an essential role in corolla elongation by reducing the friction between floral organs
Using morning glory mutants, we found that GSTs are involved in corolla elongation within floral buds

Summary

Introduction

In complex structures such as flowers, organ–organ interactions are critical for morphogenesis. The complex 3D petal shape in orchids, such as twisting, helical twisting, saddle bending, or edge waving, can be reproduced by a computational model and actual construction with hydrogel[8], suggesting that physical strength derived from growth strain gives rise to plant organ structure. These analyses clearly explain plant organogenesis at the intra-organ level, little work has been done from a mechanical perspective on floral organ interactions during development. More than 1500 lines are maintained at Kyushu University as part of the National BioResource Project (NBRP) in

Methods

Results

Conclusion