Irregular adaxial-abaxial polarity rearrangement contributes to the monosymmetric-to-asymmetric transformation of Canna indica stamen

Xueyi Tian; Xiaorong Li; Qianxia Yu; Haichan Zhao; Juanjuan Song; Jingping Liao

doi:10.1093/aobpla/plaa051

Irregular adaxial-abaxial polarity rearrangement contributes to the monosymmetric-to-asymmetric transformation of Canna indica stamen

AoB Plants. 2020 Sep 11;12(5):plaa051. doi: 10.1093/aobpla/plaa051. eCollection 2020 Oct.

Authors

Xueyi Tian^{1

2}, Xiaorong Li², Qianxia Yu¹, Haichan Zhao^{1

3}, Juanjuan Song⁴, Jingping Liao^{1

5}

Affiliations

¹ Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
² National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
³ Xinxing Vocational School of Traditional Chinese Medicine, Xinxing, Guangdong, China.
⁴ Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
⁵ Center of Conservation Biology/Economic Botany/Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China.

Abstract

In flowering plants, lateral organs including stamens develop according to the precise regulation of adaxial-abaxial polarity. However, the polarity establishment process is poorly understood in asymmetric stamens. Canna indica (Zingiberales: Cannaceae) is a common ornamental plant with an asymmetric stamen comprising a one-theca anther and a petaloid appendage. In this study, we depicted the monosymmetric-to-asymmetric morphogenesis of C. indica stamen, and the morphogenesis of the monosymmetric stamen of a sister species was used as a contrast. We chose a HD-ZIP III gene family member and a YABBY family member as the adaxial and abaxial polarity marker genes, respectively, and tested their expression using mRNA in situ hybridization. The expression patterns of the two genes changed dynamically and asymmetrically during the stamen development process. Compared with their homologues in Arabidopsis thaliana, these two genes exhibited some specific expression patterns. We hypothesize that the distinctive adaxial-abaxial polarity participates in the irregular morphogenesis of C. indica stamen, which mediates the putative stamen-to-petaloid staminode conversion in this species.

Keywords: Canna indica; Zingiberales; adaxial–abaxial polarity; floral asymmetry; petaloid stamen; stamen structure.