Anatomy and RNA-Seq reveal important gene pathways regulating sex differentiation in a functionally Androdioecious tree, Tapiscia sinensis

Abstract

BackgroundGametogenesis is a key step in the production of ovules or pollen in higher plants. The sex-determination aspects of gametogenesis have been well characterized in the model plant Arabidopsis. However, little is known about this process in androdioecious plants. Tapiscia sinensis Oliv. is a functionally androdioecious tree, with both male and hermaphroditic individuals. Hermaphroditic flowers (HFs) are female-fertile flowers that can produce functional pollen and set fruits. However, compared with male flowers (MFs), the pollen viability and number of pollen grains per flower are markedly reduced in HFs. MFs are female-sterile flowers that fail to set fruit and that eventually drop.ResultsCompared with HF, a notable cause of MF female sterility in T. sinensis is when the early gynoecium meristem is disrupted. During the early stage of HF development (stage 6), the ring meristem begins to form as a ridge around the center of the flower. At this stage, the internal fourth-whorl organ is stem-like rather than carpelloid in MF.A total of 52,945 unigenes were identified as transcribed in MF and HF. A number of differentially expressed genes (DEGs) and metabolic pathways were detected as involved in the development of the gynoecium, especially the ovule, carpel and style. At the early gynoecium development stage, DEGs were shown to function in the metabolic pathways regulating ethylene biosynthesis and signal transduction (upstream regulator), auxin, cytokinin transport and signalling, and sex determination (or flower meristem identity).ConclusionsPathways for the female sterility model were initially proposed to shed light on the molecular mechanisms of gynoecium development at early stages in T. sinensis.

The de novo genome assembly of Tapiscia sinensis and the transcriptomic and developmental bases of androdioecy

“…In previous studies, our results showed that bisexual flowers are the ancestral condition in T. sinensis 4 – 6 . Loss of female function may be the consequence of a large-scale insertion into TsRPL10A that caused the development of a sterile pistil in the hermaphroditic flower primordium (Figs.…”

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Fig. 3 Floral morphology and development of Tapiscia sinensis 5 , 6 . A Hermaphroditic T. sinensis individual showing the simultaneous occurrence of flowers and fruit.

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“…Tapiscia sinensis Oliv. (Tapisciaceae), is a woody, perennial, androdioecious species [1][2][3][4][5][6] . Androdioecy is a rare breeding system in which populations consist of only male and hermaphroditic individuals 7,8 .…”

Expression of some Epigenetic-Related Genes in Regenerated Shoots of Prunus persica

“…STM is playing an essential role in stopping the differentiation of meristem cells through cytokinins production. It maintains the shoot apical meristem development and function (Xin et al, 2019). PRC2 gene (FIE) is involved in the development of shoot through controlling STM expression and other class 1 KNOX genes.…”

SWATH-MS based quantitive proteomics reveal regulatory metabolism and networks of androdioecy breeding system in Osmanthus fragrans

“…Androdioecy is an exceedingly rare mating system in which males and hermaphrodites co-occur in a single population with normal sexual function [1]. Androdioecious plants are extremely rare in nature, less than 50 plants have been reported worldwide such as Datisca glomerata [2], Mercurialis annua [3], Pseudoxandra spiritus-sancti [4] and Tapiscia sinensis [5,6], drawing widespread interests by scientists. Surprisingly, such an unusual breeding system prefers to be distributed in the Oleaceae species including Phillyrea latifolia [7], Phillyrea angustifolia [8], Fraxinus lanuginose [9], Chionanthus retusus [10], Osmanthus serrulatus [11], O. delavayi [12] etc., accompanied by higher frequencies of males compared to other androdioecious species [13].…”